FN Archimer Export Format PT J TI Biodiversity and trophic ecology of hydrothermal vent fauna associated with tubeworm assemblages on the Juan de Fuca Ridge BT AF LELIEVRE, Yann SARRAZIN, Jozee MARTICORENA, Julien SCHAAL, Gauthier DAY, Thomas LEGENDRE, Pierre HOURDEZ, Stephane MATABOS, Marjolaine AS 1:1,2;2:1;3:1;4:3;5:1;6:2;7:4,5;8:1; FF 1:;2:PDG-REM-EEP-LEP;3:PDG-REM-EEP-LEP;4:;5:PDG-REM-EEP-LEP;6:;7:;8:PDG-REM-EEP-LEP; C1 IFREMER, Ctr Bretagne, REM EEP, Lab Environm Profond, F-29280 Plouzane, France. Univ Montreal, Dept Sci Biol, CP 6128,Succursale Ctr Ville, Montreal, PQ H3C 3J7, Canada. UMR 6539 9 CNRS UBO IRD Ifremer, Lab Sci Environm Marin LEMAR, BP 70, F-29280 Plouzane, France. Sorbonne Univ, Stn Biol Roscoff, UMR7144, F-29680 Roscoff, France. CNRS, UMR7144, Stn Biol Roscoff, F-29680 Roscoff, France. C2 IFREMER, FRANCE UNIV MONTREAL, CANADA UBO, FRANCE UNIV PARIS 06, FRANCE CNRS, FRANCE SI BREST SE PDG-REM-EEP-LEP UM LEMAR IN WOS Ifremer jusqu'en 2018 DOAJ copubli-france copubli-univ-france copubli-int-hors-europe IF 3.951 TC 17 UR https://archimer.ifremer.fr/doc/00439/55083/56515.pdf https://archimer.ifremer.fr/doc/00439/55083/56516.pdf https://archimer.ifremer.fr/doc/00439/55083/56517.mp4 https://archimer.ifremer.fr/doc/00439/55083/56518.pdf LA English DT Article AB Hydrothermal vent sites along the Juan de Fuca Ridge in the north-east Pacific host dense populations of Ridgeia piscesae tubeworms that promote habitat heterogeneity and local diversity. A detailed description of the biodiversity and community structure is needed to help understand the ecological processes that underlie the distribution and dynamics of deep-sea vent communities. Here, we assessed the composition, abundance, diversity and trophic structure of six tubeworm samples, corresponding to different successional stages, collected on the Grotto hydrothermal edifice (Main Endeavour Field, Juan de Fuca Ridge) at 2196 m depth. Including R. piscesae, a total of 36 macrofaunal taxa were identified to the species level. Although polychaetes made up the most diverse taxon, faunal densities were dominated by gastropods. Most tubeworm aggregations were numerically dominated by the gastropods Lepetodrilus fucensis and Depressigyra globulus and polychaete Amphisamytha carldarei. The highest diversities were found in tubeworm aggregations characterised by the longest tubes (18.5 ± 3.3 cm). The high biomass of grazers and high resource partitioning at a small scale illustrates the importance of the diversity of free-living microbial communities in the maintenance of food webs. Although symbiont-bearing invertebrates R. piscesae represented a large part of the total biomass, the low number of specialised predators on this potential food source suggests that its primary role lies in community structuring. Vent food webs did not appear to be organised through predator–prey relationships. For example, although trophic structure complexity increased with ecological successional stages, showing a higher number of predators in the last stages, the food web structure itself did not change across assemblages. We suggest that environmental gradients provided by the biogenic structure of tubeworm bushes generate a multitude of ecological niches and contribute to the partitioning of nutritional resources, releasing communities from competition pressure for resources and thus allowing species to coexist. PY 2018 PD MAY SO Biogeosciences SN 1726-4170 PU Copernicus Gesellschaft Mbh VL 15 IS 9 UT 000431435900004 BP 2629 EP 2647 DI 10.5194/bg-15-2629-2018 ID 55083 ER EF