Proliferation of Ice Algae in the Syowa Station Area,Antarctica

The distribution and seasonal variation of ice algae were investigated in the vicinity of Syowa Station (69°00\u27S, 39°35\u27E), Antarctica. The plant pigments, chlorophyll a and phaeophytin, were detected from top to bottom of the sea ice. However, the proliferation of ice algae occurred significantly at the bottom of the sea ice to make it brown in autumn and spring. The autumnal outburst of algae was found in the more limited regions which were covered with the ice formed newly than the regions in which the spring proliferation occurred. The autumnal proliferation of algae also occurred in the wintered ice as well as in the new ice but algal biomass in the old ice was less than in the new ice. The annual production of ice algae in the Syowa Station area was assumed as 1.50 to 3.25gC/m^2 based on the present data of algal biomass. These results show the potential importance of ice algae in the marine ecosystems of the polar regions

Copepods in the Stomach of a Nototheniid Fish,Trematomus borchgrevinki Fry at Syowa Station,Antarctica

Copepods in stomach contents of fry of a nototheniid fish, Trematomus borchgrevinki which were caught on September 6, 1970 were examined to acquire information on the winter populations of copepods in the sea covered with the fast ice near Syowa Station (69°00\u27S, 39°35\u27E), Antarctica. The stomach contents were composed of Ctenocalanus vanus, Stephus longipes, two unidentified calanoid species, Oithona similis, Oncaea curvata, a few unidentified harpacticoid species, nauplius of copepods and unidentified copepods. O. similis and copepod nauplius were dominant. The component species of the stomach contents resembled those of the samples collected by vertical hauls of a plankton net in late autumn and in early spring. However, the relative abundance of copepod species in the stomach contents differed from that in the net samples. This may be reasonably ascribed to possible food preference of fish. Therefore, it is possible to assume that the winter populations of copepods do not differ from the late autumn and early spring populations