The sampling technique used to study the fish communities is the belt transect in a UVC Underwater Visual Census.: a 25 m linear transect is placed at the center of a 2 m width belt. The delimited area is used to compute a number of fish per sqare meter.
The fish are identified to the species level (more than 160 species up to now) on the 3 stations in each determined zone. Each census is achieved in the 50 m² belt transect (fixed distance sampling) where the size of each fish is estimated (in cm).