Global Empirical Assessment of Marine Heatwaves’ Impacts on Fisheries Production and Economic Value

Marine heatwaves (MHWs) have become increasingly frequent and intense, raising concerns about their impacts on fisheries production and economic value. We present a global assessment of MHW-related impacts across 2088 marine fisheries from 1985 to 2022. Using high-resolution satellite data and standardized catch production and catch value, we identified significant reductions in catch and ex-vessel value during years of elevated thermal stress. A total of 322 fisheries (15%) showed statistically significant declines during years with high MHW activity, with regional disparities indicating that the Northeast Atlantic and Southeast Pacific experienced the highest cumulative losses, while country ranking highlighted Norway, China, Japan, and Peru as the most affected. Estimated accumulated global losses since 1985 exceeded 5.6 million tonnes and USD 6.6 billion (2005 USD equivalents), nearly 40% of which occurred during 2013–2022. These findings emphasize the need to incorporate extreme thermal events into fisheries risk assessments and adaptation strategies, especially in highly productive or strategic regions.