HARMFUL ALGAL BLOOMS

What are Harmful Algal Blooms (HABs)?

When algal colonies rapidly reproduce, they deplete the oxygen concentration in the water and create large concentrations of natural biotoxins. Prolonged seasons of sunshine and reduced ocean mixing can create optimum habitats for algal cell growth. The large concentrations of biotoxins can have negative effects on people, fish, shellfish, marine mammals, and birds. Paralytic Shellfish Poisoning (PSP) and HAB-originated human illnesses can be debilitating and potentially fatal.

Further exploration:

HAB Monitoring presentation by Rick Beauregard, Whatcom Marine Resources Committee representative

Check out our 2023 Intern presentations

Blaine High School Junior Joshua Bacon’s presentation on HABs and Harmful Plankton in the Blaine/Birch Bay Area.

Blaine High School Senior Myca Andruscavage’s presentation on HABs and her work with the Drayton Harbor Oyster Company

Summaries from the HABs team for August and September 2023.

The August 2023 report of the Drayton Harbor Harmful Algal Bloom Hunters project

HABs team data from Summer 2023.

PST refers to paralytic shellfish toxin, which the WA Department of Health found when analyzing the tissue of sampled mussels. Alexandrium is the phytoplankton that produces this type of toxin. A correlation was found between the amount of PST, Alexandrium, and the seawater temperature; PST and Alexandrium tend to peak when seawater temperatures are moderate and decrease when temperatures are either above or below Alexandrium resilience levels.

Drayton Harbor Plankton Gallery:

While not all of the following images are harmful algae, the diversity of plankton species, larvae, and diatoms is eye opening as to what exists in our local waters, and why monitoring is important.

Pseudo-nitzschia diatoms shaking off a clump of microbial detritus

Noctiluca, Drayton Harbor, 2020

Dinophysis acuminata marine dinoflagellate which can cause diarrhetic shellfish poisoning