Microplastic pollution on island beaches, Oahu, Hawai`i

Area of Science:

• Environmental Science
• Marine Biology
• Plastic Pollution Studies

Background:

• Beaches worldwide are increasingly impacted by microplastic pollution.
• Islands with high tourism face unique environmental challenges.
• Understanding microplastic distribution is crucial for conservation efforts.

Purpose of the Study:

• To quantify microplastic densities on Oahu's windward beaches.
• To investigate the relationship between sand coarseness, wave energy, and microplastic accumulation.
• To compare microplastic levels on Oahu with other global island locations.

Main Methods:

• Microplastic densities were surveyed on six beaches across Oahu.
• Data collection focused on storm tide lines and high tide lines.
• Particle counts per square meter (particles m-2) were recorded.

Main Results:

• Microplastic densities were highest on beaches with coarse sands and high wave energy.
• Observed densities ranged from 700-1700 particles m-2.
• Higher microplastic concentrations were found at storm tide lines compared to high tide lines.

Conclusions:

• Oahu's beaches exhibit high microplastic densities, comparable to remote island locations.
• Wave energy and sand characteristics significantly influence microplastic distribution.
• This study provides critical data on microplastic pollution in a highly populated and visited Hawaiian island.