Lake of the Isles is a class 32 lake located within Scenic State Park in northern Itasca County. The lake has a small gravel public access for carry-ins or small boats. The 2007 lake management plan indicates smallmouth bass and walleye as the primary species of management with northern pike as secondary species. The fish community is vulnerable to angling overharvest because the lake is only 69 acres and has low productivity.
Northern pike were the most commonly caught species in the nets. The gill-net catch of 10.0 fish/net was similar to the last two assessments. The catch exceeded the third quartile value of 8.9 fish/net. The sampled fish ranged from 9.3 to 33.2 inches and had a mean length of 16.5 inches. Six year-classes were identified from cliethra and scales ranging from age 1 to age 7. Age-2 through 4 fish represented 80 percent of the sample. Northern pike averaged 17.9 inches by age 4 which was below the statewide average of 20.5.
Walleye catch rates have ranged from 1.3 to 3.0 since 1971. In 2011, the catch of 1.3 fish/gill net was similar to the catch in 1982 and the lake class median. The sampled fish ranged from 7.4 to 19.1 inches and had a mean length of 14.2 inches. Four year classes from age 1 to 4 were identified from scales and opercles. Growth was good with lengths-at-age being slightly above the statewide averages for all ages. Walleye averaged 16.8 inches at age 4. Natural reproduction has maintained a modest walleye population with catches at or above the lake class median.
Yellow perch gill-net catch rates have been above the lake class median of 3.0/net in the last four assessments. In 2011, the catch was the second highest on record at 7.8 fish/net. The sampled fish ranged from 5.5 to 12.9 inches and had a mean length of 9.7 inches. Age and growth information was not collected.
Other species observed during the population assessment included five pumpkinseed sunfish and one white sucker. No smallmouth bass were sampled in this assessment.