Seep communities from two mud volcanoes in the deep eastern Mediterranean Sea: faunal composition, spatial patterns and environmental control
|Author(s)||Ritt Benedicte1, 2, 3, Desbruyeres Daniel1, 2, Caprais Jean-Claude1, 2, Gauthier Olivier4, Ruffine Livio1, 2, Buscail Roselyne5, Olu-Le Roy Karine1, 2, Sarrazin Jozee1, 2|
|Affiliation(s)||1 : Inst Carnot Ifremer EDROME, REM EEP, Ifremer Brest, F-29280 Plouzane, France.
2 : Inst Carnot Ifremer EDROME, REM GM, F-29280 Plouzane, France.
3 : Temple Univ, Dept Biol, Philadelphia, PA 19122 USA.
4 : Technopole Brest Iroise, UBO, IUEM, F-29280 Plouzane, France.
5 : Univ Perpignan, CNRS, UMR 5110, CEFREM, F-66860 Perpignan, France.
|Source||Marine Ecology-progress Series (0171-8630) (Inter-research), 2012-10 , Vol. 466 , P. 93-143|
|WOS© Times Cited||15|
|Keyword(s)||Mediterranean Ridge, Cold seeps, Benthic fauna, Environmental conditions, Diversity indices, Microhabitats|
|Abstract||The Mediterranean Sea constitutes a unique environment to study cold-seep ecosystems due to the presence of different geodynamic settings, from an active margin along the Mediterranean Ridge (MR) to a passive margin in the Nile Deep-Sea Fan (NDSF). We attempted to identify the structure of benthic communities associated with the Napoli and Amsterdam mud volcanoes (MVs) located on the MR and to establish the links between faunal distribution and environmental conditions at different spatial scales. Comparison between the 2 MVs revealed that the faunal distribution seemed to be mainly controlled by the characteristics of the microhabitats. On both geological structures, the variability between the different microhabitats was higher than the variability observed between replicates of the same microhabitat, and the distribution of macro-fauna was apparently linked to gradients in physico-chemical conditions. The peripheral sites from Napoli were generally more oxygenated and harboured lower species richness than the active sites. The reduced sediment microhabitat from Amsterdam presented the highest methane concentrations and was mainly colonised by symbiont-bearing vesicomyid bivalves and heterotrophic dorvilleid polychaetes. Overall, a higher taxonomic diversity was observed on Napoli. Sub-stratum type was hypothesised to be the second factor influencing faunal distribution. The results of this study highlight the high heterogeneity of faunal communities associated with seep ecosystems within this region and the need to pursue investigations at various spatial and temporal scales.|