Polymer identification of floating derelict fishing gear from O'ahu, Hawai'i

Discarded fishing gear (DFG) comprises most of the plastic in the North Pacific Ocean and causes environmental and economic losses. Building evidence on the material construction of fishing gear types is critical to develop solutions to reduce DFG amounts and impacts. We forensically assessed the construction and chemical composition of eight different gear types removed as DFG around O'ahu, Hawai'i. A thorough dissection and novel analysis was conducted including the documentation of gear constructions, polymer identification using attenuated total reflection-Fourier transform infrared spectroscopy and differential scanning calorimetry, and elemental additive detection using X-ray fluorescence. Twenty-six different polymers were identified, and most gear consisted of polyethylene variants or blends. This inventory of physical and chemical characterization of DFG can help future polymer identification of particular gear types through visual techniques. Additionally, it can aid in identifying sources of these gear types and promote recycling options.