Filling gaps in deep Atlantic Ocean: first results from a long-term colonization experiment using mammal carcasses

Since the discovery of hydrothermal vents in 1977, research in chemosynthetic-based ecosystems has provided many surprises about life in the deep-sea. One of the most startling discoveries was the diverse and specialized fauna found at large organic falls such as sunken mammal carcasses. The sulphide and lipid-rich nature of decomposing bones is thought to create an habitat intermediate to that of vents and seeps, and to have allowed several vent (and seep)/whale conspecifics to use large organic falls as dispersal stepping-stones over evolutionary or ecological time-scales. In the last 15 years detailed ecological and phylogenetic studies have been carried on mammal falls and several in situ experiments have been set. Surprisingly, all long-term studies of mammal carcasses and other large organic falls on the deep-sea have been restricted to the Pacific and the role of these habitats in the Atlantic Ocean has been overlooked. In the Atlantic, the only observations of mammal carcasses were either on shallow waters or short-term observations, which being of utmost importance to understand these habitats, are not sufficient to evaluate the role of large organic falls as sulphide-rich habitat islands in the deep-sea floor.
Here we describe the first results of an experimental deployment in the deep NE Atlantic Ocean. Cow carcasses weighting approximately 600 Kg were deployed in the Setubal canyon at 1000 m and were sampled after 18 and 26 months. Species composition and abundance of the colonizing assemblages will be determined, and bacterial-invertebrate associations, population structure and recruitment pattern of selected species will be examined. These results will provide new insights into the diversity and biogeography of organic-fall specialists as well as into the role of these habitats as stepping-stones for vent and seep species in the Atlantic.

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First Name: 
Ana
Last Name: 
Hilario
Telephone: 
+351 2344370771
Affiliation: 
CESAM & Department of Biology, University of Aveiro
First Name: 
Helio
Last Name: 
Almeida
Affiliation: 
Department of Biology, University of Aveiro
First Name: 
Luciana
Last Name: 
Genio
Affiliation: 
CESAM & Department of Biology, University of Aveiro
First Name: 
Raquel
Last Name: 
Marçal
Affiliation: 
CESAM & Department of Biology, University of Aveiro
First Name: 
Ascensão
Last Name: 
Ravara
Affiliation: 
CESAM & Department of Biology, University of Aveiro
First Name: 
Clara
Last Name: 
Rodrigues
Affiliation: 
CESAM & Department of Biology, University of Aveiro
Choose keywords that are most applicable to your abstract. (Three maximum.): 
Biogeography
Distribution and abundance
Ecological Interactions
Abstract ID: 
CBE5-186