Big Island

A targeted survey of nearshore fish species in Big Island Lake was conducted on July 20-21, 2021, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was completed at 10 sampling stations, but one station was sampled from the boat due to site conditions. Similarly, a 50-foot seine was used to sample two stations, a 15-foot seine was used at four stations, and site conditions prevented the use of seines at four stations. Nearshore sampling captured six species of fish including one species that is intolerant of disturbance (Blacknose Shiner) and no species that are tolerant of disturbance. The nearshore data were combined with trap net and gill net data from a July 2020 survey to describe the fish community and provide a Fish-based IBI (FIBI) score. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (Blacknose Shiner), while other species are tolerant of degraded conditions (Black Bullhead). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. Results from this survey indicate that the fish community in Big Island Lake is healthy as indicated by an FIBI score above the impairment threshold for aquatic life use determined for similar lakes. These results will be considered when the biological health of the lake is assessed during the Big Fork River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Big Island Lake is a 238-acre lake located just east of Marcell, MN in the Chippewa National Forest and the Big Fork River watershed. Big Island Lake has fairly clear water, is moderately developed, and has low alkalinity and fertility. There is a US Forest Service access located at the northwest corner of the lake. The lake management plan was last updated in 2006. Black Crappie and Largemouth Bass were considered primary management species, with Northern Pike and Bluegill considered secondary management species. A standard lake survey was conducted in July 2020 to assess the status of the fish community. The trap-net catch for Black Crappie was typical for the lake and lakes with similar habitat. Size structure was modest with few fish exceeding 10 inches. Ages 2 through 7 were represented indicating frequent recruitment. Growth was considered slow with crappie averaging 8.2 inches after 5 years. Big Island Lake likely provides fair angling opportunities for crappie. Fish exceeding 10 inches were more common in previous surveys. Big Island Lake has typically produced moderate numbers of Northern Pike with moderate size structure. The 2020 gill-net catch was considered average for the lake and similar lakes. Size structure remained moderate. Sampled pike ranged from 16.3 to 28.6 inches with an average length of 22.6 inches. Ages 2 through 8 were represented indicating frequent recruitment. Growth was considered average; pike exceeded 22 inches after 5 years of growth. The Bluegill population can generally be described as having moderate numbers, poor size structure and slow growth. The 2020 trap-net catch was similar to previous surveys and average for lakes with similar habitat. Size structure remained poor. Bluegill ranged from 3.0 to 7.3 inches with an average length of 5.1 inches. Ages 3 through 10 were represented indicating frequent recruitment. Growth was considered slower than average; Bluegill averaged 5.5 inches after 6 years of growth. Poor size structure likely limits popularity of the Bluegill fishery. Spring night electrofishing sampled Largemouth Bass at the rate of 68.6/hour. This was a relatively high catch rate compared to other lakes in the area. Size structure was moderate; bass ranged from 4.0 to 19.5 inches with an average length of 11.0 inches. Most year classes from age 1 through 11 were represented, with age 4 and 5 fish the most frequently sampled. Growth was considered average. Largemouth Bass averaged 14.8 inches after 6 years of growth. Big Island Lake likely provides good angling opportunities for Largemouth Bass. Yellow Perch have consistently been sampled in low numbers in Big Island Lake. The 2020 gill-net catch remained low. Sampled perch ranged from 6.3 to 8.2 inches with an average length of 6.8 inches. Other species sampled included Golden Shiner and Smallmouth Bass. In order to maintain or improve fish and wildlife populations, water quality and habitat must be protected. People often associate water quality problems with large-scale agricultural, forestry, urban development or industrial practices in the watershed. In reality, the impact of land use decisions on one lake lot may be relatively small, yet the cumulative impact of those decisions on many lake lots can result in a significant decline in water quality and habitat. For example, removing shoreline and aquatic vegetation, fertilizing lawns, mowing to the water's edge, installing beach sand blankets, failing septic systems and uncontrolled run-off, all contribute excess nutrients and sediment which degrade water quality and habitat. Understanding these cumulative impacts and taking steps to avoid or minimize them will help to insure our quality fisheries can be enjoyed by future generations.

Big Island Lake is a 238 acre lake located in the Chippewa National Forest north of Grand Rapids, MN. The lake has a maximum depth of 42 feet and a littoral area of 202 acres. The public access (U.S. Forest Service) is located on the northwest side of the lake. Big Island is best known for its panfish and bass fishing. Northern pike abundance is high with a gill net catch of 11.0/set in this survey. Catch rates have been above the median in most past assessments. Size structure was moderate. Growth of the northern pike sampled was slower than the statewide averages. The bluegill trap net catch rate was 12.8/set, above the median. Size structure was poor with none sampled over 7.5 inches. They ranged in length from 3.2 to 7.3 inches and had a mean length of 4.9 inches. High numbers (21.5/set) were observed in the gill net. This is the highest observed of any past assessment on Big Island. The size structure was similar to what was observed in the trap net. Bluegill growth rates were similar to the lake class #35 averages. The black crappie trap net catch rate was 2.2/set in this survey compared to the lake class range of 0.7-4.3/set. The gill net catch rate of 2.7/set was below the median of 4.2/set and within the lake class range of 1-10.5/set. The gill net sampled crappie ranged in length from 5.4 to 12.3 and had a mean length of 8.2 inches. The trap net sampled crappie ranged in length from 5.1 to 11.7 inches and had a mean length of 9.1 inches. Growth rates were <85% of the statewide averages. Yellow perch, typically low in abundance in Big Island, were again sampled well below the lake class median at 5.0/gill net. The fish sampled were of similar size ranging from 5.8 to 6.9 inches and had a mean length of 6.2 inches. Largemouth bass were not sampled in the trap nets but were sampled at 1.2/gill net. Spring night electrofishing was conducted on 5/20/2005 as part of this survey. Spring electrofishing has been shown to more effectively sample bass than conventional test netting. Results from this survey indicate a good population of largemouth with a catch of 38.4/hour. The 52 largemouth sampled ranged in length from 4.4 to 18.4 inches with a mean length of 11.6 inches. Size structure was good with a PSD of 47 and an RSD-P (15 inches) of 20. Walleye, never sampled in any past survey, were sampled at 0.5/gill net. Walleye were stocked only once in 1986 as fry. Another species never sampled prior to this survey was smallmouth bass. Six (1.0/set) were sampled in the gill net and 2 (0.2/set) were sampled in the trap net. The smallmouth in the gill net ranged in length from 15.7 to 18.4 inches and had a mean length of 16.7 inches. Natural reproduction was evident with two sampled in the trap net at 5.3 inches and 6.3 inches. Both were aged at 2 years old. An angler noted that he had caught several in recent years and suspected the fish were illegally introduced from nearby Three Island Lake.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Northern Pike, Black Crappie, Walleye, and Bluegill in Big Island. See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for Big Island. Check the DNR LakeFinder page for the launch type and directions before you go.

Big Island has a maximum depth of 42 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Big Island is from 2020.

No invasive species are on record for Big Island in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.