Hawaii Trials Recycled Fishing Net Polyethylene in Polymer-Modified Asphalt Sections on Oahu

The Center for Marine Debris Research partnered with the Hawaii Department of Transportation to process 84 tons of recovered fishing gear into pelletized polyethylene for asphalt modification. Three test sections used standard SBS-modified binder, residential recycled PE, and net-derived PE; each was laid by a local paving contractor using conventional hot-mix equipment. Road dust was later sampled and analyzed via pyrolysis-GC-MS to quantify polymer fragments distinct from tire wear particles.

Early results indicated no statistically significant increase in microplastic shedding from the recycled-PE sections relative to the SBS control, supporting the hypothesis that locally sourced marine plastics can substitute for imported copolymers without elevating environmental release. This approach directly addresses Hawaii’s high landfill costs and the dominance of foreign derelict gear in its marine debris load, while leveraging existing polymer-modified asphalt specifications already standard since 2020.

The single-section, 11-month observational design on one Oahu street limits statistical power and long-term durability assessment; a multi-site, multi-year randomized trial with quarterly leaching and mechanical testing would strengthen causal claims. Broader adoption could divert thousands of tons annually if performance thresholds are met.