Dynamics of developmental stability of seals and pollution in the Baltic Sea

Abstract

Zakharov V. M., Valetsky A. V. and Yablokov A. V. 1997. Dynamics of developmental stability of seals and pollution in the Baltic Sea. [In: Developmental homeostasis in natural populations of mammals: phenetic approach. V. M. Zakharov and A. V. Yablokov, eds]. Acta Theriologica, Suppl. 4: 9-16. Fluctuating asymmetry of skull characters, as a measure of developmental sta­ bility, was studied in two seal species: grey seal Halichoerus grypus (Fabricius, 1791), and ringed seal Pusa hispida Schreber, 1775 from the Baltic Sea. Seals were collected in three different periods of water pollution of the Baltic Sea. We revealed the same temporal dynamics of fluctuating asymmetry level for both species: it proved to be low in “pre-pollution period” (years 1877-1936), high for the “high-pollution period” (1964-1975), and was again low for the “low-pollution period” (1986-1990). These data suggest that changes in the condition of the seal populations in the Baltic Sea revealed by changes in developmental stability are correlated with the dynamics of the pollution level. N. K. Koltzov Institute of Developmental Biology Russian Academy of Sciences, Vavilov Str. 26, Moscow, 117808 Russia