HR: 15:45h
AN: OS53B-08    [Abstracts]
TI: Habitat heterogeneity - biological association relationships in the asphalt volcano, SW Gulf of Mexico
AU: * Escobar, E
EM: escobri@mar.icmyl.unam.mx
AF: Elva Escobar, Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del mar y Limnologia, MEXICO, DF 04510, Mexico
AU: Gaytan, A
EM: adriana.gaytan@gmail.com
AF: Elva Escobar, Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del mar y Limnologia, MEXICO, DF 04510, Mexico
AB: A new class of cold seep, named asphalt volcano, was discovered in the Campeche Knolls region of the southern Gulf of Mexico, supporting chemosynthetic communities alike those lying at similar depth on the Angolan margin and the Barbados Prism suggesting an interesting longitudinal connectivity in the faunal components. The discovery of this novel deep-sea habitat has raised questions about diversity and process dynamics in this novel poorly described milieu. Results from two previous cruises jointly sponsored by German, US and Mexican funding agencies have allowed us to recognize the presence of large densities of background benthic megafauna, mainly represented by sea-cucumbers and galatheid crabs, which occupy diverse habitats in asphalt volcano and feed on microbial assemblages on the asphalt covering extended area. Asphalt displays different degrees of hardness suggesting ongoing activity of asphalt extrusion in the site that is reflected in biological benthic communities in different states succession and complexity. The fresh asphalt and the immediately surrounding soft sediment are colonized by mats of complex microbial assemblages where both background benthic megafauna and chemosynthetic tube worms and mussels aggregate. Our results focus on the diversity of the habitats associated with methane seepage through the example of geological structures in the asphalt volcano considering the small scale with the analysis of the relationships between biological assemblages and habitat heterogeneity assessing the role of the geological structure on biological communities. Bubbling of gas, oil and the content of thermogenic gas and gas hydrate in the asphalt suggests that the asphalt plays an important role as a reservoir of methane in this marginal deep sea.
DE: 4243 Marginal and semi-enclosed seas
DE: 4800 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL (0460)
DE: 4804 Benthic processes, benthos (0408)
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly