Reintroduction of the otter (Lutra lutra) into Catalan rivers, Spain: assessing organochlorine residue exposure through diet.

摘要: Otter (Lutra lutra) populations have been declining in Europe for the last fourdecades. Several causes, such as hunting, habitat destruction or human disturbanceshave involved, but pollution from organochlorine compounds (OCs), andespecially polychlorinated biphenyls (PCBs) seemed to play an important role thisdecline. Over years, PCB concentrations otter tissues declinedannually some 7-8% and are recovering parts of Europe(Mason 1998).In Spain, thriving present West, become extinctin many Mediterranean rivers. In Catalonia (NE Spain), otters were only3.1% 392 transects rivers 1984 (Delibes 1990). four decades, amarked decline population has taken place this region. This is also casein Muga Fluvia rivers, where common 1950s becameextinct 1980s. However, since 1980s conservation beenimproved a result establishment Natural Parks created thesurroundings these by regeneration old wetlands theEmporda marshes, which more suitable otter. Moreover, thepreservation riparian forest represents opportunity maintain corridor foranimals different reserves.All facts encouraged reintroduction programs Catalan basins.However, assessment levels known pollutants responsible otterdeclines necessary. The OCs freshwater fish two studiedbasins scarce (Lopez-Martin et al. 1995), further analyses needed.This paper describes results analysis prey theMuga basins 1994 discusses feasibility otterreintroduction project.MATERIALS AND METHODSAlong Fluvia, Emporda marshes (Aiguamolls del’Emporda Park) at mouths both (Figure 1), six, six fivesampling points, respectively, analyzed. river irrigates farming area,