Dr Leonie Suter1,2, Dr Alicia Burns3,4, Dr Sophie Bestley2,5, Dr Jez Bird2, Dr Madeleine Brasier1,2, Dr Martin Cox1, Dr Derek Hamer6, Dr Olivia Johnson2, Dr So Kawaguchi1,2, Mr Rob King1, Dr Andreas Klocker7, Ms Jessica Melvin2, Dr Christine Weldrick5, Dr Simon Wotherspoon1, Dr Ben Raymond1,5
1Australian Antarctic Division, Department of Climate Change, Energy, the Environment and Water, Kingston, Australia, 2Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 3Cluster of Excellence ‘Science of Intelligence’ Technical University of Berlin, Berlin, Germany, 4Faculty of Life Science, Humboldt University Berlin, Berlin, Germany, 5Australian Antarctic Program Partnership, Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, Australia, 6Palmyra, Little Swanport, Australia, 7NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Bergen, Norway
Biography:
Dr Leonie Suter is a molecular geneticist at the Australian Antarctic division, where she investigates species distribution and community compositions of Southern Ocean animal species from the genetic material they release into the environment, known as environmental DNA (eDNA).
Abstract:
Antarctic krill (Euphausia superba) are a keystone species of the Southern Ocean ecosystem, immensely abundant and targeted by the krill fishery. For their sustainable management, biomass and distribution estimates are required. We explore how krill environmental DNA (eDNA) can add to these estimates. We collected eDNA in the East Antarctic Southern Ocean from the surface and seafloor, used quantitative PCR to measure Antarctic krill eDNA abundance and age, and eDNA metabarcoding to detect any krill species. We compared eDNA data to acoustic, visual and trawl data. Antarctic krill eDNA was common in surface samples and largely overlapped with visual and trawl detections. Highest eDNA concentrations were detected above krill swarms, with concentrations declining with increasing distance from swarms. eDNA age corresponded with distance to krill swarm detected by acoustic surveys. Krill were detected in seafloor samples in the south of the survey area, including at depths greater than 4000 m (recent eDNA) and 3000 m (visual). In eDNA and trawl data, Antarctic krill was the dominant krill species, followed by Thysanoessa macrura. We recommend the inclusion of eDNA data for Antarctic krill distribution estimates and understanding of habitat use, particularly in difficult-to-access areas, such as under ice or benthic habitats.