A ghost net 200 meters long was raised from the seabed by agents from the Marine Natural Park of Iroise (PNMI) on Tuesday 7th September. A trap for crustaceans, this polyamide net also presented a serious risk of plastic pollution, which is a growing menace encountered across the Iroise sea.
Recreational divers from the Douarnenez Aqua Club and the Annecy Underwater Club called out to the Iroise Marine Natural Park after spotting a fishing net lost 20 meters at the bottom of the sea off Douarnenez.
Agents of the southern branch of the park visited the site last week to find that many crustaceans had been trapped in the ghost net. They installed a balloon system to gather the net and bring it back to the surface.
Once the 70 kg (approx.) net was brought back on board, the environmental technicians freed and released 3 lobsters and several dozen spider crabs and rock crabs. Many crustaceans, including 5 lobsters, had sadly already died.
A plague haunting the Iroise sea
This kind of polyamide net represents a third of the waste polluting the Iroise Sea. Polyamide degrades very slowly, releasing its various chemical components into the marine environment for several hundred years.
During its long degradation, a ghost net is not only a source of pollution, but also a potential hazard for people, like sailors and divers, as well as for many animals, which can find themselves trapped or strangled by these nets.
Establishing best practice to curb plastic pollution
It is estimated that close to 155 million tonnes of nets pollueront the seabed here 2025.* The Iroise Marine Natural Park has therefore decided to focus its efforts on the fine polyamide net, most commonly used for fishing in Iroise, and is working to propose a model for the management of this waste. Looking at the problem from source to collection, working directly with fisherman and working on the recovery and recycling or safe disposal of used nets.
For example, collection points for used fishing nets have been installed in the park’s partner ports, such as Douarnenez. The marine park team also organises workshops with professional fishermen on plastic pollution and particularly ghost fishing. Finally, testing of plastic-free and biodegradable nets should start to be carried out in 2022.
*source : PLOS ONE – Feb 2015