A Recirculating Eddy Promotes Subsurface Particle Retention in an Antarctic Biological Hotspot

Palmer Deep Canyon is one of the biological hotspots associated with deep bathymetric features along West Antarctic Peninsula. The upwelling nutrient-rich Upper Circumpolar Water to surface mixed layer in submarine canyon has been hypothesized drive increased phytoplankton biomass, attracting krill, penguins and other top predators area. However, observations lack a clear in-situ signal, laboratory experiments do not illustrate physiological response by Water, residence times are too short for populations reasonably respond any locally upwelled nutrients. This suggests that local may be mechanism links activity. Previous isopycnal doming within suggested subsurface recirculating feature present. Here, using measurements circulation model, we demonstrate presence eddy contribute maintenance hotspot increasing at depth retaining distinct particles. Neutrally buoyant particle simulations showed increase ∼175 days 150 m during austral summer. In-situ scattering, flow cytometry, water samples from suggest retained particles detrital nature. Our results this seasonal, retentive important retention material hotspot.