Soviet catches of southern right whales Eubalaena australis, 1951–1971. Biological data and conservation implications

Between 1951/1952 and 1970/1971, a total of at least 3368 southern right whales Eubalaena australis were taken by Soviet whaling expeditions in the Southern Hemisphere, despite the species being internationally protected since 1935. These catches and the associated biological data (presented here for the first time) represent a unique source of information on the distribution, movements, size composition, reproduction and feeding of southern right whales during summer months. Revelation of these previously unreported catches also has implications for the assessment of the current status of right whale stocks. Incorporation of the Soviet catches into population assessments generally leads to higher estimates of the size of the population at protection, but the relative increase in this size depends on the intrinsic rate of increase in the population.