Domoic acid is a neurotoxin produced by some diatoms in the genus Pseudo-nitzschia. Domoic acid can accumulate in shellfish and fish, and cause illness or death in humans, marine mammals, and birds. In 2015, a bloom along the U.S. West Coast devastated the crab fishery and resulted in harvesting closures of fish and shellfish. We aim to quantify the oceanographic and cellular factors that regulate and promote domoic acid biosynthesis in the California Current System. 

Why We Care
Blooms of globally-distributed Pseudo-nitzschia produce domoic acid, a potent neurotoxin. Because domoic acid accumulates in seafood, such as Dungeness crab and razor clams, the toxin poses a significant threat to human health. A single, high dose of domoic acid from contaminated seafood can cause Amnesic Shellfish Poisoning in humans, a life-threatening condition that may lead to chronic short-term memory loss. Low-level, chronic consumption of domoic acid in seafood can cause kidney damage, cognitive deficit, and impairments to fetal development, making domoic acid outbreaks a human health concern with wide reaching effects.

During the spring and summer of 2015, a Pseudo-nitzschia bloom in the California Current System resulted in detection of domoic acid in marine mammals across the largest geographic extent ever recorded globally. Fishery closures prompted a federal fisheries disaster declaration, failure in commercial and tribal crab fisheries, and a congressional briefing. The detrimental impacts of the 2015 event brought about the need to improve region-wide domoic acid toxin risk management to safeguard public health, promote viable and sustainable fisheries, and protect living marine resources.

What We Are Doing
We will provide a comprehensive research program to quantify the oceanographic and cellular factors that regulate and promote domoic acid biosynthesis. Recent discovery of the domoic acid biosynthetic pathway in various Pseudo-nitzschia species, coupled with recent breakthroughs in automated sampling and biogeochemical characterization of toxigenic blooms, enables investigation of a range of hypotheses related to the oceanographic conditions and cellular physiology that govern toxin production. We will undertake four primary research activities to increase the understanding of the factors that control the distribution and activity of the domoic acid biosynthesis pathway and domoic acid concentrations in the southern and central California Current System:

1. Investigation into genetic, enzymatic, and physiological regulation of domoic acid production in laboratory cultures.
2. Comparative examination of the diversity and ecological genomics of Pseudo-nitzschia in-situ using state-of-the-art autonomous sampling and water column profiling technology.
3. Optimization of leveraged projects aimed at ecological forecasting and mechanistic hindcast modeling of domoic acid events in the ocean environment.
4. Synthesis of results into data products and outputs that are useful for coastal management.

This multidisciplinary approach will result in a new, transformative view of genetic, physiological, and oceanographic issues related to forecasting and mitigating the impact of future harmful algal bloom events.

Dr. Andrew Allen (University of California, San Diego) leads this project. Co-investigators are Drs. Bradley Moore (University of California, San Diego), Andrew Lucas (University of California, San Diego), Clarissa Anderson (University of California, San Diego, and Southern California Coastal Ocean Observing System), John Ryan (Monterey Bay Aquarium Research Institute), Jim Birch (Monterey Bay Aquarium Research Institute), Martha Sutula (Southern California Coastal Water Research Project), and Greg Doucette (NOAA NCCOS).

The project is funded through the NCCOS Ecology and Oceanography of Harmful Algal Blooms (ECOHAB).