This post may be updated as new information becomes available.

The Washington Department of Ecology has withdrawn its approval of a controversial plan to apply the pesticide imidacloprid to control burrowing shrimp in areas of oyster cultivation in Willapa Bay and Grays Harbor, on the Washington Coast.

Ecology’s prior approval of the pesticide permit caused great concern amongst some environmental advocates, restaurant owners, and shellfish lovers. This pesticide was to be used to control the native burrowing shrimp, which live in the mud in the tide flats of Willapa Bay and Grays Harbor. When in high numbers, the shrimp destabilize the cultivation area, making it difficult to grow oysters. Although native to our area and commonly found in Puget Sound, burrowing shrimp seldom pose a major problem for growers in Puget Sound waters. As such, use of the pesticide was never approved for Puget Sound.

In response to public outcry, Taylor Shellfish issued a press release on May 1, 2015 stating that they no longer plan to use the pesticide. On May 3, The Associated Press reported that Department of Ecology pulled the permit, so no growers will be spraying the pesticide.

Puget Soundkeeper has technical expertise in many areas concerning water quality, but we are a small non-profit organization and we have not thoroughly investigated the science behind this particular pesticide. At the time of the Department of Ecology decision to remove approval, Soundkeeper was looking into the matter but had not yet taken a position. It should be noted that Soundkeeper receives support from Taylor Shellfish, which has also been a great partner in many Puget Sound clean water efforts.

Shellfish growers rely on clean water for the production of safe shellfish and are subject to approval by the Department of Health before their products make it to market. They are often on the front lines for water quality impacts from agricultural use, urban runoff, wastewater and oil spills. Protecting safe seafood is a motivating goal for many Soundkeeper supporters.

Soundkeeper applauds the decision by Taylor Shellfish (and Department of Ecology) to be responsive to community concern over pesticide use. Responding to community voices is an important part of the democratic process and the protection of our aquatic environment. We all have a role to play.

Regarding the pesticide imidacloprid, we are still not experts. Here is what we know:

  • Imidacloprid is reported to be the most widely-used pesticide in North America, with residential and commercial applications. It is commonly selected because of its purported low toxicity to mammals and birds.
  • Imidacloprid is a neurotoxin that mostly affects invertebrates. There are many important invertebrates in our waterways that help form the base of the food chain.
  • Prior to imidacloprid, the pesticide Carbaryl was often used to control shrimp in oyster-growing araeas. Carbaryl was used for years but was phased out in favor of imidacloprid, a less-toxic option.
  • Use of the pesticide in land-based applications is linked to colony collapse disorder in honey bees. Much less is known about its effects in the aquatic environment.

Please feel free to contact Puget Soundkeeper if you have any questions or concerns about this matter.