A national-scale four-decade mapping of land and marine aquaculture dynamics in coastal China (1986–2024)

Aquaculture is pivotal to global food supply and security, yet its rapid coastal growth in China has reshaped landscapes and seascapes, risking ecosystem services and water quality. We compile an annual, nationwide dataset mapping both land aquaculture ponds and marine aquaculture zones across 1986–2024 using a multi-feature machine-learning workflow on dense Landsat time series. Based on the dataset, we further unraveled spatiotemporal patterns of coastal aquaculture in China. Key findings include: (1) land aquaculture ponds grew from 6578.31 km² in 1986 to a peak of 14,577.01 km² in 2016 and decreased to 10,490.99 km² in 2024. In contrast, marine aquaculture zones continued to expand from 2115.41 km² in 1986 to 5974.34 km² in 2024; (2) coastal aquaculture exhibited a spatial pattern characterized by initial decline followed by expansion from east to west, with land aquaculture ponds declining and recovering from south to north, and marine aquaculture zones showing distinct differences between northern and southern regions; (3) the development of land aquaculture was significantly driven by policies promoting ecological sustainability, while marine pasture development encouraged the expansion of marine aquaculture. The mapped spatiotemporal distributions of coastal aquaculture provide support for sustainable coastal planning and informed management strategies in China.