Contents of POLISH POLAR RESEARCH VOL. 26 No. 3
Wojciech MAJEWSKI
Benthic foraminiferal communities: distribution and ecology in Admiralty Bay, King George Island, West
Antarctica 159
Tony R. WALKER
Distribution of oxygen, sulfides and optimum temperature for sulfate reduction in Antarctic marine sediments
215
Chronicle: A Polish glaciologist appointed as SCAR Executive Officer — Bogumiła A. PIWOWAR and Leszek
KOLONDRA 231
POLISH POLAR RESEARCH VOL. 26 No. 3, pp. 159–214
Benthic foraminiferal communities: distribution and ecology in Admiralty Bay, King George Island, West
Antarctica
Wojciech MAJEWSKI 1,2
1
Instytut Paleobiologii PAN, ul. Twarda 51/55, 00-818 Warszawa, Poland
Zakład Biologii Antarktyki PAN, ul. Ustrzycka 10/12, 02-141 Warszawa, Poland
<wmaj@twarda.pan.pl>
2
Abstract: During the austral summer of 2002/2003 the author collected 38 marine and/or glacio-marine sediment
samples from Admiralty Bay on King George Island (South Shetland Islands, West Antarctica). Recent “living”
(Rose Bengal stained) and “dead” (subfossil) benthic foraminifera represented by 105 species belonging to 65
genera are recognized in samples from water depths of up to 520 m. They show large spatial variability. Four
distinctive foraminiferal zones within the fjord of Admiralty Bay were recognized and analyzed in terms of
environmental conditions. The zones are: restricted coves, open inlets, intermediate-, and deep-waters. The
major environmental factors, which dictate foraminiferal distribution, are closely related to bathymetry and
distance to open sea. Sediment composition and chlorophyll content appear to have minor influence on
foraminiferal communities. Most diverse, deep-water faunas dominate water-depths below 200 m, which seems
to be the lowest limit of atmospheric and meltwater influence. In waters shallower than 200 m, environmental
features, affecting distribution of various benthic foraminiferal assemblages, appear to be sedimentation rate and
hydrographic isolation. The results of this study gives promise to use the Admiralty Bay foraminiferal
distribution pattern as a paleoenvironmental tool for shallow- to intermediate-water Quaternary marine research
in fjord settings of the South Shetland Islands.
Key words: Antarctica, South Shetlands, Foraminifera, Recent.
POLISH POLAR RESEARCH VOL. 26 No. 3, pp. 215–230
Distribution of oxygen, sulfides and optimum temperature for sulfate reduction in Antarctic marine
sediments
Tony R. WALKER
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada
<trwalker@dal.ca>
Abstract: Measurements were made of sediment characteristics, benthic microbial activity and optimum
temperature for sulfate reduction at Signy Island, South Orkney Islands, Antarctica. There was little evidence to
support any seasonal variation in oxygen penetration of surface sediments. Oxygen penetrated to only 1.5 to 3
mm throughout the year, despite bioturbation from a dense amphipod population. The distribution of acid
volatile sulfides increased with depth below 1 cm and above this, surface sediments were lighter in colour and
contained fewer sulfides. The rates of sulfate reduction increased during winter under sea-ice cover, and
remained high after ice break up. Seasonal water temperature was relatively constant between –1.8 and 0.5°C.
Optimum temperature for anaerobic sediment respiration was investigated using different substrates and was
found to be in the range 17–27°C, suggesting that sulfate reducing bacteria are psychrotolerant as they were
inhibited by low temperatures.
Key words: Antarctica, Signy Island, coastal sediments, oxygen penetration, sulfides, temperature, sulfate
reduction.