BathyBot – a Deep-sea Crawler to See the Unseen in the NW Mediterranean Sea

Severine Martini1,2, Christian Tamburini2, Carl Gojak3, Jacopo Aguzzi4, Aurelien Arnaubec5, Laury Barnes-Davin6, Karim Bernardet3, Vincent Bertin7, Olivier Bocquet8, Bruno Bombled9, Pierre Chevaldonne10, Paschal Coyle11, Viorel Ciausu5, Philippe Cuny2, Xavier Durrieu De Madron12, Marc Garel2, Laurence Le direach13, Elodie Rouanet13, Christian Grenz2, Zouhir Hafidi3, Patrick Lamare14, Celine Laus3, Dominique Lefevre2, Nadine Le Bris15, Karim Mahiouz3, Simone Marini16, Marjolaine Matabos17, Cécile Militon2, David Nerini2, Thierry Perez10, Laura Picheral1, Marc Picheral1, Romain Piasco5, Christophe Rabouille18, Jozee Sarrazin17, Delphine Thibault2 and Laurenz Thomsen19, (1)Laboratoire d’Océanographie de Villefranche (LOV), UMR 7093, Sorbonne Université, Villefranche-sur-Mer, France, (2)Mediterranean Institute of Oceanography, Marseille, France, (3)INSU/CNRS, DT, France, (4)Institut de Ciències del Mar, ICM-CSIC, Barcelona, Barcelona, Spain, (5)IFREMER, La Seyne-sur-mer, France, (6)VICAT, L'isle d'abeau, France, (7)Centre de physique des particules de Marseille, Marseille, France, (8)Tangram Architectes, France, (9)LSCE Laboratoire des Sciences du Climat et de l'Environnement, UMR CEA-CNRS-UVSQ-UPSaclay et IPSL, Gif-Sur-Yvette Cedex, France, (10)Institut Méditerranéen de Biodiversité et d'Ecologie, Marseille, France, (11)Centre de physique des particules de Marseille, France, (12)Centre de formation et de recherche sur les environnements méditerranéens - Université de Perpignan, Perpignan, France, (13)GIS Posidonie, Marseille, France, (14)Aix Marseille Univ, CNRS/IN2P3 / CPPM, Marseille, France, (15)Sorbonne Université, Institut de Systématique, Evolution, Biodiversité, Paris, France, (16)Institute of Marine Sciences (ISMAR-CNR), Italy, (17)IFREMER, Centre de Bretagne, Plouzané, France, (18)Laboratoire des Sciences du Climat et de l'Environnement, UMR CEA-CNRS-UVSQ et IPSL, Gif sur Yvette, France, (19)Jacobs University Bremen, Bremen, Germany
The deep sea remains one of the less known environment on Earth and is characterized by high pressure, low availability of organic matter and absence of light. While there are still numerous discoveries concerning the diversity and adaptations of deep-sea organisms to their environement, this ecosystem is under an increasing anthropogenic pressure such as climate-related stressors (warming, acidification and deoxygenation), deep-sea fishing, human pollution (microplastics, POP), oil and gas extraction and could face new threats from emerging industries (e.g. mineral mining). How these changes will affect biodiversity and ecosystem functioning is one question of major importance for the future. In the darkness of the oceans, several organisms have the capability to emit light: called bioluminescence. Recent studies quantified that as much as 75% of pelagic and about 40% of benthic organisms are known to be bioluminescent. In this framework, we present a new deep-sea crawler, BathyBot, to be dedicated to the long-term exploration of deep-sea ecosystems allowing biological and-geochemical surveys. BathyBot will be deployed in 2020 in the Mediterranean Sea, at the MEUST-NUMerEnv/KM3NeT site, to strength the ecological-based monitoring capability of the European Multidisciplinary Seafloor and water column Observatory (EMSO ERIC) network. BathyBot will be able to explore an area of about 15 000 m2 at a depth of 2500m and will be devoted to 1) observe and monitor the dynamics of deep-sea pelagic and benthic organisms, 2) better define the occurrence and functions of bioluminescence in situ (increasing the dataset of bioluminescence records), 3) explore relationships between deep-sea organisms, biogeochemical (carbon content, oxygen concentrations) and environmental variables (temperature, salinity, current) in the context of global changes and their effects on the deep ocean, and 4) investigate benthic biogeochemical processes through the use of oxygen microprofiling in sediment porewaters.