Carlos García-Soto
CSIC (IEO) researcher, head of the Ocean-Climate System Assessment Unit, coordinator of the World Ocean Assessment (WOA, United Nations) and delegate to the Climate Change COP (UNFCCC), the Treaty on the High Seas (BBNJ) and the International Seabed Authority (ISA)
This study reveals a dynamic that should concern us from a governance perspective: long-term warming reduces fish biomass, while heat waves can generate temporary increases that mask the underlying trend. This combination introduces a clear risk of misinterpretation in decision-making.
Temporary gains may encourage increases in fishing effort or delay management measures, when in reality the system is losing structural productive capacity. The problem is not only extreme variability, but also confusing specific episodes with lasting changes.
In a context of accelerated climate change, policies cannot react solely to extreme events or be based on short-term signals. They need consistency between science, planning and governance, especially in shared ecosystems or on the high seas.
Ultimately, the challenge is not only to measure biomass better, but to prevent transient signals from distracting us from the structural transformations of the ocean-climate system.