Razor clamming is closed from the Columbia River to Tillamook Head after the state detected unsafe levels of domoic acid in the clams.
The state will not reopen clamming until two consecutive tests, at least one week apart, show levels of the marine biotoxin below the state’s closure limit of 20 parts per million.
Testing last week revealed levels of domoic acid in razor clams at Clatsop Beach and Sunset Beach were at 22 parts per million. In early February, domoic acid levels in the same area registered at 14 ppm. Farther south, razor clams tested at Port Orford had 62 ppm as of Feb. 22.
The closure of recreational and commercial clamming was announced Friday evening by the state Department of Agriculture and the state Department of Fish and Wildlife.
Elsewhere in Oregon, razor clamming is closed at Cape Blanco to the California border for elevated levels of domoic acid. Razor clamming remains open from Tillamook Head in Seaside to Cape Blanco.
The Clatsop Beach and the Sunset Beach areas are home to popular and highly productive razor clam beds. The 18-mile stretch of beach accounts for 95 percent of Oregon’s razor clam harvest, according to the state.
On March 1, when the beaches first reopened to harvest after an extended closure to give small clams more time to grow, approximately 600 harvesters were on Clatsop Beach. The turnout was not too bad considering the opening was midday on a Friday with high surf and a weak low tide, said Matt Hunter, state shellfish biologist.
People were eager to dig for clams even though most of the clams they were finding were still smaller than usual, just over 3.5 inches. Clatsop Beach is usually closed seasonally from mid-July through September. Last year, the beach closed to digging in July and stayed closed through the winter.
Beaches outside the closure area, such as Indian Beach, near Cannon Beach, and Short Sand Beach, north of Manzanita, also have clams but are not as productive. Clamming areas there can be harder to access depending on how low the low tide gets.
Domoic acid is a naturally occurring marine toxin that can cause amnesic shellfish poisoning. It is produced by diatoms that bloom occasionally off the West Coast.
In recent years, these blooms have become an almost constant consideration in fishery management decisions, at times delaying the opening of valuable commercial Dungeness crab fisheries and causing fishery closures in both Oregon and Washington state.