Translating physiological findings on burrowing shrimp to create "unbalanced salt treatments" for oyster beds in Willapa Bay, WA

Commodities

• Animals: shellfish

Practices

• Animal Production: aquaculture
• Pest Management: chemical control

Willapa Bay, Washington is one of the largest producers of the Pacific oyster in the US, but oyster producers are losing large plots of land and product to the native pest species Neotrypaea californiensis, or burrowing shrimp. When burrowing, shrimp displace large amounts of sediment to the surface of the mudflat, where oysters grow for bottom-culture production. This results in oyster death from smothering or sinking into the sediment, negatively affecting producers’ crop yields. Historically, carbaryl, a commercial pesticide, was used to control burrowing shrimp. Government agencies restricted the use of carbaryl as a pesticide a decade ago due to its well-documented downstream effects on terrestrial and aquatic animals. However, no practical alternative has been introduced to the producers since to combat expanding shrimp populations. The proposed research asks the question: Is sodium bicarbonate an effective and sustainable chemical for controlling burrowing shrimp populations in bottom-culture oyster beds? Our laboratory experiments described the fundamental biology of burrowing shrimp and aided in identifying weak points in their physiology as targets for control using unbalanced [compared to their blood] salt treatments. Application of sodium bicarbonate solution to burrowing shrimp in our laboratory system caused 100% mortality within one hour. We aim to extend these promising results to oyster beds experiencing high shrimp densities in partnership with operators at Taylor Shellfish Farms. We will do this by leveraging laboratory findings to optimize sodium bicarbonate applications in mudflats with the goal of reducing shrimp populations and meeting producer’s needs. We plan to go directly to producers in Willapa Bay and facilitate bidirectional learning opportunities between growers and our research team about burrowing shrimp concerns, field observations, and accessible information about burrowing shrimp biology. Updates from this research will be shared with the community through a monthly column in the Chinook Observer.

Research Objective 1: Leverage prior biological knowledge and existing chemical application methods to optimize sodium bicarbonate treatment delivery (volume, depth, concentration).

Research Objective 2: Quantify targeted and non-targeted effects of sodium bicarbonate application within burrows and in surrounding mudflat area.

Educational Objective 1: Meet producers on their farms for one-on-one conversations that facilitate two-way pathways of knowledge about the mudflats of Willapa Bay and burrowing shrimp.

Educational Objective 2:  Present project research through established producer meetings to get feedback and disseminate scientific progress by facilitating open discussions between researchers and producers.

Educational Objective 3: Maintain a monthly column in the Chinook Observer, a local paper, to engage community members.