MEPS 563:233-247 (2017)  -  DOI: https://doi.org/10.3354/meps11965

ABSTRACT: Recent legal frameworks and the limited availability of information highlight the need to understand the ecological status and impact of anthropogenic threats on marine populations. In this study, a multi-tracer approach combining stable isotopes and 14 trace elements was used to infer information concerning the feeding ecology, contamination status and ecological segregation of 2 sympatric species of the Globicephala genus which stranded off the northern and western Iberian Peninsula (NWIP): the long-finned pilot whale Globicephala melas (LFPW) and the short-finned pilot whale Globicephala macrorhynchus (SFPW). Additionally, the potential influence of biological variables was investigated. Although both species presented similar stable isotope values, there were inter-specific differences in non-essential trace elements, with higher levels reported for SFPW. There was evidence of the bioaccumulative behaviour of some elements (Ag, Hg, Se, Fe, Co). Results of this study suggest that when both SFPW and LFPW are present in the NWIP, they show similar feeding patterns over at least a short timescale, but over a long timescale different feeding and habitat preferences may occur. This study provides useful information on Globicephala. In particular, it represents the first report on the ecology and contamination status of SFPW in the northern limits of their distribution range, i.e. in the NWIP.

KEY WORDS: Stable isotopes · Trace elements · Multi-tracer approach · Feeding ecology · Ecological segregation · Toxicology · Bioaccumulation · North-west Iberian Peninsula