A hierarchical ecological approach to conserving marine biodiversity

A number of ecological models have been developed to provide an understandi ng of the various biotic and abiotic components required to conserve biodiv ersity and to reconcile objectives and methods between those interested in the conservation of species (e.g., population management) and those advocat ing the conservation of spaces (e.g, protected areas). One of the better kn own efforts-pioneered in the Pacific Northwest of the United States-is a hi erarchical ecological framework, that separates biodiversity into compositi onal, structural, and functional attributes at the genetic, population, com munity-ecosystem, and landscape levels of organization. We present an adapt ation of this terrestrial framework consistent with the ecological function of marine environments. Our adaptation differs in its treatment of the com munity and ecosystem levels of organization. In our marine framework, the c ommunity level denotes predominantly the biotic community components of bio diversity, and the ecosystem level-consistent with marine terminology-denot es predominantly physical and chemical components. The community and ecosys tem levels are further separated into those attributes based on ecological structures such as depth or species richness and those based on ecological processes such as water motion or succession. The distinction between the b iotic (genetic, population, and community) and abiotic (ecosystem) is requi red because the biological components of biodiversity such as competition o r predation are often more difficult to observe than the abiotic components such as upwellings, substratum, or temperature. As a result, efforts to co nserve marine biodiversity are often dependent on the observable abiotic (e cosystem) components, which can be used as surrogates for the identificatio n and monitoring of biotic (community) components. We used our hierarchical framework to identify, and suggest how conservation strategies could be im plemented in marine environments depending on whether existing data are to be used or new data are to be collected.