Biodegradable fishing nets are designed to break down naturally in the marine environment over time, reducing the longlasting environmental impact associated with traditional synthetic fishing nets. These nets are made from materials that can be decomposed by natural processes, such as microorganisms, sunlight, and water, into harmless components that assimilate back into the ecosystem. Kim et al., (2016) explore biodegradable polymers as a possible solution to the issue, for passive fishing gear such as gillnets and trammel nets. These nets had only slightly lower catch rates than conventional nylon nets in field tests, and yet they showed clear signs of degradation within 2 years of introduction to salt water.
BENEFITS:
- Reduce ghost fishing : Biodegradable nets break down over time, reducing the amount of time that lost nets continue to catch fish and harm marine life.
- Reduce plastic waste : Biodegradable nets break down into natural components, reducing the amount of plastic waste in the ocean.
- Reduce entanglement : Biodegradable nets reduce the risk of marine animals getting entangled in lost nets.
- Reduce microplastics : Biodegradable nets break down into natural materials instead of microplastics, which can persist in the ocean for hundreds of years.
HOW IT IS MADE?
Biodegradable fishing nets can be made from natural fibers, biodegradable polymers, or composite materials.
Natural fibers
- Jute, hemp, or sisal are renewable, biodegradable, and can be strong and durable
Biodegradable polymers
- Polylactic acid (PLA), polyhydroxyalkanoates (PHA), or polybutylene adipate terephthalate (PBAT) break down into harmless components in the ocean
- Poly(butylene succinate) (PBS) resin is used for biodegradable fishing gear
- Poly(butylene adipate-co-butylene succinate-co-ethylene adipate-co-ethylene succinate) (PBEAS) resin has good tensile strength, stiffness, and biodegradability
Composite materials
- Biodegradable polymers or natural fibers can be combined with durable structural elements to create stronger, more durable nets
CHALLENGES:
Cost
- Biodegradable nets can be more expensive than traditional nets made of nylon.
- Higher production costs may limit the availability and adoption of biodegradable nets.
Durability
- Biodegradable materials may not be as strong or durable as nylon.
- Biodegradable nets may break down more quickly, which can lead to more lost nets and increased fishing losses.
Performance
- Biodegradable nets may not have the same mechanical properties as nylon, which can affect catch rates.
- Nets that aren’t heat-treated properly may be more likely to tear or deform, which can affect fishing performance.
Disposal
- It’s important to educate fishermen on how to properly dispose of biodegradable nets.
- Nets should be collected and treated so they break down naturally without harming the environment.
Environmental impact
- Although biodegradable nets can reduce ghost fishing, it’s important to ensure that the breakdown products don’t harm the ecosystem.
- Other plastic equipment used in fishing can take centuries to break down into microplastics.
