Data archive: Trophic structure of cold-water coral communities revealed from the analysis of tissue isotopes and fatty acid composition

Data belonging to the paper: 

Dick van Oevelen, Gerard C. A. Duineveld, Marc S. S. Lavaleye, Tina Kutti and Karline Soetaert (2017) Trophic structure of cold-water coral communities revealed from the analysis of 55 tissue isotopes and fatty acid composition. Marine Biology Research, DOI: https://doi.org/10.1080/17451000.2017.1398404

Abstract:

The trophic structure of cold-water coral reef communities at two contrasting locations, the 800-
m deep Belgica Mounds (Irish margin) and 300-m deep Træna reefs (Norwegian Shelf), was
investigated using stable isotope (δ13C and δ15N) and fatty-acid composition analysis. A
broad range of specimens, with emphasis on (commercial) fish species, and organic matter
sources were sampled using a variety of tools. Irrespective of the environmental and
geographical setting, the δ15N values indicated that the food web encompasses roughly 1.5
to 3 trophic levels. Mobile echinoderms, i.e. sea urchins and sea stars, had highest δ15N
values, indicative of a high trophic position in the food web. The fraction of bacterial fatty
acids in reef fauna was generally low (<5%), indicating that enhanced bacterial production in
the water column through seafloor seepage of nutrients (‘hydraulic theory’) does not form a
significant energy pathway into the food web. The high fraction of algal and essential fatty
acids in reef fauna and fish at both locations indicates a close coupling with surface
productivity, but the transport mechanism depends on the hydrographic setting. At Træna,
Calanus copepods and euphausiids form an additional link between primary production and
fish, which is largely absent at Belgica Mounds. At Belgica Mounds, the reef community is
primarily supported by phytodetritus, as evidenced by the high contribution of algal fatty
acids in faunal tissue and seasonal chlorophyll a deposition and marine snow at the reef. The
environmental setting of cold-water coral reefs influences the structure of the associated
food web.