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SC/69A/ASI/08
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Resource ID
19938
Access
Open
Document Number
SC/69A/ASI/08
Full Title
Cruise Report from winter survey (May – September 2022) around South Georgia (Islas Georgias del Sur)
Author
Russell Leaper, Martin A Collins, Susannah Calderan, Ryan Irvine, Cecilia Liszka, Paula Olson And Jennifer Jackson
Authors Summary
A visual and acoustic survey of baleen whales in South Georgia (Islas Georgias del Sur, SG/GS) waters was carried out in July 2022, as well as combined surveys of marine mammals and seabirds in May, July and September 2022, as part of a two-year project investigating the abundance and density of krill and krill-feeding predators at SG/GS in winter. Analyses of this work are ongoing in order to relate observed distributions to krill occurrence and density, with a second year of surveys taking place in 2023.
Publisher
IWC
Publication Year
2023
Abstract
A visual and acoustic survey of baleen whales in South Georgia (Islas Georgias del Sur, SG/GS) waters was carried out in July 2022, as well as combined surveys of marine mammals and seabirds in May, July and September 2022, as part of a two-year project investigating the abundance and density of krill and krill-feeding predators at SG/GS in winter. Humpback whales (Megaptera novaeangliae) were the most frequently seen species in all periods, with the pattern of sightings suggesting possible westerly movement of this species distribution along the north SG/GS shelf over the winter period. Fin whales (Balaenoptera physalus) were also sighted in all surveys, with the highest sighting rates in May. Southern right whales (Eubalaena australis) were encountered in May and July. Blue (B. musculus intermedia), sperm (Physeter macrocephalus) and killer whales (Orcinus orca) were occasionally encountered. Acoustic surveys using DIFAR sonobuoys in July identified many humpback whale vocalisations, and located these mostly in shelf waters. Southern right whales rarely vocalised, and detections of fin and blue whales suggested that both had a more offshore distribution (i.e. outside of shelf waters) in July. Analyses of this work are ongoing in order to relate observed distributions to krill occurrence and density, with a second year of surveys taking place in 2023.