Modeling the microplastic distribution along the Delaware River Estuary: Accumulation patterns and hydrodynamic...

Area of Science:

• Environmental Science
• Oceanography
• Ecotoxicology

Background:

• Microplastic pollution is a growing global environmental issue, especially in estuaries.
• Estuarine microplastic dispersion is complex, affected by river flow, tides, and salinity.
• Aquatic ecosystems and human health face risks from microplastic contamination.

Purpose of the Study:

• To model and analyze microplastic accumulation and dispersion patterns.
• To investigate three common microplastic types: synthetic fibers, sinking films, and rising pellets.
• To identify key factors influencing microplastic distribution in the Delaware River Estuary.

Main Methods:

• Numerical modeling of microplastic transport.
• Simulation of synthetic fibers, sinking plastic films, and rising plastic pellets.
• Analysis of estuarine circulation, river discharge, and salinity intrusion.

Main Results:

• Rising microplastics accumulate in the upper estuary, linked to reduced flow velocities.
• Synthetic fibers and sinking films concentrate near the bottom salinity front.
• Seasonal variations in river discharge significantly shift microplastic accumulation zones.

Conclusions:

• Microplastic distribution is highly dependent on particle type and estuarine hydrodynamics.
• River discharge and salinity dynamics are critical drivers of microplastic accumulation hotspots.
• Tidal mixing, settling, and resuspension are key processes affecting microplastic spread.