Illustration of a fishing boat pulling its nets. – Split / SIPA
Ifremer works on more selective fishing nets that limit the catch of small fish.
Scientists help fishermen conserve the resource by developing different meshes. The gains are sometimes 50% on the mortality of baby fish.
Ifremer invites the population to count the fish deserters on videos Saturday in Lorient.
Sometimes accused of plundering the oceans or scouring the seabed, some fishermen-fishermen are trying to improve their practices to limit their impact on the environment. Salvation may pass by their nets. In Lorient (Morbihan),
Ifremer researchers have been working for some years on new and more selective nets that would save young shoots.
On Saturday, on the occasion of the Fête de la science, they invite the population to help them count fish escaping trawls to advance their research. Explanations.
Techniques that limit small catches
Imagine a fishing net with square meshes and not rhombuses. Easy. Imagine that this seemingly simple change can save the lives of tens of thousands of young fish every day. "It has been shown that with square meshes, juveniles escaped more easily," says Pascal Larnaud, head of Ifremer station in Lorient.
A rotating mesh system called T90 has also been developed with fishermen. "It reduces the catch of juveniles by 50%", the scientist continues. The smaller haddock, gurnard or pout remain at sea.
Global warming: To save the planet, it will be necessary to eat less meat https://t.co/NhTfhd5rFF via @ 20minutesplanet pic.twitter.com/iVozs4sGG7- 20 Minutes Planet (@ 20minutesplanet) October 11, 2018
Filming escaping fish
In Brittany, several fishing companies have already opted for this inexpensive solution. The stakes are high for the profession: by fishing better, trawlers avoid tedious sorting that alters the freshness of the fish. Above all, it allows to leave to the water the future catches still too small to be consumed, and to avoid killing them. "Maximum sustainable yield", in jargon.
To confirm the effectiveness of its work, Ifremer first undertook to measure unnecessary discards on trawlers, comparing the fish caught in the different nets. But the scientific institute also has underwater cameras to film fish escaping the trap live. "We have developed a powerful software that allows us to count them. But we need to calibrate it, "continues Pascal Larnaud.
To calibrate its computer system, Ifremer invites the population to come and help him count the surviving fish this Saturday, as part of the Fête de la science. "We will analyze videos of trips to sea to see how many specimens survive. Open to children and adults, this workshop will also have the benefit of raising awareness about the dangers of overfishing.