Recalcitrant organochlorine compounds in captive bottlenose dolphins (Tursiops truncatus): Biomagnification or bioaccumulation?

Organochlorine residues were measured in the diet, blood, faeces and exhaled air of captive bottlenose dolphins (Tursiops truncatus) to evaluate the absorption efficiency from food and the eliminatory potential via faeces and exhaled air. Differences between air-breathing and water-breathing animals feeding on similar prey are briefly discussed. It is concluded that high concentrations of recalcitrant organochlorines currently found in marine mammals feeding on fish are essentially. due to the lack of branchial elimination and not to their predator status.