Northwest Fisheries Science Center

Display All Information

Document Type: Journal Article
Center: NWFSC
Document ID: 9084
Title: A perfect storm:  massive marine bird mortality caused by a dinoflagellate bloom in the Northeast Pacific
Author: Timothy Jones, J. K. Parrish, A. E. Punt, Vera L. Trainer, R. Kudela, Jennifer Lang, Mary Sue Brancato, Anthony Odell, B. M. Hickey, Volunteer Participant
Publication Year: 2017
Journal: Marine Ecology Progress Series
Volume: 579
Pages: 111-127

Harmful algal blooms (HABs) are dense concentrations of phytoplankton that collectively result in deleterious effects on marine life, often via the production of toxigenic or otherwise harmful compounds. We document one of the largest marine bird mortality events ever definitively ascribed to a HAB, the cause of which was death resulting from plumage fouling by surfactant-like proteins produced by Akashiwo sanguinea. Two distinct mortality events were observed along the coast of Washington State in September and October 2009, collectively representing an estimated deposition of 10,500 carcasses, of which the majority were Surf scoters, White-winged scoters and Common murres. Each mortality event was coincident in space and time with observed bloom landfall, with each event preceded by a similar chain of environmental conditions. Prior to each event, the presence of A. sanguinea and upwelling favourable conditions likely led to bloom proliferation. In both cases, this period was followed by conditions that transported the senescent bloom into the nearshore environment, whereupon subsequent wave action lysed A. sanguinea cells, creating foam that contained surfactant-like compounds. This sequence of conditions together with the presence of aggregations of marine birds with reduced flight capacity due to wing moult, are likely the necessary requirements for a marine bird mortality event of this scale due to foam-induced plumage fouling. This mechanism of HAB-induced mortality may become more prevalent in the California Current System given the apparent increasing occurrence of HABs, and the broad environmental tolerances exhibited by A. sanguinea.

Theme: Habitats to Support Sustainable Fisheries and Recovered Populations
Foci: Characterize relationships between habitat and ecosystem processes, climate variation, and the viability of organisms.