Mermet Lake Curlyleaf Pondweed Eradication Plan

Executive Summary

 

Mermet Lake, located in extreme southern Illinois, supported an excellent sport fish population from the early 1960’s until 2003, when an exotic plant, curlyleaf pondweed, began causing annual summertime fish kills. These fish kills arise from curlyleaf pondweed changing from dominant to dormant in summer, and being replaced by significant plankton blooms which deplete the lake of dissolved oxygen during cloudy weather. This Plan outlines steps for eradicating curlyleaf pondweed from Mermet Lake and allowing more stable, native vegetation to return to dominance. Elimination of this exotic vegetation will subsequently offer an opportunity for restoration of the Mermet Lake sport fish population to its preinfestation condition, provide the potential for increased angling, and reduce the opportunity for curlyleaf pondweed to invade other high quality southern Illinois lakes and wetlands.