Reconciling classifications of ecologically and biologically significant areas in the world's oceans

The classification of marine habitats is a critical first step towards the protection of marine biodiversity and the sustainable management of the world's oceans. Recently, the topic has received heightened attention as the 2012 deadline for meeting international commitments under the convention on biological diversity (CBD) approaches. These commitments require the development of a unified approach to identifying high-seas areas in need of protection. To determine the best approach, criteria for identifying sensitive areas proposed by the CBD and the Food and Agriculture Organization of the United Nations were compared to the ecologically and biologically significant areas (EBSAs) criteria developed by Fisheries and Oceans Canada. The comparison demonstrates that, with some minor refinements, the EBSA criteria are parsimonious and encompass all other criteria proposed to date. To identify the most suitable approach for defining EBSAs, 16 classifications of the world's oceans, ranging from coastal regions to the high-seas, were reviewed for their suitability to define EBSAs. The classifications differed in substantive ways, including analytical methods (from quantitative analyses to subjective interpretations), data sources (either physical or biological), and the realm to which they were applied (high-seas, coastal, or deep-ocean). No method currently provides an integrated, whole-ecosystem approach to identifying a comprehensive set of important marine areas. To move to a singular, multi-attribute, description of EBSAs requires an explicit, reproducible methodology. Here, the EBSA approach is formalised as an adaptive method that integrates existing classifications in an efficient, holistic, and transparent manner, by explicitly considering important marine features (IMFs) and biologically sensitive areas (BSAs). The proposed approach directly addresses the EBSA criteria, and is applicable across the different realms of the world's oceans.