Parasites in antarctic krill: diversity, distribution & impact
Antarctic krill, Euphausia superba, play essential roles in the Southern Ocean. These small pelagic crustaceans are prey for most of the region’s birds, mammals, and fish, as well as influencing the carbon cycle through export to the deep sea. Additionally, krill are the target of a currently expanding commercial fishery. Sustainably managing Antarctic krill requires an understanding of the factors influencing their growth, reproduction and mortality. One such factor which remains very poorly known is the role of parasites. My recent research using new molecular tools has shown a much higher than expected diversity and prevalence of parasite infections in krill. I observed DNA sequences of a broad variety of parasites (fungi, peronosporomycetes, apicomplexa, nematodes, and ciliates) within the guts of krill, with over 10% of krill individuals containing parasite DNA. This MSCA action will build on those preliminary results – applying a combination of novel molecular approaches, traditional incubation experiments, and mathematical modelling to address three key questions: 1) What eukaryotic parasites and symbionts are found in E. superba? 2) How are parasites distributed in geographic and environmental space? and 3) What impact do parasites have on E. superba secondary production? To address these broad questions this project brings together research expertise from Australia (Australian Antarctic Division), Europe (British Antarctic Survey and the University of Stirling), and the Americas (National Polytechnic Institute of Mexico), as well as establishing new intersectoral collaborations with fisheries (Association of Responsible Krill Harvesting Companies) and tourism (Hurtigruten). The results of this research will be communicated to national and international krill fisheries management organizations – allowing the role of parasites to be taken into account to improve the sustainability of management for this key species.