Phytoplankton Blooming in the Mediterranean Sea as Seen by SeaWiFS (1998-2003)

Assessments of SeaWiFS-derived (1998-2003) chlorophyll-like pigment concentration (Chl) were used to survey phytoplankton growth patterns in the Mediterranean Sea. The Chl average basin value, computed from yearly and monthly mean images, shows a decreasing trend, modulated by bimodal seasonal patterns, with maxima in late winter and minima in late summer. Chl anomalies, computed as the normalized difference between yearly/monthly means and corresponding climatology, become smaller with time over most of the basin. Both these elements point to a decrease of blooming intensity in the period considered, suggesting a more stable stratification and a reduced nutrient input by vertical mixing in the basin, in line with its reported warming trend. Larger and larger anomalies appear in hot spots along the Catalan and the Egyptian-Israeli-Lebanese coast, possibly owing to local factors such increased runoff.JRC.H.3-Global environement monitorin