Spatial and temporal variability of microplastic abundance in estuarine intertidal sediments: Implications for...

Area of Science:

• Environmental Science
• Marine Biology
• Ecotoxicology

Background:

• Microplastic pollution (<5 mm) is widespread globally, yet studies show high variability in abundance.
• Existing surveys often lack spatiotemporal analysis, potentially misrepresenting environmental contamination levels.

Purpose of the Study:

• To investigate small-scale spatial and temporal variability of microplastic abundance, distribution, and composition.
• To understand short-term, daily spatiotemporal variations in microplastics within an urbanized US estuary's intertidal zone.

Main Methods:

• Collected intertidal sediment from low and high zones over 17 days (12 events, n=72) in South Carolina.
• Analyzed microplastic abundance, distribution, and composition, correlating with environmental factors like wind direction.

Main Results:

• Microplastic abundance varied significantly over time (p=0.00025) and even between consecutive tidal cycles (p=0.007).
• Spatial variability between low and high intertidal zones was not significant (p=0.76).
• Polyethylene, nylon, polyester, and tire wear particles were the primary microplastics found.

Conclusions:

• Significant temporal variability in microplastic abundance exists in estuarine intertidal sediments.
• Future microplastic surveys in dynamic coastal environments require consideration of spatiotemporal factors.
• Wind direction is a key environmental factor influencing temporal microplastic variability.