Heavy metals in kidney tissues of Franciscana dolphin, Pontoporia blainvillei (Cetacea: Pontoporiidae), and their relationship with biological parameters

Heavy metal (Cd, Pb, Zn, Cu, Cr,Ni) concentrations were determined in the kidney tissue of the Franciscana dolphin, Pontoporia blainvillei, and the influence of ecological and biological parameters on the bioaccumulation of these elements was established. Samples from 38 specimens, collected between 2004 and 2010 off southern Buenos Aires, Argentina, were analyzed. Histological methods were used to determine both the age and sexual maturity of the animals. Heavy metal concentrations were measured by atomic absorption spectrophotometry. No significant differences were found by sex for Zn, Cu, and Cd. However, Cd levels differed between maturity stages and were positively related to length, body weight, and age. The Cd, Cu, and Zn levels reported here in were lower than those included in previous studies done off northern Buenos Aires and Uruguay.Original Abstract: En este estudio se determino los niveles de metales pesados (Cd, Pb, Zn, Cu, Cr y Ni) en el tejido renal del delfin franciscana, Pontoporia blainvillei, y se establecio la influencia de los parametros ecologicos y biologicos sobre la bioacumulacion de estos elementos. Se analizaron muestras de 38 ejemplares colectados entre 2004 y 2010 en el sur de Buenos Aires, Argentina. La edad de los animales y el estado de madurez sexual se determinaron por metodos histologicos, y los niveles de metales pesados por Espectrofotometria de Absorcion Atomica. No se determinaron diferencias significativas para las concentraciones de Zn, Cu y Cd entre ambos sexos. Los niveles de Cd presentaron diferencias segun el estado de madurez sexual y se relacionaron positivamente con la longitud, peso corporal y edad. Los niveles de Cd, Cu y Zn resultaron menores a los informados en estudios previos realizados en el norte de Buenos Aires y Uruguay.