Distribution patterns of chaetognata, polychaeta, pteropoda and salpidae off south georgia and south orkney islands

• Published in: Brazilian Journal of Oceanography
• Main Authors: Alina María Crelier, José Roberto Dadon, Hernán G. Isbert-Perlender, Daniel Eduardo Nahabedian, María Cristina Daponte
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo 2010
• Subjects: Distribuição do mesozooplâncton; Chaetognatas; Poliquetas; Pterópodes; Salpas; Oceano Antártico; Confluência Weddell-Scotia; Mesozooplankton distribution; Chaetognaths; Polychaetes; Pteropods; Salps; Southern Ocean; Weddell-Scotia Confluence; Oceanography; GC1-1581; Antarctic; The Antarctic; Weddell; South Orkney Islands; Orcadas; Orcadas del Sur; Antarc*; Antarctica; Clione limacina; Limacina antarctica; Limacina helicina; Mesozooplankton
• Online Access: https://doi.org/10.1590/S1679-87592010000400004; https://doaj.org/article/bb6841729bf14d7685682de64af17610

The distribution pattern, frequency and density (ind./1000 m) of different mesozooplankton species from the South Georgia Islands, South Orkney Islands and the Weddell-Scotia Confluence were analyzed using data obtained in 1994. The maximum densities of the species found were: Eukrohnia hamata (5330), Sagitta gazellae (1052), Clione limacina antarctica (450), Spongiobranchaea australis (375), Clio sulcata (100), Limacina helicina (4076 x 10³), Limacina retroversa (71 x 10(4)), Pelagobia longicirrata (29170), Rhynchonereella bongraini (117), Tomopteris carpenterii (26), Tomopteris planktonis (498), Tomopteris septentrionales (498) and Salpa thompsoni (189). Species density and frequency decreased from South Georgia to the South Orkney Islands, recording intermediate values at the Weddell-Scotia Confluence. Species density in the South Orkney area seemed to be limited by variations in temperature and salinity. The southern area around South Georgia showed the highest density of species, probably due to the influence of the Southern Front of the Antarctic Circumpolar Current. The presence of species characteristic of sub-Antarctic waters such as L. retroversa in the Confluence area could be related to the southward movements of eddies that originate in the Polar Front. Foram analisados os padrões de distribuição, freqüência e densidade (ind. 1000 m) de diferentes espécies de mesozooplâncton encontradas em torno das ilhas Georgias e Orcadas del Sur no verão de 1994. As densidades máximas apresentadas pelas espécies principais foram: Eukrohnia hamata (5330), Sagitta gazellae (1052), Clione limacina antarctica (450), Spongiobranchaea australis (375), Clio sulcata (100), Limacina helicina (4076 x 10³), Limacina retroversa (71 x 10(4)); Pelagobia longicirrata (29170), Rhynchonereella bongraini (117), Tomopteris carpenterii (26), Tomopteris planktonis (498), Tomopteris septentrionales (498) y Salpa thompsoni (189). A densidade e freqüência das espécies diminuíram das ilhas Georgias em direção às Orcadas, registrando-se ...