• Home
  •  >
  • Antarctic Science
  •  >
  • Volume 8
  •  >
  • Issue 02
  •  >
  • Ecology of diatom and bacterial assemblages in water associated with melting summer sea ice in the Weddell Sea, Antarctica

Antarctic Science

Table of Contents - 1996 - Volume 8, Issue 02  


Papers—Life Sciences and Oceanography

Ecology of diatom and bacterial assemblages in water associated with melting summer sea ice in the Weddell Sea, Antarctica

Markus Gleitz a1c1, Sönnke Grossmann a1c1, Renate Scharekm a1c1 and Victor Smetacek a1c1
a1 Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Germany

Article author query
gleitz m   [PubMed][Google Scholar] 
grossmann s   [PubMed][Google Scholar] 
scharek r   [PubMed][Google Scholar] 
smetacek v   [PubMed][Google Scholar] 

Abstract

The fate of ice biota released via meltwater into pools of seawater trapped between melting ice floes (crack pools) was followed in late January in the southern Weddell Sea. Low salinity crack pools shared the following features: nitrate exhaustion, high pH and POC/PON ratios, high bacterial biomass composed of large cells, and a dense algal assemblage dominated to over 90% by only two diatom species. It is suggested that this “climax stage” evolved from a nutrient rich, moderate biomass situation prevailing in high salinity crack pools, and is representative of summer succession of sea ice biota. “Overflow” production following nitrate exhaustion by the algae resulted in internal (lipid) and external (presumably mucus) carbon pools. The latter must fuel bacterial biomass build-up, as algal mortality appeared to be low. The large algal and bacterial stocks point to low grazing pressure exerted by phagotrophic protists, presumably due to poor food quality (e.g. high C/N ratios) and/or excessive mucus production. It is concluded that environmental selection of the abundant ice algal species occurs under conditions prevailing in the disintegrating ice cover during summer, which differ drastically from those generally referred to as characteristic of the sea ice habitat at large (a combination of low temperature, low light and high salinity).

(Received July 8 1995)
(Accepted December 14 1995)


Key Words: grazing; ecology; physiology; nutrient limitation; sea ice algae; sea ice bacteria.

Correspondence:
c1 AWI/BIO II, Postfach 12 01 61, D-27515 Bremerhaven, Germany

Metrics
Related Content