Use of skin and blubber tissues of small cetaceans to assess the trace element content of internal organs

In order to evaluate the use of biopsy samples as non-destructive tool for assessing trace element concentrations in small cetaceans, the concentrations of 14 trace elements were determined in skin, blubber, liver and kidneys of four species of small cetaceans (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus and striped dolphin Stenella coeruleolba), stranded and/or by-caught along the NE Atlantic Ocean coast between 2001 and 2008. Only Cu, Fe, Hg, Mn, Ni and Zn were above the detection limit of the instruments and showed recoveries satisfactory enough to be interpreted. Among these trace elements, Hg was the only one showing a significant correlation between concentrations in and those in liver and kidneys. In consequence skin and blubber can only be used as non-invasive monitoring tissues to investigate Hg bioaccumulation in internal tissues for cetacean populations.

We greatly acknowledge the stranding networks from France (Observatoire PELAGIS), Spain (CEMMA), and Portugal (SPVS) for providing us cetacean samples. We also thank A. F. Guerra and F. Read from the Instituto de Investigaciones Marinas (C.S.I.C) in Vigo, Spain, and W. Dabin from the Observatoire PELAGIS in La Rochelle, France, for the age determination of the individuals. We also wish to thank C. Pignon-Mussaud from the Cellule Géomatique (UMR LIENSs) for providing the map of the study area and M. Kalombo from the Centre Commun d’Analyses (Fédération de Recherche en Environnement pour le Développement Durable FR 3097 CNRS-IFREMER-Université de La Rochelle) for running part of the trace element analyses. This work has been funded by the CPER 13 (Contrat de Plan Etat Région) through a post-doctoral grant to AA and PMF acknowledges support from the Portuguese Foundation for Science and Technology of the Government of Portugal (SFRH/BD/36766/2007).

published