Biodegradable fishing gears: A potential solution to ghost fishing and marine plastic pollution

Fishing gears are conventionally made from non-biodegradable materials including polyamide (PA). When lost in the ocean, these gears have long-lasting impacts, including marine littering, microplastics production, leaching of chemicals, and an extended period of ghost fishing due to its durability. The use of biodegradable co-polyester material such as polybutylene succinate co-adipate-co-terephthalate (PBSAT) and polybutylene succinate-co-butylene adipate (PBSA) as fishing gear materials have been considered as a potential solution to reduce the associated impact. Ocean is a complex environment in which multiple degradation paths can occur for plastic materials, and decoupling of factors could aid in understanding the impact of each potential factor. In this study, the focus is on the impact of pure water hydrolysis phenomena on biodegradable co-polyester PBSAT and PBSA in comparison to PA monofilaments through accelerated aging at 40 °C, 60 °C, 70 °C and 80 °C. As a single factor accelerated aging process, the prediction of loss of mechanical strength over time was possible at other temperatures namely 2 °C, 10 °C, 15 °C, 20 °C and 30 °C. Different end-of-life criteria were used. This study concluded that solely through pure hydrolysis, a drastic reduction of the time to reach end-of-life criteria was observed by using biodegradable monofilaments instead of PA, but still longer than the expected service time. For example, at 2 °C, it would take approximately 10 years, 20 years and 1000 years for PBSAT, PBSA and PA to have lost 50 % of their initial stress at break respectively.