ATOC cable survey
Project Manager: Irina Kogan
Lead Scientist: Charlie Paull
We propose to finish the second year of a two-year project to investigate the environmental impact of the Acoustic Thermometry of Ocean Climate (ATOC) cable. The ATOC cable extends between Pioneer Seamount and the Pillar Point Air Force Station in Half Moon Bay, California.
This project is a cooperative and jointly funded MBARI-NOAA project. A total of 42 hours of video and 138 push cores were collected from 13 stations using the ROVs Ventana and Tiburon, equipped with cable-tracking tools. Side-scan sonar data collected from the R/V Zephyr over the cable’s path across the shelf helped select the ROV dive sites. A cumulative distance of 15.1 kilometers of seafloor was surveyed along 13 cable and nine control transects. Thirteen percent (12.1 kilometers) of the cable route was observed and recorded on video. Quantitative comparisons between cable and control sites were performed at nine stations. Most of the cable has become buried with time in sediment substrates on the continental shelf (water depths less than 120 meters), whereas much of the cable remains exposed on the deeper seafloor. Video images from rocky near-shore areas, where wave energies are greatest, showed clear evidence that the cable has been damaged. The main observed biological differences between cable and control areas were the number of organisms attached or adjacent to the cable. Anemones colonized the cable and were more abundant in cable transects at most soft sediment sites. At three of nine stations, flatfish and rockfish congregated near the cable. The cable has had no apparent effect on infaunal abundance. The cable may also subtly affect local hydrodynamic conditions that concentrate shell hash and drift kelp near the cable.
In 2004, we will complete the data analyses and prepare a manuscript and other presentation materials on the status and impact of this cable.