Areas off the central coast of California have been identified for development of offshore floating deep-water wind farms by the U.S. Bureau of Ocean Energy Management (BOEM). The structures will be anchored to the seafloor in more than 500 meter water depth and require other infrastructure which will inevitably alter the seafloor. Before 2018, the seafloor in this area was almost unexplored making it impossible to evaluate the impact and feasibility of this potential development. Thus we joined forces with the USGS, BOEM, and NOAA (EXPRESS) in an effort to map and explore the seafloor to provide a baseline characterization of this area. MBARI’s contribution to this effort involves utilizing the technologies associated with our mapping AUVs and ROVs to conduct detailed investigations of particular features AUV Data, ROV Data. From these seafloor observations we have made an account of the existing biological communities in this area now.

A number of geologic features of special interest are clearly revealed in the new regional surface ship maps. This includes the ~5 thousand large seafloor depressions called pockmarks (average 156 meter diameter, 5 meter depth) in what is North America’s largest pockmark field. In addition to these features, the detailed bathymetry collected with MBARI’s AUV revealed the existence of seafloor pits, previously un-mapped, as they are below the resolution of surface ship mapping techniques. These smaller (average 9 meter diameter and 1 meter depth) features are ~ three times as abundant as the pockmarks, exist in amongst the pockmarks and extend outside of the pockmark field. We are focused on understanding the origins of all of these features, establishing whether they are geologically active, and determining if they are areas of special biological significance.