Ranking and mapping the impact of human activities on global ocean ecosystems

Conservation prioritization and spatially explicit management of the oceans require high-resolution maps of where human impacts to marine ecosystems occur, yet few such maps exist. Here we synthesize global data on 17 threats and 14 marine ecosystems to produce a global, 1km2 resolution map of human impacts specific to each marine ecosystem. We found that none of the ocean is unaffected by humans but that a relatively small fraction is heavily impacted, and that results vary greatly by region and ecosystem type. This research is the first such global assessment, providing important guidelines for where conservation action and threat mitigation is most critical to meet global management and conservation goals.