MEPS 438:285-302 (2011)  -  DOI: https://doi.org/10.3354/meps09269

ABSTRACT: We investigated seasonal shifts in diet and distribution of fin whales Bala­en­optera physalus occurring in the western Mediterranean Sea. For this purpose, we combined carbon and nitrogen stable isotope ratios (δ¹³C, δ¹⁵N) along 10 baleen plates collected from stranded fin whales between 1975 and 2002 with satellite tag deployments on 11 fin whales during summer 2003. Baleen plate stable isotopes were compared with those of the krill Meganyctiphanes norvegica, the main prey of fin whales in the northwestern Mediterranean Sea. Two plates collected near Malaga, Spain, exhibited larger δ¹³C variations, while only smaller variations could be detected in the other 8. While all mean baleen plate results were consistent with the δ¹³C signature of Mediterranean M. norvegica, the most depleted δ¹³C values were intermediate between those of Atlantic and Mediterranean M. norvegica, suggesting westward migrations perhaps extending to the Strait of Gibraltar but not extensive, prolonged feeding in the Northeast Atlantic. This pattern was confirmed by satellite tracking; 1 out of 8 fin whales we successfully tracked left the Mediterranean for the Atlantic. Longer-term changes in isotopic signatures of baleen plates exhibited significant depletion trends, indicating that changes due to increasing input of nutrients and anthropogenic carbon are occurring in the western Mediterranean Sea ecosystem.

KEY WORDS: Meganyctiphanes norvegica · Mediterranean Sea · Foraging · Migration · Satellite telemetry · Environmental change

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Cite this article as: Bentaleb I, Martin C, Vrac M, Mate B and others (2011) Foraging ecology of Mediterranean fin whales in a changing environment elucidated by satellite ­tracking and baleen plate stable isotopes. Mar Ecol Prog Ser 438:285-302. https://doi.org/10.3354/meps09269 Export citation Share:    Facebook - - linkedIn