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摘要
Primary production in coastal Antarctica is primarily contributed from three sources: sea ice algae, phytoplankton, and microphytobenthos. Compared to other eastern Antarctic sites, the sea ice microalgal biomass at Casey Station, in spring 2005 was relatively low, 3.84 +/- A 1.67 to 21.6 +/- A 13.3 mg chl-a m(-2) but productive, 103-163 mg C m(-2) day(-1). The photosynthetic parameters, F (v)/F (m) and rETR(max), imply a community well-acclimated to the light climate of the benthic, water column, and sea ice habitats. Phytoplankton biomass was greatest in late spring (11.1 +/- A 0.920 mu g chl-a l(-1)), which probably reflects input from the overlying sea ice. Lower biomass and depressed F (v)/F (m) values later in the season were probably due to nutrient limitation. Benthic microalgal biomass was consistently between 200 and 400 mg chl-a m(-2) and production increased through into late summer (204 mg C m(-2) day(-1)). After the sea ice broke out, the marine environment supported a small phytoplankton biomass and a large benthic microalgal biomass. Compared with previous studies, F (v)/F (m) values were relatively low but there was no evidence of photoinhibition. When sea ice was present, primary production of benthic microalgae was either very low or there was a net draw down of oxygen. The benthic microalgal community made a larger contribution to total primary production than the phytoplankton or sea ice algae at water depth less than approximately 5 m.
- 出版日期2012-12
