The hydrogen sulfide () in the anoxic layer is a serious risk to scuba divers entering this layer, as the highly-toxic gas can be absorbed through the skin. In 1977, the maximum safe threshold level for was set at 10 ppm, and concentrations at the bottom of the anoxic layer exceed that by eightfold. However, the hydrogen sulfide concentration down to the chemocline at about is reported to be zero, and if the anoxic layer is avoided, the in the lake does not pose a risk for snorkelers.