Organochlorine pesticides, PCBs, heavy metals and anticoagulant rodenticides in tissues of Eurasian otters (Lutra lutra) from upper Loire River catchment (France) Charles Lemarchand a, * , René Rosoux b , Philippe Berny a a Ecole Nationale Vétérinaire de Lyon, UMR INRA 1233, 1 Avenue Bourgelat, 69280 Marcy l’Etoile, France b Muséum des Sciences Naturelles, 6 rue M. Proust, 45000 Orléans, France article info Article history: Received 29 January 2010 Received in revised form 2 June 2010 Accepted 7 June 2010 Available online 1 July 2010 Keywords: Road-traffic killed otter Organochlorine pesticides PCBs Heavy metals Rodenticides France abstract In this study, tissues of the Eurasian otter (Lutra lutra) from a naturally expanding population along upper Loire River (France) catchment were used for contaminants analyses. nine organochlorine pesticides, 16 PCB congeners, five heavy metals (lead, cadmium, mercury, copper and arsenic) and three anticoagulant rodenticides were quantified in livers of road-traffic killed otters. Organochlorine compounds and heavy metals were found in 100% of the samples, and occasional contamination by anticoagulant rodenticides was confirmed. Total organochlorine pesticides reached a maximum of 9.4 mg kg À1 lipid weight. Higher data were observed for other contaminants, especially total PCBs and mercury. Maximal total PCBs values reached 64.8 mg kg À1 lipid weight, and maximal measured mercury concentration was 8.2 mg kg À1 fresh weight. Considering the expansion noted in the study area, global contamination does not seem to threat the short-term species conservation. Nevertheless, important values at some individual scale were noticed, suggesting high inter-individual variations in populations. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction The Eurasian otter (Lutra lutra), once widespread in Europe, has dramatically declined during 1950s–1980s, due to habitat degrada- tion and consecutively decline of the species’ main prey, and also to massive trapping for fur (Chanin, 2003; Liles, 2003; Kruuk, 2006). Global aquatic contamination by persistent pollutants (e.g. pesticides, polychlorinated biphenyls (PCBs) or heavy metals) is blamed to be the causative agent of the decline of Eurasian otter populations throughout Europe. Pesticides like DDE (main metab- olite of DDT), lindane, aldrin or dieldrin, and some highly persis- tent PCBs were often negatively correlated to otter population thrive or body condition (Mason and Macdonald, 1994; Kruuk and Conroy, 1996; Roos et al., 2001). Some studies underlined an increase in pollutants concentrations in otter tissue or scats with the increase of human population (Smit et al., 1998; Lemarc- hand et al., 2007). Mercury is generally considered as the most harmful metal to otters, and mercurialism was sometimes identi- fied as a death causal agent (Kruuk et al., 1997; Gutleb et al., 1998; Evans et al., 2000). Lead and cadmium were also found in many studies, but generally without detrimental effects on otters (Mason and O’Sullivan, 1993; Gutleb et al., 1998; Harding et al., 1998). Copper, as micronutrient, is unlikely to exceed critical lev- els in usual diet absorption but is able to illustrate background levels (Harding et al., 1998; Mason and Stephenson, 2001). Data concerning arsenic accumulation and toxicity in organisms or tro- phic webs are very scarce and should be enhanced, to complete general knowledge of heavy metals dynamic in environment. To our knowledge, only two studies mention otters contamination by arsenic (Kubota et al., 2001; Colas et al., 2005). In aquatic sys- tems, anticoagulant rodenticides have been widely and strongly used in France to control invasive rodents (muskrat Ondathra zib- ethicus and coypu Myocastor coypus). Physiological persistence of these compounds imply secondary poisoning of non-target spe- cies, especially predators and scavengers, including semi-aquatic mustelids like otter, American mink (Mustela vison), polecat (M. putorius) and even highly endangered European mink (M. lutreola) (Berny et al., 1997; Birks, 1998; McDonald et al., 1998; Shore et al., 1999; Fournier-Chambrillon et al., 2004; Giraudoux et al., 2006). So, due to their diversity, accumulation in tissues and magnification in food webs, toxic compounds are still considered as a potential threat to a global recovery of otter populations, even in apparently thriving ones (Leonards et al., 1998; Lemarc- hand et al., 2007), for which studies taking into account large pol- lutants diversity remain scarce. A natural recovery of otter is noted and studied in France since legal protection in 1972 (Bouchardy et al., 2001; Rosoux and Green, 0045-6535/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2010.06.026 * Corresponding author. Address: Université Blaise Pascal, 24, avenue des Landais – BP 80026, 63171 AUBIERE Cedex, France. Tel.: +33 4 73 40 77 12; fax: +33 4 73 40 76 70. E-mail address: Charles.LEMARCHAND@univ-bpclermont.fr (C. Lemarchand). Chemosphere 80 (2010) 1120–1124 Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere