AUTHOR=Aston Eoghan A. , Duce Stephanie , Hoey Andrew S. , Ferrari Renata 

TITLE=A Protocol for Extracting Structural Metrics From 3D Reconstructions of Corals

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.854395

DOI=10.3389/fmars.2022.854395

ISSN=2296-7745

ABSTRACT=The 3D structure of individual coral colonies provides insights into their ecological functioning. While structure from motion techniques make it possible to reconstruct 3D models of coral colonies based on overlapping images, the extraction of relevant metrics of complexity in a reproducible way remains challenging. We present a method for the 3D reconstruction of coral colonies and the automatic extraction of eleven structural complexity metrics from 3D models using two user-friendly python scripts. The eleven complexity metrics are designed to capture aspects of complexity relating to the colony’s size and shape of the 3D structure that are related to their likely ecological function. We explored the potential ecological applications of some of these metrics using linear models, comparing aspects of complexity among colonies of different size, and morphotaxa (combined information on growth morphology and taxa). Our results showed that a metric as simple as colony diameter explained 95% of the variation in shelter provisioning capability when paired with information on colony morphotaxa. Further, the habitat provisioning of colonies of comparable size was similar among the seven morphotaxa examined. During the current period of rapid uptake of this accessible method among ecologists, the results of our study provide a basis to use data derived from 3D models to further explore the nuances of the relationship between structure and function of corals at the colony scale in a replicable and comparable way.