Posts Tagged domoic acid levels

Nov 5 2015

Commission Delays Opener of Recreational Dungeness Crab Season and Closes Northern Part of Recreational Rock Crab Fishery

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The California Fish and Game Commission today voted 3-0 in favor of an emergency rulemaking to prohibit recreational take and possession of Dungeness crab and all rock crab from ocean waters, including bays and estuaries, north of the Ventura/Santa Barbara county line. Closure of the fisheries will remain in effect until the Director of the Office of Environmental Health Hazard Assessment (OEHHA), in consultation with the Director of the California Department of Public Health (CDPH), determines that domoic acid levels no longer pose a significant risk to public health and no longer recommends the fisheries be closed.

The Commission also directed the California Department of Fish and Wildlife (CDFW) to maintain a list of closed ocean waters of the state and update that list on Wednesday of each week by 1 p.m. It is the responsibility of any person, prior to taking Dungeness crab, to call CDFW’s hotline at (831) 649-2883 or visit the CDFW website to obtain the current status of any ocean water.

The recreational Dungeness crab season was scheduled to start Saturday, Nov. 7.

CDPH, in conjunction with CDFW, has been actively testing crabs since early September and results from the most recent tests showed that the health risk to humans is significant. CDHP issued a health advisory on Tuesday. OEHHA followed that with a recommendation for delays and closures of the crab fisheries.CDFW will continue to coordinate with CDPH and OEHHA to test domoic acid levels in crab along the coast to determine when the fisheries can safely be opened.

Domoic acid is a potent neurotoxin that can accumulate in shellfish, other invertebrates and sometimes fish. It causes illness and sometimes death in a variety of birds and marine mammals that consume affected organisms. At low levels, domoic acid exposure can cause nausea, diarrhea and dizziness in humans. At higher levels, it can cause persistent short-term memory loss, epilepsy, and can in some cases be fatal.

Domoic acid is produced from some species of the marine diatom Pseudo-nitzschia. Currently, a massive toxic bloom of Pseudo-nitzschia has developed, significantly impacting marine life along California’s coast. Biologists tested crab from eight ports from Morro Bay to Crescent City, and determined that domoic acid levels are exceeding the State’s action level.

Algal blooms are common, but this one is particularly large and persistent. Warmer ocean water temperatures, due to the El Niño event California is experiencing, are likely behind the large size and persistence of this bloom.

Commercial fisheries are also affected by domoic acid levels. CDFW has the authority to delay or otherwise restrict commercial fisheries, and is developing an emergency rulemaking under that authority. The commercial Dungeness crab season is currently scheduled to open Nov. 15.

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