Studies on the Community Structure of Phytoplankton and its Environmental Restriction in the Water Encircling the Antarctica

摘要

This paper focused on the cell abundance and community structure of phytoplankton and its environmental restriction in the sea area encircling the eastern Indian Ocean, Prydz Bay, the western Indian Ocean, the Southern Atlantic Ocean, the Drake Passage and returning to Prydz Bay. The results showed that there was marked feature of spatial in the sea areas surveyed. In the Antarctic waters, phytoplankton cell abundance and nutrients were higher than the subantarctic water and subtropical water. The mean phytoplankton cell abundance was 7.8×104 cells·dm-3, 3.6×104 cells·dm-3 and 1.4×104 cells·dm-3 respectively in the Antarctic water, the subantarctic water and subtropical water. In the water encircling the Antarctica, the Southern Atlantic Ocean is the most fertile, where phytoplankton cell abundance was more than in the Drake Passage and the Southern Indian Ocean. Because the temperature raised, floe ice melted, ice algae released into the seawater, the phytoplankton cell abundance was the highest at austral summer. The phytoplankton community structure were mainly composed of diatoms, such as Chaetocerous dichaeta, Corethron criophilum, Fragilariopsis curta, F. kerguelensis, Nitzschia barkleyi, Proboscia alata, Rhizosolenia styliformis, Trichotoxon reinboldii, Thalassiosira Antarctica; pyrrophyta, such as Gymnodinium gracile, G. baccatum, Gyrodinium lachryma, Protoperidinium archiovatum, Protoperidinium obovatum, etc.