Burrowing Shrimp
Burrowing shrimp threaten coastal aquaculture and marine ecosystems
Microbial Solution for Burrowing, Ghost, and Mud Shrimp Control
Neotrypaea californiensis (AKA burrowing shrimp, ghost shrimp, and mud shrimp) have been pinching oyster farmers in Washington State for decades, and Invasive Species Corporation is working to find a bio-based solution. When these shrimp overpopulate tideflats and oysterbeds, their fastidious burrowing behavior turns the sediment to quicksand that sucks oysters and other sediment dwellers beneath the silty surface.
Washington state has banned the chemical pesticides farmers used in the past to control burrowing shrimp due to their harmful off-target effects in the state’s precious coastal and estuarine ecosystems, fueling demand for a new, highly specific, and environmentally responsible control strategy. The Washington State Department of Agriculture knew who to turn to for that assignment.
Burrowing Shrimp are Threatening Washington's Coastal Shellfish Farmers
Extent and Impact of Infestation
Burrowing shrimp have become a major issue along the U.S. West Coast, especially in estuaries where oyster farming occurs. These shrimp reach high densities in tidal flats—sometimes thousands per square meter. Their digging loosens and aerates sediment, which can benefit some habitats but creates serious challenges for oyster farms.
As they burrow, they turn firm sediment into soft mud, preventing oysters and other shellfish from staying anchored. This leads to major shellfish losses, threatening oyster farmers and harming coastal aquaculture.
The economic impact is significant. The Pacific Northwest’s oyster industry, worth millions annually, is seeing reduced yields. Without action, shrimp can make oyster beds unusable, forcing farmers to relocate or quit. Ecologically, the destabilized sediment disrupts seagrass beds vital to young fish, creating broader imbalances.
Past control methods like pesticides raised environmental concerns, prompting interest in more sustainable options. Microbial-based biocontrols are now being studied as a way to curb shrimp damage while protecting coastal ecosystems.
Status of a Solution
ISC has conducted two sampling trips to Willapa Bay in Washington with support from the state’s Department of Agriculture (WSDA), the local Shoalwater Bay Tribe, the Willapa-Gray’s Harbor Oyster Grower’s Association (including Director David Beugli and members Kathleen Nisbet-Moncy of Goose Point Oysters and Brian and Jeb Sheldon of Northern Oyster Co.), and Dr. Kim Patten of Washington State University. ISC’s team collected shrimp and environmental samples from affected areas while intermittently losing their boots and their dignity while trudging through the liquified sediment.
From these samples, ISC scientists isolated over 1,200 microorganisms. They developed three bioassays in as many months (two based around model systems and one using live, adult burrowing shrimp) and selected microbes for those bioassays with cutting-edge sequencing and data mining techniques that helped determine which would be most likely to produce a molecule with activity against the burrowing shrimp.
In one year of sending thoughtfully-selected microbial extracts through our in-house bioassay pipeline, ISC discovered four extracts that show strong activity against burrowing shrimp.
On top of continued screening for more microorganisms with activity against burrowing shrimp, these extracts are being advanced in ISC’s development pipeline. That starts with steps like ecotoxicology testing, analytical chemistry, and fermentation development, and ends with effective burrowing shrimp control and more oyster farming in Washington state!
ISC is partnering with Integrated Pest Management Working Group (IPMWG) to solve the shrimp invasion responsibly.
