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Carolina Doya, Institute of Marine Sciences, CSIC, Barcelona, Spain
Damianos Chatzievangelou, Jacobs University Bremen, Germany
Nixon Bahamon, Blanes Centre for Advanced Studies, CSIC, Spain
Autun Purser, Alfred Wegener Institute, Germany
Fabio C. De Leo, Ocean Networks Canada, University of Victoria, Canada
Kim Juniper, Ocean Networks Canada, University of Victoria, Canada
Laurenz Thomsen, Jacobs University Bremen, Germany
Jacopo Aguzzi, Institute of Marine Sciences, CSIC, Barcelona, Spain
Yearly epibenthic megafaunal community dynamics at a cold seep (Barkley Canyon) using a tracked Sea Crawler

Canyons systems extreme topography may entrain diverse and variable current regimes. In some locations this lead distinct sub-habitats within, such as the cold seep provinces within the Canyon Pacific canyons which knowledge on the functioning is scarce. Cabled multiparametric platforms allows real-time monitoring of fauna and environmental processes through discrete seabed windows. By attaching a tracked Internet Operated Vehicle (IOV) to one of these platforms, the ecosystem variability can be investigated in real from anywhere in the world. In this study, we used a deep sea crawler attached to the Ocean Networks Canada (ONC) at a cold-seep site at 890m depth in the Barkley Canyon, NE Pacific; the first seasonal megafaunal study using this technology. Video transects were run with a 4-h frequency, over 15 months, with both video and environmental data collected in order to determine the modulator effect of oceanographic parameters on animal behavior (i.e. seasonal periodicities). We acquired a total of 890 (over 93 h of footage) video-transects and imaged 7698 individuals, from 7 phyla representing 23 taxa. The abundance of the various fauna were logged over time, with the 6 most abundant faunal groups (rockfish, sablefish, hagfish, buccinids, grooved Tanner crab, small crabs, ctenophores and true jellyfish) exhibiting significant seasonal abundance patterns. We found the species assemblage structure significantly linked to the sampling month, to water temperature, current velocity and dissolved oxygen. Video footage revealed the reproduction behavior of the grooved Tanner crab from February to March and the ecological function of the ctenophore Bolinopsis infundibulum in northern temperate deep sea waters peaking in November-December, followed by a dramatic reduction, presumably explained by predation from the true jellyfish Poralia rufescens. Such information is important for biodiversity conservation and the sustainable management of deep sea fisheries.


Special Session 2: Interdisciplinary studies in Barkley Canyon
Oral Presentation
Internet Operated Vehicle, seasonality in the deep sea, Barkley canyon, Bolinopsis infundibulum, Chionoecetes tanneri