FLOW-CYTOMETRY FOR MONITORING CONTAMINANT EXPOSURE IN BLACK-CROWNED NIGHT-HERONS

The flow cytometry method (FCM) was employed to determine cellular DNA content of black-crowned night-heron (Nycticorax nycticorax) embryos and 10-day-old chicks collected at sites differing in types of chemica l contamination. The coefficient of variation of DNA content (CV) in b lood collected from embryos suggested cytogenetic damage at a site in Louisiana known to be contaminated with petroleum. Blood CV from chick s suggested genetic damage at a site in Texas also known to be contami nated with petroleum. Spleen CVs in chicks were significantly lower th an respective means from the reference site. The CVs of chick blood an d liver and spleen negatively correlated, suggesting recovery of splee n and liver cells after exposure to a clastogenic compound. Thus, the lower CVs may also have been indicative of genetic damage. Based on th e findings of this study, FCM is a potential indicator of certain envi ronmental contaminants in black-crowned night-herons.