The fate of plastic litter within estuarine compartments: An overview of current knowledge for the transboundary issue to guide future assessments

Area of Science:

• Environmental Science
• Ecology
• Marine Biology

Background:

• Plastic pollution is a global issue, impacting ecosystems worldwide.
• Oceans are heavily studied, but rivers and estuaries, as primary plastic sources, are less understood.
• Transboundary plastic pollution and estuarine gradient patterns require further investigation.

Purpose of the Study:

• To review current knowledge on plastic pollution in estuarine environments.
• To identify research gaps in understanding plastic transport and accumulation.
• To highlight the need for improved methodologies and modeling for estuarine plastic pollution.

Main Methods:

• Literature review focusing on plastic pollution in rivers and estuaries.
• Analysis of existing data on plastic quantities in water, sediment, and biota.
• Identification of limitations in current sampling and analytical techniques.

Main Results:

• Estuaries show high plastic concentrations: up to 45,500 items/m³ in water, 567,000 items/m³ in sediment, and 131 items/individual in biota.
• Microfibers are the most prevalent plastic type.
• Current studies often use small sample sizes, short-term data, and site-specific sampling, underestimating plastic pollution.

Conclusions:

• Rivers and estuaries are crucial yet understudied pathways for oceanic plastic pollution.
• Accurate sampling and robust modeling are essential for understanding plastic fate in estuaries.
• Integrating socio-economic factors into models is vital for effective management strategies.