Stable Isotope composition of particulate organic matter and fauna in a deep Mediterranean cold-water coral bank


Cold-water corals (CWC) are frequently reported from deep sites with locally accelerated currents that enhance seabed food particle supply. Moreover, zooplankton likely account for ecologically important prey items, but their contribution to CWC diet remains unquantified. We investigated the benthic food web structure of the recently discovered Santa Maria di Leuca (SML) CWC province (300 to 1100 m depth) located in the oligotrophic northern Ionian Sea. We analyzed stable isotopes (delta13C and delta15N) of the main consumers (including ubiquitous CWC species) exhibiting different feeding strategies, zooplankton, suspended particulate organic matter (POM) and sedimented organic matter (SOM). Zooplankton and POM were collected 3 m above the coral colonies in order to assess their relative contributions to CWC diet. The delta15N of the scleractinians Desmophyllum dianthus, Madrepora oculata and Lophelia pertusa and the gorgonian Paramuricea cf. macrospinawere consistent with a diet mainly composed of zooplankton. The antipatharian Leiopathes glaberrima was more 15N- depletedthan other cnidarians, suggesting a lower contribution of zooplankton to its diet. Our delta13C data clearly indicate that the benthic food web of SML is exclusively fuelled by carbon of phytoplanktonic origin. Nevertheless, consumers feeding at the water sediment interface were more 13C-enriched than consumers feeding above the bottom (i.e. living corals and their epifauna). This pattern suggests that carbon is assimilated via 2 trophic pathways: relatively fresh phytoplanktonic production for 13C-depleted consumers and more decayed organic matter for 13C-enriched consumers. When the delta13C values of consumers were corrected for the influence of lipids (which are significantly 13C-depleted relative to other tissue components), our conclusions remained unchanged, except in the case of L. glaberrima which could assimilate a mixture of zooplankton and resuspended decayed organic matter.

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Metadata Access
Creator Carlier, Antoine; Le Guilloux, E; Olu, Karine ORCID logo; Sarrazin, Jozée; Mastrototaro, F ORCID logo; Taviani, Marco ORCID logo; Clavier, Jacques
Publisher PANGAEA
Publication Year 2011
Funding Reference Seventh Framework Programme Crossref Funder ID 226354 Hotspot Ecosystem Research and Mans Impact On European Seas; Sixth Framework Programme Crossref Funder ID 511234 Hotspot Ecosystem Research on the Margins of European Seas
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Publication Series of Datasets; Collection
Format application/zip
Size 2 datasets
Discipline Earth System Research
Spatial Coverage (17.688W, 39.563S, 18.509E, 39.765N); Var Canyon; Atlantis Mound
Temporal Coverage Begin 2007-10-15T05:21:00Z
Temporal Coverage End 2007-10-18T01:36:10Z