Underwater fish visual census in the Azores from 1997 to 2015

Fish assemblages surveyed by using underwater visual censuses (UVC) down to 40 m. Transects were performed between 1997 and 2015 in the Azores, Portugal. All mobile fish were identified to the lowest possible taxon. Dates, geographic coordinates and species recorded are provided.

Fish assemblages were surveyed using underwater visual censuses (UVC) down to 40 m. Following standard belt transect surveys (Brock 1954), SCUBA divers sampled transects with 50 m length and 5 m width. All mobile fish were identified to the lowest possible taxon and counted. Sampling sites were chosen based on the general representativeness of the habitat. Transects within sites were selected by stratified random sampling: different transects were done in each dive without replicating the depth strata (every 10 m) or overall bottom type or crossing transects during a single dive or day. UVCs were conducted in the scope of projects CLIPE (FCT—Praxis XXI/3/3.2/EMG/1957/95), MARÉ (LIFE B4-3200/98-509), MAREFISH (FCT-POCTI/ BSE/41207/2001), OGAMP (INTERREG IIIb/MAC/4.2/A2 2001), MARMAC (INTERREGIIIb-03/MAC/4.2/A1 2004), EmpaFish (EC-FP6, SSP8-006539), MareFish (FCT, POCTI/BSE/41207/2001), MoniZEC (FRC - M2.1.2/I/018/2011)