PlanBlue’s seafloor habitat mapping technology was deployed in a study of the Université Côte d'Azur in 2020, to assess the effectiveness of artificial reefs to stimulate natural habitats. The study compared old artificial reefs (concrete cast of simple geometric shapes), with 3D-printed artificial reefs, and natural reefs. The results were published in the peer-reviewed journal Restoration Ecology: Artificial reef effectiveness changes among types as revealed by underwater hyperspectral imagery.

The conclusion of the study was that 3D-printed reefs were not fully able to mimic the natural adjacent rocky reefs, however it was closer than the previous-generation artificial reefs. More specifically, it identified a larger community of brown algae compared to the previous-generation artificial reef, however, there was still a low level of red algae compared to natural reefs. Research on the use of 3D-printed reef for enhancing marine life is still in its infancy, but the results suggested a slight positive increase in the artificial reef’s effectiveness compared to concrete version.

The study also reflected on the use of PlanBlue’s technology. It concluded that the study is an important step toward developing hyperspectral imaging as a useful tool for mapping underwater photosynthetic communities and reducing the human and time resources required for such efforts.

Some areas for further enhancement were identified. Low light conditions and the small size of some of the organisms made visual cross-identification difficult, which could be improved with higher camera resolution and light input. This has since been implemented in the current version of PlanBlue’s DiveRay. In addition, using spectral fingerprinting would allow to distinguish organisms that do not have photosynthesis. Related work can be found in the research paper we did with the University of Guam, USA, which was published in Scientific Reports.

It also stressed the strengths of PlanBlue’s seafloor habitat mapping solution. The technology was able to identify the relative differences in the signal of the photosynthetic community on different habitats and reduce human and time effort required for underwater observations. In our study, one diver could sample 24 transects on five different sites at 30-m depth over 3 days. The authors conclude by expressing their confidence that the pioneering study will encourage further development of this approach.

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