Harmful Algal Blooms
Harmful algal blooms (HAB) produce toxins that contaminate marine food webs, leading to contaminated seafood and marine wildlife illnesses. While HABs occur naturally, there is concern about increased frequency resulting from human activities
What's the status of HABs?
How are HABs changing?
Key Findings
> HAB status along the U.S. West Coast is Meeting Expectation, with the number of shellfish advisories and closures this year consistent with the long-term average.
> There is no long-term trend in the degree of impact on shellfish harvesting on the U.S. West Coast every year.
> While shellfish closures were typical of the long-term average in 2023, another measure of HAB exposure, marine mammal strandings, was well above the historical average in Southern California.