• Colonisation of wood falls

    Colonisation of wood falls

    Wood fall represent a substantial organic resource for specialized species able to degrade this refractory material or use secondary degradation products (e.g. sulfide) as energy source to fix carbon.  We Read More
  • Deep-water coral growth

    Deep-water coral growth

    The growth of cold water corals was rarely quantified in natural deep-water environments. We developped a mark and recapture method to adress this question on coral fragments of Lophelia pertusa Read More
  • Lacaze-Duthiers canyon study site : a climate-sensitive deep-sea hotspot

    Lacaze-Duthiers canyon study site : a climate-sensitive deep-sea hotspot

    The head of the Lacaze-Duthiers canyon in the southern end of the Gulf of Lion is located only 15 miles from the coast. This incision in the continental shelf ranges Read More
  • Chemosynthesis and succession of hydrothermal species

    Chemosynthesis and succession of hydrothermal species

    We aim to investigate the response of hydrothermal ecosystem to disturbance and its role in organic matter production in the deep ocean. Our focus is on the resettlement of populations Read More
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Chemosynthesis and succession of hydrothermal species

Web chair BEMExChange MESCAL Marquage In Situ

We aim to investigate the response of hydrothermal ecosystem to disturbance and its role in organic matter production in the deep ocean. Our focus is on the resettlement of populations of invertebrate species dominating the biomass.
What is the role of geochemical changes in the succession of invertebrate species over years? What are the habitat properties favouring or inhibiting the growth of symbiotic invertebrates? The chair team investigates these issues through in situ experimental approaches linking environmental variability and growth including a custom-made marking chamber for sclerochronology studies (Nedoncelle et al. 2014)(picture) and autonomous electrochemical sensors (Nedoncelle et al. 2015).

Colonisation of wood falls

Wood fall represent a substantial organic resource for specialized species able to degrade this refractory material or use secondary degradation products (e.g. sulfide) as energy source to fix carbon.  Bois capteurs bord We developped an experimental approach to explore the transformations of this substrate into a sulfidic habitats hosting chemosynthetic fauna, from the early stages of immersion up to at least 18 Months. The approach combines  in situ experiment at 500m depth (including autonomous sulfide sensors) with seawater aquarium deployments. Aquarium studies revealed substantial and rapid (3 weeks) enrichment of the wood matrix with intermittent sulfidic pulses in surface (Yücel et al. 2013). The bacterial communities able to produce sulfide from the degradation of wood components are still largely unknown. Yet, specialized microbial consortia have been described to succeed over time and in situ experiments suggest a determining role of wood boring bivalves in the control of community succession (Kalenitchenko et al. 2015). On-going studies are exploring the role of wood borers in sulfide production and colonization dynamics by different wood mussel species.

Deep-water coral growth

The growth of cold water corals was rarely quantified in natural deep-water environments. We developped a mark and recapture method to adress this question on coral fragments of Lophelia pertusa and Madrepora oculata (Lartaud et al. 201Boutures devant Massif2
DOI: 10.1051/alr/2012029
).
In situ experiments at 520 meter depth have revealed that fragments of the two species grow relatively rapidely in the Lacaze-Duthiers canyon, but that Madrepora oculata  display  strong seasonal growth variation (Lartaud et al. 2014).
Current studies are exploring the links between growth and intermittent water convection events resulting of the meteorological regime in the western Mediterranean sea.