Spatial Distribution of Diatom Surface Sediment Assemblages on
the Laptev Sea Shelf (Russian Arctic)
H. Cremer
GEOMAR Forschungszentrumfiir marine Geowissenschaften, Wischhofstrasse 1-3, D 24148 Kiel, Germany
Recei ved 14 February 1997 and accepted in revised fonn 18 December 1997
Abstract - The spatial distribution of diatom assemblages was investigated in surface
sediments from the Laptev Sea shelf. Diatoms are an abundant and diverse microfossil
component in these sediment samples. A total of 345 diatom taxa from 56 genera could be
identified with freshwater diatoms contributing up to 62% of the total taxa number.
However, diatom assemblages are dominated by a few planktic species. A factor analysis of
21 species and species groups from 75 surface sediment samples was carried out. Four
factors (= diatom assemblages) could be extracted. They are the ice algae assemblage, the
freshwater diatom assemblage, the Chaetoceros assemblage, and the Thalassiosira
nordenskioeldii assemblage. The spatial distribution pattern of these assemblages in
sediments of the Laptev Sea shelf shows a distinct relationship to oceanography.
Parameters mainly affecting the composition and distribution of diatom sediment
assemblages on the Laptev Sea shelf are the sea-ice conditions, the freshwater intlux by
Siberian rivers, and, controlled by the river water intlux, the salinity of surface waters.
Introduction
The Laptev Sea (Figure I) is one of the largest Arctic shelf seas and has great importance for
the oceanographic situation of the Arctic Ocean. Particularly both the huge freshwater input by
the large rivers (especially by the Lena River) and its significance for the freshwater balance of
the Arctic Ocean, and the importance of the Laptev Sea as a source for new sea-ice which is
supplied to the Transpolar Drift (Figure I) have been recently pointed out (e.g. Aagaard and
Carmack, 1989; Gordeev and Sidorov, 1993; Kassens et a!., 1995; Niirnberg et a!., 1994;
Gordeev et a!., 1996; Steele et a!., 1996; Eicken et a!., 1997). The freshwater supply and the
ice cover which is present from November until May affect the biology and the evolution of
organism communities (Clark, 1990). However, compared to other Eurasian shelf seas,
scientific and especially paleoceanographic investigations in the Laptev Sea are sparse. The
reason was the unaccessibility of the Laptev Sea for scientists during Soviet times.
Diatoms in the Arctic have been studied for a long time. The first descriptions of Arctic
diatom species were given by Ehrenberg (1932) who was also the first refering to the presence
of diatoms in sea-ice (Ehrenberg 1943). Comprehensive investigations of Arctic diatoms were
first carried out by Cleve and Grunow (1880), Cleve (1883), Grunow (1884), 0strup (1895),
Gran (1904a) and Meunier (1910). However, the knowledge about the diatom flora of the
Laptev Sea is very scarce. First descriptions of plankton and sediment diatoms were published
from the famous expeditions of the "Vega" 1878-79 (Cleve, 1883) and the "Fram" 1893-96
(Gran 1904b). Later, Kisselew (1932), Shirshov (1937), and Usachev (1946) contribute
descriptions of the diatom plankton of the Laptev Sea. Above all, these publications concentrate
on a listing of idcntified genera and species.
The present study investigates the spatial distribution of diatoms in surface sediments of the
Laptev Sea shelf (Cremer, 1998). The purpose of this study is to describe distinct distribution
patterns of diatom assemblages and its species composition in surface sediments, and moreover
to recognize a relationship between the biogeographic distribution of diatom assemblages
In: Kassens, H., H.A. Bauch, I. Dmitrenko, H. Eicken, H.-W. Hubberten, M. Melles, J. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag. Berlin, 1999.533-551.
the Laptev Sea Shelf (Russian Arctic)
H. Cremer
GEOMAR Forschungszentrumfiir marine Geowissenschaften, Wischhofstrasse 1-3, D 24148 Kiel, Germany
Recei ved 14 February 1997 and accepted in revised fonn 18 December 1997
Abstract - The spatial distribution of diatom assemblages was investigated in surface
sediments from the Laptev Sea shelf. Diatoms are an abundant and diverse microfossil
component in these sediment samples. A total of 345 diatom taxa from 56 genera could be
identified with freshwater diatoms contributing up to 62% of the total taxa number.
However, diatom assemblages are dominated by a few planktic species. A factor analysis of
21 species and species groups from 75 surface sediment samples was carried out. Four
factors (= diatom assemblages) could be extracted. They are the ice algae assemblage, the
freshwater diatom assemblage, the Chaetoceros assemblage, and the Thalassiosira
nordenskioeldii assemblage. The spatial distribution pattern of these assemblages in
sediments of the Laptev Sea shelf shows a distinct relationship to oceanography.
Parameters mainly affecting the composition and distribution of diatom sediment
assemblages on the Laptev Sea shelf are the sea-ice conditions, the freshwater intlux by
Siberian rivers, and, controlled by the river water intlux, the salinity of surface waters.
Introduction
The Laptev Sea (Figure I) is one of the largest Arctic shelf seas and has great importance for
the oceanographic situation of the Arctic Ocean. Particularly both the huge freshwater input by
the large rivers (especially by the Lena River) and its significance for the freshwater balance of
the Arctic Ocean, and the importance of the Laptev Sea as a source for new sea-ice which is
supplied to the Transpolar Drift (Figure I) have been recently pointed out (e.g. Aagaard and
Carmack, 1989; Gordeev and Sidorov, 1993; Kassens et a!., 1995; Niirnberg et a!., 1994;
Gordeev et a!., 1996; Steele et a!., 1996; Eicken et a!., 1997). The freshwater supply and the
ice cover which is present from November until May affect the biology and the evolution of
organism communities (Clark, 1990). However, compared to other Eurasian shelf seas,
scientific and especially paleoceanographic investigations in the Laptev Sea are sparse. The
reason was the unaccessibility of the Laptev Sea for scientists during Soviet times.
Diatoms in the Arctic have been studied for a long time. The first descriptions of Arctic
diatom species were given by Ehrenberg (1932) who was also the first refering to the presence
of diatoms in sea-ice (Ehrenberg 1943). Comprehensive investigations of Arctic diatoms were
first carried out by Cleve and Grunow (1880), Cleve (1883), Grunow (1884), 0strup (1895),
Gran (1904a) and Meunier (1910). However, the knowledge about the diatom flora of the
Laptev Sea is very scarce. First descriptions of plankton and sediment diatoms were published
from the famous expeditions of the "Vega" 1878-79 (Cleve, 1883) and the "Fram" 1893-96
(Gran 1904b). Later, Kisselew (1932), Shirshov (1937), and Usachev (1946) contribute
descriptions of the diatom plankton of the Laptev Sea. Above all, these publications concentrate
on a listing of idcntified genera and species.
The present study investigates the spatial distribution of diatoms in surface sediments of the
Laptev Sea shelf (Cremer, 1998). The purpose of this study is to describe distinct distribution
patterns of diatom assemblages and its species composition in surface sediments, and moreover
to recognize a relationship between the biogeographic distribution of diatom assemblages
In: Kassens, H., H.A. Bauch, I. Dmitrenko, H. Eicken, H.-W. Hubberten, M. Melles, J. Thiede and L. Timokhov (eds.)
Land-Ocean Systems in the Siberian Arctic: Dynamics and History. Springer-Verlag. Berlin, 1999.533-551.