How has pollution affected Mediterranean coastal waters?

Since the mid-20th century, the Mediterranean Sea has experienced severe pollution in many coastal areas due to increased industrialization, growing shoreline populations, and tourism. Because the Mediterranean has relatively weak tidal and current movements, pollutants tend to remain concentrated near their discharge points rather than dispersing widely.1

The environmental impact of this pollution includes:

• Depletion of Fisheries: Coastal pollution, combined with overfishing, has significantly depleted natural fisheries that once supported harvests of crabs, shrimp, prawns, and other shellfish.2
• Eutrophication: Like other coastal marine systems, the Mediterranean is susceptible to cultural eutrophication, where excess nutrients from sewage, agriculture, and industry lead to high biological productivity, murky waters, and potential oxygen depletion at depth.3
• Regulatory Efforts: In response to these threats, 16 countries adopted the Mediterranean Action Plan (Med Plan) in 1975, supported by the United Nations Environment Programme. Key legal frameworks include the Barcelona Convention (1976) and the Athens Protocol (1980). While these initiatives have successfully raised awareness, measurable improvements in environmental quality have remained limited.1