Define biomanipulation and give an example of how it might be used to restore a eutrophic lake ecosystem.

Define biomanipulation and give an example of how it might be used to restore a eutrophic lake ecosystem.

• A. Biomanipulation uses chemical amendments to remove nutrients.
• B. Biomanipulation uses habitat restoration without feeding relationships.
• C. Biomanipulation uses targeted changes to the food web; removing planktivorous fish to increase zooplankton grazing and reduce algal blooms.
• D. Biomanipulation relies on invasive species to restructure the ecosystem.

Answer: (C)

Biomanipulation is the deliberate alteration of trophic interactions within an ecosystem to steer ecological processes toward a desired outcome. In a eutrophic lake, nutrient-rich conditions fuel phytoplankton blooms that reduce water clarity. By changing the food web, managers can enhance natural grazing control of algae. A classic move is to remove planktivorous fish that feed on zooplankton. With fewer planktivores, zooplankton populations rise and become more effective at grazing phytoplankton, which can lead to clearer water and reduced algal blooms. In some cases, introducing or protecting piscivores helps maintain this cascade by keeping planktivores in check, reinforcing the effect. This approach relies on ecosystem interactions rather than chemical fixes, and it is most successful when nutrient inputs are also managed and the system is closely monitored to respond to changes.

Biomanipulation is the deliberate alteration of trophic interactions within an ecosystem to steer ecological processes toward a desired outcome. In a eutrophic lake, nutrient-rich conditions fuel phytoplankton blooms that reduce water clarity. By changing the food web, managers can enhance natural grazing control of algae. A classic move is to remove planktivorous fish that feed on zooplankton. With fewer planktivores, zooplankton populations rise and become more effective at grazing phytoplankton, which can lead to clearer water and reduced algal blooms. In some cases, introducing or protecting piscivores helps maintain this cascade by keeping planktivores in check, reinforcing the effect. This approach relies on ecosystem interactions rather than chemical fixes, and it is most successful when nutrient inputs are also managed and the system is closely monitored to respond to changes.