Northwest Fisheries Science Center

Toxic blooms of Alexandrium in Puget Sound

Marine dinoflagellates in the genus Alexandrium can produce a suite of potent neurotoxins that accumulate in shellfish and cause severe illness or even death if contaminated shellfish are consumed by humans (i.e., Paralytic Shellfish Poisoning). In Puget Sound, blooms of Alexandrium typically occur in the summer and fall; however, the exact timing and location of blooms is highly variable. Research to better understand the complex life cycle of Alexandrium species, which includes benthic cyst and planktonic stages, and environmental controls on growth and toxicity, will inform ecological forecasts of blooms. The early warning provided by these forecasts will allow for better monitoring and management of toxic Alexandrium blooms.


Bill, B.D., Moore, S.K., Hay, L.R., Anderson, D.M., Trainer, V.L. 2016. Effects of temperature and salinity on the growth of Alexandrium (Dinophyceae) isolates from the Salish Sea. J. Phycology 52: 230-238.

Moore, S. K., N. J. Mantua, et al. (2010). "The relative influences of El NiƱo Southern Oscillation and Pacific Decadal Oscillation on paralytic shellfish toxin accumulation in Pacific Northwest shellfish." Limnology and Oceanography 6(55): 2262-2274.

Moore, S. K., N. J. Mantua, et al. (2011). "Past trends and future scenarios for environmental conditions favoring the accumulation of paralytic shellfish toxins in Puget Sound shellfish." Harmful Algae 10(5): 521-529.

Moore, S. K., N. J. Mantua, et al. (2009). "Recent trends in paralytic shellfish toxins in Puget Sound, relationships to climate, and capacity for prediction of toxic events." Harmful Algae 8(3): 463-477.

Trainer, V. L., B.-T. L. Eberhart, et al. (2003). "Paralytic shellfish toxins in Puget Sound, Washington State." Journal of Shellfish Research 22(1): 213-223.