Big McCarthy

Big McCarthy Lake is a 110-acre lake located 5 miles northeast of Nashwauk, MN. There is a concrete access on the northwest shore and an outlet draining to Crooked Lake and the Prairie River. The lake is long and narrow with a steep breakline around the shoreline. Water clarity was moderate due to bog stain. The lack of shallow water, sparse aquatic vegetation and lower water clarity result in low productivity and low catch rates typical of bog-stained lakes. Primary fish species include northern pike, bluegill, and black crappie. The northern pike catch rate was 4.5/net, which was similar to average of 5.0/net for similar lakes. Size structure was moderate with fish up to 30 inches sampled. Growth was similar to the statewide average with fish averaging 26 inches by age 5. Bluegill catch rate was 15.9/trap net, which was also similar to average of 14.3/net for similar lakes. Size structure was poor with a no fish exceeding 8 inches. Growth was slower than the lake class average with fish only reaching 6 inches by age 7. Black crappie trap net catch rate was 2.0/net, which was higher than the expected range and no black crappie were sampled in gill nets. Size structure was generally poor with few fish exceeding 10 inches. Growth was slow and less than 85% of statewide average with fish reaching 9 inches by age 7. Big McCarthy Lake has historically had low yellow perch catch rates in past assessments and only four fish were sampled by gill nets or trap nets in this assessment. Yellow perch are an important prey species and their low abundance likely reduces the ability of the lake to support predator species. Walleye were not sampled in this assessment and have not been sampled in past assessments despite previous fry and fingerling stocking. Other species sampled include rock bass, white sucker, brown and yellow bullhead, largemouth bass, and pumpkinseed sunfish. Lakeshore owners may affect fish populations not only through harvesting fish, but also through land use practices. It is important to leave a 30 to 50 ft buffer strip of native vegetation along the shoreline to prevent erosion and provide habitat for fish and wildlife. Nonfunctioning septic systems can also lead to water quality problems. Good water quality and fish populations are the direct result of good land use practices. Anglers can also help to improve the size structure of the fish community by harvesting smaller more abundant sized fish and releasing the medium to larger sizes.

NO WALLEYE WERE TAKEN IN THE NETS. NORTHERN PIKE ABUNDANCE IS LOW, BUT THE SIZE IS FAIR. BLACK CRAPPIE, BLUEGILL, AND PUMPKINSEED ARE COMMON BUT SMALL. THE YELLOW PERCH POPULATION IS VERY LOW. LARGEMOUTH BASS YOUNG OF THE YER WERE CAUGHT IN THE SEINE. WALLEYE, FRY, FINGERLINGS AND YEARLINGS HAVE BEEN STOCKED IN RECENT YEARS.

NORTHERN PIKE ABUNDANCE IS COMPARABLE TO OTHER LAKES OF ITS KIND IN THIS AREA. NUMBERS OF YELLOW PERCH ARE VERY LOW. ABUNDANCE OF THE OTHER SPECIES AT OR BELOW STATE AND LOCAL MEDIANS.

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

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

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

The most recent Minnesota DNR survey data for the main sport fish in Big McCarthy is from 2008. Surveys this old should be treated with some caution — fish populations change over time.

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