Recreational scuba-diving and carrying capacity in marine protected areas

Marine protected areas (MPAs) are declared principally to protect biological and environmental values in areas where such values are special. The declaration of MPAs is well accepted and widely used in a number of countries. Many recreation pursuits rely heavily upon marine resources, and marine-based tourism is growing at a significant rate. Scuba-diving is one recreational pursuit which is experiencing greater participation rates. Consequently, conflicts between recreation and conservation may occur in multi-use MPAs, with scuba-divers impacting the natural environment on which the sport relies. Heavy usage by scuba divers also reduces amenity values in MPAs. The evidence is that critical social and biological thresholds exist. Above these thresholds amenity values are reduced severely, while biological impacts may also become significant. The interrelationships between amenity and biological values are worthy of further research to identify biological and social carrying capacities in MPAs and, subsequently, to formulate suitable management responses to reduced MPA values.