The Value of Herring Spawn vs. Alternative Prey to Surf Scoters (SUSC) and White-winged Scoters (WWSC) in the Puget Sound-Georgia Basin (PSGB)

Project Number: 62

Year Funded: 2005

Lead Institution(s): University of Wyoming

Project Lead: Eric Anderson

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Collaborator(s): James Lovvorn (UW), David Nysewander (WDFW), Joseph Evenson (WDFW), Dan Esler (SFU), Sean Boyd (CWS), John Bower (WWU), John Takekawa (USGS), Susan Wainwright-De la Cruz (USGS), Matthew Wilson (USGS), John Bower (WWU), Erika Lok (SFU)

Location: Salish Sea

Focal Species: Surf Scoter (Melanitta perspicillata), White-winged Scoter (Melanitta delgandi)

Project Description: Pacific scoters and other sea ducks congregate in dramatic numbers each spring to consume herring spawn. The critical question is, does spawn availability affect population trends because alternative prey are inadequate? In the PSGB, spawning stocks have declined substantially over time, including spatial and temporal reductions in spawning activity in the Strait of Georgia and a 94% decline in spawn biomass in the dominant spawning stock in Puget Sound. For Surf Scoters (Melanitta perspicillata) and White-winged Scoters (Melanitta fusca), we are assessing (1) whether nutrient acquisition is related to variation in spawning activity, and (2) whether alternative prey at key winter foraging sites are inadequate to meet the needs of scoters when spawn is less available.