WildblueExpeditions's video: Video S2 Gelatinous carbon shapes benthic communities in shelf and slope ecosystems

Gelatinous carbon shapes benthic communities in shelf and slope ecosystems Mario Lebrato a,*, Juan-Carlos Molinero b, Elena Mateo Gonzalez c, Daniel O. B. Jones d a Christian-Albrechts-University Kiel (CAU), Kiel, Germany mario.lebrato@bcssmz.org b GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany juan-carlos.molinero@ird.fr c Universidad de Las Palmas de Gran Canaria, Spain elena.mateo101@alu.ulpgc.es d National Oceanography Centre, University of Southampton Waterfront Campus, Southampton, UK dj1@noc.soton.ac.uk Abstract After seasonal blooms of gelatinous zooplankton (Cnidaria, Ctenophora, and Thaliacea) collapse their sinking carcasses play an important role in transporting labile carbon (jelly-C) to benthic communities from the shelves to the deep-sea worldwide. To what extent sinking jelly-C shapes benthic communities and interacts with other environmental parameters is unknown but expected to be important owing to the quantity and large areas covered by these deposits. Mass jelly-C depositions from the Thaliacean Pyrosoma atlanticum were studied in combination with megafaunal benthic communities from an ROV survey of the shelf and slope off Ivory Coast (West Africa). Freshly deposited jelly-C strongly shaped benthic diversity, dominance, aggregation and triggered opportunistic feeding events along a 26 to 1276 m bathymetric gradient. We demonstrate that broad scale environmental variation controls the megafauna with finer-scale patchiness caused by the spatially variable P. atlanticum jelly-C food resource. This is something that has been hypothesized for a long time, but very rarely shown at such a broad scale. This is strong evidence on the importance of jelly-C for marine benthic ecosystems in continental margins.