Adriatic Sea, 8 neritic sites from near the Po River to near Pescara

Variable fluorescence parameters; Chlorophyll pigment concentrations in water bodies; Nitrate concentration parameters in the water column; Nitrite concentration parameters in the water column; Salinity of the water column; Temperature of the water column; Phytoplankton taxonomic abundance in water bodies; Density of the water column

Radiometers; CTD; active fluorometers

We have focused our investigation mainly on the relationship between the photosynthetic available radiation (PAR) and its attenuation and the phytoplankton biomass which is generally very high in this area. Eutrophic conditions seem to be quite chronic to the Northern Adriatic and in the last few years this has led to large proliferations of mucus aggregates produced by phytoplankton. 1) Chlorophyll-a profiling by Back-Scat Dr. Haardt fluorometer, connected to a Meerestechnik, KMS type CTD profiler. 2) Vertical profiles of downwelling, upwelling and scalar PAR quantic irradiance were measured by a photoprobe equipped with 3 LICOR cosine Li192 SA sensor, one upwelling and two downwelling (one towards the sea surface and the latter below the surface) and one spherical downwelling (Li 195 SA). 3) Water sampling at different depths was carried out using 5 l. Niskin bottles. 4) Chloropheopigments and chlorophyll-a, b and c were analyzed in the laboratory by spectrophotometry according to Jeffrey and Humphrey (1975) and Lorenzen (1967), modified by Riemann (1978) for pheophytin-a and chlorophyll-a. 5) Dissolved organic matter (yellow substance or gilvina) was estimated by spectrophotometry according to Bricaud et al. (1981). 6) Particulate organic matter was collected by filtering through Whatman GF/C filters and analyzed by CHNS. 7) Concentration of suspended particles and their size spectra by Coulter Counter. 8) Primary production has been measured by C-14 according to the integral production method of Riemann et al. (1991).

Universita' di Firenze, Laboratorio di Ecologia, Dipartimento di Biologia Vegetale
Via P.A. Michelini 1
Firenze

50121
Italy