Colonization of organic substrates deployed in deep-sea reducing habitats by symbiotic species and associated fauna.

In this study, our goal was to test whether typical vent/seep organisms harbouring symbionts or not, would be able to settle on organic substrates deployed in the vicinity of chemosynthetic ecosystems. Since 2006, a series of novel standardized colonization devices (CHEMECOLI: CHEMosynthetic Ecosystem COlonization by Larval Invertebrates) filled with three types of substrates (wood, alfalfa and carbonate) have been deployed in different types of reducing habitats including cold seeps in the eastern Mediterranean, a mud volcano in the Norwegian Sea, and hydrothermal vents on the Mid-Atlantic Ridge for durations of 2 weeks to 1 year. For all deployments, highest species diversities were recovered from CHEMECOLIs filled with organic substrates.

Highly similar prokaryotic communities of sunken wood at shallow and deep-sea sites across the oceans.

With an increased appreciation of the frequency of their occurrence, large organic falls such as sunken wood and whale carcasses have become important to consider in the ecology of the oceans. Organic-rich deep-sea falls may play a major role in the dispersal and evolution of chemoautotrophic communities at the ocean floor, and chemosynthetic symbiotic, free-living, and attached microorganisms may drive the primary production at these communities. However, little is known about the microbiota thriving in and around organic falls.