Small pond ecology : eutrophication, alternative stable states, and management options.

Abstract

"Nutrient pollution is a growing problem for freshwater bodies around the world. Cultural eutrophication associated with nutrient pollution can lead to unhealthy ecosystems with a lack of oxygen and biodiversity. This study compares three small ponds in Massachusetts to determine their trophic status, measured by water chemistry and biological indicators. Based on these criteria, Gilmore and Peacock Pond have been identified as eutrophic systems, but Wildcat is not. Eutrophic ponds can enter one of two alternative stable states, and Gilmore and Peacock Ponds reflect each of these. Gilmore Pond is in a turbid, phytoplankton dominated state, and Peacock Pond is in a clear-water, macrophyte dominated state. Wildcat Pond lies in between these two extremes, with a moderate amount of both phytoplankton and macrovegetation. Management strategies to pull Gilmore Pond out of this turbid state by reestablishing bottom vegetation are described, but ultimately I would advise managers of Gilmore Pond against taking an active approach. Gilmore Pond is a satisfactory ecosystem, and the costs of management are not likely to outweigh the benefits."