Fishing Lake Diane

Lake Diane has transformed into a predator-dominated fishery where channel catfish rule the roost, comprising 43% of fish by number and 57% by weight despite never being stocked. These catfish average 18 inches with over a third exceeding 20 inches, though growth is 3.7 inches below state average. The walleye stocking program has been a major success story, producing fish that average 26 inches with excellent growth 2.2 inches above state average—97% are over the 15-inch legal limit. White crappie have dramatically improved in size structure with 24% now over 10 inches compared to just 2% in 2001, and 75% exceed the 7-inch keeper size. The lake's thermocline sets up at 11-15 feet where dissolved oxygen drops sharply from 6.8 ppm to under 1 ppm, concentrating fish in the upper water column during summer stratification. Bluegill numbers and biomass have crashed under intense predation pressure, with only 2.5% reaching the 6-inch minimum acceptable size. Northern muskellunge from the stocking program provide trophy opportunities, though a 2011 survey caught 124 compared to just 4 in this warmer-water survey. The forage base has collapsed with only 17 gizzard shad and a few minnows collected, indicating the heavy predation pressure throughout the system. This 283-acre reservoir averages 8 feet deep with a maximum of 52 feet in the old lake basins, and turbid water from suspended clay limits visibility to 1.5-2.5 feet. The dramatic shift from a panfish-dominated lake in 2001 (where crappie comprised 67% of the catch) to today's predator-heavy system represents one of the most significant community changes documented in southern Michigan lakes.