A late winter bloom observed in March 2000

Offshore of Southern Brittany, a bloom started from clear and stratified waters located over the 120 meter depth line (March 5) and reached the coast on March 16. This bloom appeared in frontal waters, in the plume of the rivers of South Brittany (Loire, Vilaine, ?). Thanks to haline stratification, the homogeneous surface layer was thin enough (30 m) for favouring the exploitation of the incoming light by phytoplankton.

At that period of the year, the light is the limiting parameter and blooms develop outside of the turbid areas.

 

Chlorophyll-a-05-Mar-2000Chlorophyll-a by SeaWifs (Ifremer algorithm) on 05-Mar-2000 Chlorophyll-a-12-Mar-2000Chlorophyll-a by SeaWifs (Ifremer algorithm) on 12-Mar-2000 susp-matter-05-Mar-2000Inorganic suspended matter by SeaWifs (Ifremer algorithm) on 05-Mar-2000
 

 

image7Irradiance is relatively high from March 5 to 16 (here image of March 16) and the wind is weak:

image8Salinity from the hydrological model MARS-3D, soon available in the browser: