Antarctic phytoplankton assemblage in the western Bransfield Strait region, February 1993:composition, biomass, and mesoscale distributions

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 129:253-267 (1995) - doi:10.3354/meps129253 Antarctic phytoplankton assemblage in the western Bransfield Strait region, February 1993: composition, biomass, and mesoscale distributions Kang SH, Lee SH The Bransfield Strait region shows complex patterns of water circulation due to mixing of diverse water masses. Physicochemical properties of the different water types should affect the distribution, biomass, and species composition of the phytoplankton assemblages. We examined these features of phytoplankton in the western Bransfield Strait region during early February 1993. Diversity of the phytoplankton species was low. Only 5 or 6 species accounted for more than 95% of the total phytoplankton carbon biomass. Integrated phytoplankton biomass in the upper 100 m ranged from 407 to 3605 mg C m-2 (average 1906 mg C m-2). Areas with the higher biomass values (2000 to 3500 mg C m-2) were located in the northern part of the study area including waters to the north of the South Shetland Islands, and were generally related to increased stability of the surface water originating from the Bellingshausen Sea featuring lower salinity (33.69 to 33.78 ) and higher temperature (1.89 to 2.36*C). Distribution of autotrophic nanoflagellates (&LT20 um) showed a marked contrast to that of diatoms. Waters in the Bransfield Strait region were characterized by a dominance of nanoflagellates such as Cryptomonas sp. and Phaeocystis antarctica (motile stage) accounting for 83% of the total phytoplankton carbon. In the Drake Passage area, however, diatoms such as the nanoplanktonic Fragilariopsis pseudonana and the microplanktonic (&GT20 um) Rhizosolenia antennata f. semispina accounted for 84% of the total phytoplankton carbon. From measurements of upper ocean physical parameters and nutrients in combination with the data on composition, biomass, and distribution of the major phytoplankton species, it was found that mesoscale distributions of phytoplankton species reflect the physical conditions of the upper water column, particularly the profile of vertical stability of the water. Antarctic phytoplankton . Bransfield Strait . Cryptomonas sp. . Phaeocystis antarctica (motile stage) Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 129. Publication date: December 14, 1995 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1995 Inter-Research.