FN Archimer Export Format
PT J
TI Heterogeneous energetic pathways and carbon sources on deep eastern Mediterranean cold seep communities
BT 
AF CARLIER, Antoine
   RITT, Benedicte
   RODRIGUES, Clara F.
   SARRAZIN, Jozee
   OLU, Karine
   GRALL, Jacques
   CLAVIER, Jacques
AS 1:1;2:2;3:3,4;4:2;5:2;6:1;7:1;
FF 1:;2:;3:;4:;5:;6:;7:;
C1 Univ Bretagne Occidentale IRD, CNRS, UMR 6539, LEMAR IUEM, F-29280 Plouzane, France.
   Ctr Ifremer Brest, Dept Etud Ecosyst Profonds, Lab Environm Profond, F-29280 Plouzane, France.
   Univ Aveiro, Dept Biol, P-3800 Aveiro, Portugal.
   Univ Aveiro, CESAM, P-3800 Aveiro, Portugal.
C2 UBO, FRANCE
   IFREMER, FRANCE
   UNIV AVEIRO, PORTUGAL
   UNIV AVEIRO, PORTUGAL
SI BREST
SE UBO
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-europe
   copubli-univ-france
IF 2.011
TC 35
TU Centre national de la recherche scientifique
   Institut de recherche pour le développement
   Institut français de recherche pour l'exploitation de la mer
   Service Hydrographique et Océanographique de la Marine
   Université de Bretagne Occidentale
   Université de Bretagne-Sud
UR https://archimer.ifremer.fr/doc/00016/12684/9633.pdf
LA English
DT Article
CR MEDECO
   MEDINAUT
BO Unknown
   Le Nadir
DE ;gulf of Mexico;anaerobic methane oxidation;stable isotope analysis;sea hydrothermal vents;food web structure;kazan mud volcano;florida escarpment;trophic relationships;benthic communauties;lamellibrachia SP
AB Cold seep communities in the Mediterranean Sea have only been discovered two decades ago, and their trophic ecology has been the subject of very few studies. We investigated the benthic food web of two deep chemosynthesis-based ecosystems on the Napoli and Amsterdam mud volcanoes (MVs) in the eastern Mediterranean Sea (similar to 2,000 m depth). Seeping methane has been detected at the surface of both MVs during pioneering cruises and has been hypothesised to be assimilated by benthic fauna as observed in other oceans' margins. Given the extreme oligotrophic character of the eastern Mediterranean Sea, we a priori expected that chemosynthetic food sources, especially methane-derived carbon (MDC), played a major trophic role in these deep seep communities relative to what has been observed in other seep systems worldwide. We aimed at unravelling the trophic relationships on Napoli and Amsterdam MVs through the analysis of carbon, nitrogen and sulphur isotopes both in the dominant benthic invertebrates including the small endofauna (300 mu m < size < 1 cm) and in the sedimented organic matter. In particular, we assessed the fraction of MDC in the tissue of several heterotrophic and symbiotic species. Low mean delta S-34 and delta C-13 values (0.4 +/- A 4.8aEuro degrees and -31.6 +/- A 5.7aEuro degrees, respectively) obtained for mega- and macrofauna suggested that the investigated benthic food webs are virtually exclusively fuelled by carbon of chemosynthetic origin. A few grazer invertebrates (delta S-34 up to 11aEuro degrees) depart from this trend and could complement their diet with sedimented and decayed phytoplanktonic organic matter. Faunal delta C-13 values indicated that the oxidation of sulphur is likely the predominant energetic pathway for biosynthesis on both MVs. Nevertheless, mytilid bivalves and small capitellid, ampharetid and spionid polychaetes were C-13-depleted (delta C-13 < -37aEuro degrees) in a way indicating they assimilated a significant portion of MDC. For these later heterotrophic species, MDC ranged between 21 and 31% (lower estimates) and 97 and 100% (upper estimates). However, our results highlighted that the origin of assimilated carbon may be complex for some symbiotic species. The vestimentiferan tubeworm Lamellibrachia sp., which exclusively depends on its sulphur-oxidising endosymbionts, showed a similar to 20aEuro degrees inter-individual delta C-13 variability on a very small spatial scale (< 1 m) at the summit of Napoli MV. This mostly reflects the variable isotopic composition of pore-water-dissolved inorganic carbon (DIC) and evidenced that tubeworms (and subsequently their endosymbionts) uptake DIC derived from multiple methane oxidation processes in varying proportions. The lower and upper MDC estimates for the vestimentum of Napoli's individuals were 11-38 and 21-73%, respectively. Finally, data on trophic ecology of Napoli and Amsterdam MVs clearly corroborate previous geophysical results evidencing the spatial heterogeneity of Mediterranean MV environmental conditions.
PY 2010
PD NOV
SO Marine Biology
SN 0025-3162
PU Springer
VL 157
IS 11
UT 000282828900019
BP 2545
EP 2565
DI 10.1007/s00227-010-1518-1
ID 12684
ER

EF