HYDROBIOLOGICAL ORGANIZATION OF A BAHIRA TYPE PARALIC BASIN - KALLONIBAY (LESBOS, GREECE)

The deep, elongated paralic basin of Kalloni bay has been studied thro ugh comparisons between several computed hydrodynamical situations and data collected in similar situations from its water body. These inclu de salinities and phytoplanktonic biomasses. Additionally, sedimentolo gical data, which integrate the environmental variations on the long t erm, have been collected in order to help in understanding the average biogeological functioning of the system. Depending upon its direction and speed, wind forcing induces different salinity and phytoplanktoni c patterns. These generally display rather weak gradients from the ent rance and the axial deepest channel towards the farthest northeastern reaches of the basin. Moreover, the ranges of salinities and phytoplan ktonic biomasses display a very low degree of restriction from the sea (confinement), while the global phytoplanktonic composition, analysed by flow cytometry, shows the prominent marine influence over the basi n. The average hydrodynamical conditions are dominated by the axial in flux of marine water on the bottom, and by the surface-reflux of basin al waters along both side banks. Such a prevailing configuration is al so displayed by sedimentological features. Kalloni bay appears as one of the less confined systems in the Mediterranean region, due to its s hape and bathymetry, the absence of a sill between the basin and the s ea, and active exchanges with the sea under the influence of wind acti vity.