Ecotoxicological and environmental study of the Drôme river : application to the survival of the otter

• Main Author: Richard-Mazet, Alexandra
• Other Authors: Laboratoire de toxicologie Unité mixte de recherche ENVL-INRA (UMR 1233), Institut National de la Recherche Agronomique (INRA), Université Joseph-Fourier - Grenoble I, Philippe BERNY([e-mail])
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2005
• Subjects: otter; polychlorinated biphenyls; heavy metals; loutre; Lutra lutra; polychlorobiphényles; métaux lourds; Ardèche; Drôme; Alsace; [SDV]Life Sciences [q-bio]; Cora; Loutre
• Online Access: https://theses.hal.science/tel-00275129; https://theses.hal.science/tel-00275129/document; https://theses.hal.science/tel-00275129/file/These_Richard-mazet.pdf

In the late 1950s and 1960s, a steep decline in otter (Lutra lutra) populations took place throughout most of Western Europe. Many different explanations for this decline have been presented; e.g. hunting, habitat destruction, eutrophication, and toxic chemicals. A factor seems to occupy a dominating place in this disappearance: contamination of the food chains by organochlorine pesticides and polychlorinated biphenyls (PCBs). In France, otter populations disappeared from many regions, but remain present in the Massif Central and on the Atlantic coast. There is also a residual population in Alsace, coming from a reintroduction campaign. With the ZABR (Zone Atelier Bassin du Rhône) and in collaboration with the CORA (Centre Ornithologique Rhône-Alpes), we conducted a study on the Drôme river in order to evaluate the status of the local otter populations. In parallel, an ecotoxicological study of this river was undertaken, with analysis of the cumulative pollutants (PCBs, organochlorine pesticides and heavy metals) along the food chain. A sociological survey evaluated the status of knowledge and the perception of this animal by the users of the river (fishermen, hunters, kayakers, etc). Are otters present on the Drôme river bassin? Is this habitat suited to the survival of this animal? What is the status of pollution of this river? Which comparison can be made with the Ardèche and Alsace populations? Here are the major questions, which we tried to answer. Dans les années 1950-60, un déclin des populations de loutre a été observé dans tous les pays européens. Différentes causes sont à l'origine de ce déclin : chasse, destruction de l'habitat, eutrophisation et pollution chimique. Un facteur semble occuper une place prépondérante dans cette disparition : la contamination des chaînes alimentaires par les pesticides organochlorés et les polychlorobiphényles. En France, les populations de loutre ont disparu de nombreux départements, mais restent présentes dans le Massif Central et sur la côte Atlantique. Il existe ...