Frontiers in Ecology and the Environment, 2010,
8 (3), p. 124-129 ISSN 1540-9295
Marine species and their habitats are facing widespread overexploitation and degradation, respectively. In response to urgent calls for their protection, the international community agreed to establish representative networks of marine protected areas by 2012 that would conserve and protect 10-30% of specific habitats. To achieve these goals will require reliable estimates of the total area occupied by each habitat. We evaluated this assumption for coral reefs by generating estimates of coral reef area from high-spatial-resolution, remotely sensed imagery (30-m resolution Landsat data), and comparing these with existing published data (usually >1-km resolution). Discrepancies between previous estimates and our values ranged from +1316% to -64%. This uncertainty is incompatible with realistic achievement of the 10-30% conservation targets. We conclude that currently available estimates of the global extent of most coastal marine habitats are based on data that are too poorly resolved to be useful in evaluating progress toward the 2012 targets. Most countries will therefore be unable to demonstrate that they have fulfilled their commitments to marine biodiversity conservation. We urge that accurate inventories be conducted, in a cost-effective fashion, through analyses of available high-spatial-resolution satellite imagery.
