Fishing Thousand Island Lake

Thousand Island Lake offers solid multi-species fishing as part of the Cisco Chain, but the fishery is in transition due to declining predator numbers. The walleye population, historically the lake's primary predator at 39.6% of biomass in 1975, dropped to just 18.4% by 1992 following tribal spearing harvests that removed 432 walleyes in two years. Those fish averaged 16+ inches, and the remaining walleyes now average a hefty 19.4 inches with 83% legal size. Smallmouth bass numbers also crashed from 12.2 fish per net in 1988 to just 0.8 in 1992. With total predator biomass down to 27.2% (pike, walleye, and smallmouth combined), panfish are responding predictably. Bluegill reached all-time high abundance at 47% of all fish caught, though average size dropped to 6.2 inches. Black crappie are surging, jumping from 2-3% to 14.2% of total biomass and averaging a solid 9.3 inches with 87% legal size. Rock bass remain abundant but declined from their 1990 peak. The lake's structure favors fish - steep shoals of sand, gravel and peat provide good spawning areas, while logs and sunken islands offer cover. Aquatic vegetation is abundant with submergent and floating species. The mid-summer thermocline sits at 17-26 feet, and dissolved oxygen drops too low for fish below 50 feet during summer stratification, concentrating fish in the upper water column. At 1,078 acres with an 81-foot maximum depth and excellent water clarity (12-foot Secchi reading), this lake has the habitat to support a balanced fishery if predator numbers can be restored through natural reproduction or stocking.