Collaborative: Alternate States and Ecosystem Metabolism in Lakes: Interactions of Nutrients and DOC Some lakes are blue, but most are green or brown. We have learned a great deal about eutrophication, the process that turns lakes green and leads to nuisance blooms of algae. Dystrophy, the process that turns lakes brown, is less understood but has important interactions with fisheries, gas flow to and from lakes, and cycling of metals such as mercury. This project will study the interactions of biogeochemical inputs and food web structure that control dystrophy and eutrophy in lakes. We will quantify conditions that lead to change in lake ecosystem state, and assess responses of ecosystem production, respiration, gas exchange, and energy sources for fish production. This research is a collaborative study by limnologists, microbial ecologists, biogeochemists and fish ecologists. We will conduct a three year program of whole lake experiments and modeling studies to find the mechanisms, response rates, and constraints associated shifts from eutrophy to dystrophy and vi ce versa.
