South Georgia Shag shows alarming population decline

Data has revealed that South Georgia Shag has suffered a dramatic decline during the last 40 years.

A long-term study by British Antarctic Survey (BAS) scientists shows declining populations at sites in the remote islands of South Orkney and South Georgia.

South Georgia Shag is native to a few subantarctic islands in the South Atlantic Ocean (Laurent Demongin).

Published in the journal Polar Biology, a 40-year census from Signy Island and a 30-year census from Bird Island have shown significant declines at both locations. The Signy population has diminished by more than a third of its previous size and the Bird Island population has more than halved. The study confirms an ongoing long-term population decline in South Georgia Shags of 41% at Signy since 1978 and almost 60% at Bird Island since 1989.

Operated by BAS, Signy Island Research Station is a summer-only station and Bird Island Research Station is occupied by scientists all-year round. At both locations there are long-term monitoring programs on a number of seabird species, including penguins and albatrosses, as well as South Georgia Shags.

Lead author and seabird ecologist Mike Dunn explained: "Identifying these declining population trends is essential for the effective future conservation of this species. The majority of the world population of South Georgia shags are located in the South Orkney islands and South Georgia, including Bird Island. Consequently, continuation of the declines shown in this study will be of important conservation concern."

Reference

Adlard, S, Dunn, M J, Fox, D, Jackson, J A, Lynnes, A S & Morley, T I. 2021. Long term population size and trends of South Georgia Shags (Leucocarbo [atriceps] georgianus) at Signy Island, South Orkney Islands and Bird Island. Polar Biology. DOI: doi.org/10.1007/s00300-021-02978-2