Lake State Shifts After Earthquakes in Tectonically Active Regions

Earthquakes can induce substantial biogeochemical changes in lake ecosystems. However, the long-term impact of earthquake induced regime shifts in lake ecosystems remains understudied. Here, we examined changes in geochemical characteristics, diatom and prokaryotic communities over the past 130 years in sediment cores collected from a moraine-dammed lake on the Himalayan Fault. The abrupt accumulation rates of sediment total organic carbon and total nitrogen after earthquakes indicate state shifts in lake ecosystems. A switch from an oligotrophic benthic species-dominated to a eutrophic plankton-dominated state in diatom community was found after earthquakes. Prokaryote community shifted to higher diversity, elevated network stability, and closer relationship to sediment organic matter and nutrients after earthquakes. We also estimated that 1.1% of global lakes likely have experienced dramatic regime shifts induced by earthquakes. Our system-wide perspective highlights the tectonics on regime shifts, and the assessment's global scope confirms the universality of regime shifts induced by earthquakes.