Global coastal reclamation disproportionately erodes biodiversity and blue carbon stocks

Abstract Global coastal reclamation represents artificial lands gained from the sea, is a common way to meet land requirement for coastal urbanization, posing substantial threats to fragile tidal ecosystems. However, the global pattern of created artificial land and its resultant ecological consequences remain uncertain. Here, we present a global map of coastal reclamation between 1985 and 2020, using satellite imagery and deep learning. We show that coastal reclamation is a widespread phenomenon across 92 coastal countries, appropriating a total area of 16,044 km² over the 35 years, primarily driven by aquaculture (35%) and port development (30%). Coastal reclamation has affected 13% of globally threatened species and resulted in a loss of 128 Tg C in carbon stocks over the 35 years. This study identifies hotspots of human expansion into the ocean and the primary land-use drivers behind this expansion, highlighting its disproportionate impact on biodiversity and carbon stocks pertaining to eco-environmental sustainability.