Ann

A targeted survey of nearshore fish species in Ann Lake was conducted on August 16-22, 2023, 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 ten sampling stations, but two stations were sampled from the boat due soft sediments and vegetation. Similarly, a 50-foot seine was used to sample four stations, a 15-foot seine was used at four stations, and site conditions prevented the use of seines at two stations. Nearshore sampling captured ten species of fish including one species that is intolerant of disturbance (i.e., Banded Killifish) and one species that is tolerant of disturbance (i.e., Green Sunfish). A concurrent summer trap net survey was also conducted by IBI Program staff. Nine trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured nine species of fish, including one that is tolerant of disturbance (i.e., Green Sunfish). Black Crappie and Bluegill comprised a majority of the biomass. The nearshore and trap net data were combined with gill net data from a May 2022 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 (e.g., Blackchin Shiner, Least Darter, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Black Bullhead and Green Sunfish). 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 Ann Lake is adversely impacted by stressors, as indicated by an FIBI score below 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 Lower Minnesota River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Ann Lake is a 116-acre (45 littoral acres) lake with a maximum depth of 45 feet, located north of Chanhassen in northeast Carver County. Ann is primarily managed for Northern Pike (special regulation: 24-36" protected slot, possession limit three, with one over 36") and Largemouth Bass (special regulation: catch-and-release), but also supports catchable populations of Bluegill and Black Crappie. Public water access is provided by the City of Chanhassen on the southeast side of the lake off State Highway 5, within the Ann Lake City Park (up to 13 vehicle/trailer parking spaces). A Standard Survey (9 trap nets/6 gill nets) was conducted on Ann Lake during the week of 5/31/2022 to assess the fishery. Ann Lake had moderate water clarity, measured at 13 feet during the time of this survey. Dissolved oxygen was zero parts per million (ppm) below 24 feet during the survey period. Eurasian Watermilfoil has been found in Ann Lake and remains present. Very high numbers of Northern Pike were sampled with gill nets (17.3/net). The 2022 survey marked the highest Northern Pike catch rate in the previous 25 years. There were 104 Northern Pike sampled, with an average size of 19.1 inches and the longest measured at 33.5 inches. Despite high numbers, Northern Pike growth was moderate compared to similar lakes across the metro, with an average length of 17.6 inches by age 3, and 22.1 inches by age 5. Despite consistent recruitment, with 8 consecutive year classes present during sampling and age analysis; over 67% of the total catch was represented by the 2019 year class (17.6 inch average length). Northern Pike in Ann Lake are currently dominated by small, young individuals. Due to these factors future discussions should focus on a reevaluation of the current special regulation to provide additional harvest opportunity of these small individuals. Largemouth Bass were sampled during spring 2022 with nighttime boat electrofishing, the third time such a survey was conducted here. Catch rates were high, with 51.5 fish/hour. A total of 103 bass were sampled, with an average length of 12.4 inches and the largest measured at 19.8 inches. Size and count data describe a balanced population (an intermediate between high numbers of small fish and few numbers of large fish. Over 57% of Largemouth Bass sampled were greater than 12 inches, while 23% were over 15 inches. The special catch-and-release regulation appears to have maintained desirable numbers and sizes of Largemouth Bass and should provide excellent angling opportunity. Moderate numbers of Bluegill were sampled with trap nets (16.9/net). The 2022 catch rate was the lowest Bluegill catch rate on Ann Lake in the previous 25 years. There were 152 Bluegill sampled in trap nets during the 2022 survey, with an average length of 5.6 inches and the largest measured at 9.3 inches. The historic reduction in Bluegill numbers likely reduced competition among other Bluegill, increasing food and habitat availability which increases growth and sizes, as we saw with multiple 9" fish being sampled. Low numbers of Black Crappie were sampled with gill nets (2.8/net) and trap nets (1.0/net). There were 26 Black Crappie sampled during the 2022 survey, with an average length of 7.8 inches and the largest measured at 11.2 inches. Similar to Bluegill, low numbers of Black Crappie are likely benefiting from reduced competition with an increase to growth and size. The results can be seen during the 2022 sampling with a handful of 10"+ fish measured, providing excellent angling opportunity for those that can find them. Other fish species sampled in low abundances were Black Bullhead, Brown Bullhead, Green Sunfish, Pumpkinseed, and Yellow Bullhead.

A targeted survey of nearshore fish species in Ann Lake was conducted on August 26th, 2019 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 six stations, a 15-foot seine was used at three stations, and site conditions prevented the use of seines at one station. Nearshore sampling captured 13 species of fish including one species that is intolerant of disturbance (Banded Killifish) and one that is tolerant of disturbance (Green Sunfish). The nearshore data were combined with trap net and gill net data from the week of June 5th, 2017 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 (e.g. Banded Killifish, Iowa Darters, Smallmouth Bass), while other species are tolerant of degraded conditions (e.g. Green Sunfish, Black Bullhead, Common Carp). 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. Data from this survey will contribute biological information about the health of the fish community to the Lower Minnesota River Watershed assessment process in coordination with MN Pollution Control Agency.

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

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

Ann has a maximum depth of 45 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Ann is from 2023.

Yes — Ann has confirmed Eurasian watermilfoil, brittle naiad, and zebra mussel. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.