Natural lakes in the Mississippi Delta, long known for their productivity and recreational value, have declined because of poor water quality. Sediment from agricultural runoff interferes with plankton growth, the foundation of all life in freshwater lakes. ARS ecologist Scott Knight at the National Sedimentation Laboratory , Oxford, Miss., conducted a study to evaluate the restocking of sports fish in three lakes with watersheds that have been improved by implementing BMPs.
Oxbows make perfect ecology laboratories because they are essentially closed ecosystems.
Sports fish were successfully reintroduced in the two lakes whose watersheds were protected with culture-based BMPs like conservation tillage and cover crops. The third lake was protected by only structural measures which did not reduce sediment enough to ecologically improve it. The two lakes protected by culture-based BMPs had the most significant improvement in water quality. Increasing water clarity boosts plankton growth, a necessity for a good sports fishery. Bass populations, lacking before renovation and restocking, were successfully established in these two lakes.