Moon Bay Lake

Moon Bay Lake earns a D — measurements through 2024 show persistent nutrient pressure that limits clarity through the summer. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Moon Bay Lake is unusually deep for Wisconsin at 64 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. With 6,148 acres of surface and partial shoreline records, Moon Bay Lake is a large water by Wisconsin standards — recreational pressure is spread across a long shoreline. Moon Bay Lake ranks 12 of 15 in Chippewa County — at the lower end of the locally monitored distribution.

Moon Bay Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. Walleye are documented at Moon Bay Lake, one of 8 fish species on record for the lake. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.