Long-term feeding ecology and habitat use in harbour porpoises Phocoena phocoena from Scandinavian waters inferred from trace elements and stable isotopes

摘要: We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along Scandinavian coast from North Sea to Barents using time-integrative markers: stable isotopes (δ13C, δ15N) trace elements (Zn, Cu, Fe, Se, total Hg Cd), relation characteristics (bathymetry) geographic position (latitude). Among analysed, only Cd, with an oceanic specific food origin, was found be useful as ecological tracer. All other studied were not useful, most likely because physiological regulation and/or few sources web. The δ13C, δ15N signatures Cd levels highly correlated each other, well local bathymetry Variation isotopic ratios indicated a shift porpoise's habits pelagic prey species deep northern waters more coastal demersal relatively shallow Skagerrak waters. This result is consistent stomach content analyses literature. associated northward Cd-enrichment which provides further support 'anomaly' previously reported polar suggests that include Cd-contaminated their diet, such cephalopods. As provide information medium long term respectively, spatial variation found, shows experience different regimes during year coasts, adapting oceanographic conditions, without performing extensive migration.