TITLE:
Physical, Biochemical and Biological Characterization of Two Opposite Areas in the Southern Adriatic Sea (Mediterranean Sea)
AUTHORS:
Alessandra Campanelli, Marina Cabrini, Federica Grilli, Daniela Fornasaro, Pierluigi Penna, Zoran Kljajić, Mauro Marini
KEYWORDS:
Adriatic Sea; Nutrients; Dissolved Organic Matter; Phytoplankton; Temperature
JOURNAL NAME:
Open Journal of Marine Science,
Vol.3 No.2,
April
30,
2013
ABSTRACT: The Drini and ManfredoniaGulfswere investigated in May 2008 and April 2009, respectively. The gulfs are located in the South Eastern (GulfofDrini) and South Western (GulfofManfredonia)Adriatic Sea. The areas are partially influenced by two main Adriatic surface currents: the Eastern Adriatic Current-EAC that flows north-westward along the eastern side, and the Western Adriatic Current—WAC that flows south-eastward along the western side of the basin. The spatial variations of temperature, salinity, fluorescence, dissolved oxygen concentration, Coloured Dissolved Organic Matter—CDOM, nutrients, chlorophyll a and phytoplankton composition parameters in the two areas were observed and compared. CDOM regulates the penetration of UV light into the sea and plays an important role in many hydrological and biogeochemical processes on the sea surface layer including primary productivity. The phytoplankton specific diversity of the Gulf of Manfredonia showed a spring community with dinoflagellates (21 taxa) as the main important fraction, coccolithophorales (6 taxa) and diatoms with 10 identified taxa. The phytoplankton distribution along the eastern coast showed a different biodiversity: a prevalence of dinoflagellates (58 taxa) included harmful microalgae such as Alexandrium, Dinophysis and Lingulodinium genus. Diatoms were less abundant, among them Pseudo-nitzschia was also reported which could include some potentially toxic species. Nanoplankton are ever abundant in offshore waters and an exceptional bloom of cyanobacteria was registered in Buna-Boyana estuary due to strong industrial impact. The gulfs showed similar physical and biochemical characteristics despite the WAC carried out along the westernAdriatic Seathe water rich in nutrients from the major northern Italian rivers. No correlations were found between CDOM and chlorophyll a in the two areas and this implied that, probably, the primary source of CDOM might come from terrestrial input rather than the biological production from phytoplankton. The Gulf of Drini is impacted by the runoff of the Buna-Bojana River that makes this gulf an eutrophic area despite the mostly eastern side of the Adriatic being an oligotrophic basin.