Satellite remote sensing reveals rapid loss of submerged aquatic vegetation in global lakes

Aquatic vegetation (AV), as vital primary producers and carbon sinks in lakes, is crucial for lake ecosystem health, with submerged aquatic vegetation (SAV) and floating/emergent aquatic vegetation (FEAV) representing distinct states. However, global dynamics of SAV and FEAV are poorly understood due to data scarcity. We developed an innovative AV mapping algorithm using 1.4 million Landsat images from 1989 to 2021, creating a global database of 5587 lakes. On average, AV covers 108,186 km2 globally (FEAV: 15.8%, SAV: 13.1%). Over two decades, SAV decreased by 30.4% while FEAV increased by 15.6%, indicating a significant net loss of AV. This shift suggests a move towards shaded and turbid conditions, driven primarily by human-induced eutrophication until the early 2010s, with global warming likely playing a role thereafter. These trends signal deteriorating lake health globally.