Pup production and breeding distribution of the Caspian seal (Phoca caspica) in relation to human impacts.
Aerial surveys of Caspian seals on the winter ice field in Kazakhstan territorial waters were carried out in February 2005 and 2006 to assess the annual pup production for the species and natural predation on newborn pups. Estimated pup production was 21063 in 2005 and 16905 in 2006 (including an estimated figure for pups born in Russian territory in each year). The breeding population size of approximately 20 000 females is much less than published estimates from the late 1980s. Eagles were the principal natural predators of pups. Commercial icebreaker routes passed through areas of dense pup concentrations in 2006, although not in 2005. Our findings have important implications for the development of conservation strategies for the species. Natural mortality, loss to predators, and, more important, the current hunting quota substantially exceed the recruitment of the Caspian seal population. Anthropogenic sources of mortality should be managed to avoid further declines in the species.
Harkonen
Tero
T
Swedish Museum of Natural History, Stockholm, Sweden. Tero.Harkonen@nrm.se
Jüssi
Mart
M
Baimukanov
Mirgaly
M
Bignert
Anders
A
Dmitrieva
Lilia
L
Kasimbekov
Yesbol
Y
Verevkin
Mikhail
M
Wilson
Susan
S
Goodman
Simon J
SJ
D000818:Animals; D000831:Animals, Newborn; D003247:Conservation of Natural Resources; D020307:Eagles; D006801:Humans; D007623:Kazakhstan; D046049:Phoca / Q000254:growth & development*; D011157:Population Dynamics; D011235:Predatory Behavior; D012098:Reproduction; D019596:Wolves