[Effects of the fisheries along the West-African coast on nature values: fish eating birds as a quality criterion for the marine environment]

afrique du nord afrique occidentale birds coastal areas comportement alimentaire conservation de la nature environmental impact feeding habits fisheries impact sur l'environnement impacto ambiental indicator organisms monitoring nature conservation north africa oiseau organisme indicateur organismos indicadores peces marinos pesca poisson de mer saltwater fishes surveillance vigilancia west africa