DDE feeding and plasma osmoregulation in ducks, guillemots, and puffins

To assess the possibility that organochlorine pesticide disruption of osmoregulation is responsible for recent large kills of young seabirds, we have studied the effects of DDE feeding (10-250 ppm) on plasma osmoregulation and nasal gland function in the following species: mallared and white Pekin ducks (both Anas platyrhynchos), black guillemot (Cepphus grylle), and common (Fratercula arctica). Other investigators have recently reported that dietary DDE (10-1,000 ppm) inhibits nasal gland secretion in freshwater-maintained mallards; our initial experiments with white Pekins showed no such inhibition during either freshwater or seawater maintainance. Moreover, DDE had minimal effects on plasma electrolyte levels and total nasal gland Na-K-ATPase activities in all species studied. Liver DDE levels in experimental ducks and guillemots were comparable to those reported for seabirds found dead after kills; levels in starved experimental puffins were much higher. Thus DDE at environmental levels does not affect osmoregulation or nasal gland Na-K-ATPase either in ducks or in two species of oceanic birds.