Principal Investigators: Stephen Bollens, Steven Sylvester (WSU-V)
Award period: 2005-2006
The future of the multi-million dollar oyster industry in Willapa Bay, WA is currently being threatened by burrowing shrimp populations, which naturally make the sediment too soft for oyster culture. Carbaryl has been the pesticide of choice for several decades, but is soon to be banned. Thus the oyster industry is looking for any and all new control agents – chemical, physical or biological.
One important aspect of the basic biology of burrowing shrimp that is very poorly known, however, is the role of predation, especially in Willapa Bay. Burrowing shrimp have been reported to occur in the stomachs of a number of predators, including staghorn sculpin (Leptocottus armatus), cutthroat trout (Salmo clarkia), Dungeness crab, (Cancer magister), western gull (Larus occidentalis), starry flounder (Platichthys stellatus), leopard shark (Triakis semifasciata), Pacific herring (Clupea pallasii), chum and chinook salmon (Oncorhynchus keta and O. tshawytscha) and grey whale (Eschrichtius robustus).
One obvious potential biological control agent, which has a long history within pest management, is to use natural predators (e.g., Kareiva 1996, Lafferty and Kuris 1996 and references therein). Our objective is to identify the suite of natural predators, both vertebrate and invertebrate, that prey upon ghost and mud shrimp in Willapa Bay. To do so, we employ a variety of field sampling techniques (e.g. pelagic net sampling, beach seining and fyke net sampling of tidal channels), combined with microscopic dissection and molecular genetic analysis of potential predator gut contents.
This study will provide the first comprehensive identification of predators of burrowing shrimp in Willapa Bay. We will also gain information on the relative importance of the burrowing shrimp within the predators’ diet based on DNA content. Only with this information can resource managers make informed decisions regarding possible use of predators as effective biological control agents of the burrowing shrimp. As the shrimp become manageable, the oyster industry can remain a viable economic component of Willapa Bay and the State of Washington.