Recent calls for widespread implementation of reserve systems in U.S. waters have elevated this debate to the national level. As used here, it describes a defined area in marine waters where fishing is prohibited to achieve specific fishery conservation and management objectives. Marine reserves are believed to be a particularly useful tool for managing multispecies fisheries and fisheries that target species with behavioral or life history characteristics that make them vulnerable to overfishing. Marine reserves provide an ecological, multispecies approach to fishery management. Finally, further focusing management on indicator species within reserve areas could make fishery management less information-intensive by reducing the need for expensive stock assessments on multiple species.
Marine reserves improve natural population structures within their borders.
Fish populations protected from fishing pressure can become structured by natural mortality rather than fishing mortality. They are also protected from common problems associated with fishing, such as the selective removal of large breeder fish, incidental catch and mortality, and habitat degradation, each of which can alter ecosystem structure and function. Preserving the natural structure of fish populations within the reserve area can, ultimately, enhance the resiliency of these populations to outside pressures. Marine reserves increase the individual size and abundance of fish both inside and outside their borders. There is evidence from around the world that marine reserves support fish populations of increased abundance, density, size, and age classes within their borders.