Climate change and ocean acidification outweigh local stressors in Mediterranean mussels: A multi-method convergence analysis.

Climate change, primarily driven by ocean acidification, accounts for approximately 40% of biological stress variance in Mediterranean mussels, surpassing local metal contamination effects.

• Why it matters: Understanding the dominant environmental stressors affecting marine invertebrates is crucial for effective conservation and management strategies amid increasing climate pressures.
• What they did: A decade-long biomonitoring study analyzed four biomarkers in Mytilus galloprovincialis, integrating heavy metal bioaccumulation data and oceanographic records at two Mediterranean sites, using five analytical frameworks.
• The result: Climate emerged as the main driver, with 67% of metals influenced by ocean acidification, and projections indicate that under high-emission scenarios, biological stress will surpass chronic thresholds by 2035–2040, emphasizing the importance of CO2 mitigation.