A grid of 10 stations covering the whole area of the gulf, both nearshore and offshore, and near the polluting sources and aquacultures.

Ammonium and ammonia concentration parameters in water bodies; Dissolved oxygen parameters in the water column; Dissolved metal concentrations in the water column; Particulate metal concentrations in the water column; Nitrate concentration parameters in the water column; Concentration of polycyclic aromatic hydrocarbons (PAHs) in the water column; Phosphate concentration parameters in the water column; Salinity of the water column; Silicate concentration parameters in the water column; Temperature of the water column; Nitrite concentration parameters in the water column; Alkalinity, acidity and pH of the water column

Salinity sensor; pH sensors; spectrophotometers

The nutrients, trace metal and petroleum hydrocarbons were studied in the area of the Gulf of Astakos in the Ionian sea 1996 and 2000. Water samples were collected using HYDRO-BIOS sampling bottles from surface and deeper waters (surface, 10m, 20m, 50m). Basic physicochemical data were measured in situ. Analyses on nutrients (NO3, NO2, NH4, PO4., SiO4) were carried out according to the standard photometric methods of Strickland and Parsons. The particulate phase was obtained after filtration through a 0.45 micrometer Millipore membrane filter. The filters were then digested with conc. HNO3. The dissolved phase was preconcentrated on a CHELEX-100 resin and the metals were eluted with HNO3 acid. Special care was taken to eliminate any contamination problems during analysis. Trace metal concentrations were determined by GFAAS. Organic carbon was determined by a TOC analyzer and PAHs by a Perkin Elmer spectrofluorometer after extraction in n-Hexane. The sediments were collected using a grab and a Mackereth pneumatic minicorer. The cores obtained were 10 - 70cm deep and were sliced into subsamples 1 to 2cm thickness. The sediments were wet sieved through a 61 micrometer nylon net. Both fractions were digested with a mixture of HF-HNO3-HClO4 and measured for their total metal content with AAS.

University of Athens, Department of Chemistry, Division of Inorganic and Environmental Chemistry, Environmental and Marine Chemistry Group
Panepistimiopolis
Athens

157 01
Greece