Arctic | Fishes and Fish Habitats
Local environmental conditions support discrete lagoon fish communities Presenter: Sarah Laske , slaske@usgs.gov, USGS Alaska Science Center Vanessa von Biela , vvonbiela@usgs.gov, USGS Alaska Science Center Ashley Stanek , astanek@usgs.gov, USGS Alaska Science Center Kenneth Dunton , ken.dunton@utexas.edu, University of Texas at Austin
Beaufort Sea lagoons host a mix of marine resident (e.g., saffron cod Eleginus gracilis ) and diadromous fishes (e.g., Arctic cisco Coregonus autumnalis ) through the summer open-water period. However, we lack information on how spatial variation among Arctic nearshore fish communities are influenced by major environmental drivers including wind, salinity, and temperature. Specially, how does local variation in the environment control fish community composition across lagoons of the central and eastern Beaufort Sea coast of Alaska? Over three summers (2017–2019), we sampled lagoon fishes in two central (Simpson Lagoon and Stefansson Sound) and two eastern locations (Jago and Kaktovik lagoons) to assess community composition and relate fish abundance to environmental conditions. Nearshore communities were heterogeneous over larger spatial extents, with stark compositional differences between the central and eastern lagoons. Fish community composition depended on local geography and the wind driven balance between freshwater and marine water masses that dictate salinity; changes in local lagoon conditions were strongly influenced by prevailing wind direction. Easterly winds draw cold, saline waters into the lagoons and support an influx of juvenile Arctic cisco, which dominated catches in eastern lagoons. In central lagoons, adjacent large rivers that form estuarine plumes supported a greater abundance of diadromous species (e.g., least cisco Coregonus sardinella ), while in the eastern lagoons, salty conditions in the absence of large rivers supported marine species (e.g., saffron cod). Understanding current fish community composition and species distribution is highly relevant for maintaining current subsistence and potential future commercial fishing opportunities alongside natural resource extraction. More broadly, these biophysical relationships are useful for anticipating fish community response to changing climatic conditions.
Alaska Marine Science Symposium 2023 221
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