Global distribution of altered estuaries

초록

Global-scale analyses of 2,396 estuaries found thatestuarine area has changed in response to recent human impacts (e.g., land reclamation, estuarine dam construction) and economic development between 1984 and 2019, and that estuarine area shrank by 5372 km2 whereas upland submergence created 5,015 km2 of estuarine area elsewhere. Approximately 44% (n = 1,046) of today’s estuaries have been directly altered through land reclamation, estuarine dam construction, or a combination of both, and ~250,000 acres (1,027 km2) of estuarine area have been directly converted to urban or agricultural fields. Nearly 90% (923 km2) of land reclamation occurred in Asia linked to recent advances in the economic development of the middle-income stage. Additional historical mapping and 5-year interval analyses revealed that human alteration was insignificant in the lowincome stage, but estuaries were predominantely altered during their middle-income stages, where estuarine degradation is a common consequence of economic growth. This study suggests that largescale estuarine loss can be avoided by preserving estuaries in low- and mid-income countries in the early stages of economic development.