An integrated pest management plan for the control of burrowing shrimp populations on oyster beds in southwestern Washington State

Two species of burrowing shrimp (Neotrypaea californiensis and Upogebia pugettensis) occur in Pacific Coast estuaries with varying impacts on oyster and clam culture. The Pacific Coast currently produces more than a third of the nation's oysters, therefore, pest infestation is of regional and national concern. The carbamate pesticide carbaryl (Sevin) is the only effective tool currently approved for control of excess shrimp populations on oyster beds in Washington State. Objections by some crab fishers and environmentalists has led to the development of a multifarious Burrowing Shrimp Control Committee (BSCC). The BSCC developed an Integrated Pest Management Plan (IPMP) designed to evaluate alternative pest control methods and implement a plan using suitable strategies which allow continued oyster culture. Alternative methods identified include alternative culture techniques, mechanical control, enhancement of shrimp predators, electrofishing, and modification of carbaryl application. Critical timing for shrimp control requires additional study. A three year non-target species impact study commenced in 1992. Agriculture engineers are currently exploring alternative culture methods and modification of terrestrial pest control methods. Economic Threshold Determination studies are needed to determine "trigger" points for shrimp control maximum efficiency.