Polar Biology

, Volume 12, Issue 2, pp 225–235

Phytoplankton distribution in relation to sea ice, hydrography and nutrients in the northwestern Weddell Sea in early spring 1988 during EPOS

  • F. Bianchi
  • A. Boldrin
  • F. Cioce
  • G. Dieckmann
  • H. Kuosa
  • A. -M. Larsson
  • E. -M. Nöthig
  • P. -I. Sehlstedt
  • G. Socal
  • E. E. Syvertsen
Article

DOI: 10.1007/BF00238264

Cite this article as:
Bianchi, F., Boldrin, A., Cioce, F. et al. Polar Biol (1992) 12: 225. doi:10.1007/BF00238264

Summary

Phytoplankton biomass and distribution of major phytoplankton groups were investigated in relation to sea ice conditions, hydrography and nutrients along three north-south transects in the north western Weddell Sea in early spring 1988 during the EPOS Study (European Polarstern Study), Leg 1. Three different zones along the transects could be distinguished: 1) the Open Water Zone (OWZ) from 58° to 60°S with high chlorophyll a concentrations up to 3.5 μg l−1; 2) the Marginal Ice Zone (MIZ) from 60° to about 62.5° with chlorophyll a concentrations between 0.1 and 0.3 μg l−1, and 3) the closed pack-ice zone (CPI) from 62.5° to 63.2°S with chlorophyll a concentrations below 0.1 μgl−1. Nutrient concentrations increased towards the south showing winter values under the closed pack-ice. Centric diatoms such as Thalassiosira gravida and Chaetoceros neglectum forming large colonies dominated the phytoplankton assemblage in terms of biomass in open water together with large, long chain forming, pennate diatoms, whereas small pennate diatoms such as Nitzschia spp., and nanoflagellates prevailed in ice covered areas. Fairly low concentrations of phytoplankton cells were encountered at the southernmost stations and many empty diatom frustules were found in the samples. The enhanced phytoplankton biomass in the Weddell-Scotia-Confluence area is achieved through sea ice melting in the frontal zone of two different water masses, the Weddell and the Scotia Sea surface waters.

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • F. Bianchi
    • 1
  • A. Boldrin
    • 1
  • F. Cioce
    • 1
  • G. Dieckmann
    • 4
  • H. Kuosa
    • 2
  • A. -M. Larsson
    • 3
  • E. -M. Nöthig
    • 4
  • P. -I. Sehlstedt
    • 3
  • G. Socal
    • 1
  • E. E. Syvertsen
    • 5
  1. 1.Consiglio Nazionale delle RicercheIstitutio di Biologia del MareVeneziaItaly
  2. 2.Tvärminne Zoological StationTvärminne (Hanko)Finland
  3. 3.Department of OceanographyUniversity of GothenburgGothenburgSweden
  4. 4.Alfred-Wegener-Institut für Polar- und MeeresforschungBremerhavenFederal Republic of Germany
  5. 5.Universitet i Oslo, Biologisk Institut, Adv. Marin BotanikOslo 3Norway