Since May 2023, several Harmful Algal Blooms (HABs) have been detected in Alaska. HABs can be detected through the identification of harmful algae (primarily phytoplankton in the genus Alexandrium or Pseudo-nitzschia) or by the testing of food items such as shellfish for algal toxins, such as paralytic shellfish toxins (PSTs).
Elevated levels of PSTs were found primarily in two regions of Alaska. In June and early July, the Knik Tribe found high levels of PSTs in shellfish collected in Sand Point, King Cove, and Chignik Lagoon. Primarily in Juneau, the South East Alaska Tribal Ocean Research (SEATOR) consortium found high levels of PSTs in shellfish throughout July.
Alexandrium blooms were detected in the Chukchi and Bering Seas in late July by researchers at Woods Hole Oceanographic Institution. There was also a visible bloom of Mesodinium phytoplankton in Tutka Bay in June (see picture). Despite the discoloration of the water, the Tutka Bay algal bloom was not considered harmful and dissipated rapidly.
Please visit the Alaska Harmful Algal Bloom Network for more information.