biomanipulation

Biomanipulation is a management practice where humans intentionally remove or add species to an ecosystem to improve water quality. This is often done in lakes to reduce harmful algal blooms, such as toxic blue-green algae. The primary goal is to control the concentration of nutrients like phosphorus and nitrogen that fuel algal growth.12

This process often involves a trophic cascade, where changes at one level of the food chain affect other levels. For example, stocking lakes with game fish can lead to a decrease in smaller fish, an increase in herbivorous zooplankton, and a subsequent decrease in harmful phytoplankton. In some cases, removing bottom-feeding fish can also increase rooted vegetation and improve water clarity. Biomanipulation is an ethical approach to restoring aquatic ecosystems degraded by cultural eutrophication, which is human-induced nutrient enrichment.12