Network promotes awareness of harmful algal blooms

Fisheries scientists recently launched the Alaska Harmful Algal Bloom Network to educate the public on the risks associated with harmful algal blooms.

The agenda for network partners includes continued research and monitoring to track how climate change is impacting the occurrence and intensity of these toxic algal blooms. The network also plans support of research into how harmful algal blooms impact marine animal mortality, including walrus, whales and seals.

While all commercially harvested shellfish sold in stores and restaurants must pass Food and Drug Administration approved and state toxin tests to assure they are safe for human consumption, there is no required testing of shellfish caught for personal and subsistence use.

Alaska Sea Grant notes that since 1993 four people have died in Alaska and there have been 123 reported cases of paralytic shellfish poisoning, all linked to shellfish. Recent die-offs of marine mammals may also be related to harmful algal blooms.

Scientists with NOAA’s National Ocean Service note that less than one percent of algal blooms actually produce toxins. That’s enough to have an impact of at least $82 million a year on the U.S. economy, they note, in a video on the National Ocean Service website.

The harmful algal blooms occur when tiny microscopic plants called phytoplankton grow out of control, producing toxic effects on people, fish, shellfish, marine mammals and birds.

Even blooms that produce no toxins can be harmful by causing anoxic conditions where oxygen is depleted from the water, light us blocked to organisms lower in the water column, or fish gills become clogged.

Some algal blooms can actually be beneficial, and also a good indicator of environmental change in the water and on land, National Ocean Service notes.

Officials with the Alaska Department of Health and Social Services’ Division of Public Health are concerned that warming waters will extend the phytoplankton growing season and increase the likelihood of the presence of toxic blooms.

Collaborators in developing the network include state agencies, Alaska Native organizations, the University of Alaska, Alaska Ocean Observing System, Kachemak Bay National Estuarine Research Reserve, the National Centers for Coastal Ocean Science and Alaska Sea Grant.

The network is coordinated by Alaska Sea Grant and the Alaska Ocean Observing System. More information on how toxins cause paralytic shellfish poisoning is online in a video on the AOOS website,