Photogrammetric quantitative study of habitat and benthic communities of deep Cantabrian Sea hard grounds.

摘要: Abstract To study the highly complex deep-sea habitats of Cantabrian Sea and their macro-epibenthic communities a new towed underwater sled was designed to carry out quantitative visual transects based on photogrammetric analysis. The main objective undertaken provide first approach for gaining better understanding correlation between hard substrates, depth ecology in this region; thereby enabling researchers determine extent which benthic depend physical factors. results were compared from two areas with different characteristics methodological problems: one central outer shelf (150 m depth), near head Lastres Canyon, another at summit Le Danois Bank (555 m depth). Two image databases corresponding analysed, every photo being linked faunal list set environmental variables. assess amount variation densities related habitat characteristics, redundancy analysis (RDA) used. variables comprised depth, temperature, salinity, substrate type seafloor reflectivity. Using hierarchical classification proposed by EUNIS, three identified transect: A4.12—Sponge circalittoral rock (14.5% coverage), A5.35—Circalittoral sandy mud (56.8%) A5.44—Circalittoral mixed sediments (28.7%). A typical community appeared rocky habitat, made up yellow coral Dendrophyllia cornigera cup sponge Phakellia ventilabrum. On Bank, cnidarians (Caryophyllia smithii Callogorgia verticillata) sponges (Asconema setubalense, Aplysilla sp., hexactinellids) characterized patchy rock-sand habitats. This provided groundtruthing existing surficial features very valuable information about autoecology sessile vulnerable species, since scale used more appropriate kind than macroscale trawling, several microhabitats sampled same sample. Also, use non-extractive methodology, does not cause damage or alterations communities, is particularly necessary ecosystem studies Marine Protected Areas monitoring.