The experiment was performed on marine Teleost Serranus scriba with lower concentrations of lindane then MPC (due to our valid law). The aim of this study was to find the effects of lindane to fish activities connected with nutrition. This motive is among the strongest. It includes parameters as: number of fish movements in the presence of prey or without it and the number of onslaughts to the prey during one hour. The results have shown that the increasing of lindane concentration caused considerable decreasing and even complete cessation of activity. Interest for prey and decreasing activity of predators in the presence of prey (typical for Serranus - as a fish of prey and the hunter) endures till the moment of convulsion.

Studies of phytoplankton in the Montenegrin coastal sea (Adriatic Sea), Montenegro (Yugoslavia), have been done in August and September 1998. Simultaneously, investigations were carried out in the area of Boka Kotorska Bay (Kotor and Tivat Bays) and outside the Bay, i.e. in the zone exposed to the influence of the open sea (Petrovac and Budva). It was found that the density of microphytoplankton is higher during summer, than in the autumn. So in the summer-period, as a consequence of stronger eutrophication process, mean-value of microphytoplankton density was 10**5 cells/cubic dm, and in autumn 4 x 10**4 cells/cubic dm. On the contrary, mean-value of nanophytoplankton density was higher in the autumn (5.2 x 10**6 cells/cubic dm) than in summer (3.5 x 10**5 cells/cubic dm), being a consequence of a decreasing eutrophication during colder period of the year. Having in mind the direct influence of the open sea outside the Bay, it is intelligible that population density of both phytoplankton size-fractions is lower along the Montenegrin coast, than in the Boka Kotorska Bay (Montenegro, Yugoslavia).

Some new results of the monitoring and control of the sea-water quality along the Montenegrin coast of the Adriatic sea, Montenegro (Yugoslavia) are presented. The recent data from summer 1998 are compared with some previous results. So, increasing of temperature mean values and decreasing of salinity and sea-water density were found in comparison with the previous years in the whole investigated area. At the same time, the quality of the sea is growing worse, step by step. Faster changes were found in Boka Kotorska Bay, Montenegro (Yugoslavia) than outside of the bay, in the zone which is exposed to the stronger influence of the open sea. Finally, the most essential conclusion is that the solution of wastewater discharges becomes more and more important, especially in semienclosed Boka Kotorska Bay (Adriatic Sea, Montenegro, Yugoslavia).