Kordian Trella
Sea Fisheries Institute, Kołłątaja 1, 81-332 Gdynia, Poland

Key words: southern Baltic, ichthyofauna, sand eel, greater sand eel.

Abstract.
In 1998 research catches were carried out in two naturally varied basins of the southern Baltic. Sand eel and greater sand eel dominated the catches. The presence of clupeoids (sprats, herring), flatfish (flounder, brill), goby fish and eelpout were also noted. In both regions the following freshwater fish were observed: perch, common bream, pikeperch, ruffe, smelt and stickleback. Water depth in both areas did not exceed 10 m. In both of the areas investigated fish which inhabit the bottom areas, greater sand eel and sand eel, dominated. The investigations confirmed earlier observations pertaining to the migration of freshwater fish such as perch, pikeperch and common bream to the sea.