South coast crabbers await test results
BROOKINGS — Crab-lovers could learn as early as Friday afternoon whether they’ll see a return of the recreational Dungeness crab season shelved two weeks ago because of elevated biotoxins in a crab sample.
Six Dungeness samples collected Wednesday out of Brookings were to be tested Thursday in Portland to determine whether domoic acid levels in the crab are back down to acceptable levels, according to the Oregon Department of Agriculture.
If so, it would mark the second straight clean domoic acid test, which is needed in order to reopen the recreational crabbing season south of Port Orford and remove the restriction on live-crab sales among the South Coast commercial fleet. Crabs currently must to be eviscerated before they’re sold to consumers.
Each sampled Dungeness must have domoic acid levels of under 30 parts per million in the crab viscera — the guts, or so-called “butter,” where domoic acid accumulates — to be considered safe for consumption.
The closure started May 10 when one Dungeness sampled off the South Coast showed domoic acid levels of 40 parts per million, even though others in the same sample set showed levels as low as 1.6 ppm, according to ODA.
A closure triggered Feb. 14 on the South Coast also came after just one crab tested over the threshold.
“That’s all you need,” said Judy Dowell, who monitors shellfish at the ODA’s food-safety program in Salem. “Lots of times we have just one crab that’s over the limit. It’s not unusual at all.”
The Oregon Department of Fish and Wildlife has the authority to open and close sport and commercial fisheries but it does so under health and public-safety recommendations from ODA, which is in charge of food safety in the state.
The crab surveys typically are done on seven-day rotations and on Thursdays, but sometimes — like this week — samples can be taken a day early in deference to the “volatility” of the ocean and weather conditions, Dowell said.
“We’re not willing to put fishermen and captains at risk to save a day,” Dowell said.
Had the samples been collected Thursday, the results would not have been available by Friday afternoon, because the testing protocol is overnight.
Crab and shellfish products sold in retail markets and restaurants are safe for consumers, according to ODA.
Caused by algae outbreaks in the ocean, domoic acid levels had rendered recreational crabbing off-limits throughout most of last fall and winter along the south coast because of persistently high levels of the acid in Dungeness crab.
The most recent opener lasted just two weeks, same as the Jan. 31 reopener before tests again showed increased biotoxin levels.
The toxins concentrate in filter-feeders such as razor clams, which are a staple of the Dungeness diet. They collect in the crabs’ tissues and fluids and slowly dissipate.
That could be a slipping point for this week’s sampling, because May 10 biotoxin tests done on razor clams showed a razor clam sampled from Port Orford had 55 parts per million of domoic acid, and a clam sampled from Gold Beach had 140 ppm, according to ODA records.
The threshold for razor clam safety is 20 ppm, lower than that for Dungeness. Also, as filter feeders, razor clams can cleanse themselves of domoic acid faster than crabs.
The razor clam season remains closed south of Port Orford.
Domoic acid can cause minor to severe illness and even death in humans.
Severe poisoning can result in dizziness, headaches, vomiting and diarrhea. More extreme cases can result in memory loss and death.
Reach Mail Tribune reporter Mark Freeman at 541-776-4470 or firstname.lastname@example.org. Follow him on Twitter at www.twitter.com/MTwriterFreeman.