Research Technical Report

3D Models of Maritime Heritage Sites Created from ROV Video to Monitor Ecology of Artificial Substrate

Seida, M.S., R. Solymar, and S. Moore (November 2020)

Oral presentation at the Western Society of Naturalists Annual Meeting, November 5-8, 2020, Virtual Meeting

ABSTRACT

What species of sessile invertebrates initially colonize new shipwrecks? Are they different from those that colonize nearby natural reefs? Does alpa diversity and succession differ depending on substrate type? How do the resulting benthic communities impact the longevity of these maritime heritage sites? For the effective management of Monterey Bay National Marine Sanctuary’s (MBNMS) 463 known maritime heritage sites, it is critical to have comprehensive documentation of the sites and the benthic ecology they provide habitat for, both on spatial and temporal scales. However, many maritime sites are below safely accessible scuba depths. Recent master's project work by Ryan Solmar at CSUMB has demonstrated that 3D photogrammetry models generated from video captured by a small Remotely Operated Vehicle (ROV) contain sufficient detail to allow identification, quantification, and precise localization of sessile macroinvertebrates on submerged wrecks. One challenge with applying this technique in deeper, darker water is that video lights on small ROVs often generate enough backscatter to interfere with the photogrammetry algorithms. Here I present the preliminary findings of a brief engineering study to determine optimal light placement on a BlueROV2 (BlueRobotics.com) for documenting sessile macroinvertebrate communities in 3D photogrammetry models of deep wrecks. The system measured the position of the lights relative to a fixed GoPro camera to best minimize backscatter while maximizing illumination to facilitate clear video footage in a variety of marine piloting conditions.