Dear Marmammers, The following article on harbour porpoise feeding ecology and habitat use has just been published in BMC Ecology. If you are interested in, you can download freely the MS at this address: http://www.biomedcentral.com/1472-6785/7/1/abstract All the best, Michaël Fontaine MC, Tolley KA, Siebert S, Gobert S, Lepoint G, Bouquegneau JM and Das K (2007) Long-term feeding ecology and habitat use in harbour porpoises /Phocoena phocoena/ from Scandinavian waters inferred from trace elements and stable isotopes.BMC Ecology 2007, 7:1 doi:10.1186/1472-6785-7-1 Background We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative markers: stable isotopes (d13C, d15N) and trace elements (Zn, Cu, Fe, Se, total Hg and Cd), in relation to habitat characteristics (bathymetry) and geographic position (latitude). Results Among the trace elements analysed, only Cd, with an oceanic specific food origin, was found to be useful as an ecological tracer. All other trace elements studied were not useful, most likely because of physiological regulation and/or few specific sources in the food web. The d13C, d15N signatures and Cd levels were highly correlated with each other, as well as with local bathymetry and geographic position (latitude). Variation in the isotopic ratios indicated a shift in harbour porpoise's feeding habits from pelagic prey species in deep northern waters to more coastal and/or demersal prey in the relatively shallow North Sea and Skagerrak waters. This result is consistent with stomach content analyses found in the literature. This shift was associated with a northward Cd-enrichment which provides further support to the Cd 'anomaly' previously reported in polar waters and suggests that porpoises in deep northern waters include Cd-contaminated prey in their diet, such as oceanic cephalopods. Conclusion As stable isotopes and Cd provide information in the medium and the long term respectively, the spatial variation found, shows that harbour porpoises experience different ecological regimes during the year along the Scandinavian coasts, adapting their feeding habits to local oceanographic conditions, without performing extensive migration. -- Michael C. Fontaine - Aspirant FNRS MARE Center - Lab. for Oceanology (Univ. of Liege) B6c Allee de la Chimie, 3 Liege 4000, Belgium e-mail: michael.fontaine@ulg.ac.be personal webpage: http://users.skynet.be/fb683753/michaelcfontaine/Home.html CBGP (Centre de Biologie et de Gestion des Populations) - INRA Campus International de Baillarguet CS 30016, 34988 Montferrier-sur-Lez cedex France Phone : 0033 4 99 62 33 31 Fax: 0033 4 99 62 33 45