Souto, P. Methods of underwater assessment of the ichthyofauna - Aplication to the artificial reefs from the Algarve coast.

Visual methods of assessment of fish populations are commonly used to study the effects of artificial reefs in the marine environment. The objective of this work was the definition of a sampling methodology for the qualitative and quantitative assessment of the ichthyofauna community colonising the artificial reefs placed by IPIMAR off the Algarve coast.

The random search method was chosen for familiarizing the divers with the habitat, species and techniques of data collection. The qualitative approaches showed that there were no significant differences between the experienced and inexperienced divers and between the two reef systems (Faro/Olhão). With respect to the quantitative approaches, it was found that the circum-stationary method was the most appropriate for this type of habitat.