The Deep-Sea Coral Observatory (DiSCO) Project

Deep-sea coral and sponge communities have recently come into focus as a frontier of deep-sea research. This attention is motivated by the ecological and potential societal importance of these systems, as well as their high level of vulnerability to human activities (e.g. trawl fishing). Ongoing changes in ocean conditions are likely to be stressful for corals and sponges and a broader understanding of their biology and ecology in relation to anthropogenic environmental change will help promote informed decision-making and management. Deep-sea coral and sponge communities are typically remote and often sampled and observed episodically, which provides only a snapshot of the dynamic processes shaping these systems. Considering the limited understanding of processes that influence the structure and function of these ecosystems, we are developing a deep-sea coral observatory (DiSCO) to increase the breadth and resolution of measurements of coral and sponge ecosystem biology and ecology in relation to oceanographic factors. DiSCO is now under development at Sur Ridge, a system off the coast of Big Sur, CA, USA with a diverse community of corals and sponges spanning 800 m to 1200 m in depth. With the goal of recording the behavior and condition of corals and other species in relation to daily, seasonal, or episodic changes in environmental conditions that may shape these ecosystems, DiSCO currently utilizes imaging systems (wide-field and macro-time-lapse cameras) and oceanographic observing technologies (e.g. ADCP, CTD, oxygen, pH, fluorescence, sediment traps). In addition, new imaging systems focused on coral health and behavior are under development. Coupled with ROV-based observing systems (e.g. polyp behavior quantified with particle image velocimetry), in-situ respirometry, laboratory studies of eDNA, and paleo-oceanographic and food web tracer studies, DiSCO will help elucidate the ecological and environmental drivers shaping deep-sea coral and sponge communities.