Hanson

A targeted survey of the nearshore fish community was conducted on August 30, 2016 by Fisheries IBI Program Staff. Sampling stations were evenly spaced around the lake and backpack electrofishing was completed at all 10 sampling stations, but 3 stations were sampled from the boat due to site conditions. Similarly, a 50-foot seine was used to sample 4 stations, a 15-foot seine was used at 1 station, and site conditions prevented the use of seines at 5 stations. Nearshore sampling captured 13 species of fish including 2 species that are intolerant of disturbance (Blackchin Shiner and Iowa Darter) and one species that is tolerant of disturbance (Green Sunfish). Data from this survey is combined with data from a standard game fish survey completed in June 2016 to calculate a Fish-based Index of Biological Integrity (FIBI) score that describes the overall health of the lake. The FIBI score for Hanson Lake from this survey is above an impairment threshold for aquatic life use developed for similar lakes. Data from this survey will contribute biological information about the health of the fish community as part of a process to assess the condition of surface waters of the Mississippi River - Brainerd Watershed.

A special assessment targeting near shore fish species was conducted on June 28, 2016. The near shore fish survey data is combined with gill net and trap net data from a July 2016 survey to describe the fish community and provide a fish-based Index of Biotic Integrity (IBI) score based on expectations for similar lakes. Sampling sites were evenly spaced around the lake (10 stations) and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Species information was gathered as part of a statewide project to evaluate the fish IBI for Minnesota lakes. Backpack electrofishing was completed at all 10 stations, but eight sites were sampled from the boat due to unstable footing. A 50-foot seine was not used, a 15-foot seine was used at 3 stations, and site conditions prevented the use of seines at 7 sites. Nearshore sampling captured several fish species, none of which were intolerant. Hansen lake falls within lake class 32 based on the Schupp lake classification used by MnDNR and within Group 4 lakes for evaluating IBI data. IBI scores range from 0 to 100 and the draft impairment threshold for this group of lakes is 38 (CI 30-46) and the potential exceptional quality level is set at 59. The IBI score, using standard gill net and trap net data from the 2016 standard assessment, calculated from this survey was 41.4 and above the impairment threshold. This survey is contributing to a watershed assessment process in coordination with the MN Pollution Control Agency. Hanson Lake is located in the Mississippi River - Brainerd Watershed.

Hansen Lake is located adjacent to state highway 47, four miles east of Aitkin, Minnesota. The lake has two basins that have similar aquatic plants, substrates and fish species. Cattails and sedges grow on most of the lake's shoreline, white waterlily and water shield also can be found near most of the shoreline. Canada waterweed, large-leaf pondweed and flat-stem pondweed grow in a majority of the shallow water regions of the lake. Muck covers most of the near-shore lake bottom. Loons regularly nest and raise young on the lake and shoreline development has been minimal. The fishery continues to be predominately anglers seeking black crappie, bluegill, northern pike and largemouth bass. Although none of these populations of fish exhibit above-average size structure, Hansen Lake does have a nice fishery for both northern pike and largemouth bass. Black crappie abundance in Hansen Lake has remained above average for its lake class for many years. Growth rates were somewhat slower than the state-wide averages, but were comparable to the average rates for the county. Average size was approximately 7.inches, and 10 inches was the largest. Anglers can expect to see adequate catch rates of smaller crappies and more over 10 inches should be available within a couple years as two stronger year classes continue to grow. Bluegill trap net catches were somewhat below average at 13.1/net when compared to the long term average of 25.7/net, but were still within the normal range for this lake class. Growth rates were slower than the state-wide averages, but were normal compared to the county averages. Average size was 6.2 inches, and 8.5 inches was the largest. If bluegill densities remain lower, we may see an improvement in growth rates. Northern pike gill net catch rates were similar to the previous survey at 5.7/net, which is typical for this type of lake. The size structure was favorable with 26% of pike being longer than 24 inches and with individuals up to 28 inches present in 2016. Larger pike offer benefits to the aquatic community as well as in the fishery and the best way to maximize these benefits of this quality pike fishery is for anglers to recycle these fish. Largemouth bass catch rates were average for the lake class. The mean length of largemouth bass was 14 inches with individuals observed up to 18.4 inches in the electrofishing assessment. Largemouth bass reproduction is sporadic in the lake, yet yields an average abundance of bass that can reach memorable size. Continued catch and release by anglers is encouraged and will help to maintain and improve fish populations that are desirable by anglers.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Hybrid Sunfish, Northern Pike, Black Crappie, and Pumpkinseed in Hanson. See the full species list above for catch rates, size structure, and quality scores.

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

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

The most recent Minnesota DNR survey data for the main sport fish in Hanson is from 2016. Surveys this old should be treated with some caution — fish populations change over time.

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