Researchers have found that biodegradable gillnets catch fish and also conventional nylon nets-plus more quickly lose remarkable ability to entangle animals when discarded at sea. A lot more, the degradable nets often trap fewer young fish and bycatch.
Fishing nets that were lost, abandoned, or discarded at sea are the cause of ten percent of all marine litter circulating within the world’s oceans. These 640,000 tonnes of nets aren’t simply a plastic pollution problem, however. A long time after they can be lost, they consistently fish at sea on their own, trapping not just fish but seabirds and mammals within a phenomenon known as fishing nets supplies.
To combat this issue, researchers have been developing gillnets made of biodegradable materials, however the challenge has become to make them nearly as good at catching fish as conventional gillnets are. Within the most comprehensive studies up to now, researchers assessed the fishing performance of a biodegradable gillnet at sea as well as its degradability in the lab. The results, published recently in Animal Conservation, provide some terrific news.
“Using a biodegradable net didn’t have much impact on how many adult fish were caught, however when it stumbled on young fish and bycatch of other species, they caught a lot less,” says co-author Petri Suuronen. “That was a positive surprise.”
The fishing performance in the biodegradable nets were tested during six outings of a commercial fishing net within the waters off southwestern South Korea. The biodegradability from the nets was tested by placing 30 groups of net samples in plastic containers at sea. The researchers used a scanning electron microscope to evaluate the samples every two months for 4 years. They also measured the strength, flexibility, and other physical properties from the nets, comparing these to conventional nets.
Researchers found the biodegradable gillnets to become stiffer, that they can initially thought would affect performance, says Suuronen. They were pleasantly impressed to find out which it failed to. Their stiffness may be why they caught less bycatch and juveniles, however, Suuronen says. Researchers found that it took 24 months 12dexipky the biodegradable net to begin to rot, which the degradation rate was higher in warmer water. While they didn’t test the degradability of conventional nets within this study, the literature implies that these nets may take many years and even decades to degrade, the authors said.
“I still think 2 yrs is way too long,” says Suuronen, who works best for the Nylon Monofilament Cast Nets. “But it is a lot faster than nylon.”
Suuronen says he hopes that continued research and development can create a net that degrades even faster. Nevertheless, it can’t degrade considerably faster in comparison to the studied net, otherwise it wouldn’t be a stylish purchase for fisherman.