18 stations in the estuary of the Acheloos River, extending from the river mouth to 10 Km upstream, plus 11 marine stations in the area surrounding the estuary. The whole site is extending from 21° 00'50sE to 21° 10'00sE and from 38° 16'00sN to 38° 25'00sN

Ammonium and ammonia concentration parameters in water bodies; Dissolved oxygen parameters in the water column; Nitrate concentration parameters 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; Dissolved trace metalloid and inorganic selenium concentrations in water bodies; Particulate trace metalloid and inorganic selenium concentrations in water bodies

The aim of this study was to understand the prevailing mechanisms of trace metal behaviour and transport at the Acheloos estuary. For this purpose 8 water samplings were carried out at the following dates May 1983, July 1984, April 1985, December 1985, June 1986, February 1989, October 1989, June 1990 and 3 sediment samplings during September 1983, April 1984 and June 1986. During each water sampling, samples were collected from 11 stations (both marine and riverine, out of the 20 sampled throughout the project period). During February 1989 and October 1989 only 5 stations were sampled. Basic physicochemical data were measured in situ. Salinity was measured using a bench salinometer. Water samples were collected using HYDRO-BIOS sampling bottles from 3 depth intervals (surface, 20m, 40m) for the marine stations and 1 or 2 depth intervals (surface and/or 5m) for the riverine ones. The sediments were collected using a Mackereth pneumatic minicorer. The cores obtained were 10 - 70cm deep and were sliced into subsamples 1 to 2cm thickness. The particulate phase was obtained after filtration through a 0.45 micrometer Millipore membrane filters. The filters were then digested with nitric acid CHELEX-100 resin was used for the pre-concentration of metals that were eluded with 2N HNO3. Special care was taken to eliminate any contamination problems during analysis. Trace metals concentrations were determined by using an Atomic Absorption Spectrophotometer. The sediments were wet sieved through a 61 micrometer nylon net. Both fractions were digested with conc. HNO3 and measured for their total metal content. At the second part of the project additional analyses on nutrients (NO3, NO2, NH4, PO4, SiO4) were carried out according to the standard photometric methods of Strickland and Parsons. The data are stored on a DBase III Plus format with an index on sampling date, station and depth and can be processed in order to produce reports for each set of parameters (basic data, nutrients, each metal in dissolved and particulate phase, metals in sediments) as a depth series per station per sampling date or an 'historical' report as a time series per depth per station. Both these reports are stored as text files.

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

157 01
Greece