Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms

Reflection spectra obtained from hyperspectral imaging can be used as a bio-optical taxonomic identification tool if the pigment composition and the corresponding optical absorption signatures of an organism are known. In this study we elucidate species-specific absorption and corresponding reflection signatures of marine organisms and discuss optical fingerprints from underwater hyperspectral imaging (UHI) for future automated identification of organisms on the seafloor. When mounted on underwater robots, UHI has the potential to be a time- and cost-efficient identification and mapping method covering large areas over a short time. Hyperspectral imaging in vivo and in situ were used to obtain species-specific reflection signatures (optical fingerprints). High performance liquid chromatography, liquid chromatography–mass spectroscopy and nuclear magnetic resonance were used for pigment identification and to obtain species-specific absorption signatures of four marine benthic species; the spoonworm Bonellia viridis, and the sponges Isodictya palmata, Hymedesmia paupertas and Hymedesima sp. Species-specific optical fingerprints based on a UHI-based reflectance signature were verified successfully in the organisms investigated.