PARENT SESSION
Organized Oral Session 7: Ecological effects of the chernobyl disaster: Genes to ecosystems
Organizer(s): JT Morris, TA Mousseau, and MA Goni
Monday, August 8, 1:30 PM - 5:00 PM, Meeting Room 510a, Level 5, Palais des congrès de Montréal

Determinants of levels of ⁹⁰Sr and ¹³⁷Cs in birds from Chernobyl.

Gaschak, Sergey^*,1, Mousseau, Timothy², Moller, Anders³, ¹ International Radioecology Laboratory, Slavutych, Ukraine² University of South Carolina, Columbia, SC, USA³ University of Pierre et Marie Curie, Paris, France

ABSTRACT- We analyzed 228 individual birds of 23 species captured in Chernobyl, Ukraine, for presence of the two isotopes ⁹⁰Sr and ¹³⁷Cs. The two isotopes were positively correlated across individuals and species, although the slope of the relationship between ⁹⁰Sr and ¹³⁷Cs differed significantly among species. There were significant differences in levels of ⁹⁰Sr and ¹³⁷Cs among species independent of age. Variation in ⁹⁰Sr among species was predicted by use of soil invertebrates for food (higher in species eating soil invertebrates, probably because of higher levels of contamination in the upper soil level) and bird migration (lower in migrants, apparently because of reduced exposure due to presence in contaminated areas only during the breeding season). Sexes differed in levels of radiation, with males having higher levels of ¹³⁷Cs than females. The sex difference in ¹³⁷Cs was larger in hole than in open nesting species. There were significant differences among age classes, with nestling great tits Parus major having much higher levels than adult females and, in particular, than adult males. Minisatellite mutation rates estimated from published studies of paternity in birds were significantly predicted by ⁹⁰Sr, suggesting that the uptake of ⁹⁰Sr is a predictor of susceptibility to mutagens even outside Chernobyl.

Key words: age differences in isotope content, ecological correlates of isotope content in birds, mutation rates, Chernobyl