The aim of this project is the technological development of a specific instrumentation suite allowing the study of natural or accidentally perturbed ecosystems found in the deep ocean. These ecosystems are related to the emission of reduced fluids (cold seeps, hydrothermal vents), peculiar topographic structures (seamounts, deep corals), massive organic inputs (sunken woods) or to unpredictable events (pollution, earthquakes). Beside their insularity in the abyssal plain, the targeted ecosystems are characterised by patchy faunal distributions, unusual biological productivity, steep chemical and/or physical gradients, high perturbation levels and strong organism/habitat interactions at infra-metric scales. Their reduced size and unique biological composition and functioning make them difficult to study with conventional instrumentations deployed from surface vessels. Their study requires the use of submersibles able to work at reduced scales on the seafloor as well as the development of autonomous instruments for long-term monitoring (seafloor observatories).

The general objective of the EXOCET/D is to develop, implement and test specific instruments aimed at exploring, describing and quantifying biodiversity in deep-sea fragmented habitats and to identify links between community structure and environmental dynamics. Inboard experimental devices will complement the approach, enabling experiments on species physiology. The EXOCET/D working fields include: video and acoustic imagery; in situ analysis of habitat chemical and physical components; quantitative sampling of organisms; in vivo experiments; 4D integration of multidisciplinary data; implementation on European deep-submersibles as well as validation during demonstration actions. The work of IST/ISR focuses on the development of the acoustic systems that are required to acquire acoustic backscattering data obtained with a mechanical scanning pencil beam sonar. The data will be used for remote marine habitat classification. The final system developed by IST/ISR will be installed on-board the VICTOR ROV, property of IFREMER, for inspection of deep water hydrothermal vent communities. The figures below illustrate part of the activity developed during the first year of the project.