Project CONVERGE: Impacts of local oceanographic processes on Adélie penguin foraging ecology

Josh T Kohut1, Kim Sarah Bernard2, William Fraser3, Matthew J Oliver4, Hank Statscewich5, Donna Patterson-Fraser3, Peter Winsor5, Megan A Cimino4 and Travis N Miles1, (1)Rutgers University, Marine and Coastal Sciences, New Brunswick, NJ, United States, (2)Oregon State University, Corvallis, OR, United States, (3)Polar Oceans Research Group, United States, (4)University Of Delaware, Lewes, DE, United States, (5)University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fairbanks, AK, United States
Abstract:
During the austral summer of 2014-2015, project CONVERGE deployed a multi-platform network to sample the Adélie penguin foraging hotspot associated with Palmer Deep Canyon along the Western Antarctic Peninsula. The focus of CONVERGE was to assess the impact of prey-concentrating ocean circulation dynamics on Adélie penguin foraging behavior. Food web links between phytoplankton and zooplankton abundance and penguin behavior were examined to better understand the within-season variability in Adélie foraging ecology. Since the High Frequency Radar (HFR) network installation in November 2014, the radial component current data from each of the three sites were combined to provide a high resolution (0.5 km) surface velocity maps. These hourly maps have revealed an incredibly dynamic system with strong fronts and frequent eddies extending across the Palmer Deep foraging area. A coordinated fleet of underwater gliders were used in concert with the HFR fields to sample the hydrography and phytoplankton distributions associated with convergent and divergent features. Three gliders mapped the along and across canyon variability of the hydrography, chlorophyll fluorescence and acoustic backscatter in the context of the observed surface currents and simultaneous penguin tracks. This presentation will highlight these synchronized measures of the food web in the context of the observed HFR fronts and eddies. The location and persistence of these features coupled with ecological sampling through the food web offer an unprecedented view of the Palmer Deep ecosystem. Specific examples will highlight how the vertical structure of the water column beneath the surface features stack the primary and secondary producers relative to observed penguin foraging behavior. The coupling from the physics through the food web as observed by our multi-platform network gives strong evidence for the critical role that distribution patterns of lower trophic levels have on Adélie foraging.
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