10 likes | 171 Views
Use of Biological Control in Aquatic Systems. What is Biological Control? Controlling invasive species by intentional release of native/non-native: Herbivores/Predators Parasites Diseases Pesticides (most common) Mechanical Removal . What determines a Biological control?
E N D
Use of Biological Control in Aquatic Systems • What is Biological Control? • Controlling invasive species by intentional release of native/non-native: • Herbivores/Predators • Parasites • Diseases • Pesticides (most common) • Mechanical Removal • What determines a Biological control? • Respond to repeated host outbreaks • Able to survive in target area • Host specific • USES • Reduce Common Pests • Dinoflagellates: reduce mortality of fish, invertebrates, grass beds, increase toxins in shellfish • Red Algae: degrade coral reefs • Jellyfish: powerful sting, decrease fish and zooplankton • Bivalves: spread mortal diseases, reduce phytoplankton, alter diets of fish and birds, replace other suspension/filter feeders • Sea urchins: destroy kelp beds, decrease fish stocks • Burrowing shrimps: disturb sediments and filter/suspension feeders • Crabs: EUROPEAN GREEN CRAB, Carcinus maenas • Burrows into banks, causes erosion • Only control is Nermertean egg predator • Other crabs (China) can be hosts for flukes • Fishes: replace native fish • Use of Native Species • More effectively track pests • Evolve with pests • Less time consuming and expensive • Not quarentined IS A PEST, A PEST? • RISKS • Predation, Parasitism, Herbivory of Non-Target Species • “Any predator or herbivore maintained at high densities can potentially drive a rare non-target species to extinction.” (Simberloff 1966) • Competition with Native Species • Effects within Community and Ecosystem • “Non-native species that destroys a keystone species or becomes a dominant structural element, might be expected to have a huge impact, not easily predicted.” (Simberloff 1967) • Aquatic environments ‘open’—offspring disperse quickly, easily, do not stay with parents • Makes pest removal very difficult • Aquatic pests eradicated modestly/low levels to reduce effects • How much ‘control’ is needed to reduce impact of pest? • Environmental Safety References: Lafferty, Kevin D, Armand M. Kuris. “Biological Control of Marine Pests”. Ecology, Vol. 77, No. 7. Oct, 1996. 1989-2000. Sheldon, Sallie P, Robert P. Creed Jr. “Use of Native Insect as a Biological Control for an Introduced Weed”. Ecological Applications, Vol. 5, No. 4. Nov, 1995. 1122-1132. Simberloff, Daniel, Peter Stiling. “How Risky is Biological Control”. Ecology, Vol. 77, No. 7. Oct, 1996. 1965-1974.