The translated and annotated materials in this volume constitute a collection of 18 formerly secret internal reports written by Soviet scientists working aboard whaling factory ships in the North Pacific. The reports cover the period from 1955 to 1978. During most of this time, the USSR was engaged in a massive campaign of illegal whaling worldwide; these illegal catches continued until introduction of the International Whaling Commission’s International Observer Scheme in 1972. The reports were copied from the archives of the Pacific Research and Fisheries Center (TINRO) in Vladivostok by Alfred A. Berzin, the former director of TINRO’s marine mammal program. The reports were all separately produced; the represent the introductory and summary sections of much larger annual reports that are probably no longer available. The authors were all scientists who worked at different times with the whaling fleets concerned; most were affiliated with TINRO. The reports document dramatic declines in abundance, disappearances of whales from previously populous feeding and breeding areas, and a continual decline in the average size and age of animals in the catch as the over-exploitation reached critical levels. Also recorded are the repeated warnings of the reports’ authors that the catch levels could not be sustained without severe damage to (or extirpation of) the populations concerned. However, it is apparent that all such warnings were routinely ignored by the Soviet authorities in their quest to meet high production targets