Abstract

A fishery using guns and nets for the common dolphin, Delphinus delphis, Azov dolphin, Phocoena phocoena, and bottlenose dolphin, Tursiops truncatus, in the Black and Azov Seas has been pursued since about 1870 from the USSR, Turkey, Bulgaria and Romania. Steadily declining annual Soviet harvests since the maximum Soviet catch of 135 000-140 000 animals in 1938, despite an increased catching effort, led to seasonal management restrictions by the USSR in 1962, and a complete closure of the fishery in the USSR, Romania and Bulgaria in 1967. The final annual Soviet catches of 5 600-7 400 animals reported for 1964-66 represent a major collapse of the fishery and were accompanied by apparent marked changes in the age and sex composition of the harvest and a change in the species composition from the historically predominant D. delphis to predominantly P. phocoena. The fishery continues in Turkey with recent reported annual catches approaching the 1938 Soviet maximum; the loss rate is estimated to be high because of the use of guns as the harvesting method.
Limited catch statistics are available since 1927, except for Romania, and are generally reported only for all species combined in total metric weight. Analysis indicates that the exploitation rate was probably excessive at the height of the fishery in 1936 (12.5-20.0 %) and may remain so today for the Turkish fishery (7.9-100.8 %).
Annual Soviet aerial surveys initiated since the 1967 moratorium provide questionable estimates of total population size of Black Sea porpoises. Problems with these estimates and probably also with kill estimates preclude definite understanding of the present state of the population and indicate the need to refine both these statistics. Present observations are confined to recognition that the numbers of porpoise in the Black Sea have declined substantially to marginal levels due to the direct fishery; the present Turkish fishery is important, particularly as it continues now when stocks are probably reduced.