NEWS New study published by Umeå University researcher Heidi Burdett has evaluated the quality of underwater surveys taken by divers compared to remotely-operated vehicles – important information for innovating the future of marine environmental monitoring.
A coralline algae reef (commonly called maerl or rhodolith beds) from the west coast of Scotland. This hugely important habitat is difficult to monitor because of its physical complexity
ImageNick KamenosOver the past decades, climate change and human activities have degraded ocean ecosystems and reduced water quality. Regular monitoring allows us to track how these change over time and to assess the success conservation actions such as reduced pollution discharge or habitat restoration.
Coastal habitats, such as coralline algae reefs, coral reefs and seaweed forests, are some of the most important ecosystems in our oceans but their future remains uncertain. Monitoring programmes aim to inform us about the health of these ecosystems, but traditional monitoring methods are limited in the information they provide. Photogrammetry, an emerging technology where lots of photos of the seabed are ‘stitched’ together to create a 3D model of the seabed habitat, could transform monitoring programmes and provide unique insight into the health of the seabed.
Heidi Burdett, Associate professor at Department of Ecology and Environmental Science and Umeå Marine Sciences Centre (UMF).
ImageHeidi BurdettIn this new study, Heidi Burdett, Associate Professor in the Department of Ecology & Environmental Science and the Umeå Marine Sciences Centre at Umeå University, collaborated with Tritonia Scientific Ltd (an underwater survey company based in Scotland) to compare the quality of photogrammetry data acquired when conducted surveys using SCUBA divers or Remotely Operated Vehicles (ROVs). They found that both systems are good for reconstructing seabeds, but the preference will depend on the specific survey priorities. For example, reconstructions from diver surveys had lower modelling errors, but the survey area is restricted by the limited time divers can spend underwater. In contrast, ROV surveys, although associated with slightly higher modelling errors, can do large surveys very quickly.
“We surveyed 11,285 square metres in just 400 minutes of ROV deployment time. We estimate that it would have taken 28 working days to have covered a similar area using divers!”
Until higher quality ROV camera systems are readily available, the researchers recommend using a ‘hybrid’ approach, where large-scale ROV surveys are conducted for maximum survey area, supplemented by higher quality, but smaller, diver surveys in specific sites of interest.
Read the full study: Quantitative Comparison of ROV and Diver-Based Photogrammetry to Reconstruct Maerl Bed Ecosystems
