Survival and recovery of Phaeocystis antarctica (Prymnesiophyceae) from prolonged darkness and freezing
| Autor: | Kam W. Tang, Amy R. Shields, David T. Elliott, Walker O. Smith |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Chlorophyll
Light Acclimatization Oceans and Seas Antarctic Regions Dimethylsulfoniopropionate General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Water column Algae Phytoplankton Freezing Seawater General Environmental Science geography geography.geographical_feature_category General Immunology and Microbiology biology fungi Eukaryota General Medicine Darkness biology.organism_classification Photosynthetic capacity Arctic ice pack Carbon Horticulture Diatom Oceanography chemistry Seasons General Agricultural and Biological Sciences Research Article |
| Popis: | The colony-forming haptophyte Phaeocystis antarctica is an important primary producer in the Ross Sea, and must survive long periods of darkness and freezing temperature in this extreme environment. We conducted experiments on the responses of P. antarctica -dominated phytoplankton assemblages to prolonged periods of darkness and freezing. Chlorophyll and photosynthetic capacity of the alga declined nonlinearly and independently of each other in the dark, and darkness alone would potentially reduce photosynthetic capacity by only 60 per cent over 150 days (approximately the length of the Antarctic winter in the southern Ross Sea). The estimated reduction of colonial mucous carbon is higher than that of colonial cell carbon, suggesting metabolism of the colonial matrix in the dark. The alga quickly resumed growth upon return to light. Phaeocystis antarctica also survived freezing, although longer freezing durations lengthened the lag before growth resumption. Particulate dimethylsulfoniopropionate relative to chlorophyll increased upon freezing and decreased upon darkness. Taken together, the abilities of P. antarctica to survive freezing and initiate growth quickly after darkness may provide it with the capability to survive in both the ice and the water column, and help explain its repeated dominance in austral spring blooms in the Ross Sea and elsewhere in the Southern Ocean. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|