Have whales returned to a historical hotspot of industrial whaling? the pattern of southern right whale Eubalaena australis recovery at South Georgia

• Published in: Endangered Species Research
• Main Authors: Jackson, Jennifer A., Kennedy, Amy S., Moore, Michael, Andriolo, Artur, Bamford, Connor C.G., Calderan, Susannah, Cheeseman, Ted, Gittins, George, Groch, Karina, Kelly, Natalie, Leaper, Russell, Leslie, Matthew S., Lurcock, Sarah, Miller, Brian S., Richardson, Jessica, Rowntree, Vicky, Smith, Patrick, Stepien, Emilie, Stowasser, Gabriele, Trathan, Phil, Vermeulen, Els, Zerbini, Alexandre N., Carroll, Emma L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter Research 2020
• Subjects: Whale; Whaling; Antarctic; Recovery; Habitat use; Southern right whale (Eubalaena australis); Argentina; Antarc*; British Antarctic Survey; Humpback Whale; South Georgia Museum; Southern Right Whale
• Online Access: http://hdl.handle.net/2263/79160; https://doi.org/10.3354/esr01072

Around 176 500 whales were killed in the sub-Antarctic waters off South Georgia (South Atlantic) between 1904 and 1965. In recent decades, whales have once again become summer visitors, with the southern right whale (SRW) the most commonly reported species until 2011. Here, we assess the distribution, temporal pattern, health status and likely prey of SRWs in these waters, combining observations from a summertime vessel-based expedition to South Georgia, stable isotope data collected from SRWs and putative prey and sightings reports collated by the South Georgia Museum. The expedition used directional acoustics and visual surveys to localise whales and collected skin biopsies and photo-IDs. During 76 h of visual observation effort over 19 expedition days, SRWs were encountered 15 times (~31 individuals). Photo-IDs, combined with publicly contributed images from commercial vessels, were reconciled and quality-controlled to form a catalogue of 6 fully (i.e. both sides) identified SRWs and 26 SRWs identified by either left or right sides. No photo-ID matches were found with lower-latitude calving grounds, but 3 whales had gull lesions supporting a direct link with Península Valdés, Argentina. The isotopic position of SRWs in the South Georgia food web suggests feeding on a combination of copepod and krill species. Opportunistic reports of SRW sightings and associated group sizes remain steady over time, while humpback whales provide a strong contrast, with increased sighting rates and group sizes seen since 2013. These data suggest a plateau in SRWs and an increasing humpback whale presence in South Georgia waters following the cessation of whaling. This study forms part of the Ecosystems component of the British Antarctic Survey Polar Science for Planet Earth Programme, funded by The Natural Environment Research Council. EU BEST 2.0 Medium Grant 1594, a DARWIN PLUS award DPLUS057 and the World Wildlife Fund. http://www.int-res.com/journals/esr/esr-home pm2021 Zoology and Entomology