Oregon's Nearshore Biogenic Habitats: Assessment by Remotely Operated Vehicle Video

Biogenic habitat includes structure-forming invertebrates that can contribute substantial structural complexity to nearshore ocean habitats, and may provide shelter for fish and habitat structure for many other marine organisms. While we are gaining increased understanding of the physical components of seafloor habitat as a result of recent high-resolution seafloor maps for several nearshore rocky reefs, and while federal agencies are developing information on deeper-water biogenic habitat, we currently have little information on nearshore, shallow-water biogenic habitat. We initiated an investigation of methodological approaches for assessing biogenic habitat using remotely operated vehicle (ROV) video transects, with an initial focus on assessing utilization by rockfish and associated demersal fish and invertebrates. Using existing forward-facing video from past ROV surveys, we explored the efficiency of sub-sampling approaches during video review for assessing abundant invertebrates, and also examined the proximity and behavior of fish relative to nearby biogenic structures. We subsequently re-configured the ROV’s downward-facing camera and lights, and conducted new surveys covering a range of nearshore habitats. These data will be used to assess potential sampling strategies for biogenic habitats, and associations of fish and invertebrates with distinct structural components of biogenic habitat will be presented and discussed.