BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Erik Behrens (National Institute of Water and Atmospheric Research ) DTSTART:20211020T080000Z DTEND:20211020T090000Z DTSTAMP:20260423T021416Z UID:BAS-PO/23 DESCRIPTION:Title: The impact of sea-ice drift and ocean circulation on dispersal of toothfis h eggs and juveniles in the Ross Gyre and Amundsen Sea\nby Erik Behren s (National Institute of Water and Atmospheric Research) as part of BAS Po lar Oceans Seminar\n\n\nAbstract\nKnowledge about the early life history o f Antarctic toothfish (Dissostichus mawsoni) is still incomplete\, particu larly on the spatial and temporal extent of spawning and the subsequent tr ansport of eggs\, larvae\, and juveniles from the offshore spawning areas to the continental shelf. This study uses a high-resolution hydrodynamic m odel to investigate the impact of ocean circulation and sea-ice drift on t he dispersal of eggs\, larvae\, and juvenile Antarctic toothfish. The virt ual eggs are released on seamounts of the Pacific-Antarctic ridge in the R oss Gyre and advected using hydrodynamical model data. Particles are seede d annually over the years 2002 to 2016 and tracked for three years after t heir release. Recruitment success has been evaluated based on the number o f juveniles that reached known coastal recruitment areas\, between the eas tern Ross and Amundsen Seas\, within three years. Sensitivities to certain juvenile behaviours has been explored and showed that recruitment success was reduced by around 70% if juveniles drifted with sea-ice during the se cond winter season as this carries them into the open ocean away from the shelf region. Recruitment success increases during the second winter seaso n if juveniles are entrained in the Ross Gyre circulation or if they activ ely swam towards the shelf. These modelling results suggest that the ecolo gical advantage of sea-ice association in the early life cycle of toothfis h diminishes as they grow\, promoting a behaviour change during their seco nd winter.\n LOCATION:https://researchseminars.org/talk/BAS-PO/23/ END:VEVENT END:VCALENDAR