Techniques for the observation of marine biodiversity: differences in species richness and abundance through three coastal habitats

Abstract

The seabeds of the Canary Islands are known worldwide for their biodiversity, attracting millions of tourists from all over the world. In this study, we compared the biodiversity (species richness) and abundances of coastal assemblages through three different, but complementary, methods (underwater visual census, UVCs, un-baited cameras, UBCs, and baited cameras, BCs), at three types of coastal habitats: urchin-grazed barrens, vegetated rocky areas and rocky-sand ecotones. The most appropriate technique for estimating the biodiversity (species richness) and abundance of species in the study area was UVCs, in particular since cryptic species were recorded, which are not observed in UBCs and/or BCs. UBCs were effective at recording herbivorous species; in particular, the parrotfish Sparisoma cretense and the sea bream, Diplodus sargus. BCs were useful to estimate the abundance of species attracted by the bait; in this case Diplodus sargus and Boops boops, of which large concentrations are observed around the bait.