Using satellite altimetry to inform hypotheses of transport of early life stage of Patagonian toothfish on the Kerguelen Plateau

Understanding patterns of oceanic transport and their role in population connectivity, particularly for the early life stages of marine organisms, has important implications for population biology and management. Various approaches have been used to observe and model larval transport and recruitment in marine environments. In the Southern Ocean, these approaches are presented with particular challenges due to logistical difficulties in accessing and sampling remote, open water or deep-sea environments. In this study, we examine the use of remotely-sensed sea surface height data (AVISO) – which is now easily accessible and available for more than 20 years – to model transport and dispersion of eggs and early larval stages of Patagonian toothfish on the Kerguelen Plateau in the Indian Sector of the Southern Ocean. We compare simulated transport patterns from AVISO with those calculated from an ocean reanalysis product (Southern Ocean State Estimate; SOSE), and draw conclusions on likely patterns of connectivity between spawning regions and regions that offer suitable habitat for juvenile fish. The results of our study suggested regions with successful spawning that are consistent with those observed by the fishery and describe inter-annual differences in simulated connectivity between spawning and recruitment habitats.