Pacific Northwest
A seagull perches atop an oyster harvesting boat at the Herrold Fish and Oyster Co. Ilwaco headquarters Tuesday evening. Mallory Gruben, The Daily News

Oyster farmers sacrifice pesticide, still losing ground to shrimp

WILLAPA BAY — As an oyster farmer of more than 40 years, Dick Wilson knows well the havoc that burrowing shrimp can cause in oyster beds.

Wilson, a former geology professor and the owner of Bay Center Mariculture Co., has thoroughly documented the shrimp’s effect on the mudflats in photo and research albums online.

Between conference calls and lunch last week, Wilson scrolled through his photos of Willapa Bay’s soupy, pockmarked mudflats. Nothing else can thrive on these shrimp-infested grounds, he explains, because the shrimp kill off the microscopic organisms that are integral to the food chain. Plus, their burrowing makes the ground so soft that oysters sink into the mud and suffocate.

The bay has lost almost 10,000 acres of viable oyster farming ground to the shrimp so far, he said.

“The bay is already crippled, and it’s going to get worse if we don’t treat the shrimp,” Wilson said.

But in a surprise concession last month, Wilson and the Willapa Grays Harbor Oyster Growers Association agreed to end a court battle to use Imidacloprid, a controversial pesticide known among oyster growers as a proven tool for controlling the shrimp.

The growers say it just didn’t pay to fight in court anymore, and it’s better to work collaboratively with the state agencies that blocked the pesticide to find an agreed-upon solution. The association and state Department of Ecology will start a work group to find an integrated pest management solution that doesn’t use Imidacloprid. The plan could include another chemical control, but the goal is to “minimize chemical use,” according to court documents.

Read full article.