BENTHIC BIOLOGY TIME-SERIES IN THE DEEP-SEA: INDICATORS OF CHANGE Larkin, K.E.(1), Ruhl, H.A.(2), Bagley, P.(3), Benn, A.(4), Bett, B.J.(5), Billett, D.S.M.(6), Boetius A.(7), Chevaldonné, P.(8), Colaço, A.(9), Copley, J.(10), Danovaro, R.(11), Escobar-Briones, E.(12), Glover A.(13), Gooday, A.J.(14), Hughes, J.A.(15), Kalogeropoulou, V(16)., Kelly-Gerreyn, B.A.(17), Kitazato H.(18), Klages, M.(19), Lampadariou, N.(20), Lejeusne, C.(21), Perez, T.(22), Priede., I.G.(23), Rogers A.(24), Sarradin, P.M(25), Sarrazin, J.(26), Soltwedel, T.(27), Soto, E.H.(28), Thatje, S.(29), Tselepides, A.(30), Tyler, P.A.(31), van den Hove, S.(32), Vanreusel, A.(33), Wenzhöfer, F.(34) (1)National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (2) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (3) University of Aberdeen, Oceanlab, Newburgh, Aberdeenshire, AB41 6AA, (U.K.), Email: [email protected] (4)National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (5) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (6) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (7) Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen (Germany), Email: aboetius@mpi- bremen.de (8) Universite de la Mediterranee (Aix-Marseille II), 58, Bd Charles Livon - 13284 Marseille Cedex 07, (France), Email: [email protected] (9) Department of Oceanography and Fisheries, Campus of Horta, Cais de Santa Cruz, 9901-862 Horta, Açores, (Portugal), Email: [email protected] (10) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (11) Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy), Email: [email protected] (12) Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del Mar y Limnologia, Unidad Academica Ecologia Marina, Laboratorio Biodiversidad y Macroecologia, A.P. 70-305 Ciudad Universitaria, 04510 Mèxico, D.F. (Mèxico), Email: [email protected] (13) Natural History Museum, Cromwell Road, London, SW7 5BD, (U.K.), Email: [email protected] (14) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (15) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.)., Email: [email protected] (16) Hellenic Centre for Marine Research (HCMR), Institute of Oceanography, PO Box 2214, 71003 Heraklion, Crete, (Greece) Email: [email protected] (17) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (18) Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka 237-0061, (Japan), E-mail [email protected] (19) Alfred Wegener Institute Am Handelshafen 12, D-27570 Bremerhaven, (Germany), Email: [email protected] (20) Hellenic Centre for Marine Research (HCMR), Institute of Oceanography, PO Box 2214, 71003 Heraklion, Crete, (Greece) Email: [email protected] (21) Universite de la Mediterranee (Aix-Marseille II), 58, Bd Charles Livon - 13284 Marseille Cedex 07, (France), Email : [email protected] (22)Universite de la Mediterranee (Aix-Marseille II), 58, Bd Charles Livon - 13284 Marseille Cedex 07, (France), Email: [email protected] (23)University of Aberdeen, Oceanlab, Newburgh, Aberdeenshire, AB41 6AA, (U.K.), Email: [email protected] (24) Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY (U.K.), Email: [email protected] (25) Ifremer DEEP/LEP, Centre de Brest BP 70, 29 280 Plouzané, (France), Email: [email protected] (26) Ifremer DEEP/LEP, Centre de Brest BP 70, 29 280 Plouzané, (France), Email: [email protected] (27) Alfred Wegener Institute Am Handelshafen 12, D-27570 Bremerhaven, (Germany). Email:[email protected] (28) Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Casilla 5080 Reñaca, Viña del Mar, (Chile), Email: [email protected] (29) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (30) Univ. of Piraeus, Dept. of Maritime Studies, Piraeus 185 32, (Greece), E-mail: [email protected] (31) National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, (U.K.), Email: [email protected] (32) MEDIAN S.C.P, Passeig Pintor Romero, 8 08197 VALLDOREIX, (Spain), Email: [email protected] (33) Ghent University, Marine Biology Research group, Sterrecampus, Krijgslaan 281 (S8), B-9000 Ghent, (Belgium), Email: [email protected] (34) Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen (Germany), Email: fwenzhoe@mpi- bremen.de ABSTRACT: The responsiveness of benthic biological communities 1. INTRODUCTION to climatic drivers and shifts makes them powerful indicators of biogeochemical and other environmental 1.1 Content and aims change in the oceans. In addition, benthic ecosystems have an economic value and are considered a vital Long-term, high resolution time-series studies are vital marine resource. However deep-sea faunal dynamics to understand the diverse range of processes that occur and ecosystem functioning is not well defined. This has in the deep sea. These range from short-term processes placed a higher priority in recent years on developing such as daily, seasonal and inter-annual variations, to and sustaining long-term, time-series studies of benthic longer-term trends including those linked to climate biodiversity, rate processes, and ecosystem change in change, to centennial- and millennial-scale changes that deep-sea and extreme habitats. A few key long-term can only be addressed by studying the deep-sea fossil time-series sites exist across the global Ocean. Many of record. While sampling from research ships offers a these sites are reviewed in this paper. However, much of detailed snapshot of the biogeochemistry and biology of the existing research is uncoordinated and the data deep-sea ecosystems, temporal processes and cycles can collected are not integrated or standardized. This only be addressed through continuous high-resolution currently limits the use of these valuable datasets, which measurements and sampling. For instance, sustained could be used for benthic modeling, global model benthic biological time-series provide information that validation and other societal benefits related to more is crucial for understanding ecological processes in the effective and environmentally sustainable governance of deep ocean, including those involved in global human activities in the deep ocean. Furthermore, the biogeochemical cycling. In addition, continuous time scales that can be studied within existing research observation is the only method to capture periodic or frameworks are not currently sufficient to adequately episodic events such as mud slides and phytodetrital address internationally-identified science priorities. deposition, which are difficult to predict accurately. These include assessing regional and global Without a permanent observing system these events are biodiversity, ecosystem functioning and the links often missed or their importance misinterpreted. An between climate, terrestrial and marine ecosystems. In established and sustained observing system is addition, the contribution of deep-sea ecosystems to particularly vital for the deep seafloor (>1000 m water global biogeochemical cycles and the potential depth), as it is less accessible than shallow water or alteration to ecosystem value and services due to coastal environments, and routine, opportunistic or fast- anthropogenic activities is largely unknown. In order to response sampling is difficult and expensive. Time- maximize the societal benefit, biological time-series, in series research (e.g. from ocean observatories) does not particular deep-sea sites, urgently require more stand alone but complements and provides important coordination, integration, sustained funding and verification for spatial analyses (e.g. from Autonomous infrastructure. This is necessary to unify research Underwater Vehicles and Remotely Operated Vehicles). methodologies, create synergies in the use of deep-sea Combining these temporal and spatial datasets allows technology, develop benthic models, and to stimulate complex dynamic processes to be more fully more collaboration between programmes. National and understood. international research organizations may provide a Thanks to the development and suitable framework within which further advances can implementation of the Global Ocean Observing System be achieved. Only then will we better understand the (GOOS), the past decade has seen the development