Time series of pseudo-nitzschia and domoic acid production in Narragansett Bay, RI

Some strains of the diatom Pseudo-nitzschia produce the neurotoxin domoic acid (DA) which can bioaccumulate in shellfish. Toxic shellfish consumption has deleterious impacts on higher trophic levels including mortality in marine animals and amnesic shellfish poisoning in humans. In 2016 and 2017, DA toxicity closed shellfish harvest in Narragansett Bay (NB), Rhode Island, USA. While Pseudo-nitzschia have been detected in NB for over 50 years, these were the first DA closures in RI, threatening local economies and potentially human health. It is unknown what instigated these recent toxic events in NB: whether a changing environmental factor altered the physiology of Pseudo-nitzschia strains present or new DA-producing strain(s) were introduced to the NB ecosystem.