During the study, data from over 700,000 assessments of biomass changes from nearly 34,000 fish populations were analyzed, covering the waters of the Mediterranean Sea, the North Atlantic, and the northeastern Pacific Ocean from 1993 to 2021.
The researchers also discovered an interesting paradox: in cold regions, marine heatwaves can temporarily increase fish biomass by 176%, while in warm waters, similar phenomena lead to a sharp decline of up to 43.4%. The authors emphasize that this temporary increase can be misleading: if fishing quotas are raised based on short-term population data, the populations may face the threat of extinction when temperatures return to previous levels or the long-term warming trend continues.
In this regard, the scientists insist on revising traditional methods of managing fish resources. They propose three main changes: implementing emergency protective measures in the face of sharp temperature changes, considering the long-term decline in biomass when planning quotas, and the necessity of international coordination that takes into account the migration of fish populations across borders in search of comfortable temperatures. The authors believe that outdated national management models do not meet the modern challenges of climate change.
