Macrolitter trapping in mangroves: Insights from forest structure and local community knowledge

Area of Science:

• Coastal Ecology
• Environmental Science
• Marine Biology

Background:

• Mangroves are crucial coastal ecosystems that act as natural filters for marine debris.
• Macrolitter accumulation in mangroves is a growing concern with implications for ecosystem health.
• Understanding macrolitter dynamics is essential for effective coastal zone management.

Purpose of the Study:

• To assess the sources, composition, and abundance of macrolitter in Colombian mangroves.
• To investigate the relationship between macrolitter and mangrove forest characteristics (type, structure, species).
• To identify the primary contributors to mangrove macrolitter pollution.

Main Methods:

• Conducted field surveys across 29 mangrove sites in Colombia.
• Integrated community knowledge through 671 interviews to identify macrolitter sources.
• Analyzed macrolitter abundance in relation to mangrove forest type, structure, and proximity to human settlements.

Main Results:

• Residents are the main source of mangrove macrolitter, linked to inadequate waste management.
• Fringe mangroves accumulated significantly more macrolitter (2.5 items/m²) than basin (0.3 items/m²) or riverine (0.2 items/m²) types.
• Plastic constituted the vast majority (89.6%-93.1%) of the macrolitter, with variations in material type across different mangrove forest structures.

Conclusions:

• Mangroves serve as effective natural traps for macrolitter, irrespective of their structural complexity.
• Proximity to population centers significantly influences macrolitter abundance, underscoring the impact of local waste.
• Urgent public policy reforms are needed, focusing on waste management, packaging, and community education for mangrove conservation.