Clear Lake

How big is Clear Lake?

How deep is Clear Lake?

What kind of fish can you catch in Clear Lake?

What are the closest cities to Clear Lake?

Are there boat launches on Clear Lake?

Are there places to eat and drink near Clear Lake?

What aquatic invasive species are found in Clear Lake?

A targeted survey of nearshore fish species in Clear Lake was conducted on June 12-14, 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. Similarly, a 50-foot seine was used to sample eight stations, a 15-foot seine was used at one station, and site conditions prevented the use of seines at one station. Nearshore sampling captured seventeen species of fish including eight species that are intolerant of disturbance (i.e., Banded Killifish, Blacknose Shiner, Iowa Darter, Least Darter, Logperch, Mimic Shiner, Rock Bass, and Smallmouth Bass) and one 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 eleven species of fish, including one that is intolerant of disturbance (i.e., Rock Bass). Bluegill comprised a majority of the catch by number, whereas Bluegill, Bowfin, and Hybrid Sunfish comprised a majority by biomass.

The nearshore and trap net data were combined with gill net data from a June 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 Clear Lake is healthy as indicated by an FIBI score that exceeds the exceptional use threshold determined for similar lakes. These results will be considered when the biological health of the lake is assessed during the Pine River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Temperature-dissolved oxygen profiles were also collected in the deepest basins on Clear Lake on August 1st, 2023, to evaluate the amount of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee. Based on the profile from the deepest basin, the top of the thermocline (i.e., the location in the water column with the sharpest transition from warm to cold water) occurred at approximately 20 feet. Dissolved oxygen decreased to below 3.0 mg/L at 20.6 feet, which was within the thermocline, at the time of sampling. The temperature at which dissolved oxygen decreased to below 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 17.6?C (63.7?F).

TDO3 values cooler than 21.5?C indicate that oxythermal conditions are favorable for Cisco. Dissolved oxygen concentrations near the thermocline indicate that oxythermal habitat was adequate for Cisco at limited depths at the time of sampling during the summer of 2023. However, low dissolved oxygen concentrations (i.e., less than 3 mg/L) below the thermocline and warm surface temperatures would likely limit available Cisco habitat within the water column to an extent. When inadequate oxythermal habitat is available, Cisco are squeezed into unfavorable, warmer water conditions and therefore experience higher levels of stress.

What is the average air temp for Clear Lake?

Are there any state parks near Clear Lake?