Floating debris in the Mediterranean Sea.

Area of Science:

• Marine pollution
• Oceanography
• Environmental science

Background:

• Floating marine debris poses a significant threat to marine ecosystems.
• Understanding the distribution and composition of marine litter is crucial for effective management.

Purpose of the Study:

• To conduct the first large-scale survey of floating natural (NMD) and anthropogenic (AMD) debris in the Mediterranean Sea.
• To quantify debris densities and identify hotspots of pollution.

Main Methods:

• Ship-based visual surveys covering the central and western Mediterranean Sea.
• Data collection on debris size, type, and density (items/km²).

Main Results:

• Floating debris was ubiquitous, with mean densities of 24.9 AMD items/km² and 6.9 NMD items/km².
• Anthropogenic debris constituted 78% of all items, primarily plastics and styrofoam (95.6%).
• Highest AMD densities were in the Adriatic Sea and Algerian basin; lowest in the Central Tyrrhenian and Sicilian Sea.

Conclusions:

• An estimated 62 million macro-litter items currently float in the Mediterranean Sea.
• The study highlights the pervasive nature of plastic pollution in the Mediterranean.
• Regional variations in debris density necessitate targeted mitigation strategies.