Thalassiosira scotia, sp. nov.: observations on a phytoplankton increase in Early Austral Spring North of the Scotia Ridge

• Published in: Journal of Plankton Research
• Main Authors: Fryxell, G.A., Villareal, T.A., Hoban, M.A.
• Format: Text
• Language: English
• Published: Oxford University Press 1979
• Subjects: Articles; Antarctic; Austral; Argentine; South Georgia Island; Orcadas; Antarc*; Antarctica
• Online Access: http://plankt.oxfordjournals.org/cgi/content/short/1/4/355; https://doi.org/10.1093/plankt/1.4.355

The dominant species in an early spring phytoplankton increase in characteristically antarctic waters north of South Georgia Island is described as Thalassiosira scotia G. Fryx. et Hoban and compared to related species in the South Atlantic, such as T. antarctica Comber and T. austratis Peragallo. Found on a cooperative US-Argentine cruise of the ISLAS ORCADAS 17–78, T. scotia dominated the phytoplankton in the well-mixed water columns of two stations more than 100 km apart. The maximum abu dance of the new species recorded in a discrete water sample was about 315,000 cells/liter, with up to 18.4 × 109 cells under a m2 in the top 100 m, in spite of the fact that there was no well-marked thennocline to aid in maintaining one water mass and thus netaining the population in the euphotic zone. A few resting spores were noted in one station. The water temperature in the area was about 1°C, and the salinity 33.9 o/oo.