Seasonal and interannual variability of phytoplankton biomass west of the Antarctic Peninsula
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more
Also appears in:Le Fèvre, J.; Tréguer, P. (Ed.) (1998). Carbon Fluxes and Dynamic Processes in the Southern Ocean: Present and Past. Selected papers from the International JGOFS Symposium, Brest, France, 28-31 August 1995. Journal of Marine Systems, 17(1-4). Elsevier: Amsterdam. 1-619 pp., more
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| Keywords |
Algal blooms
Aquatic communities > Plankton > Phytoplankton
Population characteristics > Biomass
Spatial variations
Spatial variations > Latitudinal variations
Temporal variations > Periodic variations > Seasonal variations
Topographic features > Submarine features > Continental shelves
Topographic features > Submarine features > Continental slope
PSW, Antarctica, Antarctic Peninsula [Marine Regions]
Marine/Coastal |
| Authors | | Top |
- Smith, R.C.
- Baker, K.S.
- Vernet, M.
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| Abstract |
The spatial and temporal variability of phytoplankton biomass, estimated as chlorophyll-a (chl-a) concentration, is examined in the continental shelf-slope region west of the Antarctic Peninsula. Relationships between temporal observations in the nearshore Palmer Station grid (64°46.77'S, 64°04.36'W) and spatial observations in a larger regional grid 200 km on/off-shore and 900 km alongshore are presented. Average chl-a concentrations in the upper layers of the water column in the immediate vicinity of Palmer Station show strong seasonal and interannual variability. Biomass accumulation typically starts during mid-November, while strong blooms develop from December through January. The 1991/1992 and 1994/1995 seasons developed higher overall chl-a concentrations (average maximum water column values reaching 8 and 16 mg chl-a m-3, respectively) than the 1992/1993 and 1993/1994 seasons (average maximum water column values of less than 3 mg chl-a m-3). The 1994/1995 season of extremely high chl-a concentrations also showed a prolonged bloom period into February, while the 1991/1992 season did not. Similar interannual variability was observed in the regional grid. Average chl-a concentration in the top 30 m was 0.91, 1.24 and 1.66 mg chl-a m-3 for January of 1993, 1994 and 1995, respectively. The regional grid contains an on/off-shore gradient in bottom topography, measured physical and optical characteristics, as well as chl-a concentrations. Regional inshore grid stations in January had, on average, almost four times more chl-a biomass than off-shore stations (2.18 vs. 0.59 mg chl-a m-3, respectively). There is evidence that this on/off-shore gradient is modulated alongshore by latitudinal variability which follows the annual advance and retreat of sea ice. |
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