|Marine mammals from the southern North Sea: feeding ecology data from d13C and d15N measurements|Das, K.; Lepoint, G.; Leroy, Y.; Bouquegneau, J.-M. (2003). Marine mammals from the southern North Sea: feeding ecology data from d13C and d15N measurements. Mar. Ecol. Prog. Ser. 263: 287-298. dx.doi.org/10.3354/meps263287
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630, more
Food webs; Isotopes; Marine mammals; Stable isotopes; Mammalia [WoRMS]; ANE, North Sea [Marine Regions]; Marine
north sea; marine mammals; stable isotopes; food web
|Authors|| || Top |
- Das, K., more
- Lepoint, G., more
- Leroy, Y.
- Bouquegneau, J.-M., more
The harbour porpoise Phocoena phocoena, grey seal Halichoerus grypus, harbour seal Phoca vitulina and white-beaked dolphin Lagenorhynchus albirostris are regularly found stranded along southern North Sea coasts. Occasionally, offshore species such as the fin whale Balaenoptera physalus, the white-sided dolphin L. acutus and the sperm whale Physeter macrocephalus are also found stranded. In order to trace their diet, we measured d13C and d15N in their muscles as well as in 49 invertebrate and fish species collected from the southern North Sea. The d15N data indicate that the harbour seal, grey seal and white-beaked dolphin occupy the highest trophic position, along with ichtyophageous fishes such as the cod Gadus morhua (mean muscle values of 18.7, 17.9, 18.8 and 19.2‰ respectively). The harbour porpoise occupies a slightly lower trophic position (mean d15N value of 16.2‰), reflecting a higher amount of zooplanktivorous fishes in its diet (mean d15N of 14.7‰); 2 suckling harbour porpoises displayed a significant d15N enrichment of 2.2‰ compared to adult females. Adult females are d15N-enriched compared to adult male harbour porpoises. Fin whales, sperm whales and white-sided dolphins are 13C-depleted compared to southern North Sea particulate organic matter and species, suggesting that despite regular sightings, they do not feed within the southern North Sea area.