Biogeochemistry

, Volume 113, Issue 1, pp 189–212

Trophodynamics and functional feeding groups of North Sea fauna: a combined stable isotope and fatty acid approach

Authors

    • Helmholtz Centre for Ocean Research Kiel | GEOMAR
  • Inmaculada Frutos
    • Departamento de Zoología y Antropología FísicaUniversidad de Alcalá
  • Ulrich Struck
    • Museum für Naturkunde, Leibniz-Institut für Evolutions-und Biodiversitätsforschung an der Humboldt-Universität zu Berlin
  • Suzanne J. Painting
    • Centre for Environment, Fisheries and Aquaculture Science (CEFAS)
  • Nicholas V. C. Polunin
    • School of Marine Science and TechnologyNewcastle University
  • Jack J. Middelburg
    • Centre for Estuarine and Marine EcologyNetherlands Institute of Ecology (NIOO-KNAW)
    • Faculty of GeosciencesUtrecht University
Article

DOI: 10.1007/s10533-012-9701-8

Cite this article as:
Kürten, B., Frutos, I., Struck, U. et al. Biogeochemistry (2013) 113: 189. doi:10.1007/s10533-012-9701-8

Abstract

The trophodynamics of pelagic and benthic animals of the North Sea, North Atlantic shelf, were assessed using stable isotope analysis (SIA) of natural abundance carbon and nitrogen isotopes, lipid fingerprinting and compound-specific SIA (CSIA) of phospholipid-derived fatty acids (PLFAs). Zooplankton (z), epi- and supra-benthic macrofauna were collected in the Southern Bight, at the Oyster Grounds and at North Dogger, 111 km north of the Dogger Bank. The study included 22 taxonomic groups with particular reference to Mollusca (Bivalvia and Gastropoda) and Crustacea. Primary consumers (Bivalvia) were overall most 15N enriched in the southern North Sea (6.1‰) and more depleted in the Oyster Grounds (5.5‰) and at North Dogger (2.8‰) demonstrating differences in isotopic baselines for bivalve fauna between the study sites. Higher trophic levels also followed this trend. Over an annual cycle, consumers tended to exhibit 15N depletion during spring followed by 15N enriched signatures in autumn and winter. The observed seasonal changes of δ 15N were more pronounced for suspension feeders and deposit feeders (dfs) than for filter feeders (ffs). The position of animals in plots of δ 13C and δ 15N largely concurred with the expected position according to literature-based functional feeding groups. PLFA fingerprints of groups such as z were distinct from benthic groups, e.g. benthic ffs and dfs, and predatory macrobenthos. δ 13CPLFA signatures indicated similarities in 13C moiety sources that constituted δ 13CPLFA. Although functional groups of pelagic zooplankton and (supra-) benthic animals represented phylogenetically distinct consumer groups, δ 13CPLFA demonstrated that both groups were supported by pelagic primary production and relied on the same macronutrients such as PLFAs. Errors related to the static categorization of small invertebrates into fixed trophic positions defined by phylogenetic groupings rather than by functional feeding groups, and information on seasonal trophodynamic variability, may have implications for the reliability of numerical marine ecosystem models.

Keywords

Benthic–pelagic coupling Food web structure Phospholipid-derived fatty acids Suprabenthos Trophodynamics Zooplankton

Supplementary material

10533_2012_9701_MOESM1_ESM.doc (780 kb)
Supplementary material 1 (DOC 603 kb)

Copyright information

© Springer Science+Business Media B.V. 2012