Collaborative Research: Food Limitation in the Deep Sea: A Test of a Paradigm using Long Time-Series Photographic Monitoring with Real-Time data Acquisition

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

Investigators at the Scripps Institution of Oceanography and the Woods Hole Oceanographic Institution will collaborate on a project to tackle a major paradigm in marine ecology: the coupling between a pelagically-derived food supply and the dynamics of deep-sea benthic communities. This coupling has been difficult to establish without appropriate long time-series measurements, which in turn have been limited by data storage capacity, longevity of battery power to operate instrumentation, the inability to collect/analyze data and alter sampling frequencies in real time, and the inability to correct or compensate for malfunctions in real time. The PIs will establish a long-term seafloor observing site by tapping into the Hawaii-2 Observatory (H20) at 5000 m depth in the central North Pacific. H2O is a prototype seafloor observing system that has made long-term monitoring possible in the deep sea, by providing electrical power from shore with real-time data acquisition and control via an underwater telephone cable. By plugging a suite of sensors into H2O, the PIs will study the short and long-term importance of a temporally-varying food supply on an abyssal benthic community. The following questions will be afddressed: 1) What is the quality and quantity of sinking particulate matter reaching the sea floor at the H20 site as representative of the North Pacific central gyre? 2) What responses are elicited in the epibenthic megafauna, as a proxy for benthic community activity, by the quality and quantity of particulate matter arriving on the sea floor on time scales from hours to years? A monitoring system will be attached consisting of a sedimentation sensor and digital time-lapse cameras, to monitor the flux of particulate matter as well as the activity of epibenthic megafauna in two 20m2 areas of the sea floor at the H20 site in real-time. Temporal changes in particle flux to the sea floor will be compared with the abundance and activity of the mobile epibenthic megafauna in the replicate photographic areas. A one-year test with real-time data acquisition and analyses combined with the ability to alter sampling frequencies from shore will provide the first long-term ecological monitoring of the abyssal sea floor to resolve the importance of food limitation on deep-sea benthic communities.