Biodiversity of mud volcanoes along deep-reaching transform faults in the SW Iberian Margin (NE Atlantic)

The accumulated knowledge on chemosynthesis-based ecosystems faded the distinction between hydrothermal vents and cold seeps. The occurrence of hydrothermal circulation connecting the oceanic basement and the seafloor, well known for relatively young oceanic crust, has been reported now from old, sedimented oceanic crust, a phenomenon that may represent a link between hydrothermal vents at mid-ocean ridges and cold seeps at continental margins. Several mud volcanoes sitting on the accretionary wedge in the Gulf of Cadiz are aligned along transform faults extending westwards across the Horseshoe Abyssal Plain. The source of fluids in these mud volcanoes is several kilometres below the seafloor and their geochemical composition indicates that they are affected, in different degrees, by oceanic crust alteration. The recent discovery of three new mud volcanoes at ca. 4500m depths on the lower continental rise further expands this environmental gradient. This series of mud volcanoes spanning from shelf to abyssal depths in the South Iberian margin provides unique conditions to investigate the intricate effects of water depth and relevant changes in the oceanographic and geologic settings on the composition and structure of the biological assemblages from reducing environments. Here we report on the variability in α- and β-diversity of macrofaunal assemblages at different spatial scales along the bathymetric gradient and on the relationship between microbial, meio- and macrofaunal biodiversity in the new mud volcanoes. This study is supported by the FCT project SWIMGLO (PTDC/MAR/100522/2008).

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First Name: 
Marina R.
Last Name: 
Cunha
Telephone: 
+351 234 370 969
Affiliation: 
Universidade de Aveiro - Dep. Biologia & CESAM, Portugal
First Name: 
Helena
Last Name: 
Adão
Affiliation: 
Universidade de Évora, Portugal
First Name: 
Newton
Last Name: 
Gomes
Affiliation: 
Universidade de Aveiro - Dep. Biologia & CESAM, Portugal
First Name: 
Ana
Last Name: 
Hilário
Affiliation: 
Universidade de Aveiro - Dep. Biologia & CESAM, Portugal
First Name: 
Clara F.
Last Name: 
Rodrigues
Affiliation: 
Universidade de Aveiro - Dep. Biologia & CESAM, Portugal
First Name: 
Rui P.
Last Name: 
Vieira
Affiliation: 
Universidade de Aveiro - Dep. Biologia & CESAM, Portugal
Choose keywords that are most applicable to your abstract. (Three maximum.): 
Distribution and abundance
Ecological Interactions
Abstract ID: 
CBE5-178