Gulf of Alaska | Lower Trophic Levels MASTER’S POSTER PRESENTATION Two-decades of observations on pelagic tunicates and pelagic snails in the northern Gulf of Alaska (NGA)
Presenter: Emily Stidham , eastidham@alaska.edu, University of Alaska Fairbanks Russell Hopcroft , rrhopcroft@alaska.edu, University of Alaska Fairbanks, CFOS
Mucus-net feeders are under-appreciated in the literature with limited information regarding their abundance and biomass. In the Northern Gulf of Alaska (NGA) and Prince William Sound (PWS) this group is represented primarily by pelagic tunicates (larvaceans, doliolids, salps) and pelagic snails (pteropods). These organisms are important prey for many seabirds and fishes, making up to 30% of the diet of pink salmon alone. Their presence can also have a large impact on how organic matter moves through food webs and sinks in the water column. Analysis of the populations of these mucus-net feeders in the NGA and PWS from 2012-2021 is combined with data from preceding years to create a 20-year time-series. We show how abundance and species composition of these zooplankters change across seasons and between years, and how these are influenced by both abiotic and biotic factors (e.g. temperature and food). We explore how these are related to climate indices and marine heat waves. Our long-term species-level records of mucus- net feeders in the NGA and PWS provide a better understanding of how the zooplankton community may continue to shift in the face of a changing ocean.
Alaska Marine Science Symposium 2023 140
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