Microphytoplankton assemblages in shallow waters at Admiralty Bay (King George Island, Antarctica) during the summer 2002–2003

• Published in: Polar Biology
• Main Authors: Lange, P, Tenenbaum, D, De Santis Braga, E, Campos, L
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2019
• Subjects: Antarctic; King George Island; Admiralty Bay; Ferraz; Antarc*; Antarctica
• Online Access: https://doi.org/10.1007/s00300-007-0309-8; https://ora.ox.ac.uk/objects/uuid:e26697e7-f12d-486b-b2c2-a7d61cec754b

Microphytoplankton populations were studied in shallow coastal water (<60 m) near the Brazilian Antarctic Station Comandante Ferraz (EACF) and three reference areas in Admiralty Bay in early and late summer (2002–2003). Phytoplankton was diverse (113 taxa), but not abundant (103 cells l−1). The highest abundances (>104 cells l−1) were caused by pennate benthic diatoms (Fragilaria striatula Lyngbye) that occurred mainly in early summer, associated with the presence of ice. In late summer, when the water temperature (−0.4 to 1.5°C), salinity (34 to 35), and phosphate (2.6 to 4.5 μmol l−1) were highest and the dissolved oxygen was lowest (6.4 to 2.9 ml l−1), centric diatoms (Thalassiosira spp.) were more abundant, suggesting an influence of oceanic waters. Phytoplankton abundance (≤102 cells l−1) and chlorophyll a concentrations (0.22 μg l−1) were lowest close to EACF. Pennate diatoms were dominant close to shore and in surface waters elsewhere, probably because of ice melting or sediment resuspension caused by water mixing.