"The paper aims to develop and test a semi-quantitative method that generates scenarios for the zooplankton community development under salinity and nutrients fluctuations. First, we identified the relationships between the mesozooplankton component and the environmental factors by analyzing data (N=2566) collected within the warm season (May-September) of a decade (2008-2018). The biotic and abiotic parameters were investigated at 37 stations within the monitoring network of the Romanian Black Sea waters, covering all three marine reporting units (waters with variable salinity, coastal and marine) according to Marine Strategy Framework Directive (MSFD). We identified 32 mesozooplankton species belonging to ten taxonomic classes, copepods representing the bulk of the community. In waters with variable salinity and coastal waters, the fodder component of the mesozooplanktonic community was dominant, while in marine waters the nonfodder component was better and exclusively represented by Noctiluca scintillans. Physicochemical parameters that showed significant correlations with the mesozooplankton species were S (salinity) and nutrients - NO2- (nitrite), NO3-(nitrate), PO43-(phosphate) and NH4+(ammonium). The number of species significantly correlated with the physicochemical parameters showed variations generally correlated with the increasing salinity gradient: in waters with variable salinity nine species being correlated, in coastal waters ten species, and in marine waters five species. Key-Words: mesozooplankton, fodder, nonfodder, correlations, physicochemical "

"Pelagic fish species can be affected by a series of infectious and parasitic diseases. The data used for this study are represented by the biological material collected between 2018 and 2019, from trap nets along the Romanian Black Sea waters. To establish the degree of parasitism, the following species of pelagic fish were studied: Sprattus spratus -sprat, Engraulis encrasicholus - anchovy and Trachurus mediterraneus- horse mackerel. Four species of endoparasites were identified, belonging to nematodes, as follows: Hysterothylacium aduncum, Contracaecum sp., Porrocaecumsp. and Anisakis sp. The parasites, especially found as larvae, more in free state and less trapped in the internal organs, infested the abdominal cavity, leading to degenerations, atrophies and reduction of the fish functions. The intensity of the parasitism infestation could be lethal, the size of the stocks being severely damaged. At the analysed fish species, the infestation degree was under 20 parasites per host, a low number of species recording the maximum value of 40 parasites per host. The parasites tend to accumulate with the increase of the fish's size, young stages being less affected. Key-Words: parasites, fish, nematodes, intensity, infestation degree "

As copepods are an important food source for most fish larvae, there is a continuing interest in developing techniques for culturing marine copepods as live food in aquaculture. Studies have shown that several species of calanoid copepods can be used successfully in aquaculture, acclimatized and grown in the laboratory over several generations and serve as testing organisms in acute toxicity tests. However, significant difficulties in cultivating calanoid copepods in high quantities were reported. They are related to their low tolerance to changes in water quality and reduced production capacity compared to other taxonomic groups. Therefore, working methods for obtaining viable cultures of calanoid copepods are dependent highly on the local environmental context. Until now, such a method has not been implemented for calanoid species from the Romanian Black Sea coast. This paper details the methodology we adapted and used for achieving a viable Acartia (Acartiura) clausi (Giesbrecht, 1889) culture using specimens collected along the Romania Black Sea coast Reproduction and egg hatching occurred under laboratory-controlled conditions, and viable individuals of A. clausi were obtained. Our results open the possibility of integrating this species in toxicity tests and food production for the marine aquaculture industry.

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