The present investigation was initiated to report on species compositions and dynamics in the
Norwegian-Greenland Sea during low production phases in spring and early summer. Thus,
the distribution patterns of living coccolithophores during June to July, 1990, February and
May, 1991, and March to April, 1995 were investigated. In general, the seasonal development
of the phytoplankton started after the yearly dark period and coccolithophores increased in
abundance when the water column was more stratified and both temperatures and insolation
increased. Cell densities reached a maximum of 207x10~c occospheres/l in the southeastern
part of the studied area. However, these high cell densities probably resulted from ,,old" populations,
drifted to the Norwegian-Greenland Sea from the North Atlantic. Some of the collected
samples did not contain any coccolithophores.
In total, 15 coccolithophore species were identified. The diversity was generally higher in the
eastern part of the Norwegian-Greenland Sea and to the west the coccolithophore communities
often were monospecific. Emiliania huxleyi is the dominant species, but Calciopappus caudatus
and Algirosphaera robusta also considerably contribute to the communities. High cell densities
of C. caudatus were interpreted as the result of a bloom or more probably close to bloom conditions
during the general low productive period. In addition, many of the E. huxleyi coccolith
from the surface waters of the southeastern Norwegian-Greenland Sea were heavily corroded.
These specimens may have drifted within the Atlantic water for a longer time.