In last years it has been a major change in the quantity and diversity of fish caught in the Black Sea. The study of fish species diversity caught in Romanian seaside area was carried out in June 2016, the data being compared with the 2004-2006 period. In 2004-2006, 10 species were identified from 10 fish families, and in 2016 were identified 16 species from 15 fish families. In 2016, the eudominant species were: Red mullet (Mullus barbatus ponticus), Black Sea horse mackerel (Trachurus mediterraneus), Round goby (Neogobius melanostomus), European anchovy (Engraulis encrasicolus); dominant was Whiting (Merlangius merlangus), and rare were Black Sea shad (Alosa tanaica), Bluefish (Pomatomus saltatrix), Garfish (Belone belone), Long-snouted seahorse (Hippocampus guttulatus), Black scorpionfish (Scorpaena porcus). In 2004-2006, the eudominant species were Round goby (Neogobius melanostomus), European sprat (Sprattus sprattus), Red mullet (Mullus barbatus ponticus); dominants were Black Sea horse mackerel (Trachurus mediterraneus), European anchovy (Engraulis encrasicolus), Turbot (Psetta maeotica), and rare were Starry sturgeon (Acipenser stellatus), European flounder (Platichthys flesus), Common sole (Solea solea). The percentage of global similarity within the specific composition between the samples collected in 2016 and 2004-2006 was 36%. In the two analyzed periods, the common species were Black Sea horse mackerel, European sprat, European anchovy, Whiting, Round goby, Red mullet and Common sole. Data and results obtained from samples taken from fishing grounds serve to compile fishery statistics and carry out work to assess the exploitable potential of the main fish stocks.