Application of SeaWiFS data for studying variability of bio-optical characteristics in the Barents, Black and Caspian Seas

We report the results of our study of spatial and temporal variability of the bio-optical characteristics in the Barents, Black and Caspian seas derived from SeaWiFS data in 1998–2001. The modified bio-optical algorithms were used to derive chlorophyll concentration, particle backscattering, and yellow substance absorption coefficients. The mean monthly distributions of the above characteristics were constructed, and variations of their monthly means in the different regions were analyzed. No significant correlation was found between the variations of chlorophyll concentration in open parts of the basins and the coastal regions with river run-off, suggesting no direct effect of the processes in the coastal zone on bio-productivity in the open parts. Of particular interest is the sharp increase of chlorophyll concentration and particle backscattering found in the Middle and Southern Caspian in July–August 2001, perhaps the result of invasion of the ctenophore, Mnemiopsis leidyi. That event as well as the suspected coccolithophorid bloom in the Middle Barents in July–August needs field evidence.