Ocean colour and the spatial and seasonal distribution of phytoplankton in the Barents Sea

The temporal and spatial distributions of phytoplankton biomass in polar seas are strongly influenced by physical factors, the most important of which are the light regime and mixing processes in the water masses. Field measurements and estimates for chlorophyll based on satellite data from the experimental Coastal Zone Color Scanner show that the distribution of chlorophyll concentrations in surface waters is closely related to the different water masses in the region. As expected, the highest chlorophyll-like concentrations are found in the coastal waters and in the Atlantic waters south of the Polar Front. Surface chlorophyll concentrations near the ice edge in the north are high during a short period following ice melting but decrease rapidly due to nutrient depletion. The intensity of this ice-edge bloom decreases with increasing latitude. The chlorophyll distribution patterns observed in satellite imagery are consistent with field observations, but remote sensing data provide additional information because of their higher spatial resolution. Local phytoplankton blooms can be observed on the banks near Svalbard and Novaya Zemlya. Improved ocean colour satellites available in the near future will provide more frequent coverage and will allow more detailed studies of seasonal variations in phytoplankton distribution and primary production in this highly productive region.