Lessons from photo analyses of Autonomous Reef Monitoring Structures as tools to detect (bio-)geographical, spatial,
Romain David1, Maria C Uyarra2, Susana Carvalho3
1Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), CNRS, Aix Marseille Univ, IRD, Avignon Univ, Marseille, France.
Abstract:
We investigated the validity of Autonomous Reef Monitoring Structures (ARMS) as monitoring tools for hard bottoms across a wide geographic and environmental range. We deployed 36 ARMS in the northeast Atlantic, northwest Mediterranean, Adriatic and Red Sea at 7-17 m depth. After 12-16 months, community composition was inferred from photographs, in six plate-faces for each ARMS. Overall, we found a highly significant effect of sea region, site (within seas), and plate-face on community composition. Plate-faces thus represent distinct micro-habitats and provide pseudo-replicates, increasing statistical power. Within each sea region taken individually, there was also a highly significant effect of site and plate-face. Because strong effects were obtained despite the fusion of taxonomic categories at high taxonomic ranks (to ensure comparability among biogeographic provinces), ARMS photo-analysis appears a promising monitoring tool for each sea region. We recommend keeping three ARMS per site and analyzing more numerous sites within a sea region to investigate environmental effects.
