St. Anna

A targeted survey of nearshore fish species in St. Anna Lake was conducted beginning on August 18, 2025, by Lake Biological Monitoring and Assessment (LBMA) 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. Similarly, a 50-foot seine was used to sample five stations, and a 15-foot seine was used at three stations. Two stations were electrofished from the boat and not seined due to heavy vegetation and soft bottom. Nearshore sampling captured 11 species of fish including two species that are intolerant of disturbance (i.e., Blacknose Shiner and Iowa Darter) and one that is tolerant of disturbance (i.e., Green Sunfish). A summer trap net and gill net survey was also conducted by LBMA 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, none that are intolerant of disturbance, and two that are tolerant of disturbance (I.e., Black Bullhead and Green Sunfish). Bluegill comprised a majority of the catch by number and by biomass. The nearshore and trap net data were combined with gill net data from a survey conducted during the week of June 20, 2024 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., Iowa Darter and Blacknose Shiner), 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 provide evidence that the fish community in St. Anna Lake may be adversely impacted by stressors as indicated by an FIBI score that is near the aquatic life use impairment threshold determined for similar lakes. The survey results will be considered when the biological health of the lake is assessed during the Sauk River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. You can help protect the fish community in St. Anna Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.

A targeted survey of nearshore fish species in St. Anna Lake, was conducted beginning on June 24th, 2024, 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. Similarly, a 50-foot seine was used to sample 7 stations, and a 15-foot seine was used at one station. Two stations were not seined due to depth of muck substrate and dense vegetation. Nearshore sampling captured 8 species of fish including 2 species that are intolerant of disturbance (i.e., Blacknose Shiner and Iowa Darter) and one that is tolerant of disturbance (i.e., Fathead Minnow). 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 7 species of fish. Bluegill and Black Crappie comprised a majority of the catch by number, whereas Bluegill and Northern Pike comprised a majority by biomass. A concurrent summer gill net survey was conducted on June 24th to June 27th, 2024, by IBI Program Staff. Six gill nets were set in offshore locations that encompassed deeper littoral habitat. Northern Pike and Largemouth Bass comprised a majority of the gill net catch by number and biomass The number of Northern Pike sampled per net (8.8/net) at the 75% quartile for similar Lake Class 23 lakes (0.87/net) and the average length was 22.7 inches. Conversely, the number of Largemouth Bass sampled per net (2.50/net) was above the 75% quartile for Lake Class 27 lakes (1.7/net) with an average length of 16.4 inches. Data from all gears were combined 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, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Green Sunfish and 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. The survey results will be considered when the biological health of the lake is assessed during the Sauk River watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. You can help protect the fish community in St. Anna by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.

A targeted survey of the nearshore fish community in St. Anna Lake was conducted by Fisheries Index of Biological Integrity (IBI) Program Staff starting July 2, 2018. Ten sampling sites were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 15-foot or 50-foot seine, where possible. Backpack electrofishing was completed at all ten sites with three sites sampled from the boat. Similarly, a 50-foot seine was used to sample two sites, a 15-foot seine was used at five sites, and deep water and soft sediments prevented the use of seines at three sampling sites. Nearshore sampling captured 12 native species of fish including one species that is intolerant of disturbance (Iowa Darter) and two species that are tolerant of disturbance (Common Carp and Green Sunfish). Data from this targeted nearshore survey is combined with trap net and gill net data from a June 2015 standard survey to describe the fish community and provide a Fish-based Index of Biological Integrity (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. 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. The FIBI score for St. Anna Lake from this survey is just below an impairment threshold for aquatic life use determined for similar lakes. 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 Sauk River Watershed assessment of surface waters process completed in coordination with MN Pollution Control Agency.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Northern Pike, Hybrid Sunfish, Walleye, and Bluegill in St. Anna. See the full species list above for catch rates, size structure, and quality scores.

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

St. Anna has a maximum depth of 107 feet and a mean depth of 46 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in St. Anna is from 2025.

Yes — St. Anna has confirmed Eurasian watermilfoil. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.