A note on the size-fractionated pigments of the phytoplankton of the Strait of Magellan (February-March 1991)

During an oceanographic cruise, carried out at the end of the austral summer (February-March 1991) in the Strait of Magellan, spatial patterns of size-fractionated chlorophyll and primary production were studied in relation to hydrographic patterns.
Phytoplankton biomass, in terms of active Chl a, ranged between 10 and 51 mg m-2 and primary production between 275 and 1 170 mg C m-2 d-1.
The most important features concern the confinement of the microphytoplanktonic fraction to the Pacific opening and to the embayements between the two Narrows. In the internal part of the Strait, an uniform dimensional structure (< 5 um) of phytoplankton communities was observed, with the picophytoplanktonic fraction always dominant.