Quantifying the Human Footprint and Cumulative Impacts on Earth's Coastal Areas

Abstract

Coastal regions are home to hundreds of millions of people around the planet, with most of the world’s countries having coastal areas. Connecting marine and terrestrial environments, coastal ecosystems are diverse, supporting rich biodiversity and providing a wide range of ecosystem services. However, these ecosystems are also vulnerable to multiple marine and land based stressors. To help effectively address the many threats to coastal areas, there is an urgent need for comparable systematic mapping and quantification of cumulative coastal impacts globally. To address this gap, we collated digital databases of human impacts at the global extent, including both land and marine based impacts, and quantified the human footprint and cumulative impacts across Earth’s coastal areas. We found that outside the polar areas, over 99% of all coastal areas on Earth had quantifiable direct human impacts. Human population density strongly explaining the variability in coastal human footprint scores around the globe with Singapore, Gibraltar and Israel’s Mediterranean coast showing the highest footprint globally. The lowest coastal footprint scores globally were found for Antarctica and the Arctic. Beyond the polar coastal areas, we identified 122 “coastal wilderness” areas with low human impacts. Amongst these, only nine across the whole globe have been fully designated as protected areas. We highlight the need to create platforms specifically targeting coastal environments to help address the gaps in coastal area conservation and management around the world.