Coastal/deep ocean interactions in the Black Sea and their ecological/environmental impacts

Abstract Satellite (CZCS, AVHRR) and in-situ (CTD, ADCP) data are utilized to characterize the impact of meso-scale motions and boundary currents on transport and productivity along the wide Western Black Sea Shelf. Various forms of isolated transient features including filaments, coherent dipole and monopole eddies and jets transport materials and momentum across the continental shelf. Unstable meandering motions generated at topographic irregularities propagate along the continental slope. As a result of the meandering motions, the material transported spreads into an area several times wider than the continental shelf/slope region. The spring-time surface productivity in the southern Black Sea is modulated by transient dynamics. Species differentiation and competition are evident along the boundary current system. Early summer plankton blooms coincide with peak flood discharges from major rivers, and influence the spread of eutrophication in the basin. Upwelling patches are evident along the west Anatolian coastline, in response to transient surface divergence. The upwelling locally has an adverse effect on fish eggs and larvae. In winter, cold water is formed on the western continental shelf. As the band of cold water follows the coast and interacts with coastal geometry, it leads to winter plankton blooms, particularly along the southern coast. Coherent meso-scale/synoptic eddies and turbulent features are shown to evolve rapidly in the system, indicating rapid conversions between different forms of energy in the upper layers of the ocean.