NAHCOTTA — An official decision is still about a month away, but things are not looking good for commercial oyster and clam growers on Willapa Bay who want to use a pesticide to control a spreading population of burrowing shrimp that wreck traditional shellfish beds and degrade habitat important for other native species.
On Jan. 5 the Washington State Department of Ecology issued a final Environmental Impact Statement on the issue of spraying shrimp with imidacloprid, a man-made chemical that has been the subject of considerable controversy due to its impacts on honeybees and other non-targeted species. Of eight key findings in the study, four appear to be negative, two are somewhat neutral and two cite a lack of information.
“It does look sad for the oyster industry and the bay,” Richard Wilson, Ph.D., of Bay Center Mariculture said last week. Wilson, a scientist and oyster grower, said shrimp “damage effects many more estuarial species besides the oysters and clams. The ghost shrimp have a negative impact on the basic food web so vital to the health of these two important near-shore marine areas” of Willapa Bay and Grays Harbor.
The apparent direction now being taken by DOE “seems more a political review rather than science,” Wilson said.
DOE used to support spraying
Oyster growers had a spray permit in hand in April 2015 but attempted to put it on hold after industry giant Taylor Shellfish Farms bowed to pressure from Seattle-based environmentalists and a Seattle Times columnist. DOE interpreted the delay by the Willapa-Grays Harbor Oyster Growers Association as an outright surrender of the permit. Without Taylor, growers started the permit process over again, hoping to start spraying up to 2,000 of Willapa Bay’s 150,000 acres of privately owned tideland this past summer.
Imidacloprid was set to replace carbaryl, an older insecticide commonly used in flea collars for pets. Carbaryl’s use in the bay resulted in lawsuits and increasing regulations, and the Willapa Bay and Grays Harbor shellfish industry agreed more than a decade ago to phase it out. An adverse DOE decision on imidacloprid will leave growers with no obvious alternative for controlling the shrimp, a naturally occurring species whose filter-feeding process smothers oysters in fine sediment.
New decision leans against pesticide
As indicated by its earlier OK for imidacloprid, DOE staffers initially shared the view of Washington State University’s Dr. Kim Patten and others in Pacific County that the chemical would be less harmful than carbaryl and result in no significant problems. Now, however, a fresh look by the agency cites these key findings:
• Significant impacts to sediment quality and benthic invertebrates.
• Adverse impacts to juvenile worms and crustaceans in the areas treated with imidacloprid and the nearby areas covered by incoming tides.
• Concern about non-lethal impacts to invertebrates in the water column and sediment.
• New information shows a risk of impacts from imidacloprid even at low concentrations.
• Likely indirect impacts to fish and birds if food sources are disrupted.
• Little known direct risk to fish, birds, marine mammals, and human health.
• Increased uncertainty about long-term, non-lethal, and cumulative impacts.
• Continued knowledge gaps about imidacloprid.
DOE estimates it will announce a decision about the spray permit by early February. Its latest study can be read at www.ecology.wa.gov/burrowingshrimp. DOE said it received 8,287 comments on the draft of this report.
Inslee notes problem
Gov. Jay Inslee toured Willapa shellfish beds on July 25, including areas infested with shrimp, and said he was struck by how much shrimp affect the bay’s bottom.
“It’s shrimp and ooze [in infested areas], and that’s it. It’s a very different ecosystem. That was something I was not aware of before I came out,” Inslee told the Observer. “When you see somebody sink up to their knees, it’s pretty impressive.”
However, earlier last year, on June 30 he vetoed legislation that would have required DOE to report where it is in the process of issuing a new permit to spray burrowing shrimp, stating, “Burrowing shrimp is a serious problem for the shellfish industry in Willapa Bay and Grays Harbor.” However, he said, the legislation “inappropriately presumes the outcome of the environmental review and permitting process.”
It is unclear what growers will do if DOE denies the permit. No other chemical answer is in the regulatory pipeline. Several Willapa shellfish operations have cut back on oyster cultivation as shrimp have moved into scarce, nutritionally rich areas where oysters are fattened.