Distribution and Habitat
The Caspian seal is endemic to the Caspian Sea. Whelping occurs in the northern basin in waters controlled by Russia and Khazakstan.
Adult Caspian seals are typically 130-140 cm long and may reach 180 cm. They average 50-60 kg and may be as heavy as 86 kg. Newborn pups are 67-79 cm and weigh ca. 5 kg. Adult coat is as illustrated, with males dark-spotted and females light-spotted. Pups are silvery-grey at birth. Females mature at age 4-5 years and males at 6-7 years. Life expectancy is approximately 35 years and annual pregnancy rates have ranged between 40-70%. Currently the annual pregnancy rate is at historically low values and is believed to be on the order of 30%. Diet is primarily fish, including freshwater species captured in estuaries, and crustaceans.
Entered in the IUCN Red Data List as Vulnerable, a number of national and international agencies have expressed concern recently about the poor condition, low reproductive success and high mortality of Caspian seals. The most recent estimate of Caspian seal numbers was made in 1989, at which time they were estimated to number approximately 420,000.
Threats to the Species
Threats to the species include competition for resources with commercial fishing interests, toxic pollution, habitat degradation and destruction, human disturbance, disease and commercial exploitation. Recent data indicate that Caspian seals are in poor condition and mass mortalities have been reported. Canine distemper virus has been isolated from one dead seal, raising the possibility that contagious disease has been a factor. Since the dissolution of the Soviet Union, the commercial hunt for Caspian seals has been prosecuted in both Russia and Khazakstan, complicating management. As well, resources available to managers have been sharply reduced. Oil extraction has not been concentrated in the northern basin where the Caspian seals whelp, but exploration is now taking place there and it appears that drilling platforms will be constructed more or less in the middle of the whelping grounds.
Reijnders, P. et al. 1993. Seals, Fur Seals, Sea Lions, and Walrus. Status Survey and Conservation Action Plan. IUCN Seal Specialist Group. Gland, Switzerland. 87pp.
Rice, D.W. 1998. Marine mammals of the world: systematics and distribution. The Society for Marine Mammalogy Special Publication Number 4. 231 pp.