Abstract Title
It All Adds Up: Complex Threshhold Effects of HPAI, Biotoxins, and Other Stressors in a Recent Seabird Mortality Event
Abstract
Recent spread of HPAI among marine birds and mammals in the Bering Sea region appears to be rapidly increasing in species affected and in geographic scope. In our rapidly changing climate, harmful algal blooms (HABs) have emerged as a growing threat to the health of seabirds. The specific biotoxins produced by some algal species, such as saxitoxin (STX) and domoic acid (DA), are ultimately fatal at high concentrations. Very little is understood, however, about the interactions of sublethal concentrations of biotoxins, influenza, and other avian pathogens in affected seabird species. Between late July and early August 2023, we conducted a comprehensive survey of seabirds in the Near Islands group (Agattu, Attu, Alaid-Nizki, Shemya Islands), concurrently during a significant algal bloom. Five breeding species (Common Murres, Glaucous-winged Gulls, Black-legged Kittiwakes, Pigeon Guillemots, Tufted Puffins) were observed dead or in distress, exhibiting symptoms such as respiratory difficulties and uncoordinated muscular movements. By contrast, other breeding species (Pelagic and Red-faced Cormorants, Aleutian Terns, Marbled and Kittlitz's Murrelets, Whiskered Auklets, Horned Puffins, and Northern Fulmars) appeared unaffected, as did many individuals of the affected species. The observation that not all species nor individuals were affected raises questions about whether this event represented a minor mortality occurrence or the beginning of a potentially escalating event, coincident with presence of HPAI. Initial results suggest that there are complex interactions among H5N1, pathogens and seabirds, particularly in the modification of threshhold effects of tolerance levels in species and individuals
Co-Author(s)
Douglas Causey, Dept Biological Sciences, U Alaska Anchorage; Arctic Initiative, Belfer Center, Harvard Kennedy School
Beth Granstrom, Dept Biological Sciences, U Alaska Anchorage
Elizabeth Byrd, Dept Biological Sciences, U Alaska Anchorage
Eric Bortz, Dept Biological Sciences, U Alaska Anchorage
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds