ICES Journal of Marine Science: Journal du Conseil Advance Access originally published online on June 19, 2008
ICES Journal of Marine Science: Journal du Conseil 2008 65(7):1102-1111; doi:10.1093/icesjms/fsn099
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Megafauna community structure and trophic relationships at the recently discovered Concepción Methane Seep Area, Chile,
36°S
1 Facultad de Ciencias del Mar, Departamento de Biología Marina, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile, and Centro de Investigación Oceanográfica en el Pacífico Sur-Oriental (COPAS), Universidad de Concepción, Casilla 160-C, Concepción, Chile
2 Centro de Investigación en Ecosistemas de la Patagonia (CIEP), Bilbao 449, Coyhaique, Chile
3 Integrative Oceanography Division, Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093-0218, USA
Correspondence to J. Sellanes: tel: +56 51 205974; fax: +56 51 209812; e-mail: sellanes{at}ucn.cl.
Sellanes, J., Quiroga, E., and Neira, C. 2008. Megafauna community structure and trophic relationships at the recently discovered Concepción Methane Seep Area, Chile,The fauna, community composition, and trophic support of the newly discovered Concepción Methane Seep Area (CMSA) are compared with those at a nearby non-seep control. The assemblage of chemosymbiotic bivalves is defined by eight species, including the families Lucinidae, Thyasiridae, Solemyidae, and Vesicomyidae. Seep polychaetes are represented by Lamellibrachia sp. and two commensal species of the vesicomyid Calyptogena gallardoi. Although taxonomic analysis is still under way, most of the chemosymbiotic species seem to be endemics. The CMSA is a hotspot for non-seep benthic megafauna too; 101 taxa were present, but most of them are colonists or vagrants (i.e. not endemics of methane seeps). Isotope analysis supported the belief that non-symbiont-bearing species utilize photosynthetically fixed carbon, because they were isotopically distinct from the chemosymbiotic bivalve species present. It is our opinion that, at this site, which underlies one of the most productive coastal upwelling regions of the world, spatial heterogeneity and the availability of hard substratum, generated by the presence of authigenic carbonate crusts, are more important factors in attracting non-seep fauna than the availability of locally produced chemosynthetic food.36°S. – ICES Journal of Marine Science, 65: 1102–1111.
Keywords: bathyal benthos, chemosynthesis, Chilean margin, cold seep, stable isotopes
Received 25 January 2008; accepted 17 May 2008; advance access publication 19 June 2008.
36°S. – ICES Journal of Marine Science, 65: 1102–1111.