Temporal dynamics of fishes assemblages on two artificial reefs in Morrosquillo Gulf, Colombian Caribbean

Abstract

From August 2001 to August 2002, the fish assemblages in two benthic artificial reefs (ARs) situated in the Morrosquillo Gulf were evaluated through visual census at regular time intervals. In 176 visual census, 62 species were recorded, 49 in Punta de Piedra (PP) and 52 in Tolú (T), with 39 species in common. PP presented a relative total abundance of 7,088.8 individuals and T 5,523.8 individuals. This difference was related to the greater volume and structural complexity in PP. The families with the greatest species numbers were also of high economic importance (Haemulidae, Lutjanidae, Serranidae, and Carangidae). The species with the greater relative abundance were Anchoa sp. in PP and Ophistonema oglinum in T. The assemblages showed high similarity in composition, resident category and dynamics, which relates with the stability of environmental conditions and similar location and design of the ARs. During the monitoring, the fish assemblages accumulated species and individuals in a non-systematic pattern in the group of non-resident species, as defined here, but the ARs should be close to their carrying capacity. There is circumstantial evidence of the biomass production potential of the ARs (development of residents) besides their aggregating effect. These findings support the notion of ARs as tools for fishery and biological management, but their implementation should be guided by the precautionary principle.