The Michigan Department of Natural Resources uses the Trophic State Index (TSI) to determine the status of Michigan Lakes. The TSI value based on the transparency readings for Fumee Lake is 44 and 43 for Little Fumee Lake. The TSI value for total phosphorus was 50.6 for Fumee Lake and 37.4 for Little Fumee Lake. These trophic levels are excellent and reflect lakes with moderate production, enough to have fish growth but not rich enough to have extensive weed or algae problems.