The Use of Fish Assemblages as Reserve Effect Indicators for Small Mpas. A Case Study in Southern Spain (Strait of Gibraltar)

Marine protected areas (MPAs) are considered a useful tool for marine biodiversity and ecosystems conservation and management. Nevertheless, concern has arisen about the negative effects experienced on marine reserves with low levels of protection. In terms of fish conservation, small MPAs cannot provide effective protection for highly mobile species but can serve as reserve for low-mobility fishes. Therefore, these species could serve as indicators for small MPAs effectivity assessment. In this study, rapid surveys on fish assemblages were carried out in a small (1.8km long, 0.8km wide) no-take/no-entry zone of El Estrecho Natural Park (Alboran Sea, Spain) and a directly adjacent non-protected zone. Species of commercial interest and showing homing behaviour were used as indicators of reserve effect. Species with homing behaviour and of commercial interest could be good indicators of small coastal MPAs effectivity. Nevertheless, fish abundance and community structure did not vary in composition between protected and unprotected areas, which could suggest low to no protection for fish species in El Estrecho Natural Park. Additionally, insufficient resources for effective enforcement have been reported for this MPA. Therefore, management and effective surveillance of this marine protected area should be properly implemented to make protection effective in the studied area.