The U.S. Government is closed. This site will not be updated; however NOAA websites and social media channels necessary to protect lives and property will be maintained. To learn more, visit www.commerce.gov. For the latest forecast and critical weather information, visit www.weather.gov. 

The U.S. government is closed. This site will not be updated; however, NOAA websites and social media channels necessary to protect lives and property will be maintained. To learn more, visit commerce.gov. 

For the latest forecasts and critical weather information, visit weather.gov.

Alexandrium catenella blooms in the Gulf of Maine produce potent neurotoxins that accumulate in shellfish

image showing surface wind fields and modeled near-surface bloom conditions on May 31, 2025

Annual Alexandrium catenella blooms in the Gulf of Maine produce potent neurotoxins that accumulate in shellfish and can cause Paralytic Shellfish Poisoning (PSP) in human consumers. Our experimental Gulf of Maine harmful algal bloom model allows us to better predict and monitor these blooms – and shellfish toxicity – with the goal to minimize impacts to public health and coastal economies. Learn more: https://coastalscience.noaa.gov/science-areas/habs/hab-forecasts/gulf-of-maine/