Neretva river estuary is important ecosystem and fishery ground along the Eastern Adriatic coast and it always supported local population with significant income from fishery.the main commercial fish were mullets, eel, and few sparids species. Although, huge land reclamations of delta wetlands in the last 40 years significantly affected local fish community and fishery, it still presents important additional income to artisanal and small fishermen.However, during the last decade we observed changes with significantly affected this situation. The most dangerous is arrival of bluefish, Pomatomus saltatrix wich established strong population and reproduction cycle. It preyed massively on all species of mullets either swimming or caught in nets. It was also observed that it preyed on migrating silver eels. The recent change is also domination of leaping grey mullet, Liza saliens among all mullets species and significant decline of the most valuable flathead grey mullet, Mugil cephalus. The present situation is caracterized by lowering of total catch quality, and significant loss of income of small and artisanal fishermen, due to recent changes. Furthermore, bluefish destroyes frequently traditional driftnets making losses higher. Still, there are no efficient fishery tools or ways to catch bluefish in biger quantites. the local bluefish life cycle- mainly reproductive migration and spawning grounds is unknown, and this make impossible catch during migration and spawning aggregations using purse-seine fishery. The scientific research is needed to describe the life cycles of new species in this area in order to protect and enhance fishery activity as significant socio - economic factor of traditional life style.

Biology