Lessons from a global remote sensing mapping project. A review of the impact of the Millennium Coral Reef Mapping Project for science and management

Anthropogenic and natural impacts threaten the sustainability of ecosystem services provided by the ocean and its coastlines. Coral reefs are an endangered and important component of the tropical realm. Coral reef science, management and conservation programs greatly benefit from habitat maps when they are available. This study reviews the use of the Millennium Coral Reef Mapping Project (MCRMP), which hierarchically mapped since 2004 coral reefs worldwide using Landsat satellite multispectral imagery at 30 meter spatial resolution. Tracking in the scientific literature the impact of MCRMP products proved to be difficult because of frequent lack of citations (omission errors) and confusion with products that have integrated MCRMP data but degraded them (commission errors). To categorize the applications themes, we selected 62 representative studies that unambiguously used MCRMP products. MCRMP products were used prominently to achieve new results in coral reef inventories; conservation planning; enhancement of biodiversity and fishery resource mapping, monitoring and modeling; connectivity and climate change modeling. The products were also useful to map other ecosystems. We evaluate the main strengths, weaknesses, opportunities, and threats to MCRMP products. From this review, we also make recommendations and reflect more generally on the value of future global-scale mapping projects targeting specific ecosystems