Biodegradable fishing gear is not good enough

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For commercial fishermen, losing gear is part of doing business. Fishing lines and nets break and fray over time or have to be cut when fishing gear gets stuck on the seabed. According to one estimate, at least 50,000 tons of nets, lines and traps disappear into waters globally every year. In California alone, as many as 14,000 lobster traps are lost or discarded each season. Most of these materials are plastic, and many of them are still partially functional, meaning they can continue to catch and kill marine life for centuries – a process known as ghost hunting.

For several years, scientists, fishermen and conservation organizations have been eyeing a not-so-new solution: biodegradable fishing gear. Made from things like microalgae fibers or biodegradable polyester, this equipment can be broken down by aquatic microorganisms. However, while these environmentally friendly nets provide benefits, recent field trials conducted largely in Norway and South Korea show that biodegradable nets catch far fewer fish than synthetic nets.

“Biodegradable equipment right now is not very good,” says Benjamin Drakeford, a marine resource economist at the University of Portsmouth in England.

In the Atlantic cod fishery, for example, nylon nets catch up to 25 percent more fish than biodegradable alternatives. A team of scientists attributed this deficiency to the tendency of biodegradable materials to be more flexible and stretchable, which may allow fish to vibrate freely.

But Drakeford and his colleagues wanted to look at the bigger picture: whether biodegradable nets and traps reduce fishermen’s catches – but they also Reducing environmental damage caused by lost and neglected equipment – ​​is this financial hit worth taking? After all, fishermen have a vested interest in keeping fish populations healthy. The scientists analyzed previous studies on the effectiveness of biodegradable fishing gear, then interviewed 29 fishermen, boat owners and representatives of fishing industry groups in England about their expenses, profits and other financial details.

In conclusion, Drakeford and his colleagues wrote in a recent paper, the industry’s shift to biodegradable nets will not reduce the effects of ghost fishing enough to offset declining catches by fishermen. Biodegradable nets would leave more fish in the water and reduce false catch rates, helping fishermen catch fish in the future. But to compensate for the decline in catches, fishermen will need financial incentives.

But scientists say that if biodegradable fishing gear can be improved, the benefits “compared to conventional fishing gear will grow exponentially.”

One big problem, scientists say, is that a certain degree of ghost hunting is currently restricted: equipment has already been lost. Even if fishermen everywhere replace their gear, the decline in ghost fishing — and the resulting rise in fish stocks — will not happen for years. So instead of improving their catches by reducing bogus catches, fishermen are trading environmental sustainability for less catch without seeing much direct benefit.

This lack of cost-effectiveness could be overcome through government support, notes Brandon Kuczynski, an industrial ecologist at the University of California, Santa Barbara, who was not involved in the work.

Drakeford and his team’s analysis comes amid growing concern about marine plastic pollution, which is flowing into the world’s oceans at alarming rates and could haunt marine ecosystems forever. Large pieces of plastic can suffocate marine life, while micro and ultrafine plastics – the inevitable result of plastic degradation – can have more serious impacts.

Jeff Chester, campaign director for the conservation organization Oceana, says that while he supports efforts to develop biodegradable gear, he believes it would be easier and faster to implement a punishment-and-reward system to incentivize hunters not to lose or throw away their gear the first time. place. Such a system would require all commercial fishing gear to be registered and tracked, he says.

“If you park your fishing gear, you have to prove you’re going to get it back,” he says. He adds that currently there is no penalty for fishermen who lose their equipment other than having to buy new equipment. It is believed that such a system could be more effective in reducing waste.

There is also another option: holding net manufacturers financially responsible for plastic gear contamination and the costs incurred by fishermen as a result of switching to biodegradable gear. This concept, known as extended producer responsibility, is briefly discussed in Drakeford’s paper.

For his part, Drakeford believes the low efficiency of biodegradable nets represents a speed bump on the road to widespread adoption. He believes that equipment will follow the path of electric cars, getting better and better. He points out that in just one decade, the range of electric cars has increased several times.

Drakeford sees some irony in the fact that the switch to biodegradable equipment, at least in concept, is not so much a leap forward as a step backward.

“In the past, we used biodegradable materials to make crab pots, fishing nets, etc.,” he says. “We know the answer to that question, we just need to go back to what we used to do.”