A pesticide that was approved two years ago for oyster growers to kill burrowing shrimp has now been prohibited by the Washington Department of Ecology. After a lengthy evaluation of the environmental impacts of the pesticide, imidacloprid, the state announced Monday that it is too harmful to the ecosystem and decided to deny a request for its approval.
“The science around imidacloprid is rapidly evolving and we can’t ignore it. New findings make it clear that this pesticide is simply too risky and harmful to be used in Washington’s waters and estuaries,” state Ecology Director Maia Bellon said in a press release.
The Willapa Grays Harbor Oyster Growers Association originally asked for permission to use the pesticide in 2015, and the state approved of its use. But public outcry, notably from Seattle seafood restaurant owners and articles in major media outlets quickly followed the approval of the pesticide, leading the oyster growers to withdraw their permit application while the state did additional study.
Since then, the state further investigated the environmental effects of imidacloprid, which has never been used previously in salt water other than experimental trial applications by WGHOGA while the 2015 permit was being developed, according to state ecology communications director Jessica Payne.
The state reported in February that use of the pesticide in oyster farms causes significant negative impacts to water quality, crustaceans in the area, and affects fish and birds by killing sources of food.
Many of the oyster growers were hoping to get the chemical approved, so they could eliminate the growing populations of shrimp, which burrow in the mud, softening oyster beds to an even muckier condition than usual and leading to the suffocation of oysters.
Since the backlash from the pesticide’s initial approval, the state and oyster growers have worked to find an alternative way to combat the burrowing shrimp, but no effective solutions have been found.
Ken Wiegardt, who is president of the oyster growers association and Jolly Roger Oysters in Ocean Park, said he believes the decision to prohibit the pesticide’s use runs counter to the results of an environmental impact statement released in September, and that it is more so a political decision.
“We believe this decision is based on politics and not on sound science,” said Wiegardt, president of the WGHOGA. “The department has reversed itself completely from the scientific findings of its own Draft Supplemental Environmental Impact Statement, released in September, without any actual new research. If this political, non-scientific decision stands, burrowing shrimp will continue to destroy our oyster beds and severely damage our industry, our estuary and our entire rural economy.”
Correction: April 13, 2018
This article had reported that imidacloprid had never been used to kill burrowing shrimp in the U.S. The state Department of Ecology originally approved a permit for imidacloprid, a pesticide, to be used by oyster growers in the Willapa Grays Harbor Oyster Growers Association in 2015, and some growers did perform experimental trial applications of the pesticide as that permit was being developed. Following public reaction, the 2015 permit was cancelled at the request of the growers.