The walleye gillnet catch rate in 1998 was 7.60 fish per net, the third highest index of abundance for Rainy Lake on record. The historical average was 5.20. Several strong year-classes were present in the catch. The 1995 year-class dominated contributing 30% to the total. In 1999, these fish should average 13-15 inches in length and provide the bulk of the angler harvest. The 1994 year-class also contributed substantially to the 1998 catch. In 1999 these fish will average 15-17 inches in length with many of the faster growing individuals entering the protected size range beginning at 17 inches (the Minnesota waters of Rainy Lake have an experimental regulation in place requiring the release of walleye between 17 and 25 inches in length. One walleye over 25 inches may be kept in a possession limit of 6 fish). The 1996 year-class also contributed substantially to the 1998 catch. These fish averaged 10 inches during the fall of 1998 but should grow to an acceptable size for harvest in 1999. Other strong year-classes present in the fishery include 1991 and 1997. The 1998 gillnet catch of walleye over 17 inches was at its lowest level since 1994. Prior to 1998, the abundance of walleye over 17 inches had been steadily increasing over several years. The decline may be related to poor year-classes that hatched during the springs of 1992 and 1993. These year-classes should be contributing the bulk of the catch of fish over 17 inches in length. Instead, the strong 1991 year-class contributed most of the fish caught over 17 inches. Abundance of large fish should rebound in 1999 as individuals of the 1994 year-class grow into the protected length interval. The gillnet catch rate of northern pike was 2.00, slightly higher than that recorded in 1997 but still below the historicalaverage of 2.79. The pike catch was dominated by young fish. Age-2 and 3 fish contributed 58% of the 1998 catch. As a result, the number of fish over 21 inches in length was at a 20 year low. The sauger gillnet catch rate was 2.10, the second lowest index of abundance on record. The 1998 catch fell within thebottom 25% of all catches from large softwater lakes similar to Rainy. There is little evidence that sauger abundance will improve in the near future. Sauger make up a minor component of the angler harvest on Rainy Lake. The black crappie trapnet catch improved for the second straight year increasing to 2.11. The index of abundance,however, was still well below levels recorded in the early 1990's. Crappie size structure has shifted to younger and smaller fish,however, 1.0-1.5 pound fish are still caught on occasion. Results of the 1998 open water creel survey for Rainy Lake indicate that fishing effort continues to increase as word of theimproved fishery spreads. The estimate of effort exceeded 240,000 angler-hours and was 30% greater than the previous high recorded in 1997.
","surveyID":"111916"},{"headerInfo":{"wb_id":"69069400","survey_type":"Large Lake Survey","survey_id":"650622232176006","wb_alt_name":"","county":"St. Louis","wb_name":"Rainy","wb_type":"Lake","id_date":"2006-09-05"},"surveyDate":"2006-09-05","narrative":"The 2006 large lake sampling program provided valuable insight to the status of the Rainy Lake fishery. Walleye, yellow perch, northern pike, smallmouth bass, and black crappie populations are doing well as indicated by various sampling methods. Several trends in the long-term gill net data show the Rainy Lake walleye fishery has recovered from years of overharvest and continual suppression seen through the early 1990s.
\n
\nThe 2006 gill netted walleye catch consisted of 15 age groups. Ages ranged from age-0 to age-17 with a mean of 4.6 years. Age-3 walleye made up 35.0% of the gill-net catch while age-5 accounted for 22.7%. Lengths of gill netted walleye ranged from 4.3 to 26.8 inches. The mean walleye length was 13.6 inches and the mean weight was 1.10 pounds.
\n
\nFor the past 12 years walleye gill net CPUE has been at historically high levels. The 2006 CPUE was the third highest since the large lake program began in 1983. Rainy Lake walleye abundance has reached a new peak. Walleye CPUE from 1983 to 1994 averaged 3.98 per net, since 1995 the average is 7.14 per net. Only twice (2001 and 2002) during the past ten years has the walleye CPUE been below six per net. Consistent recruitment has been the main factor contributing to the observed increase in CPUE.
\n
\nCatch rates of larger walleye (over 17\") have significantly increased in the past 30 years. During the past 12 years the CPUE of walleye over 17 inches has remained greater than one per net, a feat that was achieved only twice prior to 1990. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations.
\n
\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the 10 year-classes were rated as strong. Netting surveys show that the 2000 year-class is weak. However, the 2001 year-class stands to be the strongest on record. Indications of the 2002 and 2004 year-classes are weak. In contrast the 2003, 2005, and 2006 are very strong.
\n
\nThroughout the history of monitoring and management on Rainy Lake we have observed the recovery of the walleye population. Indications from recent sampling are that the population has reached a plateau and has remained sustainable at the current population structure. Current regulations have directed harvest on Minnesota waters to sustainable yields.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. The 2001 and 2003 year-classes will continue to be main contributors to the harvest. While the 2005 and 2006 year-classes are showing good potential, it will be a couple of years before they begin recruitment to the sport fishery.
\n
\nNorthern pike gill-net CPUE has been low for the past three years. Northern pike assessment shows there are several average year-classes present in the catch; however, recruitment may be slowing. While large northern pike were present there was a downward trend in pike growth rates during the late 1990s into the early 2000s, this trend has changed and growth rates are increasing while recruitment is slowing. During the early 1990s mean northern pike length at age-3 was approximately 23 inches, during the late 1990s into the early 2000s length at age-3 dropped into the mid to upper teen range. In 2006 the mean northern pike length for age-3 was 20.4 inches, illustrating the faster growth rates.
\n
\nSpring sampling indicated the black crappie population is in a transitional phase. Younger year-classes were present and mortality (natural and fishing) has greatly reduced the population of the strong year-classes from the mid-1990s. Recruitment is necessary to bring the crappie numbers back to trap net numbers observed in the early 2000s. The variable recruitment of crappie in Rainy Lake is consistent with crappie populations from around the country.
\n
\nSmallmouth bass numbers from the nighttime electrofishing indicates good recruitment. The 2006 smallmouth bass CPUE was near normal for Rainy Lake. Smallmouth bass populations have grown and have been protected only by the catch-and-release ethics common to most bass anglers. Bass growth on Rainy Lake is slow compared to area and state averages. However, there are plenty of memorable and trophy sized smallmouth bass present as demonstrated by the catch during the spring electrofishing and reports from anglers. Angler opportunities in 2007 should remain good.
\n
The 2009 field season on Rainy Lake was in many ways similar to 2008. A cold spring appears to have delayed growth for the lake\u0019s coolwater species even more so than in 2008. Below normal temperatures and windy conditions kept surface water temperatures low until late August before they peaked in early to mid September. When combined with the high water experienced in the spring these cold temperatures may have contributed to a second year of higher than normal catches of coregonids in several of our gears including record catches of lake whitefish in the annual fall gill-net assessment.
\n
\nHigh numbers of walleye were again encountered in seine hauls at predictably small sizes given the cool water temperatures. We again experienced an abnormally warm fall with peak water temperatures occurring during our fall gill-net assessment. Our catch rate for walleyes rebounded to slightly above the average catch rate for Rainy Lake. Much of this rebound was driven by strong recruitment from the 2006 year class that is growing into the holes left by a nearly absent 2004 year class. No creel was conducted in 2009 due to fiscal limitations, but anecdotal reports indicated that, much like 2008, 2009 was characterized by good catches of large fish protected by the 17\"-28\" protected slot and fish smaller than the harvest size for most anglers.
\n
\nDespite confounding environmental factors the 2009 large lake sampling program provided valuable insight to the status of the Rainy Lake fishery. Walleye, yellow perch, northern pike, smallmouth bass, and black crappie populations are healthy as indicated by various sampling methods.
\n
\nFor the past 14 years walleye gill net CPUE has been at historically high levels. The 2009 CPUE of 5.79 per gill net was up slightly from the 4.83 per gill net captured in 2008. Walleye CPUE from 1983 to 1994 averaged 3.98 per net, since 1995 the average is 7.77 per net. Consistent recruitment has been the main factor contributing to the observed increase in CPUE.
\n
\nSeveral factors may have contributed to the reduced numbers of walleye in the gill nets during recent years. A warm fall with water temperatures above normal for the time of year may have negatively affected the success of our fall netting. The below average temperatures during the summers of 2008 and 2009 certainly led to slower growth rates which may be affecting gill-net catchability of younger walleyes. The mean length of age-1 through age-4 fish in 2009 was from 1.0\" to 1.9\" lower than the mean length at capture for their respective ages from 1998-2008. The age-5 and age-6 fish also experienced the cold summer of 2004 and show even slower growth being 4.1\" and 2.4\" below the 1998-2008 mean length. Additionally, poor production during 2002 and a near total failure of the 2004 year-class translates to poor numbers of 13-17 inch walleye in the gill net catch. Only age-2, -3, -6, and -8 walleye were caught rates above normal for their respective ages.
\n
\nCatch rates of larger walleye (over 17\") have significantly increased in the past 30 years. After the CPUE of walleye over 17 inches in 2008 dipped below one per net for the first time since the protected slot was put in place it rebounded slightly to 1.33 per net in 2009. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. Creel data from 2008 indicated that walleye 17 inches or greater in length made up 39% of the total catch for 2008 which had the highest walleye catch on record for Rainy Lake.
\n
\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the ten year-classes were rated as strong. During the first half of the 2000s three of the seven year-classes recruited to date are strong including record breaking 2001 year class and the 2006 year-class which recruited to the gear in 2009. Early indications are that one or two more strong year-classes are likely awaiting recruitment, though slower growth due to recent cool summers may expose them to predation longer and delay full recruitment to the gill nets.
\n
\nSeining and electrofishing data have been used to predict future walleye year-class strength on Rainy Lake. Prior to 1995 length data from summer seining provided the most reliable predictors. Since 1995 electrofishing indices have been more significant. This change may have arrived from changes in growth observed during the past 15 years. Seining data indicated the 2009 year-class will be weak, while the electrofishing data indicates it will be average. The unique weather associated with the initial growth of the 2009 year-class may make it difficult to predict which model will be more accurate. A cold spring and summer appears to have slowed summer growth for juvenile fish, but with some of the warmest surface temperatures of the year encountered over an extended period in September the length of the growing season may have been extended.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. The 2003 and 2006 year-classes will continue to be the main contributor to the harvest, though the most recent creel indicated that contributions from the poor 2005 year-class were already recruiting to the sport fishery in 2008. The 2007 year-class is showing good potential, and will likely begin to contribute heavily to the sport fishery over the next several years.
\n
\nNorthern pike gillnet CPUE decreased to below the first quartile for Rainy Lake in 2009 after a sharp increase in 2007 and equally sharp decline in 2008. Northern pike densities have great influence on northern pike growth; northern pike growth is negatively correlated with pike abundance (Pierce and Tomcko 2003, Pierce et al. 2003). Northern pike assessment shows there are several average year-classes present in the catch. The 2005 year-class has emerged as being strong. While large northern pike were present there was a downward trend in pike growth rates during the late 1990s into the early 2000s, this trend has changed and growth rates are increasing while recruitment is slowing. During the early 1990s mean northern pike length at age-3 was approximately 23 inches, during the late 1990s into the early 2000s length at age-3 dropped into the mid to upper teen range. In 2009 the mean northern pike length for age-3 was 22.11 inches, illustrating the faster growth rates.
\n
\nSauger abundance has steadily declined for the past 16 years. The CPUE observed in 2009 was tied for the lowest ever with 2008. This trend may demonstrate density dependent and interspecies competition that influences the abundance and growth of walleye and sauger. Staggs and Ottis (1996) found that competition did exist between walleye and sauger and that regardless both species grew better in years with high forage abundance. Sauger fishing on Rainy Lake is a result of indirect catch, no angling parties contacted during 2008 were targeting sauger (Schlesser 2009). Low sauger abundance, small average size, and a healthy walleye fishery likely are the cause for effort being directed towards walleye.
\n
\nLake whitefish are commercially fished on Rainy Lake and there is very little sport-fishing effort directed toward this species. Annual commercial harvest of lake whitefish has remained below the target quota every year since 1999. FCIN provides a standardized methodology for monitoring of this population. Based on four years of observation the lake whitefish population is showing no signs of overexploitation, however, more years of observation are needed to quantify this statement. Good recruitment in the past five years indicates the population is sustainable. FCIN is scheduled to be conducted again during the summers of 2011-12.
\n
\nSpring sampling indicated the black crappie population is doing very well. Younger year-classes were present and mortality (natural and fishing) has greatly reduced the population of the strong year-classes from the mid-1990s. The recruitment of the 2003 year-class to the sport fishery (and trap nets) has resulted in a very abundant fishery with exceptional opportunities to catch crappies. The 2008 creel reported the highest harvest of crappies ever recorded for Rainy Lake. The variable recruitment of crappie in Rainy Lake is consistent with crappie populations from around the country (Sammons et al 2002 and Allen 1997). The current status of the fishery indicates that crappie fishing should be exceptional during the next few years as the 2003 year-class contributes numbers of fish and the 2005 year class grows more fully into the acceptable size for harvest.
\n
\nThe 2009 smallmouth bass CPUE was down considerably from normal for Rainy Lake, but again was likely affected by the cold spring temperatures. Smallmouth bass populations have grown and have been protected only by the catch-and-release ethics common to most bass anglers. Bass growth on Rainy Lake is slow compared to area and state averages. However, there are plenty of memorable and trophy sized smallmouth bass present as demonstrated by the catch during the spring electrofishing and reports from anglers. Angler opportunities in 2010 should remain good.
\n
\nYellow perch gill-net numbers were above the third quartile for Rainy Lake. The length distribution of perch captured in the gill nets was predominantly in the less than nine-inch category. However, 25% of the perch sampled were more than nine inches in length and they should provide some decent harvest opportunities for the next few years. With the exception of 2004 recruitment has been exceptional for the past eight years, providing a strong forage base and developing angling opportunities.
\n
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe walleye gillnet catch in 2016 was 5.2 fish/net, which is near the historic median for Rainy Lake. For the past 18 years the Walleye gill net catch rate has been at historically high levels. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.42 per net. The 2015 and 2016 catch rates were down from the 7.96 per gill net captured in 2013 but within the range from recent years. Age 4 walleyes from the 2012 year-class composed the largest portion of the catch at 21.0 percent. The 2011 year-class is the most recent strong year-class to recruit to the fishery. However, this large year-class is growing slower than average for Rainy ranging from 10.7 to 17.7 inches long and averaging 13.6 inches in the 2016 survey. Overall, gillnetted Walleyes ranged in length from 5.2 to 25.7 inches long and had an average length of 13.3 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally larger Sauger are encountered in the Black Bay area. The overall gill net catch rate was 1.63 Sauger/net in 2016. Lengths ranged from 7.4 to 14.7 inches and averaged 10.3 inches.
\n
\nThe gillnet catch of Northern Pike was 1.75 fish/net, lower than the historic average for Rainy. Northern Pike catch rates have been consistently low in recent years. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 17.2 to 36.9 inches in 2016. The average length was 23.5 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes have increased in recent years in Rainy Lake. The 2016 gill net catch rate was lower than recent surveys at 5.83 fish/net and slightly lower than the historic average. Yellow Perch lengths ranged from 4.8 to 11.7 inches and the overall average was 8.3 inches. Yellow perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Fifty-five percent of the 2016 gill net catch measured eight inches or longer and 21 percent were 10 inches or longer.
\n
\nAn electrofishing boat is used as the standard sampling gear for smallmouth bass because they are not effectively caught in standard assessment nets. Thirty-four smallmouth bass were caught while electrofishing in 2016 for a catch rate of 21.1 fish/hour, similar to what has been seen in recent surveys. Lengths ranged from 3.9 to 19.3 inches and averaged 11.5 inches. Smallmouth Bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized smallmouth bass present. Smallmouth bass over 19 inches are often caught in our sampling gear including a 19.3 inch bass caught during electrofishing in 2016. A smallmouth bass measuring 19.2 inches long and weighing 4.4 pounds was caught in a 2013 gill net on Rainy Lake. Smallmouth bass harvest numbers are very low on Rainy Lake, and angler opportunities in 2016 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting Black Crappies. A total of 115 crappies were caught in 2016 for a catch rate of 5.75 per net. This catch rate is lower than 2015 but among the highest ever recorded for Rainy Lake. Lengths ranged from 5.4 to 15.0 inches and averaged 11.0 inches. Fifty-one percent of the catch was from the 2012 year-class. Three consecutive years of good Black Crappie production and recruitment on Rainy from 2010-2012 is driving the increase in numbers. The 2010 year-class averaged 12.3 inches long while the 2012 year-class averaged 10.1 inches in 2016. Eighty percent of the Black Crappies caught in the 2016 survey were over 10 inches long and 30 percent were 12 inches or longer. The high catch rates and large sizes will provide good angler opportunities over the next few years.
\n
\nRainy Lake is known to be infested with spiny waterfleas. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
\n
Walleye gillnet CPUE increased in 2002 to 5.6 per net (Table 1, Figure 1). The 2002 gillnetting CPUE was above the long-term mean, falling between the median and third quartile. Sand Bay produced a walleye CPUE of 9.5, this is nearly a 50% increase from last years catch but is the second lowest level since being added as a station in 1998. The four year mean of the Sand Bay sets is 15.5 per net. Surface water temperatures during the sampling were higher than normal for this time of year and may have effected gillnetting success.Initial aging of walleye indicated that 12 year-classes were present in the gillnet catch. The 1998 (age-4) and 2001(age-1) year-classes each contributed over 20% to the walleye gillnet catch. The CPUE for age-4 walleye of 1.25, was well above the 20 year mean of 0.90 per net. The mean length of the age-4 walleye was 12.3 inches, ranging from 8.6 to 15.4 inches. The 1998 year-class should make a strong contribution to the angler catch and harvest throughout the 2003 season. The CPUE for age-1 walleye was 1.15, doubling the 20 year mean of 0.57 per net. The mean length of age-1 walleye was 7.1 inches. The 2001 year-class will likely be a small contributor to the harvest during the 2003 season, but should be a strong contributor in the future.In 2002 the catch rate of age-5 or greater walleye was 2.4 per net, this is a record high and well above the long-term mean of 1.43. Most notable were the 1997 (age-5) and 1995 (age-7) year-classes. The 1997 year-class as age-5 fish were caught at a CPUE of 0.75. The 1995 year-class as age-7 fish exhibited a higher CPUE (0.75) than the 1991 year-class as age-7's. None of the age-5 walleye collected were greater than 17 inches (mean = 14.5 inches), thus they should provide good harvest opportunities to anglers during 2003. Conversely, most of the 1995 year-class walleye collected were within the protected slot (length: mean = 18.0, min = 13.5, max = 20.0).Few individuals of the 2000 (age-2) walleye year-class were captured in the 2002 gillnet catch. The CPUE for age-2 walleye was 0.20 compared to a historical mean of 1.04. Results from previous surveys have suggested that the 2000 year-class was weak, our 2002 fall gillnetting assessment supports those results. The 1999 year-class was also collected in below average numbers. The CPUE of the 1999 (age-3) year-class was 0.55, which is less than half of the long-term mean of 1.12 age-3 fish per net.The northern pike gillnet CPUE was 2.6 per net, which is right at the historical median CPUE for Rainy Lake. Lengths ranged from 16.1 to 32.1 inches (Table 2) with a mean of 21.1 inches.The sauger gillnet CPUE of 1.85 was the lowest since 1985. The historical median was 3.60. The sauger length-frequency distribution was bimodal with peaks occurring at 8.5 inches and 12.0 inches. The lower peak was probably dominated by an apparent strong 1998 year-class. Previous assessments have indicated that no other strong year-classes are currently present in the fishery. The black crappie trap net CPUE reached a record high of 7.15 per net. From 1996 to 2000, CPUE had steadily increased from 0.94 per net to 5.11. In 2001 CPUE declined to a record low. Black crappie caught in the trap nets during our 2002 spring trap netting ranged from 2.7 to 14.3 inches with a mean of 10.8 inches. Anglers harvested an estimated 2,074 pounds of crappie from Rainy Lake in 2002, the second highest harvest since 1994. No parties interviewed by our clerk reached the inland daily and possession limit of 15. Targeting anglers produced a catch rate of 0.606 fish per angler hour and a harvest rate of 0.481. Harvested crappie had a mean length of 10.8 inches. Results of the 2002 summer angler creel survey indicated that angling effort decreased for the second year in a row. The estimated angler effort of 225,662 hours was the lowest level in the past five years, however still well above the long term mean of 168,192.Anglers caught an estimated 122,153 walleye, the second most on record. The 2002 walleye harvest rate of 0.169 was slightly below the historical mean of 0.175 fish per angler hour. The lower effort coupled with the lower harvest rate resulted in a total harvest of 38,158 walleye. Despite the low harvest rate, the total harvest was the fifth highest on record (since 1977). The total walleye yield was 35,988 pounds. An estimated 83,995 walleyes (172,445 pounds) walleye were caught and released during the 2002 open-water season. Of those walleyes released an estimated 6,292 (10,800 pounds) walleye were lost to hooking mortality. The mean targeting catch and harvest rates were 0.596 and 0.190, respectively. The mean targeting catch rate of walleye over 17 inches was 0.221.
","surveyID":"112009","headerInfo":{"wb_name":"Rainy","wb_type":"Lake","id_date":"2002-09-03","wb_id":"69069400","survey_id":"112009","survey_type":"Population Assessment","wb_alt_name":"","county":"St. Louis"},"surveyType":"Standard Survey","surveySubType":"Population Assessment","lengths":{},"fishCatchSummaries":[{"averageWeight":"0.27","totalCatch":7,"totalWeight":1.89,"species":"TLC","quartileCount":"1.1-10.1","quartileWeight":"0.3-0.9","CPUE":"0.35","gear":"Standard gill nets","gearCount":20},{"gearCount":20,"CPUE":"2.60","gear":"Standard gill nets","quartileWeight":"2.8-4.3","quartileCount":"1.1-2.4","species":"NOP","totalWeight":105,"totalCatch":52,"averageWeight":"2.02"},{"quartileCount":"0.2-0.8","quartileWeight":"0.2-0.6","CPUE":"0.30","gear":"Standard gill nets","gearCount":20,"totalCatch":6,"averageWeight":"0.17","totalWeight":1.04,"species":"BLC"},{"totalWeight":29.83,"species":"BLB","totalCatch":71,"averageWeight":"0.42","gearCount":20,"gear":"Standard gill nets","CPUE":"3.55","quartileWeight":"0.1-0.2","quartileCount":"0.1-4.7"},{"totalWeight":64.83,"species":"WTS","averageWeight":"1.85","totalCatch":35,"gear":"Standard gill nets","CPUE":"1.75","gearCount":20,"quartileCount":"1.4-3.0","quartileWeight":"1.7-2.2"},{"CPUE":"5.60","gear":"Standard gill nets","gearCount":20,"quartileCount":"3.6-10.8","quartileWeight":"0.8-1.3","species":"WAE","totalWeight":120.5,"averageWeight":"1.08","totalCatch":112},{"totalCatch":3,"averageWeight":"0.24","species":"SMB","totalWeight":0.71,"quartileCount":"0.2-0.6","quartileWeight":"0.7-1.2","CPUE":"0.15","gear":"Standard gill nets","gearCount":20},{"quartileCount":"0.1-3.0","quartileWeight":"0.9-2.8","gear":"Standard gill nets","CPUE":"0.05","gearCount":20,"totalCatch":1,"averageWeight":"0.22","totalWeight":0.22,"species":"LKW"},{"gear":"Standard gill nets","CPUE":"1.85","gearCount":20,"quartileCount":"2.1-4.3","quartileWeight":"0.3-0.5","species":"SAR","totalWeight":16.63,"totalCatch":37,"averageWeight":"0.45"},{"gearCount":20,"gear":"Standard gill nets","CPUE":"1.50","quartileWeight":"0.1-0.2","quartileCount":"1.4-6.8","species":"YEP","totalWeight":6.76,"totalCatch":30,"averageWeight":"0.23"},{"totalCatch":15,"averageWeight":"0.33","totalWeight":5.02,"species":"RKB","quartileWeight":"0.2-0.3","quartileCount":"0.6-1.6","gearCount":20,"CPUE":"0.75","gear":"Standard gill nets"}]},{"lengths":{"WAE":{"maximum_length":29,"fishCount":[[13,1],[14,6],[15,13],[16,8],[17,12],[18,8],[19,14],[20,9],[21,24],[22,14],[23,6],[24,5],[25,8],[26,5],[28,1],[29,1]],"minimum_length":13}},"fishCatchSummaries":[{"quartileWeight":"N/A","quartileCount":"N/A","gearCount":21.1413888888889,"CPUE":"6.39","gear":"Special electrofishing","averageWeight":"3.11","totalCatch":135,"totalWeight":190565,"species":"WAE"}],"surveyType":"Targeted Survey","surveySubType":"Special Assessment","headerInfo":{"county":"St. Louis","wb_id":"69069400","survey_type":"Special Assessment","survey_id":"10521411250286000","wb_alt_name":"","id_date":"2014-04-01","wb_name":"Rainy","wb_type":"Lake"},"surveyID":"10521411250286000","surveyDate":"2014-04-01","narrative":"This was a continuation of a Study 4 project that included tagging Walleyes on the Rat Root River spawning run from 2010-2014. See \"Spawning Site Locations and Fidelity, Population Estimate, and Dispersal in Rainy Lake of Walleye Spawning in the Rat Root River\", Study 4, Job 943 for more information.
"},{"surveyType":"Standard Survey","surveySubType":"Large Lake 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nets","CPUE":"1.71","totalCatch":41,"averageWeight":"0.29","species":"RKB","totalWeight":5398},{"quartileCount":"0.9-1.9","quartileWeight":"0.9-1.3","CPUE":"1.40","gear":"Standard trap nets","gearCount":20,"totalCatch":28,"averageWeight":"3.33","totalWeight":42308,"species":"WAE"},{"totalWeight":55751,"species":"NOP","averageWeight":"3.23","totalCatch":38,"CPUE":"1.58","gear":"Standard gill nets","gearCount":24,"quartileCount":"1.1-2.4","quartileWeight":"2.8-4.3"},{"totalWeight":0,"species":"LGP","totalCatch":92,"averageWeight":"0.00","gear":"Survey seining","CPUE":"1.67","gearCount":55,"quartileCount":"N/A","quartileWeight":"N/A"},{"CPUE":"0.45","gear":"Survey seining","gearCount":55,"quartileCount":"N/A","quartileWeight":"N/A","species":"JND","totalWeight":0,"totalCatch":25,"averageWeight":"0.00"},{"quartileCount":"N/A","quartileWeight":"N/A","CPUE":"35.44","gear":"Survey 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nets","CPUE":"1.46","gearCount":24},{"averageWeight":"0.40","totalCatch":5,"totalWeight":911,"species":"RKB","quartileCount":"1.2-4.0","quartileWeight":"0.2-0.4","gear":"Standard trap nets","CPUE":"0.25","gearCount":20},{"totalCatch":34,"averageWeight":"0.29","totalWeight":4535,"species":"YEP","quartileWeight":"0.2-0.2","quartileCount":"2.2-8.5","gearCount":20,"gear":"Standard trap nets","CPUE":"1.70"},{"totalWeight":66507,"species":"NOP","totalCatch":67,"averageWeight":"2.19","gearCount":20,"CPUE":"3.35","gear":"Standard trap nets","quartileWeight":"N/A","quartileCount":"N/A"},{"species":"CIS","totalWeight":26,"totalCatch":101,"averageWeight":"0.00","gear":"Survey seining","CPUE":"1.84","gearCount":55,"quartileCount":"N/A","quartileWeight":"N/A"},{"quartileCount":"N/A","quartileWeight":"N/A","CPUE":"1.71","gear":"Survey seining","gearCount":55,"totalCatch":94,"averageWeight":"0.00","species":"SMB","totalWeight":0},{"totalWeight":0,"species":"FHM","totalCatch":1,"averageWeight":"0.00","gearCount":55,"CPUE":"0.02","gear":"Survey seining","quartileWeight":"N/A","quartileCount":"N/A"}],"headerInfo":{"id_date":"2015-05-20","wb_name":"Rainy","wb_type":"Lake","county":"St. Louis","survey_type":"Large Lake Survey","wb_alt_name":"","survey_id":"13231513860302000","wb_id":"69069400"},"surveyDate":"2015-05-20","narrative":"Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe walleye gillnet catch in 2015 was 6.7 fish/net, higher than the historic average for Rainy Lake. For the past 18 years the Walleye gill net catch rate has been at historically high levels. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.53 per net. The 2014 and 2015 catch rates were down slightly from the 7.96 per gill net captured in 2013 but similar to catch rates in other recent years. Age 4 walleyes from the 2011 year-class composed the largest portion of the catch at 29.2 percent. Overall, gillnetted walleyes ranged in length from 4.1 to 25.9 inches long and had an average length of 13.7 inches. There is a special regulation for walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally larger sauger are encountered in the Black Bay area. The overall gill net catch rate was 1.33 sauger/net in 2015. Lengths ranged from 5.5 to 14.3 inches and averaged 9.9 inches.
\n
\nThe gillnet catch of northern pike was 1.6 fish/net, lower than the historic average. Northern pike catch rates have been consistently low in recent years. However, northern pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 15.8 to 35.4 inches in 2015. The average length was 23.9 inches. Reports of anglers catching large northern pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow perch numbers have increased in recent years in Rainy Lake. The 2015 gill net catch rate was 7.9 fish/net, higher than the historic average. Yellow perch lengths ranged from 5.0 to 13.1 inches and the overall average was 8.4 inches. Yellow perch size structure has improved over time providing more opportunity for anglers to harvest quality sized fish. Fifty-six percent of the 2015 gill net catch measured eight inches or longer and 17 percent were 10 inches or longer.
\n
\nAn electrofishing boat is used as the standard sampling gear for smallmouth bass because they are not effectively caught in standard assessment nets. Fifty-four smallmouth bass were caught while electrofishing in 2015 for a catch rate of 24.7 fish/hour, similar to what has been seen in recent surveys. Lengths ranged from 5.1 to 17.8 inches and averaged 12.1 inches. Smallmouth Bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized smallmouth bass present. Smallmouth bass over 19 inches are often caught in our sampling gear including a 19.3 inch bass caught during electrofishing in 2014. A smallmouth bass measuring 19.2 inches long and weighing 4.4 pounds was caught in a 2013 gill net on Rainy Lake. Smallmouth bass harvest numbers are very low on Rainy Lake, and angler opportunities in 2015 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting black crappies. A total of 167 crappies were caught in 2015 for a catch rate of 8.4 per net. This catch rate is the second highest ever on Rainy Lake behind only the 2007 catch. Lengths ranged from 7.7 to 15.0 inches and averaged 11.6 inches. Forty-five percent of the catch was from the 2010 year-class. This year-class is driving much of the recent increase in black crappie catch rates and ranks as one of the strongest ever produced on Rainy. A good catch of crappies from the 2011 and 2012 year-classes in the 2015 trap nets also helped bolster the total catch rate.
\n
\nRainy Lake is known to be infested with spiny waterfleas. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe Walleye gillnet catch in 2018 was 6.0 fish/net, which is slightly greater than the historic median for Rainy Lake. For the past 18 years the Walleye gill net catch rate has been at historically high levels. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.35 per net. Catch rates over the past 10 years have primarily been between six and eight Walleyes per gill net. Age-3 Walleyes from the 2015 year-class composed the largest portion of the catch at 19.7 percent. The 2011 year-class is the most recent strong year-class to recruit to the fishery and made up 13.1 of the 2018 gill net catch. However, this large year-class is growing slower than average for Rainy ranging from 13.6 to 20.6 inches long and averaging 16.7 inches in the 2018 survey. Overall, gill netted Walleyes ranged in length from 7.2 to 28.9 inches long and had an average length of 14.2 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in the Black Bay area. The overall gill net catch rate was 3.0 Sauger/net in 2018. Lengths ranged from 7.1 to 14.5 inches and averaged 10.2 inches.
\n
\nThe gill net catch of Northern Pike was 2.1 fish/net, near the historic average for Rainy. Northern Pike catch rates have historically been relatively low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 17.8 to 42.4 inches in 2018. The average length was 24.4 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes have increased in recent years in Rainy Lake. The 2018 gill net catch rate was lower at 7.1 fish/net but similar to the historic average. Yellow Perch lengths ranged from 4.9 to 13.0 inches and the overall average was 8.0 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Forty percent of the 2018 gill net catch measured eight inches or longer. Large Yellow Perch are more common in Rainy Lake than in the past.
\n
\nAn electrofishing boat is used as the standard sampling gear for Smallmouth Bass because they are not effectively caught in standard assessment nets. Forty Smallmouth Bass were caught while electrofishing in 2018 for a catch rate of 28.8 fish/hour, similar to what has been seen in recent surveys. Lengths ranged from 4.5 to 18.4 inches and averaged 13.2 inches. Smallmouth Bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized Smallmouth Bass present. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Smallmouth Bass harvest numbers are very low on Rainy Lake, and angler opportunities in 2019 should remain good.
\n
\nRainy Lake is known to be infested with spiny waterfleas. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
\n
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest Walleye lakes in Minnesota. The Large Lake Program includes annual standard fish assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during standard assessments to collect the various fish species and life stages. These gear types include gill nets, trap nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe 2024 Walleye gill net catch rate was 5.4 fish/net, which is slightly less than the historic average of 6.1 fish/net for Rainy Lake. Walleye catch rates have increased following historic overfishing prior to the 1990s. Walleye numbers quickly increased as the population recovered in the 1990s and reached an all-time high of 10.0 Walleyes per net in 2004. The Walleye catch rate from 1983 to 1994 averaged 4.0 per net; since 1995 the average is 7.0 per net. Catch rates over the past 15 years have ranged from 4.6 to 8.0 Walleyes per gill net. Age-3 Walleyes from the 2021 year-class composed the largest portion of the 2024 catch at 36.4 percent. Most age-3 Walleyes in the 2024 survey were in the 10 to 12-inch length groups but overall ranged from 9.4 to 14.1 inches long. The 2024 survey also caught a good number of age-5 Walleyes from the 2019 year-class. Most fish from this year-class were in the 12- to 14-inch length groups but ranged in length from 9.8 to 20.3 inches long. Overall, the 2024 survey caught above average numbers of 10 to 14-inch Walleyes and below average numbers of 15-17-inch Walleyes. This high abundance of smaller fish in the system is the result of the above average 2019 and 2021 year-classes. There are fewer 15-17 inch Walleyes because of weak year-classes produced in 2017 and 2018. Anglers are likely to encounter more harvestable-sized fish over the next couple of years as the strong 2019 and 2021 year-classes continue to grow. Overall, gill netted Walleyes ranged in length from 3.7 to 25.6 inches and had an average length of 13.2 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in and around Black Bay and Sand Bay. The 2024 overall gill net catch rate was 1.6 Sauger/net. Lengths ranged from 7.4 to 13.0 inches and averaged 10.0 inches. Eighty-two percent of Saugers caught in gill nets were less than 11 inches long.
\n
\nThe 2024 gill net catch of Northern Pike was 1.7 fish/net, slightly less than the historic average for Rainy. Northern Pike catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 18.1 to 40.2 inches in 2024. The average length was 25.6 inches. Reports of anglers catching large Northern Pike of 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes were at historic highs from 2003-2012. The record high catch rate occurred in 2012 at 13.5/net. The 2024 gill net catch rate was 6.6/net which is slightly less than the long-term average for Rainy Lake. Rainy Lake saw good Perch production from the 2018, 2019, and 2020 year-classes. In fact, the 2020 year-class appears to be one of the strongest ever produced. Weak year-classes in 2021 and 2022 led to lower overall numbers in 2024 gill nets. However, preliminary numbers suggest the 2023 year-class may be above average. Individuals from the 2020 year-class ranged in length from 6.9 to 10.5 inches and most were in the 8-10-inch length groups in 2024. Overall, 2024 Yellow Perch lengths ranged from 5.2 to 12.0 inches and the overall average was 8.3 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish.
\n
\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are low on Rainy Lake, and angler opportunities in 2024 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting adult Black Crappies. A total of 377 crappies were caught in 2024 for a catch rate of 18.9 per net, which is the highest ever on Rainy Lake. Black Crappie catch rates have been above average in seven of the past eight surveys. Good Black Crappie production and recruitment on Rainy was observed from the 2016, 2017, 2019, and 2020 year-classes and is the driver of the high catch rates in recent years. Lengths ranged from 7.0 to 13.9 inches and averaged 10.3 inches in 2024. Sixty-three percent of the catch was from the 2020 year-class and an additional 10.9 percent from the 2019 year-class. The 2020 year-class dominated the 2024 catch and ranged from 8.3 to 11.3 inches and averaged 9.5 inches long. Forty percent of the Black Crappies caught in the 2024 survey were over 10 inches long and 20 percent were 12 inches or longer.
\n
\nRainy Lake is infested with spiny waterfleas and zebra mussels. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual standard fish assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during standard assessments to collect the various fish species and life stages. These gear types include gill nets, trap nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe 2023 Walleye gill net catch rate was 7.5 fish/net, which is greater than the historic average of 6.1 fish/net for Rainy Lake. Walleye catch rates have increased following historic overfishing prior to the 1990s. Walleye numbers quickly increased as the population recovered in the 1990s and reached an all-time high of 10.0 Walleyes per net in 2004. The Walleye catch rate from 1983 to 1994 averaged 4.0 per net; since 1995 the average is 7.0 per net. Catch rates over the past 15 years have ranged from 4.6 to 8.0 Walleyes per gill net. Age-2 Walleyes from the 2021 year-class composed the largest portion of the 2023 catch at 24.4 percent. Most age-2 Walleyes in the 2023 survey were in the nine, ten, and eleven-inch length groups but overall ranged from 6.9 to 12.2 inches long. The 2023 survey also caught a good number of age-4 Walleyes from the 2019 year-class. Most fish from this year-class were in the 12- to 14-inch length groups but ranged in length from 9.4 to 18.5 inches long. Overall, the 2023 survey caught above average numbers of eight-to-14-inch Walleyes and below average numbers of 15-17-inch Walleyes. This high abundance of smaller fish in the system is the result of the above average 2019 and 2021 year-classes. There are fewer 15-17 inch Walleyes because of weak year-classes produced in 2017 and 2018. Anglers are likely to encounter more harvestable-sized fish over the next couple of years as the strong 2019 and 2021 year-classes continue to grow. Overall, gill netted Walleyes ranged in length from 3.7 to 27.4 inches and had an average length of 13.7 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in and around Black Bay and Sand Bay. The 2023 overall gill net catch rate was 1.9 Sauger/net. Lengths ranged from 7.9 to 13.5 inches and averaged 9.8 inches. Eighty percent of Saugers caught in gill nets were less than 11 inches long.
\n
\nThe 2023 gill net catch of Northern Pike was 2.3 fish/net, similar to the historic average for Rainy. Northern Pike catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 17.1 to 40.9 inches in 2023. The average length was 25.3 inches. Reports of anglers catching large Northern Pike of 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes were at historic highs from 2003-2012. The record high catch rate occurred in 2012 at 13.5/net. The 2023 gill net catch rate was 9.0/net which is greater than the long-term average for Rainy Lake. Rainy Lake saw good Perch production from the 2018, 2019, and 2020 year-classes. In fact, the 2020 year-class appears to be one of the strongest ever produced. Individuals from the 2020 year-class ranged in length from 6.1 to 9.4 inches but most were in the seven- and eight-inch length groups in 2023. Overall, 2023 Yellow Perch lengths ranged from 5.5 to 12.2 inches and the overall average was 8.3 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish.
\n
\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are low on Rainy Lake, and angler opportunities in 2024 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting adult Black Crappies. A total of 170 crappies were caught in 2023 for a catch rate of 9.1 per net, which is among the highest ever on Rainy Lake. Black Crappie catch rates have been above average in six of the past seven surveys. Good Black Crappie production and recruitment on Rainy was observed from the 2016, 2017, 2019, and 2020 year-classes and is the driver of the high catch rates in recent years. Lengths ranged from 6.9 to 14.0 inches and averaged 10.7 inches in 2023. Twenty percent of the catch was from the 2019 year-class and an additional 19.4 percent from the 2016 year-class. Sixty-five percent of the Black Crappies caught in the 2023 survey were over 10 inches long and 29 percent were 12 inches or longer.
\n
\nRainy Lake is known to be infested with spiny waterfleas and zebra mussels. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
Introduction
\n
\nThis investigation was designed to document the population characteristics of Lake Whitefish (Coregonus clupeaformis) in Rainy Lake, Minnesota. Changes in water level management enacted by the International Joint Commission (IJC) in 2000 were expected to be beneficial to Lake Whitefish in the Namakan Reservoir and could impact Rainy Lake whitefish as well. Lake Whitefish spawn in shallow water during October and November with eggs hatching early in the following spring. Whitefish eggs, therefore, are susceptible to desiccation during winters with significant water level drawdown.
\n
\nThis investigation used the Fish Community Index Netting (FCIN) protocol developed by the Province of Ontario to collect baseline population characteristics of Lake Whitefish in Rainy Lake. FCIN is carried out on a two of four-year rotation. The 2024 sampling season represents the second of two surveys in the current four-year rotation on Rainy Lake. There is currently one commercial fishing license issued on the Minnesota side of the lake; however, the fisherman has not harvested Lake Whitefish since 2018.
\n
\nMethods
\n
\nTwelve FCIN nets were set from August 19th through August 23rd, 2024. Sets were approximately 24-hours in duration. The deeper portions of the lake were broken into four sectors, with each sector having three net stations. Gill nets used were eight feet tall and consisted of nine 50-foot panels of various mesh gill net (1.0, 2.25, 0.75, 1.5, 2.5, 1.75, 0.5, 2.0, and 1.25 inch bar measure). Net locations were selected to sample two depth strata (60'-80' and greater than 80'). Eight nets were set in the shallow-water stratum and four were set in the deep-water stratum. Net location and orientation were chosen randomly within strata, however, nets could not be within 330 feet of shore or exposed shoals.
\n
\nAll fish captured in each net were separated by species and capture mesh. Total length, weight, sex, and state of maturity were recorded for all Lake Whitefish captured. Otoliths were collected from Lake Whitefish for aging.
\n
\nFive metrics were incorporated to track long-term trends in the Lake Whitefish population.
\n1)\tMean age of first maturity
\n2)\tMean age of FCIN catch
\n3)\tRelative abundance (Catch per unit effort (CPUE))
\n4)\tRecruitment/ juvenile abundance (CPUE of age 3, 4 and 5)
\n5)\tSpatial distribution of FCIN catch
\n
\nResults and Discussion
\n
\nTen species totaling 372 individual fish were caught in the 2024 summer FCIN assessment. Cisco species were the most common fish, making up 36.6% of the total catch by number while Lake Whitefish made up the largest portion by weight at 41.0% of the catch. A total of 110 Lake Whitefish were sampled for a catch rate of 9.2 per lift. A total of 136 Cisco (CPUE = 11.3 per net), 65 Walleyes (CPUE = 5.4 per net), 46 Burbot (CPUE = 3.8 per net) and five Northern Pike (CPUE = 0.4 per net) were caught during the survey.
\n
\nLake Whitefish ranged in length from 8.5 to 24.7 inches, with a mean of 17.7 inches. The mean weight was 2.1 pounds. Eighteen age-classes were represented in the 2024 catch with the age-5 year-class composing 23.6 percent of the total catch while the age-3 and age-4 year-classes made up an additional 12.7 and 10.9 percent of the total catch, respectively.
\n
\nIn addition to overall catch rate, four metrics for evaluating the Lake Whitefish population were calculated. The age of 50% maturity (females) was 9.4 years. The mean age of Lake Whitefish in the FCIN catch was 7.4 years. Recruitment criteria showed that the juvenile catch rate (CPUE of age 3, 4, 5) of Lake Whitefish was 10.4 per net which is the greatest catch rate since sampling began in 2003. Lake Whitefish were sampled at 12 of 12 stations.
\n
\nFCIN sampling from recent years suggest the Lake Whitefish population is stable and healthy. Sampling was carried out in a two of four-year rotation resulting in 12 years of sampling between 2003 and 2024. The catch rate of Lake Whitefish has been relatively stable over the long-term. However, the 2023 catch rate of 3.8 per net was the lowest overall Lake Whitefish catch rate since sampling began in 2003. This was followed by one of the highest catch rates in 2024 at 9.2 per net. Only the 2007 gill net catch rate was greater at 10.4 per net. The mean age of the commercial catch (11.6 years) had been consistently higher than the mean age at 50% maturity for females (9.5 years in 2024) allowing a few years of spawning opportunities before becoming vulnerable to harvest. However, this is no longer a factor as the last commercial fisherman has not harvested Whitefish since 2018. There is no discernible change in the mean age of the FCIN catch over time and there were several age classes of Lake Whitefish present in the 2024 catch with individuals up to 22 years old. Consistent catch rates of juvenile Lake Whitefish suggest good reproduction and recruitment. Monitoring of the Lake Whitefish population and the commercial harvest (if commercial fisherman starts fishing again) for signs of overexploitation or stress should continue.
TO BE INCLUDED IN THE FINAL LARGE LAKE REPORT.
"},{"headerInfo":{"county":"St. Louis","wb_alt_name":"","survey_id":"111969","survey_type":"Population Assessment","wb_id":"69069400","id_date":"2000-09-05","wb_name":"Rainy","wb_type":"Lake"},"surveyID":"111969","narrative":"Rainy Lake walleye abundance, as indicated by gillnet catch rates, remained high in 2000. The gillnet catch of 7.2 per lift exceeded the historical average of 4.7 and marked the sixth consecutive year that catch rates exceeded 6.0. The presence of several strong year-classes including 1991, 1994, 1995, 1996 and1997 have bolstered stock abundance.Lengths of walleye sampled ranged from 6.1 to 27.3 inches. The average length was 13.2 inches. Abundance of walleye over 17 inches, fish protected by the 17-28 inch protected slot interval,remained high with a gillnet catch rate of 1.5 compared to a historical average of 0.9. Growth rates of Rainy Lake walleye have been below average over the last few years.Both shoreline seining and fall night electrofishing indicated that the 2000 walleye year-class exhibited slow growth in their first summer. Generally, slow first year growth is correlated with poor survival to adulthood.Northern pike gillnet catch rates in 2000 were 2.4 per lift compared to a historical average of 2.2. Pike ranged in length from 13.4 to 38.8 inches. The average length was 21.9 inches. The 1994, 1995, 1996 and 1997 year-classes were all above averagein abundance. Northern pike in Rainy Lake grow fast compared to other Area lakes.Black crappie spring trapnet catch rates increased in 2000 for the fourth consecutive year. The trapnet catch rate of 5.1 per net was the highest recorded since 1992. Two strong year-classes, 1994 and 1995, comprised 70% of the total crappie catch and ranged in length from 9.9 to 12.5 inches. The proportion of the catch comprised of crappie over 12 inches in length declined to its lowest level since 1992.Smallmouth bass fall electrofishing catch rates were the lowest since 1996 but approximately equal to the historical average since 1991. In 2000, as is common, age-0 bass dominated the catch. Lengths of all bass caught ranged from 1.8 to 16.1 inches with an average of 6.3 inches. Lengths of 122 bass caught by anglers during the Denny's Super 30 Bass Tournament on the Minnesota waters of Rainy Lake ranged from 12.0 to 20.7 inches. The average length was 15.4 inches. Age and growth analysis of these fish indicated that Rainy Lake bass grow very fast relative to other northern Minnesota lakes.The sauger gillnet catch rates of 2.2 was well below the historical average of 3.2 per net. Sauger abundance has been below average for four consecutive years. No strong year-classes have been detected in the sauger stock since 1991. Generally, small size make sauger a minor component of the Rainy Lake fishery.The yellow perch gillnet catch rate in 2000 was 3.1 compared to the historical average of 5.1. Perch abundance had declined dramatically since 1992 reaching 1.1 per net in 1996. The average 1995 and strong 1997 year-classes have bolstered abundance in recent years.
","surveyDate":"2000-09-05","lengths":{},"fishCatchSummaries":[{"CPUE":"1.00","gear":"Standard gill nets","gearCount":20,"quartileCount":"1.1-10.1","quartileWeight":"0.3-0.9","species":"TLC","totalWeight":12.94,"totalCatch":20,"averageWeight":"0.65"},{"quartileWeight":"2.8-4.3","quartileCount":"1.1-2.4","gearCount":20,"CPUE":"2.35","gear":"Standard gill nets","averageWeight":"2.66","totalCatch":47,"totalWeight":125.13,"species":"NOP"},{"quartileWeight":"0.2-0.6","quartileCount":"0.2-0.8","gearCount":20,"CPUE":"0.75","gear":"Standard gill nets","averageWeight":"0.28","totalCatch":15,"species":"BLC","totalWeight":4.16},{"gear":"Standard gill nets","CPUE":"8.25","gearCount":20,"quartileCount":"0.1-4.7","quartileWeight":"0.1-0.2","totalWeight":24.25,"species":"BLB","totalCatch":165,"averageWeight":"0.15"},{"gearCount":20,"CPUE":"2.25","gear":"Standard gill nets","quartileWeight":"1.7-2.2","quartileCount":"1.4-3.0","totalWeight":107.5,"species":"WTS","totalCatch":45,"averageWeight":"2.39"},{"totalCatch":144,"averageWeight":"1.08","species":"WAE","totalWeight":156.19,"quartileCount":"3.6-10.8","quartileWeight":"0.8-1.3","CPUE":"7.20","gear":"Standard gill nets","gearCount":20},{"totalWeight":12,"species":"SMB","averageWeight":"1.33","totalCatch":9,"gearCount":20,"gear":"Standard gill nets","CPUE":"0.45","quartileWeight":"0.7-1.2","quartileCount":"0.2-0.6"},{"species":"SHR","totalWeight":0.31,"totalCatch":1,"averageWeight":"0.31","gearCount":20,"gear":"Standard gill nets","CPUE":"0.05","quartileWeight":"1.6-2.9","quartileCount":"0.1-1.0"},{"gearCount":20,"gear":"Standard gill nets","CPUE":"0.10","quartileWeight":"0.9-2.8","quartileCount":"0.1-3.0","totalWeight":4,"species":"LKW","totalCatch":2,"averageWeight":"2.00"},{"quartileWeight":"0.1-0.2","quartileCount":"1.4-6.8","gearCount":20,"gear":"Standard gill nets","CPUE":"3.10","totalCatch":62,"averageWeight":"0.19","species":"YEP","totalWeight":11.63},{"CPUE":"2.15","gear":"Standard gill nets","gearCount":20,"quartileCount":"2.1-4.3","quartileWeight":"0.3-0.5","totalWeight":16.94,"species":"SAR","totalCatch":43,"averageWeight":"0.39"},{"totalWeight":3.38,"species":"RKB","averageWeight":"0.21","totalCatch":16,"gear":"Standard gill nets","CPUE":"0.80","gearCount":20,"quartileCount":"0.6-1.6","quartileWeight":"0.2-0.3"}],"surveySubType":"Population Assessment","surveyType":"Standard Survey"},{"headerInfo":{"id_date":"2020-07-20","wb_name":"Rainy","wb_type":"Lake","county":"St. Louis","wb_id":"69069400","survey_type":"Large Lake Survey","survey_id":"15622020251747000","wb_alt_name":""},"narrative":"Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe 2020 Walleye gill net catch rate was 4.6 fish/net, which is less than the historic median for Rainy Lake of 5.7 fish/net. Walleye catch rates have increased following historic overfishing prior to the 1990s. Walleye numbers quickly increased as the population recovered in the 1990s and reached an all-time high of 10.0 Walleyes per net in 2004. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.35 per net. Catch rates over the past 13 years have primarily been between 5.7 and 8.0 Walleyes per gill net. Age-4 Walleyes from the 2016 year-class composed the largest portion of the 2020 catch at 20.4 percent. Most age-4 Walleyes in the 2020 survey were 12 inches or longer but ranged from 8.2 to 16.2 inches. The 2011 year-class is the most recent strong year-class to recruit to the fishery and made up 4.6 percent of the 2020 gill net catch. Walleye production has been characterized by more average year-classes and fewer strong and weak year-classes in recent years. The result is a wide distribution of lengths in the population. Overall, gill netted Walleyes ranged in length from 7.5 to 26.5 inches and had an average length of 13.9 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in and around Black Bay. The overall gill net catch rate was 2.2 Sauger/net in 2020. Lengths ranged from 6.7 to 13.7 inches and averaged 9.7 inches. Sixty-two percent of Saugers caught in gill nets were less than 10 inches long.
\n
\nThe gill net catch of Northern Pike was 2.3 fish/net, similar to the historic average for Rainy. Northern Pike catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 16.5 to 41.7 inches in 2020. The average length was 25.3 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes were at historic highs from 2003-2012. The record high catch rate occurred in 2012 at 13.5/net. Catch rates were lower during the most recent four surveys. However, the 2020 gill net catch rate was 7.8 fish/net which is above average for Rainy Lake. The 2020 Yellow Perch lengths ranged from 5.5 to 12.7 inches and the overall average was 7.9 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Forty-six percent of the 2020 gill net catch measured eight inches or longer.
\n
\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are very low on Rainy Lake, and angler opportunities in 2021 should remain good.
\n
\nRainy Lake is known to be infested with spiny waterfleas. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
\n
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest Walleye lakes in Minnesota. The Large Lake Program includes annual standard fish assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during standard assessments to collect the various fish species and life stages. These gear types include gill nets, trap nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nExcellent Walleye angling opportunities continue to exist on Rainy Lake. The 2025 Walleye gill net catch rate was 7.2 fish per net, which is greater than the historic average of 6.1 fish per net for Rainy Lake. Walleye catch rates have increased following historic overfishing prior to the 1990s. Rainy Lake produced a good hatch of Walleyes in 2021 and most of these age-4 Walleyes in the 2025 survey were in the 12 to 14-inch length groups but overall ranged from 9.2 to 20.4 inches long. The 2025 survey also caught a good number of age-3 Walleyes from the 2022 year-class. Most fish from this year-class were in the nine- to 11-inch length groups but ranged in length from 8.8 to 17.7 inches long. Overall, the 2025 survey caught above average numbers of seven to 10-inch and 12 to 14-inch Walleyes. Rainy Lake also produces large Walleyes over 25 inches for those interested in catching memorable and trophy-sized Walleyes. The good size distribution we are currently seeing in Rainy Lake Walleyes is the result of consistent recruitment in recent years. Overall, gill netted Walleyes ranged in length from 6.1 to 26.8 inches and had an average length of 13.4 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26-inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. The 2025 overall gill net catch rate was 1.7 Sauger per net. Lengths ranged from 7.2 to 14.4 inches and averaged 10.1 inches. Eighty percent of Saugers caught in gill nets were less than 11 inches long. Occasionally larger, harvestable-size Sauger are encountered in and around Black Bay and Sand Bay. While anglers can occasionally catch larger Sauger in these areas, the species is not a primary target for harvest on Rainy Lake.
\n
\nThe 2025 gill net catch of Northern Pike was 2.7 fish per net, slightly more than the historic average for Rainy. Northern Pike gill net catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 17.5 to 39.4 inches in 2025. The average length was 26.9 inches. Anglers regularly report catching Pike over 40 inches, making Rainy Lake a popular destination for trophy Pike fishing. These large fish provide exciting angling action and help maintain the ecological balance of the lake by preying on smaller fish species.
\n
\nYellow Perch numbers and sizes were at historic highs from 2003-2012. The record high catch rate occurred in 2012 at 13.5 per net. The 2025 gill net catch rate was 7.3 per net which is similar to the long-term average for Rainy Lake. Rainy Lake saw good Perch production from the 2018, 2019, and 2020 year-classes. In fact, the 2020 year-class appears to be one of the strongest ever produced. Weaker year-classes were produced in 2021 and 2022, but preliminary numbers suggest the 2024 year-class may be above average. Overall, 2025 Yellow Perch lengths ranged from 4.8 to 11.4 inches and the average was 8.1 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Fifty-five percent of the 2025 Yellow Perch caught in gill nets were eight inches or greater in length. These conditions give anglers ample opportunity to harvest quality-sized perch while still maintaining a sustainable population for the future.
\n
\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are low on Rainy Lake, and angler opportunities in 2025 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting adult Black Crappies. A total of 162 crappies were caught in 2025 for a catch rate of 8.1 per net, which is above average for Rainy Lake. Black Crappie catch rates have been above average in eight of the past nine surveys. Good Black Crappie reproduction and recruitment on Rainy was observed from the 2016, 2017, 2019, and 2020 year-classes and is the driver of the high catch rates in recent years. Lengths ranged from 5.5 to 14.7 inches and averaged 11.2 inches in 2025. Fifty-nine percent of the catch was from the 2020 year-class and an additional 11.4 percent from the 2017 year-class. The 2020 year-class dominated the 2025 catch and ranged from 9.6 to 12.4 inches and averaged 10.7 inches long. Ninety percent of fish were over 10 inches, and 27 percent exceeded 12 inches, providing excellent angling opportunities for panfish enthusiasts seeking both numbers and trophy-sized crappies.
\n
\nRainy Lake is infested with spiny waterfleas and zebra mussels. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
TO BE INCLUDED IN THE FINAL LARGE LAKE REPORT.
","surveyDate":"1991-09-03"},{"headerInfo":{"id_date":"1996-09-30","wb_name":"Rainy","wb_type":"Lake","county":"St. Louis","wb_id":"69069400","wb_alt_name":"","survey_id":"111891","survey_type":"Population Assessment"},"narrative":"TRAP NETTING:TWENTY 3/4 INCH MESH TRAPNET SETS WERE MADE IN BLACK BAY OF RAINY LAKE AND THE RAT ROOT RIVER, A TRIBUTARY TO BLACK BAY, DURING JUNE OF 1996 WITH THE PURPOSE OF ASSESSING BLACK CRAPPIE STOCKS. THE CRAPPIE CATCH RATE OF 0.94 FISH PER LIFT WAS BELOW THE HISTORICAL MEAN OF 3.71 FISH PER LIFT. TRAP NETTING PRODUCED MORE ADULT CRAPPIE THAN ALL OTHER ASSESSMENT GEAR. MOST ANGLING REPORTS INDICATE THAT FISHING SUCCESS FOR CRAPPIE ALSO WAS LOW.THE NORTHERN PIKE TRAPNET CATCH RATE WAS SLIGHTLY BELOW THAT OF 1994 AND 1995 HOWEVER, AS WAS THE CASE IN 1995, SMALL FISH MADE UP MOST OF THE CATCH. OVER 68 PERCENT OF THE PIKE CAPTURED WERE LESS AND 20 INCHES IN LENGTH. LENGTHS OF FISH CAUGHT SUGGEST THAT TWO RECENT YEAR CLASSES DOMINATED THE CATCH. ADULT PIKE ABUNDANCE HAD DECLINED IN RECENT YEARS DUE TO LACK OF RECRUITMENT BY YOUNG FISH.SEINING:SHORELINE SEINING IN 1996 WAS CONDUCTED EVERY TWO WEEKS FROM JUNE 24 TO AUGUST 20. THREE HUNDRED NINETY AGE-0 WALLEYE WERE CAPTURED FOR A CPUE OF 3.55 FISH PER HAUL. THIS WAS THE HIGHEST CPUE EVER RECORDED. CATCH RATES HOWEVER, HAVE BEEN POORLY CORRELATED WITH FUTURE YEAR CLASS STRENGTH. FIRST YEAR GROWTH, IS A BETTER PREDICTOR OF FUTURE ABUNDANCE. IN 1996, AVERAGE LENGTH OF AGE-0 WALLEYE WAS BELOW THE AVERAGE OF THE PREVIOUS 13 YEAR CLASSES SUGGESTING THAT IT IS UNLIKELY THAT THE 1996 COHORT WILL BECOME A STRONG YEAR CLASS.THE RECORD HIGH SEINE CATCH OF AGE-0 NORTHERN PIKE INDICATES THAT THE 1996 COHORT MAY BE ABUNDANT IN THE FUTURE. UNLIKE WALLEYE, HIGH SEINE CATCHES OF AGE-0 PIKE HAVE BEEN INDICATIVE OF STRONG YEAR CLASSES. HIGH WATER LAST SPRING MAY HAVE PLAYED A ROLE IN PRODUCING THIS STRONG YEAR CLASS. AUGUST ELECTROFISHING:ONE HUNDRED SEVENTY-SIX WALLEYE WERE CAPTURED DURING LATE AUGUST ELECTROFISHING FOR A CPUE OF 43.1 FISH PER HOUR ON TIME. THIRTY-FOUR AGE-0 WALLEYE WERE CAPTURED FOR A CPUE OF 8.3 FISH PER HOUR. THE HISTORICAL AVERAGE WAS 17.4 AGE-0 WALLEYE PER HOUR. AVERAGE LENGTH RATHER THAN CPUE, WAS BEST CORRELATED TO THE GILLNET CATCH OF AGE-1 FISH THE FOLLOWING YEAR. AGE-0 WALLEYE IN 1996 HAD AN AVERAGE LENGTH OF 4.2 INCHES SUGGESTING THAT THE 1996 COHORT WILL NOT BECOME A STRONG YEAR CLASS.AGE-1 WALLEYE DOMINATED THE ELECTROFISHING CATCH MAKING UP 70 PERCENT OF THE TOTAL. THE AGE-1 WALLEYE CPUE OF 29.6 WAS THE SECOND HIGHEST EVER RECORDED WHICH DEMONSTRATES THE HIGH ABUNDANCE OF THIS YEAR CLASS.SIXTY-THREE SMALLMOUTH BASS WERE CAPTURED DURING AUGUST ELECTROFISHING FOR A CPUE OF 15.4 FISH PER HOUR. LENGTHS RANGED FROM 1.2 TO 15.0 INCHES WITH AN AVERAGE OF 8.4 INCHES. BASS AGES RANGED FROM 0 TO 7 YEARS. FEW AGE-4 AND NO AGE-3 BASS WERE CAPTURED SUGGESTING THAT THE COLD SUMMERS OF 1992 AND 1993 PRODUCED POOR BASS YEAR CLASSES. IN ADDITION, FEW AGE-0 BASS WERE CAPTURED WHICH SUGGESTS THAT THE 1996 YEAR CLASS ALSO MAY BE POOR. THE 1991, 1994 AND 1995 COHORTS WERE WELL REPRESENTED IN THE CATCH.GILL NETTING:THE 1996 WALLEYE GILLNET CPUE OF 7.25 FISH PER LIFT WAS THE HIGHEST RECORDED IN THE LAST 34 YEARS AND FELL WITHIN THE SECOND AND THIRD QUARTILES FOR CLASS 2 LAKES. THE HISTORICAL AVERAGE WAS 5.10 FISH PER LIFT. THE HIGH CPUE WAS DUE PRIMARILY TO THE PRESENCE OF THREE STRONG YEAR CLASSES, 1991, 1994 AND 1995.THE 1994 YEAR CLASS DOMINATED THE GILLNET CATCH AS AGE-2 FISH, MAKING UP 41 PERCENT OF THE TOTAL. NEXT YEAR WHEN FULLY RECRUITED, THE 1994 YEAR CLASS SHOULD SCORE HIGHER ON SCHUPP'S SCALE OF YEAR CLASS STRENGTH THAN ALL PREVIOUS COHORTS. MEMBERS OF THE 1994 COHORT RANGED IN LENGTH FROM 9.7 TO 14.0 INCHES WITH AN AVERAGE OF 11.6 INCHES. DURING THE 1997 FISHING SEASON, THEY SHOULD RANGE FROM 10.0 TO 16.5 INCHES.THE 1995 YEAR CLASS CONTRIBUTED NEARLY 24 PERCENT TO THE GILLNET CATCH. THIRTY-FOUR AGE-1 WALLEYE WERE CAPTURED FOR A CPUE OF 1.70 FISH PER LIFT. ONLY THE STRONG 1994 YEAR CLASS HAS PRODUCED MORE AGE-1 FISH DURING GILL NETTING. MEMBERS OF THE 1995 COHORT RANGED IN LENGTH FROM 6.9 TO 9.8 INCHES AND SHOULD BE CATCHABLE BY MID-JULY OF NEXT SUMMER.THE 1991 YEAR CLASS WAS THE THIRD MOST ABUNDANT COHORT IN THE CATCH CONTRIBUTING 12.5 PERCENT. THE 1991 COHORT WAS THE STRONGEST YEAR CLASS ON RECORD. AGE-5 FISH RANGED IN SIZE FROM 15.5 TO 19.3 INCHES WITH AN AVERAGE OF 17.3 INCHES. FIFTY-SIX PERCENT OF THE AGE-5 WALLEYE WERE OVER 17 INCHES AND PROTECTED BY THE EXPERIMENTAL REGULATION ON RAINY LAKE. BASED ON ANGLER REPORTS, THE 1991 YEAR CLASS MADE UP A SIGNIFICANT PORTION OF THE CATCH DURING THE 1996 OPEN-WATER SEASON. WALLEYE OVER 17 INCHES CONTRIBUTED 22 PERCENT TO THE GILLNET CATCH. THE CPUE OF WALLEYE OVER 17 INCHES OF 1.60 FISH PER LIFT WAS THE THIRD HIGHEST RECORDED. CATCH RATES OF FISH OVER 17 INCHES HAVE BEEN INCREASING SINCE 1970 PROBABLY DUE TO THE GRADUAL PHASE OUT OF THE COMMERCIAL FISHERY.NORTHERN PIKE CATCH RATES IMPROVED OVER 1995. THE GILLNET CPUE OF 2.30 WAS THE HIGHEST RECORDED SINCE 1990. IMPROVED ABUNDANCE WAS DUE PRIMARILY TO THE PRESENCE OF THE 1993 AND 1994 YEAR CLASSES WHICH CONTRIBUTED 33 AND 37 PERCENT OF THE TOTAL CATCH, RESPECTIVELY. PIKE LENGTHS RANGED FROM 9.8 TO 35.0 INCHES WITH AN AVERAGE OF 22.1 INCHES.THE YELLOW PERCH GILLNET CPUE OF 1.05 FISH PER LIFT WAS THE LOWEST EVER RECORDED. LOW PERCH NUMBERS MAY BE RELATED TO THE HIGH DENSITY OF PREDATORS PRESENT IN THE LAKE.ANGLER CREEL SURVEY:COMPLETE RESULTS OF THE 1996 RAINY LAKE CREEL SURVEY ARE NOT AVAILABLE YET, HOWEVER, SOME PRELIMINARY FINDINGS HAVE BEEN MADE. EARLY INDICATIONS ARE THAT APPROXIMATELY 70,239 BOAT-HOURS OF EFFORT WERE EXPENDED DURING THE OPEN-WATER SEASON ON RAINY LAKE. THIS WAS A 7 PERCENT INCREASE OVER THE PREVIOUS HIGH RECORDED IN 1995. IF THE NUMBER OF ANGLERS PER BOAT WAS SIMILAR TO PAST YEARS, THEN THE ESTIMATE OF ANGLER-HOURS ALSO SHOULD BE A RECORD. VARIOUS REPORTS BY ANGLERS INDICATE THAT CATCH RATES FOR WALLEYE ALSO WERE ABOVE AVERAGE, POSSIBLY WELL ABOVE AVERAGE.
","surveyDate":"1996-09-30","surveyID":"111891","surveySubType":"Population Assessment","surveyType":"Standard Survey","lengths":{},"fishCatchSummaries":[{"totalCatch":5,"averageWeight":"0.39","totalWeight":1.94,"species":"TLC","quartileWeight":"0.3-0.9","quartileCount":"1.1-10.1","gearCount":20,"CPUE":"0.25","gear":"Standard gill nets"},{"species":"NOP","totalWeight":112.94,"totalCatch":46,"averageWeight":"2.46","CPUE":"2.30","gear":"Standard gill nets","gearCount":20,"quartileCount":"1.1-2.4","quartileWeight":"2.8-4.3"},{"averageWeight":"0.07","totalCatch":6,"species":"BLC","totalWeight":0.41,"quartileCount":"0.2-0.8","quartileWeight":"0.2-0.6","gear":"Standard gill nets","CPUE":"0.30","gearCount":20},{"species":"BLB","totalWeight":0.31,"totalCatch":3,"averageWeight":"0.10","CPUE":"0.15","gear":"Standard gill nets","gearCount":20,"quartileCount":"0.1-4.7","quartileWeight":"0.1-0.2"},{"totalWeight":63.09,"species":"WTS","totalCatch":38,"averageWeight":"1.66","gear":"Standard gill nets","CPUE":"1.90","gearCount":20,"quartileCount":"1.4-3.0","quartileWeight":"1.7-2.2"},{"gearCount":20,"gear":"Standard gill nets","CPUE":"0.40","quartileWeight":"0.7-1.2","quartileCount":"0.2-0.6","totalWeight":8.88,"species":"SMB","totalCatch":8,"averageWeight":"1.11"},{"gearCount":20,"CPUE":"0.05","gear":"Standard gill nets","quartileWeight":"1.6-2.9","quartileCount":"0.1-1.0","species":"SHR","totalWeight":3.63,"totalCatch":1,"averageWeight":"3.63"},{"gearCount":20,"CPUE":"0.05","gear":"Standard gill nets","quartileWeight":"N/A","quartileCount":"N/A","totalWeight":30,"species":"LKS","totalCatch":1,"averageWeight":"30.00"},{"gear":"Standard gill nets","CPUE":"1.05","gearCount":20,"quartileCount":"1.4-6.8","quartileWeight":"0.1-0.2","totalWeight":3.34,"species":"YEP","totalCatch":21,"averageWeight":"0.16"},{"totalWeight":31.5,"species":"SAR","totalCatch":86,"averageWeight":"0.37","gear":"Standard gill nets","CPUE":"4.30","gearCount":20,"quartileCount":"2.1-4.3","quartileWeight":"0.3-0.5"},{"CPUE":"0.55","gear":"Standard gill nets","gearCount":20,"quartileCount":"0.6-1.6","quartileWeight":"0.2-0.3","totalWeight":4.03,"species":"RKB","totalCatch":11,"averageWeight":"0.37"}]},{"lengths":{},"fishCatchSummaries":[{"gear":"Standard gill nets","CPUE":"0.65","gearCount":20,"quartileCount":"1.1-10.1","quartileWeight":"0.3-0.9","totalWeight":4,"species":"TLC","totalCatch":13,"averageWeight":"0.31"},{"species":"NOP","totalWeight":106.4,"totalCatch":54,"averageWeight":"1.97","gearCount":20,"gear":"Standard gill nets","CPUE":"2.70","quartileWeight":"2.8-4.3","quartileCount":"1.1-2.4"},{"gearCount":20,"CPUE":"0.25","gear":"Standard gill nets","quartileWeight":"0.2-0.6","quartileCount":"0.2-0.8","totalWeight":0.3,"species":"BLC","totalCatch":5,"averageWeight":"0.06"},{"totalCatch":168,"averageWeight":"0.19","totalWeight":31.8,"species":"BLB","quartileWeight":"0.1-0.2","quartileCount":"0.1-4.7","gearCount":20,"CPUE":"8.40","gear":"Standard gill nets"},{"CPUE":"2.40","gear":"Standard gill nets","gearCount":20,"quartileCount":"1.4-3.0","quartileWeight":"1.7-2.2","totalWeight":100.4,"species":"WTS","totalCatch":48,"averageWeight":"2.09"},{"totalCatch":140,"averageWeight":"1.06","species":"WAE","totalWeight":148.8,"quartileWeight":"0.8-1.3","quartileCount":"3.6-10.8","gearCount":20,"CPUE":"7.00","gear":"Standard gill nets"},{"gear":"Standard gill nets","CPUE":"0.15","gearCount":20,"quartileCount":"0.2-0.6","quartileWeight":"0.7-1.2","species":"SMB","totalWeight":2.3,"totalCatch":3,"averageWeight":"0.77"},{"totalWeight":3.1,"species":"LKW","totalCatch":3,"averageWeight":"1.03","gearCount":20,"CPUE":"0.15","gear":"Standard gill nets","quartileWeight":"0.9-2.8","quartileCount":"0.1-3.0"},{"totalCatch":48,"averageWeight":"0.36","totalWeight":17.1,"species":"SAR","quartileWeight":"0.3-0.5","quartileCount":"2.1-4.3","gearCount":20,"gear":"Standard gill nets","CPUE":"2.40"},{"quartileCount":"1.4-6.8","quartileWeight":"0.1-0.2","CPUE":"6.50","gear":"Standard gill nets","gearCount":20,"totalCatch":130,"averageWeight":"0.16","totalWeight":20.3,"species":"YEP"},{"totalWeight":3.1,"species":"RKB","totalCatch":13,"averageWeight":"0.24","CPUE":"0.65","gear":"Standard gill nets","gearCount":20,"quartileCount":"0.6-1.6","quartileWeight":"0.2-0.3"}],"surveySubType":"Population Assessment","surveyType":"Standard Survey","surveyID":"111933","narrative":"The 1999 fall investigation found walleye numbers remaining good at 7.0 per net compared to the long term average of 4.7. Strong year classes from 1991, 1994, 1996, and 1997 were present. The number of walleye over 17 inches, fish protected by the experimental regulation, increased to 1.5 per net compared to the long term average of 1.1 per net. The average walleye measured 13.5 inches. The slow growth rate was typical of large, natural walleye lakes in the International Falls area. Northern pike numbers were near the long term average of 2.8 pike per net, however, most of the northerns sampled in 1999 were young fish. Average length was 21.4 inches with a range from 16.5 to 27.4 inches. The black crappie trapnet catch improved for the third straight year, increasing to 2.4 per net. The average since 1992 was 2.6 per trapnet. Most of the sampled crappies were between 9 and 11 inches (average of 10.1 inches) and weighed an average of 3/4 of a pound. Sauger numbers, a minor component of the angler's catch, were low at 2.4 per net. Long term average was 4.5 per net. Average length was 10.6 inches with only 1 fish over 15 inches sampled in 1999. Fall electrofishing sampled smallmouth bass, especially young of the year, at a rate of 38.4 fish per hour. The historic average was 27.9 fish per hour. Previous investigations have indicated that 1991 and 1995 produced strong year classes. Preliminary results of the 1999 angler creel survey found angling pressure continuing to rise. Most anglers surveyed lived over 30 miles from Rainy Lake. Anglers kept about the same number of walleye per trip, however, with the highest angling pressure ever, an estimated 50,166 walleyes weighing 52,576 pounds were taken from Rainy Lake in 1999.
","surveyDate":"1999-09-07","headerInfo":{"survey_type":"Population Assessment","survey_id":"111933","wb_alt_name":"","wb_id":"69069400","county":"St. Louis","wb_name":"Rainy","wb_type":"Lake","id_date":"1999-09-07"}},{"narrative":"The 2007 large lake sampling program provided valuable insight to the status of the Rainy Lake fishery. Walleye, yellow perch, northern pike, smallmouth bass, and black crappie populations are doing well as indicated by various sampling methods. Several trends in the long-term gill net data show the Rainy Lake walleye fishery has recovered from years of overharvest and continual suppression seen through the early 1990s.
\n
\nFor the past 13 years walleye gill net CPUE has been at historically high levels. The 2007 CPUE was slightly down from the past 3 years, but still above the long-term mean. Walleye CPUE from 1983 to 1994 averaged 3.98 per net, since 1995 the average is 7.07 per net. Only twice (2001 and 2002) during the past ten years has the walleye CPUE been below six per net. Consistent recruitment has been the main factor contributing to the observed increase in CPUE.
\n
\nThe slight decline in walleye abundance in the gill nets can largely be attributed to poor production during 2002 and 2004. Age-5 and age-3 walleye typically make up a large portion of the gill net catch. In 2007, both age-5 and age-3 walleye were caught at very low rates for their respective ages. Their absence and the slight decline in CPUE is no reason for alarm as it reflects natural variation in walleye production.
\n
\nCatch rates of larger walleye (over 17\") have significantly increased in the past 30 years. During the past 13 years the CPUE of walleye over 17 inches has remained greater than one per net, a feat that was achieved only twice prior to 1990. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations.
\n
\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the 10 year-classes were rated as strong. Netting surveys show that the 2000 year-class is weak. However, the 2001 year-class stands to be the strongest on record. Indications of the 2002 and 2004 year-classes are week. In contrast, the 2003 and 2006 are very strong.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. The 2003 year-class will continue to be the main contributor to the harvest. While the 2006 and 2007 year-classes are showing good potential, it will be a couple of years before they begin recruitment to the sport fishery.
\n
\nNorthern pike gill-net CPUE showed a sharp increase in 2007. Northern pike assessment shows there are several average year-classes present in the catch. The 2004 year-class has emerged as being strong. While large northern pike were present there was a downward trend in pike growth rates during the late 1990s into the early 2000s, this trend has changed and growth rates are increasing while recruitment is slowing. During the early 1990s mean northern pike length at age-3 was approximately 23 inches, during the late 1990s into the early 2000s length at age-3 dropped into the mid to upper teen range. In 2006 the mean northern pike length for age-3 was 21.9 inches, illustrating the faster growth rates.
\n
\nSauger abundance has steadily declined for the past 15 years. The CPUE observed in 2007 was the lowest ever. This trend may demonstrate density dependent and interspecies competition that influences the abundance and growth of walleye and sauger. Sauger fishing on Rainy Lake is a result of indirect catch, no angling parties contacted during 2007 were targeting sauger. Low sauger abundance and a healthy walleye fishery likely are the cause for effort being directed towards walleye.
\n
\nLake whitefish are commercially fished on Rainy Lake and there is very little sport-fishing effort directed toward this species. Annual commercial harvest of lake whitefish has remained below the target quota every year since 1999. FCIN provides a standardized methodology for the monitoring of this population. Based on three years of observation the lake whitefish population is showing no signs of overexploitation, however, more years of observation are needed to quantify this statement. Good recruitment in the past five years indicates the population is sustainable. FCIN is scheduled to be conducted again during the summer of 2008 and again in 2011-12.
\n
\nSpring sampling indicated the black crappie population is doing very well. Younger year-classes were present and mortality (natural and fishing) has greatly reduced the population of the strong year-classes from the mid-1990s. The recruitment of the 2003 year-class to the sport fishery (and trap nets) has resulted in a very abundant fishery with exceptional opportunities to catch crappies. The current status of the fishery indicates that crappie fishing should be exceptional during the next few years as the 2003 year-class continues to grow to desirable lengths.
\n
\nSmallmouth bass numbers from the nighttime electrofishing indicates good recruitment. The 2007 smallmouth bass CPUE was near normal for Rainy Lake. Smallmouth bass populations have grown and have been protected only by the catch-and-release ethics common to most bass anglers. Bass growth on Rainy Lake is slow compared to area and state averages. However, there are plenty of memorable and trophy sized smallmouth bass present as demonstrated by the catch during the spring electrofishing and reports from anglers. Angler opportunities in 2008 should remain good.
\n
\nYellow perch gill-net numbers were above average for Rainy Lake. The length distribution of perch captured in the gill nets was predominantly in the less than nine-inch category. However, larger individuals are common and should provide some decent harvest opportunities for the next few years. Recruitment has been exceptional for the past five years, providing a strong forage base.
\n
Walleye
\n
\nEleven fish species were captured during the annual fall gill netting on Rainy Lake in 2011. Walleye made up 25.7% of the catch by number. Walleye and northern pike represented 61.5% of the catch by total weight.
\n
\nThe 2011 walleye gill net catch rate was 7.67 fish per net. The 1998 to 2010 mean catch rate (historical average) was 7.71. The 2011 gill-net catch rate was above the median of 5.47 for Rainy Lake. Catch rates of larger walleye (over 17\") have increased in the past 30 years. The catch rate of walleye over 17 inches peaked in 2005 at 3.0 walleye per net before beginning a declining trend. After the catch rate of walleye over 17 inches in 2008 dipped below one per net for the first time since the protected slot was put in place it rebounded strongly to 1.88 per net in 2010. The catch rate of walleye over 17 inches in length was 1.63 in 2011, slightly lower than 2010 but above the normal range for Rainy Lake. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. Creel data from 2011 indicated that walleye 17 inches or greater in length made up 29 percent of the total catch for 2011.
\nLengths of gill netted walleye ranged from 4.2 to 27.3 inches. The average walleye length was 14.1 inches and the average weight was 1.21 pounds.
\n
\nThe walleye catch consisted of 18 age groups. Ages ranged from age-0 to age-20 with an average of 5.1 years. Age-5 walleye made up 26.6 percent of the gill-net catch and age-3 and age-4 made up 13.6 percent and 17.9 percent, respectively. Altogether, 11.1 percent of the catch was represented by individuals ten years of age or older. Of the cohorts represented in the gill net catch from the past 10 years, the 2001, 2003, 2006 and 2007 year-classes are considered strong.
\n
\nFor the past 17 years, walleye gill net catch rates have been at historically high levels. The walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.66 per net. The 2011 catch rate of 7.67 per gill net was up slightly from the 6.13 per gill net captured in 2010 and represents the third year of increase since 2008. Consistent recruitment has been the main factor contributing to the observed increase in walleye catch rates.
\n
\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s, Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the ten year-classes were rated as strong. During the first half of the 2000s three of the seven year-classes recruited to date are strong including record breaking 2001 year class, and the 2006 year-class which recruited to the gear in 2009. The 2007 year class also appears strong, marking the first time since 1997-98 that Rainy Lake has produced consecutive strong year classes.
\n
\nSince 1996 walleye growth rates on Rainy Lake have decreased. Length at capture for walleye in 2011 was less than the historical average. This decrease in growth coincided with an increase in walleye abundance. These observations indicate potential density-dependent growth. Hartman and Margraf (1992) found that high densities of walleye (strong year-classes) suppressed the forage base and consequently reduced walleye growth in Lake Erie. On Rainy Lake this relation has not been demonstrated; specifically, there has been no discernable decreasing trend in the forage (yellow perch) abundance but rather an increase in yellow perch abundance since 2003 based on fall gill netting. The observed growth pattern may be the fisheries return to pre-overexploited growth rates.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. The 2006 and 2007 year-classes will continue to be the main contributors to the harvest.
\n
\nNorthern Pike
\n
\nThe northern pike gill-net catch rate was 1.93, which is at the normal range for Rainy Lake, but above the median for Lake Class 2 lakes statewide. Northern pike lengths ranged from 14.3 to 37.0 inches. The mean length was 22.4 inches and the mean weight was 2.79 pounds.
\n
\nAge-3 and age-4 northern pike made up 26.7 percent of the northern pike catch, while age-2 made up 24.4 percent of the northern pike catch. Northern pike ages ranged from age-1 to age-13. The mean northern pike age was 3.9 years. The calculation of the year-class strength index indicated that there has not been a strong year-class of northern pike since 2005. However, early indications suggest that 2009 may be strong.
\n
\nThe northern pike gillnet catch rate decreased to below the normal range for Rainy Lake in 2009 after a sharp increase in 2007 and equally sharp decline in 2008. The 2010 northern pike catch rate rebounded slightly, but remained below the normal range for Rainy Lake. The 2011 catch continued the upward trend landing near the bottom end of the normal range for Rainy Lake. Northern pike assessment shows there were only two individuals from strong year-classes present in the catch (1998 and 2000 year-classes).
\n
\nSauger
\n
\nThe sauger catch rate of 2.67 fish per gill net continued the upward trend which began in 2010. The 2011 sauger catch rate was above the normal range for the Rainy Lake historical record but below the historical median. Sauger lengths ranged from 7.2 to 16.1 inches. The mean length was 10.4 inches with a mean weight of 0.33 pounds.
\n
\nAge-3 and age-4 sauger each represented 21.9 percent of the sauger catch in the 2011 gill net catch while age-1 sauger made up an additional 18.8 percent of the catch. The mean sauger age was 3.6 years. The year-class strength index indicates that 2001 was the most recent strong year-class of sauger produced in Rainy Lake.
\n
\nSauger abundance has steadily declined for the past 16 years. The catch rate observed in 2011 was an increase from the record low values recorded in 2008 and 2009. This declining trend may demonstrate density dependent and interspecies competition that influences the abundance and growth of walleye and sauger. Staggs and Ottis (1996) found that competition did exist between walleye and sauger and that regardless both species grew better in years with high forage abundance.
\n
\nYellow Perch
\n
\nThe yellow perch catch rate of 9.58 fish per gill net was above the normal range for Rainy Lake and above the third quartile for all Lake Class 2 lakes. Yellow perch ranged in length from 5.0 to 12.6 inches, with a mean of 8.1 inches and a mean weight of 0.31 pounds.
\n
\nAge-4 yellow perch made up 29.1 percent of the perch catch and age-3 perch made up an additional 24.6 percent of the catch. Yellow perch from nine year-classes up to age-10 were represented in the 2011 gill-net catch. The 2005, 2006, and 2007 year-classes were all strong as were the 2001, 2002, and 2003 year-classes. The 2008 year class appears average. These consecutive strong year-classes are driving the recent increases in yellow perch gill net catch rates.
\n
\nYellow perch gill-net numbers appear to have increased in Rainy Lake since the consecutive low catch years of 2001 and 2002. The length distribution of perch captured in the gill nets was predominantly in the less than nine-inch category with just 15 percent of the catch larger than nine inches. However, the total number of yellow perch caught in gill nets in 2011 was higher than 2010, resulting in a greater number of nine inch or larger fish which should provide some good harvest opportunities for the next few years. With the exception of 2004, recruitment has been exceptional for the past ten years with six of the seven best year-classes for Rainy Lake occurring since 2001. This strong yellow perch production should continue providing a good forage base and developing angling opportunities for years to come.
\n
\nSmallmouth Bass
\n
\nDue to short staffing, spring electrofishing targeting smallmouth bass took place during a single sampling event on the night of June 14th through June 15th resulting in fewer stations being sampled than previous years. A total of 6,375 seconds (1.77 hours) of \"on-time\" were recorded. The total smallmouth bass catch was 24 for a catch rate of 13.6 fish per hour. This catch rate is slightly lower than recent years but within the range observed in past surveys. Smallmouth bass ranged in length from 10.7 to 19.25 inches in length with a mean of 13.8 inches. Age-5 smallmouth bass represented 39.1 percent of the bass catch with age-7 contributing 21.7 percent. Based on spring electrofishing catch rates, the 2001, 2002, 2003, and 2006 year-classes are strong year classes.
\n
\nSmallmouth bass growth on Rainy Lake is slow compared to area and state averages. However, there are plenty of memorable and trophy sized smallmouth bass present as demonstrated by the catch during the spring electrofishing and reports from anglers. Angler opportunities in 2012 should remain good.
\n
\nBlack Crappie
\n
\nAnnual trap netting targeting black crappie has been carried out in Black Bay since 1992 using standard lake survey trap nets. Trap netting consists of 20 set locations throughout Black Bay and the lower Rat Root River and was conducted from May 16 through May 18 in 2011. Length, weight, sex, maturity, and a scale sample were collected from captured black crappie.
\n
\nA total of 35 black crappies were caught for a catch rate of 1.75 fish per net. This catch rate was slightly lower than the 2010 catch of 2.2 crappies per net and below the long-term average of 3.70 per net. Crappie lengths ranged from 7.95 to 13.66 inches with a mean of 11.61 inches. The 2003 and 2006 year-classes appear strong based on trap netting and the 2005 year-class is about average.
\n
\nAlthough catch numbers were down slightly in 2011, spring sampling indicated the black crappie population is doing well. The recruitment of the 2003 year-class to the sport fishery (and trap nets) in 2009 has resulted in an abundant fishery with exceptional opportunities to catch crappies. The 2008 creel reported the highest harvest of crappies ever recorded for Rainy Lake. The variable recruitment of crappie in Rainy Lake is consistent with crappie populations from around the country (Sammons et al 2002 and Allen 1997). The current status of the fishery indicates that crappie fishing should be good during the next couple years as the strong 2003 year-class continues to contribute larger fish and the 2006 year class continues to provide numbers for harvest. An early and relatively warm spring in 2010 and good numbers of black crappie sampled in seines suggest that a strong year-class of black crappie may have been produced on Rainy Lake in 2010.
\n
\nOther species
\n
\nThe catch rate of cisco species was 2.67 fish per net, which is down from the record high in 2010 of 5.79 but higher than the normal range for Rainy Lake. No lake whitefish were captured in standard gill nets in Rainy Lake in 2011. White suckers were caught at a rate just above the bottom end of the normal range for Rainy Lake with a catch rate of 1.58 fish per gill net. Black bullhead, black crappie, brown bullhead, longnose sucker, smallmouth bass, and rock bass were also captured in the 2011 gill nets.
\n
Walleye
\n
\nTwelve fish species were captured during the annual fall gill netting on Rainy Lake in 2012. Walleye made up 20.2% of the catch by number. Walleye and northern pike represented 51.5% of the catch by total weight.
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\nThe 2012 walleye gill net catch rate was 6.38 fish per net which is above the long-term median of 5.47 per net for Rainy Lake. The 1998 to 2010 average catch rate (historical mean) was 7.62 per net. For the past 17 years the walleye gill net catch rate has been at historically high levels. The walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.59 per net. The 2012 catch rate of 6.38 per gill net was down from the 7.67 per gill net captured in 2011 but represents the second highest catch rate since 2007 and is above the long-term median of 5.50 walleyes per net. Consistent recruitment has been the main factor contributing to the observed increase in walleye catch rates.
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\nCatch rates of larger walleye (over 17\") have increased in the past 30 years. The catch rate of walleye over 17 inches peaked in 2005 at 3.0 walleye per net before beginning a declining trend. After the catch rate of walleye over 17 inches in 2008 dipped below one per net for the first time since the protected slot was put in place it rebounded strongly to 1.88 per net in 2010. The catch rate of walleye over 17 inches in length was 1.33 in 2012, slightly lower than 2011 and just below the third quartile for Rainy Lake. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. Creel data from 2011 indicated that walleye 17 inches or greater in length made up 29% of the total catch for 2011. Lengths of gill netted walleye ranged from 6.9 to 25.16 inches. The average walleye length was 12.9 inches and the average weight was 0.93 pounds.
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\nThe walleye catch consisted of 12 age groups. Ages ranged from age-1 to age-16 with an average of 4.2 years. Age-1 walleye made up 26.1 percent of the gill-net catch and age-2 and age-6 each made up 16.3 percent. Of the cohorts represented in the gill net catch since 2000, the 2001, 2003, 2006 and 2007 year-classes are considered strong.
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\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s, Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six of the ten year-classes were rated as strong. During the first half of the 2000s three of the seven year-classes recruited to date are strong including the record breaking 2001 year class, and the 2006 year-class which recruited to the gear in 2009. The 2007 year class is also strong marking the first time since 1997-98 that Rainy Lake has produced consecutive strong year-classes.
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\nSince 1996 walleye growth rates on Rainy Lake have decreased. Length at capture for walleye in 2012 was less than the historical mean for almost all age classes over age-4. This decrease in growth coincided with an increase in walleye abundance. These observations indicate potential density-dependent growth. Hartman and Margraf (1992) found that high densities of walleye (strong year-classes) suppressed the forage base and consequently reduced walleye growth in Lake Erie. On Rainy Lake this relation has not been demonstrated: specifically, there has been no discernable decreasing trend in the forage (yellow perch) abundance but rather an increase in yellow perch abundance since 2003 based on fall gill netting. The observed growth pattern may be the fisheries return to pre-overexploited growth rates.
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\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. As the 2006 year class moves into the slot the strong 2007 year-class will be the main contributor to the harvest. The future looks promising as several age-1 and age-2 fish were caught in the gill nets in 2012.
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\nNorthern Pike
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\nThe 2012 northern pike gill net catch rate was 1.54, which is slightly below the normal range for Rainy Lake and just below the median for Lake Class 2 lakes statewide. The northern pike gill net catch rate decreased below the normal range for Rainy Lake in 2009 after a sharp increase in 2007 and equally sharp decline in 2008. The catch rate has been relatively stable in recent assessments fluctuating between 1.5 and 2.0 per gill net. Northern pike lengths ranged from 14.3 to 38.4 inches. The average length was 24.9 inches and the average weight was 3.78 pounds.
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\nAge-3 and age-4 northern pike made up 19.4 and 25.0 percent of the northern pike catch, respectively, while age-6 made up 16.7 percent of the northern pike catch. Northern pike ages ranged from age-1 to age-12. The average northern pike age was 4.9 years. The calculation of the year-class strength index indicated there has not been a strong year-class of northern pike since 2005. The 2009 year-class initially appeared strong but was caught in lower numbers in 2012.
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\nSauger
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\nThe 2012 sauger gill net catch rate of 2.08 per net was similar to recent years and near the first quartile for Rainy Lake. Sauger lengths ranged from 7.7 to 13.7 inches. The average length was 10.3 inches with an average weight of 0.30 pounds.
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\nAge-5 sauger represented 26.0 percent of the sauger catch in the 2012 gill net catch while age-2 sauger made up an additional 18.0 percent of the catch. The average sauger age was 4.8 years. The year-class strength index indicates that 2001 was the most recent strong year-class of sauger produced in Rainy Lake, but good numbers from the 2010 cohort in the 2011 and 2012 gill nets suggest the 2010 year-class may be strong.
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\nRelative sauger abundance has steadily declined from the catch rates observed in the mid-1990s and has been relatively stable near the first quartile for Rainy Lake. This decrease coincides with a large increase in the catch rate of walleyes and may demonstrate density dependent and interspecies competition that influences the abundance and growth of walleye and sauger. Staggs and Ottis (1996) found that competition did exist between walleye and sauger and that regardless both species grew better in years with high forage abundance. Sauger fishing on Rainy Lake is a result of indirect catch; no angling parties contacted during the most recent creel survey in 2011 were targeting sauger (Vondra 2012). Low sauger abundance, small average size, and a healthy walleye fishery are likely the cause for effort being directed towards walleye.
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\nYellow Perch
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\nThe 2012 yellow perch catch rate of 13.5 per net was the highest catch rate ever recorded on Rainy Lake and well above the normal range for all Lake Class 2 lakes. Yellow perch ranged in length from 5.0 to 12.1 inches, with an average of 7.7 inches and an average weight of 0.26 pounds.
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\nAge-2 yellow perch made up 47.9 percent of the perch catch and age-1 made up an additional 14.6 percent of the catch. Yellow perch from eight year-classes up to age-9 were represented in the 2012 gill-net catch. The 2005, 2006, and 2007 year-classes were all strong as were the 2001, 2002, and 2003 year-classes. The 2008 and 2009 year classes appear to be weak. Good gill net catch rates of age-1 and age-2 yellow perch suggest the 2010 and 2011 year-classes may be strong. Strong, consistent recruitment of yellow perch appears to be driving the recent increase in the yellow perch gill net catch rate.
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\nYellow perch gill net numbers appear to have increased in Rainy Lake since the consecutive low catch years of 2001 and 2002. The length distribution of perch captured in the gill nets suggest larger fish are more common in Rainy Lake than in the past as 24 percent of the perch caught in gill nets in 2012 were nine inches or longer. This increase in larger fish should provide some good harvest opportunities for the next few years. With the exception of 2004, recruitment has been exceptional for the past 11 years with six of the seven best year-classes for Rainy Lake occurring since 2001. This strong yellow perch production should continue providing a strong forage base and angling opportunities.
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\nSmallmouth Bass
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\nDue to poor weather and a heavy spring workload, spring electrofishing targeting smallmouth bass took place during a single sampling event on the night of June 5th with just two stations being sampled. A total of 2,721 seconds (0.76 hours) of \"on-time\" were recorded. The total smallmouth bass catch was 12 fish for a catch rate of 15.9 per hour. This catch rate is slightly lower than recent years but within the range observed in past surveys. Smallmouth bass ranged in length from 11.3 to 18.7 inches in length with an average of 13.9 inches. Five age classes were represented in the catch.
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\nSmallmouth bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized smallmouth bass present. Smallmouth bass harvest numbers are low on Rainy Lake and angler opportunities in 2013 should remain good.
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\nBlack Crappie
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\nAnnual trap netting targeting black crappie has been carried out in Black Bay since 1992 using standard lake survey trap nets. Trap netting consists of 20 set locations throughout Black Bay and the lower Rat Root River and was conducted from May 14 through May 16 in 2012. Length, weight, sex, maturity, and a scale sample for aging were collected from captured black crappie.
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\nA total of 111 black crappies were caught for a catch rate of 5.55 fish per net. This catch rate was the fifth highest on record and the highest since 2007 (9.1 per net). The 2012 catch rate is more than double the median catch rate of 2.59 per net. Crappie lengths ranged from 5.91 to 14.57 inches with an average of 11.91 inches. Twenty-nine percent of the catch was from the 2006 year-class with an additional 22.2 percent from the 2003 year-class. The 2003 year-class appears to be the strongest year-class ever produced in Rainy Lake and when combined with an average year-class in 2005 and a strong 2006 year-class explains much of the high trap net catch rate in 2012.
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\nOther species
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\nThe 2012 catch rate of cisco species was 3.38 per net, which is down from the record high in 2010 of 5.79 but higher than the third quartile for Rainy Lake and the third highest catch rate ever recorded on Rainy Lake. One lake whitefish was captured in standard gill nets in Rainy Lake. White suckers were caught at a rate near the median for Rainy Lake at 2.17 per net. Black crappie, rainbow smelt, rock bass, shorthead redhorse, and smallmouth bass were also captured in the 2012 gill nets.
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Walleye
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\nEleven fish species were captured during the annual fall gill netting on Rainy Lake in 2013. Walleye made up 32.3% of the catch by number. Walleye and Northern Pike represented 62.6% of the catch by total weight.
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\nThe 2013 Walleye gill net catch rate was 7.96 fish per net which is above the average range for Rainy Lake. The 1998 to 2012 average catch rate (historical average) was 7.64. For the past 17 years the Walleye gill net catch rate has been at historically high levels. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.61 per net. The 2013 catch rate of 7.96 per gill net was up from the 6.38 per gill net captured in 2012 and the highest since 2006. Consistent recruitment has been the main factor contributing to the observed increase in catch rates.
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\nLengths of gill netted Walleye ranged from 6.8 to 25.1 inches. The average Walleye length was 12.9 inches and the average weight was 0.86 pounds.
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\nCatch rates of larger Walleye (over 17\") have increased in the past 30 years. The catch rate of Walleye over 17 inches peaked in 2005 at 3.0 Walleye per net before beginning a declining trend. After the catch rate of Walleye over 17 inches in 2008 dipped below one per net for the first time since the protected slot was put in place it rebounded strongly to 1.88 per net in 2010. The catch rate of Walleye over 17 inches in length was 1.43 in 2013 which is near the upper end of the average range for Rainy Lake. Currently Walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. The most recent creel survey conducted in 2011 showed that Walleye 17 inches or greater in length made up 29% of the total catch for 2011.
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\nThe 2013 Walleye catch consisted of 17 age groups. Ages ranged from age-0 to age-19 with a mean of 4.5 years. Age-2 Walleyes made up 31.4 percent of the gill-net catch and age-3 an additional 19.9 percent. Age-7 Walleyes composed 12.6 percent of the 2013 catch. Of the cohorts represented in the gill net catch since 2000, the 2001, 2003, 2006, 2007, and 2010 year-classes are considered strong.
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\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s, Rainy Lake Walleye produced a strong year-class once every four years. Throughout the 1990s, six of the ten year-classes were rated as strong. During the 2000s four of the ten year-classes recruited to date are strong including the record breaking 2001 year class, and the 2006 year-class which recruited to the gear in 2009. The 2007 year class is also strong marking the first time since 1997-98 that Rainy Lake has produced consecutive strong year-classes. The 2010 year-class is strong and early indications suggest the 2011 and 2012 year-classes may also be strong which would be the longest string of above average year-classes since the 1994-1998 run of strong year-classes.
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\nSince 1996 Walleye growth rates on Rainy Lake have decreased. Length at capture for Walleye in 2013 was less than the historical mean for almost all age classes over age-3. This decrease in growth coincided with an increase in Walleye abundance. These observations indicate potential density-dependent growth. Hartman and Margraf (1992) found that high densities of Walleye (strong year-classes) suppressed the forage base and consequently reduced Walleye growth in Lake Erie. On Rainy Lake this relation has not been demonstrated: specifically, there has been no discernable decreasing trend in the forage (Yellow Perch) abundance but rather an increase in Yellow Perch abundance since 2003 based on fall gill netting. The observed growth pattern may be the fisheries return to pre-overexploited growth rates.
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\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large Walleye and uphold reproduction. As the 2006 year class moves into the slot (currently averaging 16.6 inches long) the strong 2007 year-class will be the main contributor to the harvest. Members of the strong 2010 year-class are already reaching harvestable size and will continue to do so over the next few years. In addition, the future looks promising as the 2011 year-class has the potential to be a very strong year-class.
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\nNorthern Pike
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\nThe 2013 Northern Pike gill net catch rate was 2.00 per net, which is near the lower end of the average range for Rainy Lake and just below the median for similar lakes statewide. The Northern Pike gill net catch rate decreased below the normal range for Rainy Lake in 2009 after a sharp increase in 2007 and equally sharp decline in 2008. The catch rate has been relatively stable in recent assessments fluctuating between 1.5 and 2.0 per gill net. Northern Pike lengths ranged from 14.1 to 39.5 inches. The mean length was 23.2 inches and the mean weight was 3.47 pounds.
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\nAge-3 and age-5 Northern Pike made up 33.3 and 22.9 percent of the Northern Pike catch, respectively while age-4 made up 14.6 percent of the Northern Pike catch. Northern Pike ages ranged from age-1 to age-11. The mean Northern Pike age was 4.5 years. The calculation of a year-class strength index indicated there has not been a strong year-class of Northern Pike since 2005. The 2009 year-class initially appeared strong but was caught in lower numbers in 2012 and 2013.
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\nRainy Lake has a low density population of Northern Pike that grow relatively fast. As a result there are good opportunities to catch large and trophy sized fish. Four fish over 36 inches long were caught in 2013 gill nets including one that was 39.5 inches long and weighed 17.5 pounds.
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\nSauger
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\nThe 2012 Sauger gill net catch rate of 2.00 per net was similar to recent years and near the lower end of the normal range for Rainy Lake. Sauger lengths ranged from 4.5 to 14.2 inches. The average length was 9.5 inches with a mean weight of 0.26 pounds.
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\nAge-3 Sauger represented 42.6 percent of the Sauger catch in the 2013 gill net catch while age-2 Sauger made up an additional 19.2 percent of the catch. The mean Sauger age was 3.4 years. The year-class strength index indicates that 2010 was the most recent strong year-class of Sauger produced in Rainy Lake. The 2010 year-class is the strongest produced since 1991.
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\nSauger abundance has steadily declined from the catch rates observed in the mid-1990s and has been relatively stable near the first quartile for Rainy Lake. This decrease coincides with a large increase in the catch rate of Walleyes and may demonstrate density dependent and interspecies competition that influences the abundance and growth of Walleye and Sauger. Staggs and Ottis (1996) found that competition did exist between Walleye and Sauger and that regardless both species grew better in years with high forage abundance. Sauger fishing on Rainy Lake is a result of indirect catch; no angling parties contacted during the most recent creel survey in 2011 were targeting Sauger. Low Sauger abundance, small average size, and a healthy Walleye fishery are likely the cause for effort being directed towards Walleye.
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\nYellow Perch
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\nThe 2013 Yellow Perch catch rate of 7.4 per net near the top of the normal range for Rainy Lake and higher than average for similar lakes. Yellow Perch ranged in length from 5.1 to 12.2 inches, with an average of 8.3 inches and an average weight of 0.33 pounds.
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\nAge-3 Yellow Perch made up 43.9 percent of the perch catch and age-2 made up an additional 29.0 percent of the catch. Yellow Perch from nine year-classes up to age-10 were represented in the 2013 gill-net catch. Since 2000, there have been seven strong year-classes of Yellow Perch produced on Rainy Lake. This level of Yellow Perch production is unprecedented in the history of Rainy Lake sampling. The 2010 year-class now appears to be the strongest year-class ever produced on Rainy Lake and follows a weak 2009 year-class and an average 2008 year-class.
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\nYellow Perch gill net numbers appear to have increased in Rainy Lake since the consecutive low catch years of 2001 and 2002. Strong, consistent recruitment of Yellow Perch is driving this increase in the Yellow Perch catch rate. The dip in Yellow Perch catch numbers in 2013 following a record high in 2012 is due in part to the first two average or weak year-classes (2008 and 2009) on Rainy since 2004. However, the record setting 2010 year-class will be the foundation for continued high Yellow Perch numbers over the next few years in addition to the 2011 and 2012 year-classes that also appear strong from preliminary data. The length distribution of Yellow Perch captured in the gill nets suggest larger fish are more common in Rainy Lake than in the past as 32 percent of the Yellow Perch caught in the 2013 gill nets were nine inches or longer. This increase in larger fish should provide some good harvest opportunities for the next few years.
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\nSmallmouth Bass
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\nSpring electrofishing targeting Smallmouth Bass took place during the nights of June 10th and June 11th with seven stations sampled. A total of 9,659 seconds of \"on-time\" were recorded. The total Smallmouth Bass catch was 34 fish for a catch rate of 12.7 per hour. This catch rate is similar to recent years. Smallmouth Bass ranged in length from 2.7 to 18.4 inches in length with a mean of 10.4 inches. Ten age classes were represented in the catch.
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\nSmallmouth Bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized Smallmouth Bass present. Although gill nets typically to do not sample Smallmouth Bass very well, a Smallmouth Bass measuring 19.2 inches long and weighing 4.4 pounds was caught in a 2013 gill net on Rainy Lake. Smallmouth Bass harvest numbers are very low on Rainy Lake, and angler opportunities in 2013 should remain good.
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\nBlack Crappie
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\nAnnual trap netting targeting Black Crappie has been carried out in Black Bay since 1992 using standard lake survey trap nets. Trap netting consists of 20 set locations throughout Black Bay and the lower Rat Root River and was conducted from May 27 through May 29 in 2013. Length, weight, sex, maturity, and a scale sample for aging were collected from captured Black Crappie.
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\nA total of 43 Black Crappies were caught for a catch rate of 2.15 fish per net. This catch rate is near bottom of the average range for Rainy Lake. Crappie lengths ranged from 5.8 to 15.0 inches with a mean of 10.7 inches. Fifty-three percent of the catch that was able to be aged was from the 2010 year-class with an additional 13.9 percent each from the 2004, 2005, and 2011 year-classes. The 2003 year-class appears to be the strongest year-class ever produced in Rainy Lake and was also the most recent strong year-class. The 2010 year-class appears to be strong based on preliminary data and appears nearly as strong as the 2003 year-class. The 2010 year-class averaged 9.1 inches long in 2013 and should provide quality fishing opportunities over the next few years. This sporadic recruitment on Rainy Lake is typical of Black Crappie populations.
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\nOther species
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\nThe catch rate of cisco species was 1.13 per net, which is down from recent assessments and near the median for Rainy Lake. Warm water temperatures in September may have contributed to lower catches in 2013. Two Lake Whitefish were caught in the 2013 standard gill nets in Rainy Lake. White Suckers were caught at a rate just below the median for Rainy Lake at 1.88 per net. Black Crappie, Burbot, Rock Bass, and Smallmouth Bass were also captured in the 2013 gill nets.
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Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
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\nThe 2021 Walleye gill net catch rate was 4.8 fish/net, which is less than the historic median for Rainy Lake of 5.8 fish/net. Walleye catch rates have increased following historic overfishing prior to the 1990s. Walleye numbers quickly increased as the population recovered in the 1990s and reached an all-time high of 10.0 Walleyes per net in 2004. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.0 per net. Catch rates over the past 14 years have primarily been between 5.7 and 8.0 Walleyes per gill net. Age-2 Walleyes from the 2019 year-class composed the largest portion of the 2021 catch at 27.6 percent. Most age-2 Walleyes in the 2021 survey were in the eight to 10 inch length groups but ranged from 6.9 to 11.5 inches long. The 2021 survey also saw average or better numbers of Walleyes in the 15, 16 and 17 inch length groups compared to historical catch rates of these groups. The 2011 year-class is the most recent strong year-class to recruit to the fishery and made up 4.3 percent of the 2021 gill net catch. Walleye production has been characterized by more average year-classes and fewer strong and weak year-classes in recent years. The result is a balanced distribution of lengths in the population. Overall, gill netted Walleyes ranged in length from 6.9 to 25.3 inches and had an average length of 13.8 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
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\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in and around Black Bay. The overall gill net catch rate was 1.7 Sauger/net in 2021. Lengths ranged from 7.8 to 14.7 inches and averaged 10.7 inches. Sixty-three percent of Saugers caught in gill nets were less than 11 inches long.
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\nThe gill net catch of Northern Pike was 2.0 fish/net, similar to the historic average for Rainy. Northern Pike catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 16.2 to 41.1 inches in 2021. The average length was 25.4 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
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\nYellow Perch numbers and sizes were at historic highs from 2003-2012. The record high catch rate occurred in 2012 at 13.5/net. Catch rates were lower during the most recent four surveys. However, the 2021 gill net catch rate was more in line with historic highs at 10.6 fish/net well above average for Rainy Lake. The 2021 Yellow Perch lengths ranged from 5.1 to 12.5 inches and the overall average was 7.9 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Forty-six percent of the 2021 gill net catch measured eight inches or longer.
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\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are very low on Rainy Lake, and angler opportunities in 2022 should remain good.
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\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting adult Black Crappies. A total of 101 crappies were caught in 2021 for a catch rate of 5.1 per net. This catch rate is above average for Rainy Lake. Lengths ranged from 4.3 to 14.3 inches and averaged 10.6 inches. Thirty-five percent of the catch was from the 2016 year-class. Good Black Crappie production and recruitment on Rainy was observed from the 2014-2017 year-classes resulting in several consecutive years of above average catch rates. The 2015, 2016, and 2017 year-classes combined to compose 80 percent of the total catch in 2021. These fish ranged in size from 8.9 to 13.6 inches. Sixty-nine percent of the Black Crappies caught in the 2021 survey were over 10 inches long and 16 percent were 12 inches or longer. The high catch rates and large sizes will provide good angler opportunities over the next few years.
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\nRainy Lake is known to be infested with spiny waterfleas and zebra mussels. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
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ABUNDANCE OF WALLEYE, YELLOW PERCH, AND SAUGER REMAINS LOW. RELATIVE ABUNDANCE OF THESE SPECIES FOR THE LAST TWO YEARS IS ABOUT HALF OF THAT FOR 1983-84. RELATIVE ABUNDANCE OF SAUGER HAS INCREASD ABOUT 25% FROM 1985. BULLHEAD ABUNDANCE IS SIMILAR TO 1985. MEAN WEIGHT OF MOST SPECIES HAVE REMAINED SIMILAR TO PAST FOUR YEARS.
","surveyID":"111624","headerInfo":{"wb_name":"Rainy","wb_type":"Lake","id_date":"1986-09-03","wb_id":"69069400","survey_id":"111624","survey_type":"Population Assessment","wb_alt_name":"","county":"St. Louis"},"surveyType":"Standard Survey","surveySubType":"Population Assessment","fishCatchSummaries":[{"averageWeight":"0.46","totalCatch":16,"totalWeight":7.3,"species":"TLC","quartileCount":"1.1-10.1","quartileWeight":"0.3-0.9","gear":"Standard gill nets","CPUE":"0.80","gearCount":20},{"quartileCount":"1.1-2.4","quartileWeight":"2.8-4.3","gear":"Standard gill nets","CPUE":"2.55","gearCount":20,"averageWeight":"2.77","totalCatch":51,"totalWeight":141.5,"species":"NOP"},{"quartileWeight":"0.1-0.2","quartileCount":"0.1-4.7","gearCount":20,"CPUE":"7.85","gear":"Standard gill nets","totalCatch":157,"averageWeight":"0.19","species":"BLB","totalWeight":29.25},{"species":"WTS","totalWeight":82.15,"totalCatch":41,"averageWeight":"2.00","gear":"Standard gill nets","CPUE":"2.05","gearCount":20,"quartileCount":"1.4-3.0","quartileWeight":"1.7-2.2"},{"gearCount":20,"CPUE":"2.15","gear":"Standard gill nets","quartileWeight":"0.8-1.3","quartileCount":"3.6-10.8","species":"WAE","totalWeight":47.25,"totalCatch":43,"averageWeight":"1.10"},{"totalCatch":9,"averageWeight":"0.67","totalWeight":6,"species":"SMB","quartileWeight":"0.7-1.2","quartileCount":"0.2-0.6","gearCount":20,"CPUE":"0.45","gear":"Standard gill nets"},{"totalCatch":1,"averageWeight":"0.60","totalWeight":0.6,"species":"LKW","quartileCount":"0.1-3.0","quartileWeight":"0.9-2.8","CPUE":"0.05","gear":"Standard gill nets","gearCount":20},{"quartileCount":"2.1-4.3","quartileWeight":"0.3-0.5","CPUE":"2.25","gear":"Standard gill nets","gearCount":20,"totalCatch":45,"averageWeight":"0.32","totalWeight":14.2,"species":"SAR"},{"quartileWeight":"0.1-0.2","quartileCount":"1.4-6.8","gearCount":20,"CPUE":"3.90","gear":"Standard gill nets","averageWeight":"0.21","totalCatch":78,"species":"YEP","totalWeight":16.6},{"gearCount":20,"CPUE":"0.80","gear":"Standard gill nets","quartileWeight":"0.2-0.3","quartileCount":"0.6-1.6","totalWeight":2.65,"species":"RKB","totalCatch":16,"averageWeight":"0.17"}],"lengths":{}},{"narrative":"WILL BE INCLUDED IN THE LARGE LAKE REPORT. SEE PAGE 13 FOR A HISTORICAL LOOK AT NET CATCHES (INCLUDES 1987).
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The walleye gill net CPUE (catch per unit effort: number per net) was 6.95. For the past 10 years walleye CPUE has been at historically high levels. Gill net CPUE was at the seventh highest level since the large lake program began in 1983. Rainy Lake walleye abundance has reached a new peak. Walleye CPUE from 1983 to 1994 averaged 3.98 per net, since 1995 the average is 6.92 per net. Only twice (2001 and 2002) during the past nine years has the walleye CPUE been below six per net. Consistent recruitment has been the main factor contributing to the observed increase in CPUE. The walleye catch consisted of 12 age groups. Ages ranged from age-1 to age-17 with a mean of 4.59 years. Age-3 walleye made up 44.9% of the gill-net catch while age-7 accounted for 11.6%. Of the cohorts represented, the 1991, 1994, 1995, 1997, and 2001 cohorts are considered strong year-classes.Recruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the 10 year-classes were rated as strong. Netting surveys show that the 2000 year-class is weak. However, the 2001 year-class stands to be the strongest on record. Early indications of the 2002 and 2004 year-classes are weak. The 2003 year-class is showing moderate abundances early on. Lengths of gill netted walleye ranged from 6.9 to 23.9 inches. The mean walleye length was 13.2 inches and the mean weight was 1.06 pounds. The CPUE of walleye over 17 inches in length was 1.65, which was above the third quartile for Rainy Lake. Catch rates of larger walleye (over 17\") has significantly increased in the past 30 years. During the past 10 years the CPUE of walleye over 17 inches has remained greater than one per net, a feat that was achieved only twice prior to 1990. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. The northern pike gill-net CPUE was 2.30, which is the long-term mean for Rainy Lake. Northern pike lengths ranged from 18.9 to 32.9 inches. The mean length was 23.1 inches. The mean weight was 2.71 pounds.Spring trap net sampling indicated the black crappie population is in great condition. The catch rate of crappies was at a record high during 2004. Currently, three very strong black crappie year-classes are in the desired length range (>10\") and will provide good angling opportunities for the next few years. The 1998 year-class ranks as the strongest on record. This year-class was caught at a higher rate than any other year-class regardless of age. Besides the impressive 1998 year-class, the 1997 and 1995 year-classes were captured in record numbers. Smallmouth bass numbers from the nighttime electrofishing indicates good recruitment. The 2004 smallmouth bass CPUE was below normal for Rainy Lake. Smallmouth bass populations have grown and have been protected only by the catch-and-release ethics common to most bass anglers. Results of the 2004 angler creel survey show that angling pressure was below the recent five-year average. The summer of 2004 was the coldest summer on record in northern Minnesota. The cold temperatures and high winds made fishing difficult at times. However, the 2004 estimate of 236,944 angling hours was the sixth highest on record. The five-year mean on Rainy Lake is approximately 251,000 angler hours.Walleye were the most common fish species anglers sought, caught and harvested. Of the 88,107 walleye caught by anglers, 26,780 were harvested for a total yield of 25,783 pounds or 0.48 pounds per acre. An estimated 61,327 (140,904 pounds) walleye were caught and released by anglers during the 2004 open-water season. Of those walleye released an estimated 4,470 (8,734 pounds) died as a result of hooking mortality. Anglers targeting walleye reported catch and harvest rates of 0.435 and 0.135 fish per angler hour, respectively.
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nets","CPUE":"3.35"},{"species":"SMB","totalWeight":3621,"averageWeight":"0.23","totalCatch":34,"CPUE":"24.89","gear":"Fall electrofishing","gearCount":1.36611111111111,"quartileCount":"N/A","quartileWeight":"N/A"},{"averageWeight":"0.00","totalCatch":215,"species":"SMB","totalWeight":0,"quartileCount":"N/A","quartileWeight":"N/A","CPUE":"4.39","gear":"Survey seining","gearCount":49},{"gearCount":49,"CPUE":"0.02","gear":"Survey seining","quartileWeight":"N/A","quartileCount":"N/A","species":"FHM","totalWeight":0,"averageWeight":"0.00","totalCatch":1},{"CPUE":"5.79","gear":"Standard gill nets","gearCount":24,"quartileCount":"1.1-10.1","quartileWeight":"0.3-0.9","species":"TLC","totalWeight":62703,"totalCatch":139,"averageWeight":"0.99"}],"surveySubType":"Large Lake Survey","surveyType":"Standard Survey","headerInfo":{"wb_alt_name":"","survey_type":"Large Lake Survey","survey_id":"3941011630893000","wb_id":"69069400","county":"St. Louis","wb_name":"Rainy","wb_type":"Lake","id_date":"2010-04-01"},"surveyID":"3941011630893000","narrative":"A record early ice out on Rainy Lake kick started a growing season that while not overly warm was extremely long. Early season water levels were extremely low resulting in what appears to be poor reproduction by northern pike on Rainy Lake. Windy conditions and short staffing hampered fisheries sampling efforts off and on throughout the summer.
\n
\nLow numbers of walleye were encountered in the greatly reduced number of seine hauls collected. Early growth indicated that even though sampling began two weeks ahead of schedule walleyes may have already grown to a point where they were moving offshore to feed. At the beginning of July it was noted that some young of year (YOY) walleye in the seine where nearly equal in length to age-1 walleye caught in other hauls that same day.
\n
\nThe strong 2006 year-class of walleye continued to drive small improvements in the catch per unit effort (CPUE) of walleyes in the fall gill nets. Walleye, yellow perch, northern pike, smallmouth bass, and black crappie populations are healthy as indicated by various sampling methods.
\n
\nFor the past 16 years walleye gill net CPUE has been at historically high levels. The 2010 CPUE of 6.13 per gill net was up slightly from the 5.79 per gill net captured in 2009. Walleye CPUE from 1983 to 1994 averaged 3.98 per net, since 1995 the average is 7.66 per net. Consistent recruitment has been the main factor contributing to the observed increase in CPUE.
\n
\nSeveral factors may have contributed to the reduced numbers of walleye in the gill nets during recent years. The below average temperatures during the summers of 2008 and 2009 certainly led to slower growth rates which may be affecting gill-net catchability of younger walleyes. The mean length of age-1 through age-4 fish in 2009 was from 1.0\" to 1.9\" lower than the mean length at capture for their respective ages from 1998-2008. Some of the poor growth from the last several years was likely moderated by the long growing season of 2010. However, only future sampling will be able to quantify this potential change.
\n
\nCatch rates of larger walleye (over 17\") have significantly increased in the past 30 years. After the CPUE of walleye over 17 inches in 2008 dipped below one per net for the first time since the protected slot was put in place it rebounded strongly to 1.88 per net in 2010. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. Creel data from 2010 indicated that walleye 17 inches or greater in length made up 33% of the total catch for 2010.
\n
\nPrior to the 1990s Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the ten year-classes were rated as strong. During the first half of the 2000s three of the seven year-classes recruited to date are strong including record breaking 2001 year class, and the 2006 year-class which recruited to the gear in 2009. Early indications are that one or two more strong year-classes are likely awaiting recruitment, though slower growth due to recent cool summers may expose them to predation longer and delay full recruitment to the gill nets. The 2007 year-class which recruited to the gill nets in 2010 is just below the classification as a strong year-class, but may increase in strength next year as a result of more complete recruitment following one more year of growth.
\n
\nSeining and electrofishing data have been used to predict future walleye year-class strength on Rainy Lake. Seining data indicated the 2010 year-class will be very strong, while the electrofishing data indicates it will be average. Neither of these indices carries a great deal of confidence in 2010 due to limited catch during the seining period potentially due to fast growth and offshore movement of YOY walleye and limited catch during fall electrofishing due to weather and short staffing which resulted in only one night of sampling effort. The unique weather associated with the initial growth of the 2010 year-class may make it difficult to predict which model will be more accurate. An early spring appears to have increased summer growth for juvenile fish indicating that winter survival rates should be good, but with the low numbers of fish captured by each gear an accurate picture of the relative size of the 2010 year-class is difficult to predict.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. The 2006 and 2007 year-classes will continue to be the main contributor to the harvest.
\n
\nNorthern pike gillnet CPUE decreased to below the first quartile for Rainy Lake in 2009 after a sharp increase in 2007 and equally sharp decline in 2008. The 2010 northern pike CPUE rebounded slightly, but remained below the first quartile for Rainy Lake.
\n
\nSauger abundance has steadily declined for the past 16 years. The CPUE observed in 2010 was a slight increase from the record low values recorded in 2008 and 2009. This trend may demonstrate density dependent and interspecies competition that influences the abundance and growth of walleye and sauger. Sauger fishing on Rainy Lake is a result of indirect catch, no angling parties contacted during 2010 were targeting sauger (Schlesser 2010). Low sauger abundance, small average size, and a healthy walleye fishery likely are the cause for effort being directed towards walleye.
\n
\nSpring sampling indicated the black crappie population is doing well. Mortality (natural and fishing) appears to have greatly reduced the population of the strong year-classes from the mid-1990s. The recruitment of the 2003 year-class to the sport fishery (and trap nets) in 2009 has resulted in a very abundant fishery with exceptional opportunities to catch crappies. The 2008 creel reported the highest harvest of crappies ever recorded for Rainy Lake. The current status of the fishery indicates that crappie fishing should be exceptional during the next few years as the 2003 year-class contributes numbers of fish and the 2005 year class grows more fully into the acceptable size for harvest. An early and relatively warm spring in 2010 combined with early indications from seining in indicate that a good year-class of black crappie may have been produced on Rainy Lake in 2010.
\n
\nSmallmouth bass numbers from nighttime electrofishing indicates good recruitment. Despite limited sampling effort age-0 smallmouth bass made up 75.8% of the fall smallmouth catch on Rainy Lake indicating the potential for a good year class of smallmouth bass being produced in 2010. Smallmouth bass populations have grown and have been protected only by the catch-and-release ethics common to most bass anglers. Smallmouth bass growth on Rainy Lake is slow compared to area and state averages. However, there are plenty of memorable and trophy sized smallmouth bass present as demonstrated by the catch during the spring electrofishing and reports from anglers. Angler opportunities in 2011 should remain good.
\n
\nYellow perch gill-net numbers dropped below the median for Rainy Lake in 2010. The length distribution of perch captured in the gill nets was predominantly in the less than nine-inch category. However, more than 30% of the perch sampled were more than nine inches in length and they should provide some good harvest opportunities for the next few years. With the exception of 2004 recruitment has been exceptional for the past nine years, with six of the seven best year-classes for Rainy Lake occurring since 2001. This strong yellow perch production should continue providing a strong forage base and developing angling opportunities for years to come.
\n
Walleye
\n
\nFifteen fish species were captured during the annual fall gill netting on Rainy Lake in 2014. Walleye made up 23.8% of the catch by number. Walleye and Northern Pike represented 51.2% of the catch by total weight.
\n
\nThe 2014 Walleye gill net catch rate was 6.79 fish per net which is near the top of the average range for Rainy Lake. The 1998 to 2013 mean catch rate (historical mean) was 7.59 walleye per net. For the past 18 years the Walleye gill net catch rate has been at historically high levels. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.57 per net. The 2014 catch rate was down slightly from the 7.96 per gill net captured in 2013 but similar to catch rates in recent years.
\n
\nWalleye lengths in gill nets ranged from 3.6 to 24.6 inches. The mean Walleye length was 13.5 inches and the mean weight was 1.05 pounds.
\n
\nCatch rates of larger Walleye (over 17\") have increased in the past 30 years. The catch rate of Walleye over 17 inches peaked in 2005 at 3.0 Walleye per net before beginning a declining trend. After the catch rate of Walleye over 17 inches dipped below one per net in 2008 for the first time since the protected slot was put in place it rebounded strongly to 1.88 per net in 2010. The catch rate of Walleye over 17 inches in length was 1.75 in 2013 which is higher than the average range for Rainy Lake. Currently, Walleye greater than 17 inches (and less than 28 inches) are protected by length regulations. The most recent creel survey conducted in 2011 showed that Walleye 17 inches or greater in length made up 29% of the total catch for 2011.
\n
\nThe 2014 Walleye catch consisted of 17 age groups. Ages ranged from age-0 to age-20 with a mean of 5 years. Age-3 Walleyes made up 30.1 percent of the gill-net catch and age-2 an additional 16.0 percent. Age-4 Walleyes composed 12.9 percent of the 2014 catch. Of the cohorts represented in the gill net catch since 2000, the 2001, 2003, 2006, 2007, 2010, and 2011 year-classes are considered strong.
\n
\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s, Rainy Lake produced a strong Walleye year-class once every four years. Throughout the 1990s, six of the ten year-classes were rated as strong. During the 2000s six of the 12 year-classes recruited to date are strong including the record breaking 2001 year class, and the 2006 year-class which recruited to the gear in 2009. The 2007 year class was also strong marking the first time since 1997-98 that Rainy Lake had produced consecutive strong year-classes. Following consecutive weak year-classes in 2008-09, Rainy Lake again produced back to back strong year-classes in 2010 and 2011. In fact, the 2011 cohort now appears tied as the second strongest year-class on record.
\n
\nSince 1996 Walleye growth rates on Rainy Lake have decreased. Length at capture for Walleye in 2014 was less than the historical mean for all age classes from age-0 to age-9. This decrease in growth coincided with an increase in Walleye abundance. These observations indicate potential density-dependent growth. Hartman and Margraf (1992) found that high densities of Walleye (strong year-classes) suppressed the forage base and consequently reduced Walleye growth in Lake Erie. On Rainy Lake this relation has not been demonstrated: specifically, there has been no discernable decreasing trend in the forage (Yellow Perch) abundance but rather an increase in Yellow Perch gill net catch rates beginning in 2003. The observed growth pattern may be the fisheries return to pre-overexploited growth rates.
\n
\nSeining and electrofishing data have been used to predict future Walleye year-class strength on Rainy Lake. Prior to 1995, length data from summer seining provided the most reliable predictor. Since 1995 electrofishing indices have been more significant. This change may have arrived from changes in growth observed during the past 16 years. Fifty seine hauls in 2014 resulted in 15 different species of fish caught totaling 7,525 individual fish. Sixty-three percent were age-0 Yellow Perch and an additional 13 percent were Walleyes. The catch rate of age-0 Yellow Perch was 94 per haul, lower than the long-term mean of 238 per haul. Nine hundred ninety-eight age-0 Walleyes were caught; the highest catch total since 2009 (1,947 age-0 Walleyes). The 2014 age-0 Walleye catch rate was 20 per seine haul which is higher than the historical mean of 5.1 per haul.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large Walleye and uphold reproduction. As the 2006 and 2007 year classes have now largely grown into the protected slot, most of the harvest over the next few years will come from the strong 2010 and 2011 cohorts that averaged 13.7 and 11.1 inches long, respectively, in 2014 gill netting.
\n
\nNorthern Pike
\n
\nThe 2014 Northern Pike gill net catch rate was 2.21 per net, which is near the median for Rainy Lake and just below the top end of the normal range for similar lakes. The Northern Pike gill net catch rate decreased below the normal range for Rainy Lake in 2009 after a sharp increase in 2007 and equally sharp decline in 2008. The catch rate has been relatively stable in recent assessments fluctuating between 1.5 and 2.2 per gill net. Northern Pike lengths ranged from 13.7 to 34.5 inches. The mean length was 23.7 inches and the mean weight was 2.99 pounds.
\n
\nAge-4 Northern Pike made up 34.0 percent of the Northern Pike catch while age-2 and age-3 each contributed 18.9 percent of the Northern Pike gill net catch. Northern Pike ages ranged from age-0 to age-7. The mean Northern Pike age was 3.5 years. The calculation of a year-class strength index indicated there has not been a strong year-class of Northern Pike since 2005. The 2010 year-class appears to be average and preliminary numbers suggest the 2012 year-class will be strong.
\n
\nRainy Lake has a low density population of Northern Pike that grow relatively fast. As a result there are good opportunities to catch large and trophy-sized fish. Four fish over 36 inches long were caught in 2013 gill nets including one that was 39.5 inches long and weighed 17.5 pounds.
\n
\nSauger
\n
\nThe 2014 Sauger gill net catch rate of 2.54 per net was similar to recent years and slightly lower than the median for Rainy Lake. Sauger lengths ranged from 5.9 to 14.7 inches. The mean length was 9.7 inches with a mean weight of 0.26 pounds.
\n
\nAge-4 Sauger represented 36.7 percent of the Sauger catch in the 2014 gill net catch while age-3 Sauger made up an additional 13.3 percent of the catch. The mean Sauger age was 4.6 years. The year-class strength index indicates that 2010 was the most recent strong year-class of Sauger produced in Rainy Lake and early data suggests the 2012 and 2013 year-classes will be strong. The 2010 year-class is the strongest produced since 1990.
\n
\nSauger abundance has steadily declined from the catch rates observed in the mid-1990s and has been relatively stable near the first quartile for Rainy Lake. This decrease coincides with a large increase in the catch rate of Walleyes and may demonstrate density dependent and interspecies competition that influences the abundance and growth of Walleye and Sauger. Staggs and Ottis (1996) found that competition did exist between Walleye and Sauger and that regardless both species grew better in years with high forage abundance. Sauger fishing on Rainy Lake is a result of indirect catch; no angling parties contacted during the most recent creel survey were targeting Sauger. Low Sauger abundance, small average size, and a healthy Walleye fishery are likely the cause for effort being directed towards Walleye.
\n
\nYellow Perch
\n
\nThe 2014 Yellow Perch catch rate of 6.3 per net is near the median for Rainy Lake and just below the top of the normal range for similar lakes. Yellow Perch ranged in length from 5.4 to 13.4 inches, with a mean of 8.6 inches and a mean weight of 0.35 pounds.
\n
\nAge-2 Yellow Perch made up 29.4 percent of the perch catch and age-3 and age-4 made up an additional 27.5 and 21.9 percent of the catch, respectively. Yellow Perch from nine year-classes up to age-9 were represented in the 2014 gill-net catch. Since 2000, there have been eight strong year-classes of Yellow Perch produced on Rainy Lake including the third strongest year-class ever in 2010. This level of Yellow Perch production is unprecedented in the history of Rainy Lake sampling.
\n
\nYellow Perch gill net numbers appear to have increased in Rainy Lake since the consecutive low catch years of 2001 and 2002. Strong, consistent recruitment of Yellow Perch is driving the recent increase in the Yellow Perch gill net catch rate. The 2012 yellow perch catch rate was the highest ever recorded on Rainy Lake, but catch rates were lower in 2013 and 2014. The decline in 2013 appears to be the result of the first two average or weak year-classes (2008 and 2009) since 2004. Low catches of age-1 Yellow Perch in 2014 resulted in a slightly lower overall gill net catch rate. However, the strong 2010 year-class is now averaging just less than 10 inches long with individuals as long as 12 inches caught in 2014 gill netting. Due in large part to this year-class, the length distribution of Yellow Perch captured in the gill nets suggest larger fish are more common in Rainy Lake than in the past. This increase in larger fish will provide good harvest opportunities for the next few years.
\n
\nSmallmouth Bass
\n
\nSpring electrofishing targeting Smallmouth Bass took place during the nights of June 24th and June 25th with six stations sampled. A total of 7,462 seconds of \"on-time\" were recorded. The total Smallmouth Bass catch was 56 fish for a catch rate of 27.0 per hour. This catch rate is similar to recent years but the highest since 2003 (58.6 bass per hour). Smallmouth Bass ranged in length from 3.7 to 19.3 inches in length with a mean of 12.5 inches. Ten age classes were represented in the catch.
\n
\nSmallmouth Bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized Smallmouth Bass present. Smallmouth bass over 19 inches are often caught in our sampling gear each year including a 19.3 inch bass caught during electrofishing in 2014. A Smallmouth Bass measuring 19.2 inches long and weighing 4.4 pounds was caught in a 2013 gill net on Rainy Lake. Smallmouth Bass harvest numbers are very low on Rainy Lake, and angler opportunities in 2015 should remain good.
\n
\nBlack Crappie
\n
\nAnnual trap netting targeting Black Crappie was carried out in Black Bay since 1992 using standard lake survey trap nets. Trap netting consists of 20 set locations throughout Black Bay and the lower Rat Root River and was conducted from May 27 through May 29 in 2014. Length, sex, maturity, and a scale sample for aging were collected from captured Black Crappie.
\n
\nA total of 69 Black Crappies were caught for a catch rate of 3.45 fish per net. This catch rate is higher than the median of all past assessments on Rainy Lake (2.59 per trap net). Crappie lengths ranged from 5.8 to 14.7 inches with a mean of 10.7 inches. Thirty-six percent of the catch that was able to be aged was from the 2010 year-class and an additional 17.6 percent from the 2011 year-class. The 2003 year-class appears to be the strongest year-class ever produced in Rainy Lake and was also the most recent strong year-class. The 2010 and 2011 year-classes appear to be strong based on preliminary data. The 2010 year-class averaged 10.4 inches long in 2014 and should provide quality fishing opportunities over the next few years. This sporadic recruitment on Rainy Lake is typical of Black Crappie populations.
\n
\nOther species
\n
\nThe catch rate of cisco species was 5.96 per net, which is higher than the catch rate of 1.10 per net in 2013 and the highest catch rate ever recorded on Rainy Lake. Two Lake Whitefish were caught in the 2014 standard gill nets in Rainy Lake. White suckers were caught at a rate of 1.46 per net which is near the first quartile for Rainy Lake. Rock Bass were caught at an all-time high of 2.33 per gill net in 2014. Black Bullhead, Black Crappie, Burbot, Longnose Sucker, Pumpkinseed, Shorthead Redhorse and Smallmouth Bass were also captured in the 2014 gill nets.
\n
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe Walleye gillnet catch in 2017 was 5.7 fish/net, which is near the historic median for Rainy Lake. For the past 18 years the Walleye gill net catch rate has been at historically high levels. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.35 per net. Catch rates over the past 10 years have primarily been between six and eight Walleyes per gill net. Age 6 Walleyes from the 2011 year-class composed the largest portion of the catch at 26 percent. The 2011 year-class is the most recent strong year-class to recruit to the fishery. However, this large year-class is growing slower than average for Rainy ranging from 12.3 to 22.0 inches long and averaging 15.5 inches in the 2017 survey. Overall, gillnetted Walleyes ranged in length from 6.9 to 25.2 inches long and had an average length of 14.1 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally larger Sauger are encountered in the Black Bay area. The overall gill net catch rate was 1.33 Sauger/net in 2017. Lengths ranged from 6.7 to 14.5 inches and averaged 10.2 inches.
\n
\nThe gillnet catch of Northern Pike was 2.29 fish/net, near the historic average for Rainy. Northern Pike catch rates have historically been relatively low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 15.8 to 36.1 inches in 2017. The average length was 23.3 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes have increased in recent years in Rainy Lake. The 2017 gill net catch rate was lower than recent surveys at 6.58 fish/net but similar to the historic average. Yellow Perch lengths ranged from 5.4 to 12.2 inches and the overall average was 8.2 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Fifty-four percent of the 2017 gill net catch measured eight inches or longer. Large Yellow Perch are more common in Rainy Lake than in the past.
\n
\nAn electrofishing boat is used as the standard sampling gear for Smallmouth Bass because they are not effectively caught in standard assessment nets. Electrofishing was not done in 2017 due to time constraints. Smallmouth Bass growth on Rainy Lake is slow compared to area and state averages. However, there are memorable and trophy sized Smallmouth Bass present. Smallmouth Bass over 19 inches are often caught in our sampling gear including a 19.3 inch bass caught during electrofishing in 2016. A Smallmouth Bass measuring 19.2 inches long and weighing 4.4 pounds was caught in a 2013 gill net on Rainy Lake. Smallmouth Bass harvest numbers are very low on Rainy Lake, and angler opportunities in 2017 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting adult Black Crappies. A total of 98 crappies were caught in 2017 for a catch rate of 4.90 per net. This catch rate is above average for Rainy Lake. Lengths ranged from 5.2 to 15.0 inches and averaged 11.6 inches. Thirty-three percent of the catch was from the 2012 year-class. Three consecutive years of good Black Crappie production and recruitment on Rainy from 2010-2012 is driving the increase in numbers and sizes. The 2010 year-class averaged 13.1 inches long while the 2012 year-class averaged 11.4 inches in 2017. Eighty-four percent of the Black Crappies caught in the 2017 survey were over 10 inches long and 43 percent were 12 inches or longer. The high catch rates and large sizes will provide good angler opportunities over the next few years.
\n
\nRainy Lake is known to be infested with spiny waterfleas. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
\n
Introduction
\n
\nThis investigation was designed to document the population characteristics of Lake Whitefish (Coregonus clupeaformis) in Rainy Lake, Minnesota. Changes in water level management enacted by the International Joint Commission (IJC) in 2000 were expected to be beneficial to Lake Whitefish in the Namakan Reservoir and could impact Rainy Lake whitefish as well. Lake Whitefish spawn in shallow water during October and November with eggs hatching early in the following spring. Whitefish eggs, therefore, are susceptible to desiccation during winters with significant water level drawdown.
\n
\nThis investigation used the Fish Community Index Netting (FCIN) protocol developed by the Province of Ontario (LNFAU 2001) to collect baseline population characteristics of Lake Whitefish in Rainy Lake. FCIN is carried out on a two out of four year rotation. The 2020 sampling season represents the second of two surveys in the current four year rotation on Rainy Lake. There is currently a small commercial fishery that exists on the Minnesota side of the lake.
\n
\nMethods
\n
\nTwelve FCIN nets were set from August 17th through August 26th, 2020. Sets were approximately 24-hours in duration. The deeper portions of the lake were broken into four sectors, with each sector having three net stations (Figure 1). Gill nets used were eight feet tall and consisted of nine 50-foot panels of various mesh gill net (1.0, 2.25, 0.75, 1.5, 2.5, 1.75, 0.5, 2.0, and 1.25 inch bar measure). Net locations were selected to sample two depth strata (60'-80' and greater than 80'). Eight nets were set in the shallow-water stratum while the other four were set in the deep-water stratum. Net location and orientation was chosen randomly within strata, however, nets could not be within 330 feet of shore or exposed shoals.
\n
\nAll fish captured in each net were separated by species and capture mesh. Total length, weight, sex, and state of maturity were recorded for all Lake Whitefish captured. A data error resulted in only 26 of 69 Lake Whitefish having state of maturity recorded in 2020. Otoliths were collected from Lake Whitefish for aging.
\n
\nFive metrics were incorporated to track long-term trends in the Lake Whitefish population (LNFAU 2001).
\n1)\tMean age of first maturity
\n2)\tMean age of FCIN catch
\n3)\tRelative abundance (Catch per unit effort (CPUE))
\n4)\tRecruitment/ juvenile abundance (CPUE of age 3, 4 and 5)
\n5)\tSpatial distribution of FCIN catch
\n
\nResults and Discussion
\n
\nEight species totaling 470 individual fish were caught in the 2020 summer FCIN assessment (Table 1). Cisco species were the most common fish, making up 52.8% of the total catch by number while Lake Whitefish made up the largest portion by weight at 32.2% of the catch (Table 1). Sixty-nine Lake Whitefish were sampled for a catch rate of 5.8 per lift. A total of 58 Walleyes (CPUE = 4.8 per net), four Northern Pike (CPUE = 0.9 per net), and 76 Burbot (CPUE = 6.3 per net) were caught during the survey. The Cisco catch rate was 20.7 per net with 248 caught in total.
\n
\nLake Whitefish ranged in length from 7.9 to 21.9 inches, with a mean of 17.2 (Table 2). The mean weight was 2.0 pounds. Eighteen age-classes were represented in the 2020 catch with the age eight year-class composing 11.6 percent of the total catch while the age-7 and age-11 year-classes each made up an additional 10.1 percent of the total catch (Table 3).
\n
\nFive metrics for evaluating the Lake Whitefish population were calculated. The age of 50% maturity (sexes combined) was 5.5 years. The mean age of Lake Whitefish in the FCIN catch was 8.9 years. Recruitment criteria showed that the juvenile abundance (CPUE of age 3, 4, 5) of Lake Whitefish was 0.9 per net. Lake Whitefish were sampled at 12 of 12 stations (Figure 2).
\n
\nFCIN sampling from recent years suggest the Lake Whitefish population is not being overexploited. Sampling was carried out in a two of four year rotation resulting in 10 years of sampling between 2003 and 2020. The catch rate of Lake Whitefish has been high and consistent in recent years (Figure 3). In addition, the mean age of the commercial catch (11.6 years) has been consistently higher than the mean age at 50% maturity (5.5 years in 2020) allowing a few years of spawning opportunities before becoming vulnerable to harvest. There is no discernible change in the mean age of the FCIN catch over time and there were several age classes of Lake Whitefish present in the 2020 catch with individuals up to 20 years old. Consistent catch rates of juvenile Lake Whitefish suggest good reproduction and recruitment. Monitoring of the Lake Whitefish population and the commercial harvest for signs of overexploitation or stress should continue.
\n
\nAcknowledgments
\n
\nKristen Patterson (MNDNR), Dan Schermerhorn (MNDNR), and Kevin Peterson (MNDNR) helped with the field work associated with the 2020 FCIN survey. Kevin Peterson and David McCormack (MNDNR) reviewed the document.
\n
\n
\nReferences
\nLNFAU, 1999. Lake Nipigon Fisheries Assessment Unit: Fish Community Index Netting (FCIN). Ontario Ministry of Natural Resources. Ontario, Canada.
Introduction
\n
\nThis investigation was designed to document the population characteristics of Lake Whitefish (Coregonus clupeaformis) in Rainy Lake, Minnesota. Changes in water level management enacted by the International Joint Commission (IJC) in 2000 were expected to be beneficial to Lake Whitefish in the Namakan Reservoir and could impact Rainy Lake whitefish as well. Lake Whitefish spawn in shallow water during October and November with eggs hatching early in the following spring. Whitefish eggs, therefore, are susceptible to desiccation during winters with significant water level drawdown.
\n
\nThis investigation used the Fish Community Index Netting (FCIN) protocol developed by the Province of Ontario (LNFAU 2001) to collect baseline population characteristics of Lake Whitefish in Rainy Lake. FCIN is carried out on a two of four year rotation. The 2023 sampling season represents the first of two surveys in the current four-year rotation on Rainy Lake. There is currently one commercial fishing license issued on the Minnesota side of the lake, however, the fisherman has not harvested Lake Whitefish since 2018.
\n
\nMethods
\n
\nTwelve FCIN nets were set from August 14th through August 18th, 2023. Sets were approximately 24-hours in duration. The deeper portions of the lake were broken into four sectors, with each sector having three net stations (Figure 1). Gill nets used were eight feet tall and consisted of nine 50-foot panels of various mesh gill net (1.0, 2.25, 0.75, 1.5, 2.5, 1.75, 0.5, 2.0, and 1.25 inch bar measure). Net locations were selected to sample two depth strata (60'-80' and greater than 80'). Eight nets were set in the shallow-water stratum while the other four were set in the deep-water stratum. Net location and orientation were chosen randomly within strata, however, nets could not be within 330 feet of shore or exposed shoals.
\n
\nAll fish captured in each net were separated by species and capture mesh. Total length, weight, sex, and state of maturity were recorded for all Lake Whitefish captured. Otoliths were collected from Lake Whitefish for aging.
\n
\nFive metrics were incorporated to track long-term trends in the Lake Whitefish population (LNFAU 2001).
\n1)\tMean age of first maturity
\n2)\tMean age of FCIN catch
\n3)\tRelative abundance (Catch per unit effort (CPUE))
\n4)\tRecruitment/ juvenile abundance (CPUE of age 3, 4 and 5)
\n5)\tSpatial distribution of FCIN catch
\n
\nResults and Discussion
\n
\nNine species totaling 314 individual fish were caught in the 2023 summer FCIN assessment (Table 1). Cisco species were the most common fish, making up 39.5% of the total catch by number while Walleye made up the largest portion by weight at 31.9% of the catch (Table 1). Forty-six Lake Whitefish were sampled for a catch rate of 3.8 per lift. A total of 53 Walleyes (CPUE = 4.4 per net), six Northern Pike (CPUE = 0.5 per net), and 67 Burbot (CPUE = 5.6 per net) were caught during the survey. The Cisco catch rate was 10.3 per net with 124 individuals caught in total.
\n
\nLake Whitefish ranged in length from 8.5 to 23.0 inches, with a mean of 17.0 (Table 2). The mean weight was 1.9 pounds. Thirteen age-classes were represented in the 2023 catch with the age-3 year-class composing 23.9 percent of the total catch while the age-2, age-4, age-6 and age-7 year-classes each made up an additional 10.9 percent of the total catch (Table 3).
\n
\nIn addition to overall catch rate, four metrics for evaluating the Lake Whitefish population were calculated. The age of 50% maturity (females) was 7.0 years. The mean age of Lake Whitefish in the FCIN catch was 5.9 years. Recruitment criteria showed that the juvenile abundance (CPUE of age 3, 4, 5) of Lake Whitefish was 1.4 per net. Lake Whitefish were sampled at 12 of 12 stations (Figure 2).
\n
\nFCIN sampling from recent years suggest the Lake Whitefish population is not being overexploited. Sampling was carried out in a two of four-year rotation resulting in 11 years of sampling between 2003 and 2023. The catch rate of Lake Whitefish has been high and consistent in recent years (Figure 3). However, the 2023 catch rate of 3.8 per net was the lowest overall Lake Whitefish catch rate since sampling began in 2003. The 2023 catch rate was only slightly less than the 2003 catch rate of 3.9 per net. The mean age of the commercial catch (11.6 years) has been consistently higher than the mean age at 50% maturity (7.0 years in 2023) allowing a few years of spawning opportunities before becoming vulnerable to harvest. This is becoming less of a factor as the last commercial fisherman has not harvested Whitefish since 2018. There is no discernible change in the mean age of the FCIN catch over time and there were several age classes of Lake Whitefish present in the 2023 catch with individuals up to 19 years old. Consistent catch rates of juvenile Lake Whitefish suggest good reproduction and recruitment. Monitoring of the Lake Whitefish population and the commercial harvest for signs of overexploitation or stress should continue.
\n
\nAcknowledgments
\n
\nDee Dee Crist (MNDNR), Mike Vaske (MNDNR), and Jake Erickson (MNDNR intern) helped with the field work associated with the 2023 FCIN survey. Phil Talmage and Dave Weitzel (MNDNR) reviewed the document.
\n
\n
\nReferences
\nLNFAU, 1999. Lake Nipigon Fisheries Assessment Unit: Fish Community Index Netting (FCIN). Ontario Ministry of Natural Resources. Ontario, Canada.
WILL BE INCLUDED IN THE LARGE LAKE REPORT. SEE PAGE 13 FOR A HISTORICAL LOOK AT NET CATCHES.
","surveyDate":"1988-08-30","surveyID":"111655","headerInfo":{"wb_name":"Rainy","wb_type":"Lake","id_date":"1988-08-30","wb_id":"69069400","survey_id":"111655","wb_alt_name":"","survey_type":"Population Assessment","county":"St. Louis"}},{"surveyType":"Targeted Survey","surveySubType":"Targeted Survey","lengths":{"WAE":{"fishCount":[[13,1],[14,3],[15,1],[17,2],[19,2],[20,2],[21,1],[24,4],[26,2],[29,1]],"minimum_length":13,"maximum_length":29}},"fishCatchSummaries":[{"quartileWeight":"N/A","quartileCount":"N/A","gearCount":7.72111111111111,"CPUE":"2.46","gear":"Special electrofishing","totalCatch":19,"averageWeight":"3.52","totalWeight":30309,"species":"WAE"}],"surveyDate":"2023-05-01","narrative":"Walleye (Sander vitreus) are the most sought after gamefish on Rainy Lake (69-0694-00). Historically a large run of Walleyes from Rainy Lake spawned in the Rat Root River near Ericsburg, MN. The Rat Root River flows through Rat Root Lake (36-0006-00) and empties into Black Bay (Rainy Lake). From 1933-1943 and again from 1971-1978 a Walleye trap was operated by the Minnesota Department of Natural Resources (MNDNR) just downstream from Rat Root Lake as part of an egg take operation. During the early egg take period an average of 3,887 female Walleye were captured annually using a trap with leads that stretched the entire width of the river (area office files). During trap operations in the 1970s the average number of females captured annually dropped to 243. Periodic monitoring of this spawning run by Department of Natural Resources (DNR) - Fisheries personnel using boat electrofishing equipment began in 1991 and continues to the present.
\n
\nThe spring 2023 Walleye spawning run in the Rat Root River occurred over a shorter period of time than recent years and catches were low. Water levels were high. The 2023 season was marked by a late and rapid warmup that saw Rat Rot River water temperatures quickly approach 50 degrees Fahrenheit with very few fish encountered.
\n
\nElectrofishing methods were similar to past years with most of the sampling taking place in the stretch of river below the snowmobile bridge and upstream of the overpass at Highway 53. All fish sampled were measured and checked for tags and other marks from previous years. They were then clipped on the upper caudal fin to be able to detect fish caught multiple times in 2023.
\n
\nElectrofishing on the Rat Root River included four days of sampling beginning on May 2nd and concluding on May 9th. Water temperatures ranged from 40 degrees Fahrenheit on the morning of May 2nd to 49 degrees Fahrenheit on the afternoon of May 5th. Nineteen Walleyes were caught in the Rat Root River during 2023 sampling (Table 2). No fish were caught multiple times resulting in a catch of 19 individual fish. A tagging study initiated in 2010 and completed in 2014 resulted in 844 tagged Walleyes. None of the 19 individual Walleyes caught in 2023 were previously tagged. The highest catch rate occurred on 5/4/2023 when seven Walleyes were caught for a catch rate of 3.6 per hour of on-time. The water temperatures ranged from 45-47 degrees Fahrenheit during the sampling on the day of the peak catch rate. Overall, 12 Walleyes were male and seven were females. Female lengths ranged from 24.6 inches to 29.2 inches and averaged 25.9 inches (Table 3). Male lengths ranged from 13.4 inches to 21.6 inches and averaged 17.4 inches (Figure 2).
The 2008 field season on Rainy Lake was characterized by abnormalities. A cold spring appears to have delayed growth for the lake\u0019s coolwater species by approximately two weeks. When combined with the high water experienced in the spring these same cold temperatures may have contributed to record catches of whitefish and tullibee in the annual shoreline seining assessment. Similarly record numbers of walleye were encountered in seine hauls and the angler creel survey, only to have gill net catch rates be dramatically lower than expected. The later of these findings may be related to a warm fall that might have affected typical walleye movements during that time of year, a view expressed by many anglers to the clerk conducting creel interviews.
\n
\nDespite confounding environmental factors the 2008 large lake sampling program provided valuable insight to the status of the Rainy Lake fishery. Walleye, yellow perch, northern pike, smallmouth bass, and black crappie populations are healthy as indicated by various sampling methods. Gillnet sampling of walleye in 2008 indicates a need for close scrutiny over the next several years, but one year of low catch rates, particularly in a year where all catch rates were low, is not a reason for undue concern.
\n
\nFor the past 13 years walleye gill net CPUE has been at historically high levels. The 2008 CPUE of 4.83 per gill net was slightly down from the 6 per gill net captured in 2007. Walleye CPUE from 1983 to 1994 averaged 3.98 per net, since 1995 the average is 7.07 per net. Only twice (2001 and 2008) during the past ten years has the walleye CPUE been below six per net. Consistent recruitment has been the main factor contributing to the observed increase in CPUE.
\n
\nSeveral factors may have contributed to the reduced numbers of walleye in the gill nets. A warm fall with water temperatures above normal for the time of year may have negatively affected the success of our fall netting. Anecdotal reports from anglers as well as conversations with the creel clerk operating at the same time indicate that walleye were not following their typical fall patterns in Rainy Lake for location or behavior. Additionally, poor production during 2002 and a near total failure of the 2004 year-class translates to poor numbers of 12-15 inch walleye in the gill net catch. Both age-4 and age-6 walleye were caught at very low rates for their respective ages. Their absence and the slight decline in CPUE is no reason for immediate alarm as it likely reflects natural variation in walleye production and annual variation in environmental factors.
\n
\nGill-net catch rates of larger walleye (over 17\") have significantly increased in the past 30 years. In 2008 the CPUE of walleye over 17 inches dipped below one per net for the first time since the protected slot was put in place. Creel data from 2008, however, indicated that walleye 17 inches or greater in length made up 39% of the total catch for 2008 which had the highest walleye catch on record for Rainy Lake. Currently walleye greater than 17 inches (and less than 28 inches) are protected by length regulations.
\n
\nRecruitment, expressed as year-class strength, is more consistent and higher than it was 15 years ago. Prior to the 1990s Rainy Lake walleye produced a strong year-class once every four years. Throughout the 1990s, six out of the ten year-classes were rated as strong. During the first half of the 2000s two of the six year-classes recruited to date are strong including the record breaking 2001 year class. Early indications are that two more strong year-classes are likely awaiting recruitment.
\n
\nSeining and electrofishing data have been used to predict future walleye year-class strength on Rainy Lake. Prior to 1995 length data from summer seining provided the most reliable predictors. Since 1995 electrofishing indices have been more significant. This change may have arrived from changes in growth observed during the past 15 years. Seining data indicated the 2008 year-class will be weak, while the electrofishing data indicates it will be average. The unique weather associated with the initial growth of the 2008 year-class may make it difficult to predict which model will be more accurate. A cold, wet spring appears to have set growth back by ~2 weeks, though growth rates appear normal. A warm fall may mitigate the late start the YOY walleyes got in 2008 though only further sampling will tell.
\n
\nWalleye fishing should remain exceptional on Rainy Lake. There are several strong year-classes within the protected slot that should provide good catch rates of large walleye and uphold reproduction. The 2003 year-class will continue to be the main contributor to the harvest, though the most recent creel indicated that early contributions from the 2005 and 2006 year-classes were already recruiting to the sport fishery. The 2006 and 2007 year-classes are showing good potential, and will likely begin to contribute heavily to the sport fishery over the next several years.
\n
\nNorthern pike gillnet CPUE returned to nearly normal levels after a sharp increase in 2007. Northern pike densities have great influence on northern pike growth; northern pike growth is negatively correlated with pike abundance (Pierce and Tomcko 2003, Pierce et al. 2003). Northern pike assessment shows there are several average year-classes present in the catch. The 2005 year-class has emerged as being strong. While large northern pike were present there was a downward trend in pike growth rates during the late 1990s into the early 2000s, this trend has changed and growth rates are increasing while recruitment is slowing. During the early 1990s mean northern pike length at age-3 was approximately 23 inches, during the late 1990s into the early 2000s length at age-3 dropped into the mid to upper teen range. In 2008 the mean northern pike length for age-3 was 21.73 inches, illustrating the faster growth rates.
\n
\nSauger abundance has steadily declined for the past 15 years. The CPUE observed in 2008 was the lowest ever. This trend may demonstrate density dependent and interspecies competition that influences the abundance and growth of walleye and sauger. Sauger fishing on Rainy Lake is a result of indirect catch, no angling parties contacted during 2008 were targeting sauger. Low sauger abundance, small average size, and a healthy walleye fishery likely are the cause for effort being directed towards walleye.
\n
\nLake whitefish are commercially fished on Rainy Lake and there is very little sport-fishing effort directed toward this species. Annual commercial harvest of lake whitefish has remained below the target quota every year since 1999. Fish Community Index Netting (FCIN) provides a standardized methodology for monitoring of this population. Based on four years of observation the lake whitefish population is showing no signs of overexploitation, however, monitoring should continue. Good recruitment in the past five years indicates the population is sustainable. FCIN is scheduled to be conducted again during the summers of 2011-12.
\n
\nSpring sampling indicated the black crappie population is doing very well. Younger year-classes were present and mortality (natural and fishing) has greatly reduced the population of the strong year-classes from the mid-1990s. The recruitment of the 2003 year-class to the sport fishery has resulted in a very abundant fishery with exceptional opportunities to catch crappies. The 2008 creel reported the highest harvest of crappies ever recorded for Rainy Lake. The current status of the fishery indicates that crappie fishing should be exceptional during the next few years as the 2003 year-class contributes numbers of fish and the 2005 year class grows more fully into the acceptable size for harvest.
\n
\nThe 2008 smallmouth bass CPUE was down considerably from normal for Rainy Lake, but again was likely affected by the cold spring temperatures. Smallmouth bass populations have grown and have been protected only by the catch-and-release ethics common to most bass anglers. Bass growth on Rainy Lake is slow compared to area and state averages. However, there are plenty of memorable and trophy sized smallmouth bass present as demonstrated by the catch during the spring electrofishing and reports from anglers. Angler opportunities in 2009 should remain good.
\n
\nYellow perch gill-net numbers were above average for Rainy Lake. The length distribution of perch captured in the gill nets was predominantly in the less than nine-inch category. However, 28% of the perch sampled were more than nine inches in length and they should provide some decent harvest opportunities for the next few years. With the exception of 2004 recruitment has been exceptional for the past seven years, providing a strong forage base and developing angling opportunities.
\n
\n
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year in order to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe 2019 Walleye gill net catch rate was 5.7 fish/net, which is the historic median for Rainy Lake. Walleye catch rates have increased following historic overfishing prior to the 1990s. Walleye numbers quickly increased as the population recovered in the 1990s and reached an all-time high of 10.0 Walleyes per net in 2004. The Walleye catch rate from 1983 to 1994 averaged 3.98 per net; since 1995 the average is 7.35 per net. Catch rates over the past 13 years have primarily been between 5.7 and 8.0 Walleyes per gill net. Age-3 Walleyes from the 2016 year-class composed the largest portion of the 2019 catch at 26.1 percent. Most age-3 Walleyes in the 2019 survey were less than 13 inches long but ranged from 9.0 to 17.8 inches. The 2011 year-class is the most recent strong year-class to recruit to the fishery and made up 7.2 percent of the 2019 gill net catch. This large year-class is growing slower than average for Rainy with sampled Walleyes ranging from 15.8 to 22.2 inches long. Walleye production has been characterized by more average year-classes and fewer strong and weak year-classes in recent years. The result is a wide distribution of lengths in the population. Overall, gill netted Walleyes ranged in length from 4.6 to 26.1 inches long and had an average length of 13.6 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in and around Black Bay. The overall gill net catch rate was 3.8 Sauger/net in 2019. Lengths ranged from 7.5 to 14.5 inches and averaged 9.6 inches. Seventy-three percent of Saugers caught in gill nets were less than 10 inches long.
\n
\nThe gill net catch of Northern Pike was 2.0 fish/net, less than the historic average for Rainy. Northern Pike catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 15.6 to 36.6 inches in 2019. The average length was 24.2 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes were at historic highs from 2003-2012. Catch rates were lower during the most recent four surveys. The 2019 gill net catch rate was 5.1 fish/net which is lower than average for Rainy Lake. The record high catch rate occurred in 2012 at 13.5/net. Yellow Perch lengths ranged from 5.1 to 11.4 inches and the overall average was 8.2 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. Fifty-four percent of the 2019 gill net catch measured eight inches or longer. Large Yellow Perch are more common in Rainy Lake than in the past.
\n
\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are very low on Rainy Lake, and angler opportunities in 2020 should remain good.
\n
\nRainy Lake is known to be infested with spiny waterfleas. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
\n
Rainy Lake is part of the statewide Large Lake Program, an intensive fisheries management program on the 10 largest lakes in Minnesota. The Large Lake Program includes annual fish population assessments, annual water quality monitoring, and regularly scheduled creel surveys. A variety of sampling gear is used during population assessments to collect the various fish species and life stages. These gear types include gill nets, trap nets, beach seines, and an electrofishing boat on Rainy Lake. Sampling for each gear type is conducted at the same time and place each year to determine population trends for the major species. Data is also collected on length, weight, age, and growth for each of the major species.
\n
\nThe 2022 Walleye gill net catch rate was 6.9 fish/net, which is greater than the historic average of 6.1 fish/net for Rainy Lake. Walleye catch rates have increased following historic overfishing prior to the 1990s. Walleye numbers quickly increased as the population recovered in the 1990s and reached an all-time high of 10.0 Walleyes per net in 2004. The Walleye catch rate from 1983 to 1994 averaged 4.0 per net; since 1995 the average is 7.0 per net. Catch rates over the past 15 years have ranged from 4.6 to 8.0 Walleyes per gill net. Age-1 Walleyes from the 2021 year-class composed the largest portion of the 2022 catch at 25.9 percent. Most age-1 Walleyes in the 2022 survey were in the seven- and eight-inch length groups but overall ranged from 7.1 to 9.4 inches long. The 2022 survey also caught a good number of age-3 Walleyes from the 2019 year-class. Most fish from this year-class were in the 10- to-12-inch length groups but ranged in length from 9.4 to 15.7 inches long. The 2022 survey also saw average numbers of 14- and 15-inch Walleyes from various year-classes. The 2011 year-class is the most recent strong year-class to recruit to the fishery but are now being caught in very low numbers in our surveys. However, the 2019 year-class appears to be above average, and the 2021 year-class was caught in large numbers with potential to recruit to the fishery as a future strong year-class. Anglers are likely to encounter a lot of small fish with large numbers of young fish in the system from the 2019 and 2021 year-classes. Overall, gill netted Walleyes ranged in length from 5.1 to 24.9 inches and had an average length of 12.6 inches. There is a special regulation for Walleye on Rainy Lake; an 18-26 inch protected slot, with one fish allowed over 26 inches, and a four-fish bag limit. The goal of the regulation is to keep harvest at a safe level and maintain adequate spawning stock.
\n
\nSauger numbers are low, growth is slow, and they generally do not reach a large size in Rainy Lake. Occasionally, larger Sauger are encountered in and around Black Bay and Sand Bay. The overall gill net catch rate was 1.8 Sauger/net in 2022. Lengths ranged from 6.7 to 13.3 inches and averaged 10.2 inches. Seventy-three percent of Saugers caught in gill nets were less than 11 inches long.
\n
\nThe gill net catch of Northern Pike was 2.4 fish/net, similar to the historic average for Rainy. Northern Pike catch rates have historically been low on Rainy Lake. However, Northern Pike grow relatively fast and reach large and even trophy sizes. Pike ranged from 16.3 to 41.4 inches in 2022. The average length was 23.8 inches. Reports of anglers catching large Northern Pike 40 inches or longer are not uncommon on Rainy Lake.
\n
\nYellow Perch numbers and sizes were at historic highs from 2003-2012. The record high catch rate occurred in 2012 at 13.5/net. The 2022 gill net catch rate was the second highest ever catch rate at 13.4/net and follows a period of relatively lower catch rates from 2013-2019. The increase in 2022 appears to be driven by good Perch production from the 2018, 2019, and 2020 year-classes. The 2022 Yellow Perch lengths ranged from 5.1 to 12.8 inches and the overall average was 7.9 inches. Yellow Perch size structure has improved over time providing more opportunity for anglers to harvest quality-sized fish. However, anglers can expect to encounter smaller perch with age-2 composing 45 percent of the 2022 catch and averaging 6.7 inches.
\n
\nRainy Lake is home to a good Smallmouth Bass fishery both in numbers and size structure. Smallmouth Bass over 19 inches are often caught in our sampling gear and by anglers. Harvest numbers are low on Rainy Lake, and angler opportunities in 2023 should remain good.
\n
\nTrap nets are set in Black Bay and the lower Rat Root River each spring targeting adult Black Crappies. A total of 38 crappies were caught in 2022 for a catch rate of 1.9 per net. This catch rate is below average for Rainy Lake and lower than the 2021 catch rate. However, high water levels from historic flooding in 2022 likely affected the effectiveness of our trap nets. Lengths ranged from 5.2 to 13.8 inches and averaged 10.0 inches. Thirty-four percent of the catch was from the 2017 year-class and an additional 21.5 percent from the 2016 year-class. Good Black Crappie production and recruitment on Rainy was observed from the 2014-2017 year-classes, resulting in several consecutive years of above average catch rates. Sixty-six percent of the Black Crappies caught in the 2022 survey were over 10 inches long and 11 percent were 12 inches or longer.
\n
\nRainy Lake is known to be infested with spiny waterfleas and zebra mussels. Anglers and boaters should always take preventative measures to avoid moving invasive species to other lakes. For more information on invasive species and other DNR programs, go to the DNR website at mndnr.gov.
Walleye gillnet catch rate (CPUE) in 2001 dropped to its lowest level since 1994. The CPUE of 4.50 fish per lift was slightly below the historical median of 4.63. Factors other than walleye abundance in Rainy Lake appear to be responsible for the downturn in CPUE. Surface water temperatures during the first week of sampling ranged from 67o to 68 o F. Temperatures typical for this time of year are considerably lower. Aging of walleye indicated that 11 year-classes were present in the gillnet catch. Like last year, the 1997 cohort was the most abundant year-class contributing 30% to the total and ranging in length from 8.8 to 17.7 inches with a mean of 14.2 inches. This year-class ranks fourth most abundant of the last 40 and should make up a large portion of the angler catch and harvest during the 2002 season. The 1998 walleye year-class contributed 25% of the gillnet catch. The CPUE for age-3 walleye was similar to the historical mean of 1.12. Age-3 walleye ranged in length from 7.8 to 14.0 inches with a mean of 10.5 inches. The 1998 year-class should also provide a substantial contribution to the angler catch and harvest during 2002. The 1995 and 1996 walleye cohorts each contributed 11% of the gillnet catch. The 1995 year-class produced a CPUE of 0.50 compared to a historical mean of 0.32. Nine of the ten age-6 walleye captured exceeded 17 inches in length. The 1995 year-class was the third strongest on record dating back to 1959. The 1996 year-class exhibited average abundance for age-5 walleye on Rainy Lake and ranged in length from 13.2 to 19.2 inches with a mean of 15.9 inches. Thirty percent of the age-5 walleye captured were over 17 inches in length. Few individuals of the 1999 and 2000 walleye year-classes were captured in the 2001 gillnet catch. The CPUE for age-2 walleye was 0.30 compared to a historical mean of 1.08. Assessment of this year-class has been difficult since both first summer electrofishing and the 2000 gillnet assessment indicated that this cohort was abundant. Results of this assessment are contrary. First summer electrofishing did indicate that the 2000 year-class would not be a strong year-class and this year's gillnetting supported that observation. The CPUE of age-1 fish was 0.15 compared to a historical mean of 0.59. Two walleye year-classes set record CPUE estimates for their respective age-groups. The 1991 year-class as age-10 fish produced a CPUE of 0.20 compared to the historical mean of 0.05. These fish had a mean length of 23.2 inches. The 2001 year-class also set a record producing more age-0 walleye in the catch than ever before. Recruitment by young-of-the-year walleye to DNR nets indicates good growth which generally corresponds to good survival to adulthood. The northern pike gillnet CPUE of 2.05 fell within common ranges for Rainy Lake. The historical median was 2.60. Lengths ranged from 6.2 to 33.8 inches however, 83% of the catch was between 18 and 23 inches and presumably from a strong 1999 year-class. Thirty age-0 northern pike were captured while shoreline seining in 2001. This was the second highest catch recorded since 1983 and suggests that the 2001 year-class will be abundant. The high catch in 2001 may have been related to the highest spring water levels recorded since 1968. The 2001 sauger gillnet CPUE of 2.65 was low for Rainy Lake. The historical median was 3.68. The length-frequency distribution indicated that two sizes of sauger; 8.5 and 12.0 inches, were most common. The fish near 8.5 inches in length were probably from a strong 1998 year-class. Previous assessments have indicated that no other strong year-classes are currently present in the fishery. Sauger make up a minor component of the Rainy Lake summer harvest. The black crappie trapnet catch rate (CPUE) declined in 2001. From 1996 to 2000, CPUE had steadily increased from 0.94 per lift to 5.11. The 2001 CPUE of 1.20 fish per lift was unexpectedly low and seems to be contrary to results of the 2001 summer creel survey. Anglers harvested an estimated 4,400 pounds of crappie from Rainy Lake in 2001, the highest harvest since 1994. Anglers targeting crappie produced a catch rate of 1.18 fish per angler hour and a harvest rate of 1.07. Harvested crappie had a mean length of 11.3 inches. Results of the 2001 summer angler creel survey indicated that angling effort decreased for the first time in eight years. The 246,500 angler-hours recorded in 2001 was the lowest effort estimate since 1998. Both the early (May/June) and late summer (July-Sept.) estimates were lower in 2001 than during the previous two seasons. The 2001 walleye harvest rates of 0.194 exceeded the historical average but was less than that recorded during the 2000 season. That coupled with lower effort resulted in a total harvest of 47,700 walleye weighing 44,200 pounds, the third highest on record. The average targeting catch and harvest rates were 0.51 and 0.24, respectively. The average targeting catch rate of walleye over 17 inches was 0.15. Fifty-two percent of the walleye harvested by anglers were from the 1997 year-class. An additional 23% were from the 1996 year-class. Beginning with the 2002 open water season a daily and possession limit of four walleye will be in effect for Rainy Lake.
","headerInfo":{"wb_id":"69069400","survey_type":"Population Assessment","survey_id":"111990","wb_alt_name":"","county":"St. Louis","wb_name":"Rainy","wb_type":"Lake","id_date":"2001-09-05"}},{"lengths":{"WAE":{"fishCount":[[16,1],[17,1],[18,2],[19,4],[20,2],[21,3],[22,1],[23,3],[24,4],[25,2],[26,2],[27,1]],"minimum_length":16,"maximum_length":27}},"fishCatchSummaries":[{"totalCatch":26,"averageWeight":"4.05","totalWeight":47784,"species":"WAE","quartileWeight":"N/A","quartileCount":"N/A","gearCount":9.41388888888889,"gear":"Special electrofishing","CPUE":"2.76"}],"surveyType":"Targeted Survey","surveySubType":"Targeted Survey","surveyID":"13231510334157000","surveyDate":"2015-04-13","narrative":"Walleye (Sander vitreus) are the most sought after gamefish on Rainy Lake (69-0694-00). Historically a large run of Walleyes from Rainy Lake spawned in the Rat Root River near Ericsburg, MN. The Rat Root River flows through Rat Root Lake (36-0006-00) and empties into Black Bay (Rainy Lake). From 1933-1943 and again from 1971-1978 a Walleye trap was operated by the Minnesota Department of Natural Resources (MNDNR) just downstream from Rat Root Lake as part of an egg take operation. During the early egg take period an average of 3,887 female Walleye were captured annually using a trap with leads that stretched the entire width of the river (area office files). During trap operations in the 1970s the average number of females captured annually dropped to 243. Periodic monitoring of this spawning run by Department of Natural Resources (DNR) - Fisheries personnel using boat based electrofishing equipment began in 1991 and continues to the present.
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\nThe spring 2015 Walleye spawning run in the Rat Root River was marked by very low catches due in part to exceptionally low water. Due to low water we were only able to sample waters below the Galvin Line Bridge in 2015. There were logs and debris two bends below the Galvin that impeded traveling upstream any farther. The recently constructed Walleye spawning riffle just downstream of the Galvin Line Bridge was also a barrier to boating traffic in 2015.
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\nElectrofishing on the Rat Root River included six days of sampling beginning on April 15th and concluding on April 27th. Water temperatures ranged from 39 degrees Fahrenheit on the morning of April 23rd to 55 degrees Fahrenheit in the afternoon of April 27th. Twenty-six Walleyes were caught in the Rat Root River in 2015. One fish was caught multiple times resulting in a catch of 25 individual fish. A tagging study initiated in 2010 and completed in 2014 resulted in 844 tagged Walleyes. Thirteen of the 25 individual Walleyes caught in 2015 were previously tagged. The highest one day catch total in 2015 was eight fish on April 23rd when water temperatures ranged from 39 to 45 degrees Fahrenheit. All eight fish were males. Overall, 12 Walleyes were male, 12 were females, and 1 was unknown sex and maturity. Female lengths ranged from 21.5 inches to 27.2 inches and averaged 24.8 inches. Male lengths ranged from 16.7 inches to 23.1 inches and averaged 19.8 inches.
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Fish Community Index Netting (FCIN) consists of deep water gill net sets that target cold water fish species. This sampling has been carried on a two of four year rotation on Rainy Lake since 2003 with the primary goal of monitoring the Lake Whitefish population. There are a total of 12 gill net sets during each assessment. Each set is 24 hours long and the net locations are chosen randomly from four sections of the lake (three net sets per section) in order to distribute sets throughout the lake. Eight nets were set in depths ranging from 60-80 feet while the other four were set at depths greater than 80 feet. Sampling took place from August 24th through August 28th.
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\nNine fish species totaling 561 individual fish were caught in the 2015 FCIN assessment. Ciscoes were the most numerous fish caught with 237 individuals followed by Walleyes (140 individuals). Ninety four Lake Whitefish were caught for a catch rate 7.83 per net. Lake Whitefish lengths ranged from 8.8 to 23.4 inches long. Whitefish ages ranged from age-0 to age-17.
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\nDeepwater FCIN sampling suggests the Lake Whitefish population in Rainy Lake is healthy. Catch rates averaged 7.31 Lake Whitefish per net since 2003 and have been very consistent in recent assessments. Whitefish from multiple year-classes suggest good reproduction and survival to maturity.
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