Animal forests promote marine habitats morphological complexity and functioning. The red gorgonian, Paramuricea clavata, is a key structuring species of the Mediterranean coralligenous habitat and an indicator species of climate effects on habitat functioning.

Paramuricea clavata metrics such as population structure, morphology and biomass inform on the overall health of coralligenous habitats, but the estimation of these metrics is time and cost consuming, and often requires destructive sampling.

This study proposes a novel and transferable Structure from Motion (SfM)* based method for the estimation of gorgonian population structure, morphometries and biomass. The method includes the estimation of a novel metric (3D canopy surface) describing the gorgonian forest as a mosaic of planes generated by fitting multiple 5 cm x 5 cm facets to a SfM generated point cloud.

The obtained results show that the method could complement traditional sampling methods by enabling effective long-frequency wide-area monitoring of gorgonian forests, enhancing current management practices of and compliance with legislative requirements for coralligenous areas including MPAs.

It is concluded that the methodology presented in the study highlights the potential of SfM based methods for fast and reliable monitoring of demography and morphometry of gorgonian forests.

*SfM is a topographic survey technique for the reconstruction of real scale three dimensional models of subjects or scenarios, using imagery collected at unknown camera positions.

Palma M et al. (2018) SfM-based method to assess gorgonian forests (Paramuricea clavata (Cnidaria, Octocorallia)). Remote sensing 10:1154.