Determining the connectivity of Antarctic silverfish along the Antarctic circumpolar current

Large-scale transport by the Antarctic Circumpolar Current (ACC) can promote spatially complex population structure in the Southern Ocean through advection.  Since the unidirectional flow of the ACC is concentrated in fronts that are found around the continent and penetrate to depth, connectivity may be predictable at regional scales.   We use predictions from ocean circulation models to build hypotheses of connectivity between the Ross Sea, Weddell Sea, and West Antarctic Peninsula; and between areas along the Peninsula.  We examine these using Pleuragramma antarcticum (Antarctic silverfish), a pelagic, neutrally buoyant notothenioid that is distributed around the Antarctic and is a vital prey species for many birds, seals, whales, and other fish in the Southern Ocean.   To test our predictions of connectivity, we use measurements of abundance, length, age, and otolith nucleus chemistry from fish sampled in the different regions.  Results from this study will provide important information on how the physical oceanography in the Southern Ocean affects pelagic marine organisms such as silverfish, and the role of connectivity in the persistence of populations around the Antarctic.