Harmful Algal Blooms

The Cochlan Lab has been working on harmful algal blooms (HABs) for many years. Domoic acid (DA), a neurotoxin produced by many species of the diatom, Pseudo-nitzschia, poses a significant health threat to marine mammals, seabirds, and humans. Their current studies are testing the hypothesis that increased levels of DA are driven by the environmental stressors associated with the future ocean: warmer temperatures, increased light availability and more acidic (lower pH) ocean conditions. Their research seeks to understand multiple environmental stressors and their interactions on the production of domoic acid. The insights from controlled laboratory studies and regular monitoring of multiple sites around the perimeter of San Francisco Bay will include an understanding of which environmental parameters are valuable predictors of potential DA exposure in coastal and estuarine ecosystems and will establish the critical windows of opportunity for enhanced growth and toxin production under climate change scenarios, thus characterizing the degree of risk of biotoxicity to marine ecosystems, crucial fisheries and human health.

Dr. Ed Carpenter is currently involved in a study of HABs in Alaska. The 2018 Arctic Report Card noted that the Arctic region is warming at twice the rate as the rest of the planet and these warming conditions lead to an expansion of HABs such as cyanobacteria species. These produce toxins that bioaccumulate in fish and mussels and can cause serious long-term damage to the human liver. Kotzebue Sound, north of the Arctic Circle on the West Coast of Alaska, is commercially important to the Native Alaskan community and collection of resources from the Sound provides up to 70% by weight of their annual food harvest. Carpenter and colleagues have initiated a long-term observational program of the microbial population and physical and chemical characteristics of the waters around the Native village of Kotzebue, Alaska to understand the forcing factors that lead to the cyanobacterial blooms.

Photo: Kai Schumann