Space-borne study of seasonal, multi-year, and decadal phytoplankton dynamics in the Bay of Biscay
It is shown that in the shelf zone of the Bay, the diatom-dominated phytoplankton community variations are predominantly controlled by river discharge variations, by water column stratification conditions (forming in winter–early spring), and by wind action (resulting in such phenomena as up-wellings and sediment re-suspension).
Satellite data indicate that while in river deltas and adjoining waters the L. chlorophorum blooming events occur annually, in the Iroise Sea and near the Bailiwick of Guernsey, they happen irregularly. It is thought that such an irregular pattern, possibly, arises from L. chlorophorum competing with other phytoplankton species for nutrients.
E miliania huxleyi blooms are found to occur nearly every year in the northern part of the Bay, whereas in the central area, this phenomenon occurs very irregularly. Satellite data indicate that variations in the water chemistry (variations in the nitrogen : phosphorus ratio due to preceding blooms of diatoms), and the incident irradiance level (degree of cloudiness), are important factors controlling the occurrence of E. huxleyi blooming in the central part of the Bay. Covering a 30 year period, the bridged data from CZCS, AVHRR, SeaWiFS, and MODIS imply that climate change might be responsible for the observed increase in E. huxleyi blooming events in the Bay since 1979.
Document Type: Research Article
Affiliations: 1: Nansen International Environmental and Remote Sensing Centre, 199034,St. Petersburg, Russia 2: Plymouth Marine Laboratory, Plymouth,PL1 3DH, UK 3: Department of Oceanography, UNESCO Section Remote Sensing and Modelling in Oceanography,Russian State Hydrometeorological University, 195196,St. Petersburg, Russia 4: Max-Planck Institute for Meteorology, 20146,Hamburg, Germany
Publication date: 2013-02-20