Variability in Transport and Recruitment of Antarctic Krill Across the Scotia Sea

Old Dominion University Research Foundation, Norfolk VA

Investigators

Abstract

Connection between Antarctic krill populations from the Antarctic Peninsula region with those at South Georgia is dependant upon: 1) successful recruitment of larval and juvenile age groups at the Antarctic Peninsula, 2) entrainment of Antarctic Peninsula krill into the currents associated with fronts in the southern portion of the Antarctic Circumpolar Current, 3) survival of the krill during transport across the Scotia Sea, and 4) successful recruitment to the local krill population at a range of space and time scales. The overall goal of this research is to examine environmental and biological variability associated with each of these components to determine the relative effect on Antarctic krill survival and recruitment. The first research question considers the factors that control/influence variability in location of the large-scale circulation features, such as the southern Antarctic Circumpolar Current front and boundary. The rationale underlying this question is that the location of these circulation features affects krill entrainment, the volume of Upper Circumpolar Deep water that is upwelled arrival time of krill at South Georgia, and potentially the extent of the Polar Slope Current outflow from the Weddell Sea. The second research question considers the environmental and biological factors that allow successful transport of Antarctic krill between the Antarctic Peninsula and South Georgia. The third research question considers the physical and biological factors that result in successful recruitment of Antarctic krill to South Georgia populations. The fourth research question is focused on the entire Antarctic Peninsula-Scotia Sea system and is directed at determining the locations and/or conditions that result in success or failure in recruitment of Antarctic krill. This question will consider if other locations for krill production and recruitment are possible given the constraints of passive advection, food availability, and recruitment. This study is a joint effort between E. Hofmann and J. Klinck at Old Dominion University and Dr. Eugene Murphy at the British Antarctic Surve (BAS) in Cambridge, England. The study will closely link to the BAS Ocean Ecosystem Dynamics Programme, which is investigating the variability of the South Georgia ecosystem. The research will include analyzing, synthesizing, and integrating the large environmental and krill data sets collected by BAS around South Georgia with those from the Antarctic Peninsula region that are from historical sources, such as BIOMASS and the Palmer Long-Term Ecological Research (LTER) Program, and those from the South Shetland Islands and Elephant Island region obtained as part of the various data sets with biological and circulation models are essential for addressing the research questions and will lead to a greater understanding of the Antarctic Marine Ecosystem.