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

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“…Instead, the observed high concentrations were mostly resulted from different study area (e.g. coastal waters), The earlier studies on the primary production along the Black Sea showed two distinct periods (early spring and autumn) of enhanced PP and recently additional summer blooms have frequently been reported in the coastal and open waters (Hay et al, 1990;Sur et al, 1996;Yilmaz et al, 1998). The spring bloom along the coastal waters is mainly dependent on riverine input and commences during early spring (i.e.…”

“…Overall, PP in the Black Sea displays two phytoplankton peaks throughout the year; the major bloom of mainly diatoms occur in early spring while a secondary bloom of mainly coccolithophores appear during autumn in both the coastal and open waters (Sorokin, 1983;Vedernikov and Demidov, 1997). Recently, additional summer blooms of dinoflagellates and coccolithophorids (mainly Emiliana huxleyi) have frequently been reported (Hay et al, 1990;Sur et al, 1996;Yilmaz et al, 1998;Yayla et al, 2001). The most important changes in the Black Sea ecosystem recorded over the last decade are changing of the ratio of major phytoplankton groups (Bat et al, 2011;BSC 2008;Feyzioglu and Seyhan, 2007) resulted from the deterioration of the Black Sea ecosystem (Kideys, 2002;Kopelevich et al, 2002).…”

Long-term variations of surface chlorophyll a and primary production in the open Black Sea

“…The Danube alone was reported to have introduced 60 000 t yr -1 of total phosphorus and about 340 000 t yr -1 of total inorganic nitrogen to the northern and northwestern regions of the Black Sea before 1992 (Mee 1992). In contrast, in the southern region of the basin, the major Turkish rivers were estimated to have contributed only 1700 t yr -1 of orthophosphate and 25 000 t yr -1 of total inorganic nitrogen in the same period (Sur et al 1996).…”

“…In addition to these features, a series of anti- cyclonic eddies are confined inshore of the Rim Current (Eremeev et al 1992). The meandering and filamenting structure of the Rim Current may realize the water exchanges between shelf and deep waters of the Black Sea (Sur et al 1994(Sur et al , 1996. Significant quantities of freshwater bearing nutrients, heavy metals, pesticides and hydrocarbons discharged by major rivers (mainly the Danube) are transported along the coast by the meandering boundary current, which may introduce them into the interior of the basin via turbulent exchanges and filament formations.…”

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“…So it provides an ideal site for exploration of microbial processes (Murray et al, 1995;Oguz et al, 1999). The Black Sea fed by many large rivers runoff which carry considerable loads of anthropogenic nutrients and contaminants, and the shelf waters are generally more turbid and polluted than the gyre waters (Murray, 1991;Sur et al, 1996). …”