Domoic Acid Closures

The California Department of Public Health monitors domoic acid levels in the water, bottom sediment, shellfish and fish so that the Department of Fish and Wildlife can issue health advisories or fishery closures when domoic acid levels in seafood approach concerning levels for human health. Santa Barbara crabbers and lobstermen have been deeply engaged in discussions with regulators and policymakers about how to better avoid unnecessary fishery losses in the future while protecting public health during domoic acid events. They have also been guiding new science and improved monitoring, pushing for more rational sampling strategies and faster processing of seafood samples for domoic acid testing. They have been working with their supply chain and the Dept. of Public Health to come up with new market solutions to enable the sale of crab meat after the removal of viscera (guts) when the meat is safe to eat. Collectively, CFSB reps have logged many dozens of hours attending meetings to make progress on these issues. Thankfully, the oceanographic conditions of fall 2016 do not predispose us to likely domoic acid fishery closures in the near future as the community works to recover from last year’s losses.

Domoic acid is a neurotoxin produced under certain conditions by the diatom Pseudo-nitzschia that can result in the illness called amnesic shellfish poisoning (ASP). There has only been one confirmed event of ASP in humans, following mussel consumption in 1987 in Prince Edward Island, Canada; however, ASP is not uncommonly blamed for marine mammal illness.

At moderate levels of domoic acid, crab consumers are advised to remove the viscera (internal organs or ‘butter’ where domoic acid concentrates) before eating the crabmeat, and discard the water used to boil crab to minimize potential exposure. Elevated domoic acid levels have occurred in the Santa Barbara Channel for decades without any evidence of harm to seafood consumers. Upset stomach and dizziness are main symptoms; amnesia can occur in severe cases.

In 2015, a persistent bloom of Pseudo-nitzchia stretched from Santa Barbara to Washington State, fueled by the "warm blob" and El Nino conditions. The bloom produced the most far reaching and intense domoic acid event in history. Dungeness and rock crab fisheries were hit especially hard and remained closed for many months in some places, leading to devastating economic losses for fishing families. California congressional representatives are now seeking a Federal Disaster Relief package for these families, but are likely to be unsuccessful in this political climate.

Click the following titles to view updates and additional information regarding domoic acid.

CFSB Letters and Reports on Domoic Acid

  1. Letter from CPDH responding to the inquiry from CFSB (November 18, 2015)
  2. Letter to Sen. McGuire: CFSB Solutions for Domoic Acid (June 6, 2016)
  3. Rock Crab CFSB Domoic Acid Regulatory Update (June 17, 2016)
  4. Lobster Fleet Proposed Management Responses (August 24, 2016)
  5. Summary of Recent Events (September 10, 2016)
  6. Minutes of Lobster Fleet meeting (September 16, 2016)
  7. Report of meeting about Lobster DA testing with DFW (September 21, 2016)

Agency releases about Domoic Acid

  1. Coastal Dungeness Crab Tri-State Committee 2016 Meeting Summary (June 8 & 9, 2016)
  2. Harmful Algal Blooms and Domoic Acid: Latest Forecast and a Look Ahead to the Upcoming Season (August 1, 2016)
  3. FAQ: Harmful Algal Blooms and California Fisheries (August 1, 2016)
  4. Domoic Acid Background and Potential Options for Future Events (August 5, 2016)

Scientific Research on Domoic Acid

  1. Graduate Dissertation: Examining the Toxicity, Exposure, and Regulatory Approach to Potential Human Health Risks of the Algal Toxin Domoic Acid