Sentinel Lake Assessment Report Lake Carlos (21-0057) Douglas County, Minnesota

The Minnesota Pollution Control Agency (MPCA) is working in partnership with the Minnesota Department of Natural Resources (MDNR) on the Sustaining Lakes in a Changing Environment (SLICE) Sentinel Lakes Program. The focus of this interdisciplinary effort is to improve understanding of how major drivers of change such as development, agriculture, climate change, and invasive species can affect lake habitats and fish populations, and to develop a long-term strategy to collect necessary information to detect undesirable changes in Minnesota Lakes (Valley 2008). To increase our ability to predict consequences of land cover and climate change on lake habitats, SLICE utilizes intensive lake monitoring strategies on a wide range of representative Minnesota lakes. This includes analyzing relevant land cover and land use, identifying climate stressors, and monitoring effects on the lake's habitat and biological communities. The Sentinel Lakes Program has selected 24 lakes for long-term intensive lake monitoring (Figure 1). The "Deep" lakes typically stratify during summer months only. "Shallow" lakes are defined as mixing continuously throughout summer. "Cold water" lakes are defined as lakes that either harbor cisco, lake whitefish, or lake trout and are the focus of research funded by the Environmental Trust Fund (ETF). "Super sentinel" lakes also harbor cold-water fish populations and research on these lakes is also funded by the ETF. Lake Carlos is a cold water, super sentinel, lake that has a resident cisco population. Lake Carlos is a popular recreation lake that has a surface area of 1055 hectare (ha; 2,607 acres) and has a maximum depth of 50 meters (163 feet). Nearly all (98%) of the shoreline of Lake Carlos is developed. The State of Minnesota (Carlos State Park), owns 2.3 kilometers (1.4 miles) of shoreline on the north end of the lake. The lake supports a large range of water recreational activities.