Ribeiro, J. Underwater visual methods for evaluation of fish communities: application to the Sparidae of the Baleeira Bay (Sagres, South Portugal).

The objective of this study was to compare two visual methods: the transect and the stationary method, used to quantify the Sparidae communities and distributions with depth, in the Enseada da Baleeira, on the South coast of the APPSACV. 62 underwater census were carried out in the Enseada da Baleeira from August 20 September 15, 1992. 8 stations were sampled, with a total of 5 hours and 10 minutes spent identifying and counting sea breams (Sparidae).

A total of 9 species were identified and counted. In the quantification terms the two methods differed and it was concluded that the transect method was more suitable for quantifying the Sparidae community of the Enseada da Baleeira. The abundance and the biomass, as well as the diversity decreased with depth differed by the high abundance of Sarpa salpa only in the first 8 meters. The distribution by size was characterised by the dominance of small and medium individuals at depths to 12 meters. Below 12 meters the fish community was dominated by medium sized sea breams.