Climate change reduces pelagic biomass in a coastal upwelling ecosystem
摘要
Global fisheries rely heavily on oceanic primary and secondary productivity. However, how regional food webs will respond to ongoing climate change—and the resulting implications for fish biomass—remains poorly understood. Coastal upwelling systems are among the most biologically productive regions on Earth. Their responses to warming are often non-linear and vary by region, making it essential to examine them in detail to anticipate ecosystem-level impacts. Here we used a machine learning framework to project future changes in marine community dynamics, scaling from nutrient speciation to fish biomass. While recycled nitrogen forms (ammonium) are projected to increase, a long-term decline in new nitrogen inputs (nitrate) is associated with reduced phytoplankton growth and fish biomass, particularly under high-emission scenarios. Our findings highlight the critical benefits of pursuing low greenhouse gas emission pathways to limit fishery declines and support the resilience and partial recovery of upwelling ecosystems in a warming ocean.