(CNN) — A group of Maldivian fishermen lines up at the back of a boat. As they cast their fishing rods and barbless hooks into the water, they lure in fish by throwing tiny baitfish on the surface. The trick is to create an illusion of prey for the tuna.
This method is called pole and line fishing. It is believed by some to have originated in the Maldives -- an archipelago in the Indian Ocean -- and been passed down through generations for centuries.
Once they feel a bite, the fishermen swing the pole overhead and the fish crash on the deck behind them. They repeat this technique for hours, catching one fish at a time.
"Pole and line fishing is very different from casting nets or catching fish by nets," says Hamid Abdallah, a Maldivian fisherman. "We catch fish by pole and line because we want to be able to keep doing it for as long as we can."
"This is what my family have been doing for generations," he adds. "Going back to my forefathers this has been our livelihood."
Pole and line fishing from a boat in the Maldives.
Maldivians catch nearly 100,000 tons of tuna per year and the fish is the country's biggest export. To conserve this food source, the Maldives is encouraging people to practice all kinds of sustainable fishing. Pole and line fishing helps eliminate bycatch -- where unwanted species of fish are caught accidentally -- which can be a huge problem with other fishing methods. "When you cast a net, it indiscriminately scoops up everything -- regardless of the species or size," says Abdallah. "Pole and line fishing catches fish one by one." The global fishing industry is vital for food security but overfishing and excessive bycatch threaten marine life and disturb ecosystems. Across the world, more than 7 million metric tons of tuna and tuna-like species are caught annually. Tuna fishing was worth at least $40 billion in 2018, but according to the WWF, most tuna stocks are fully exploited and some could be in danger of collapsing.
Unloading tuna catch in The Maldives.
Carl Court/Getty Images AsiaPac/Getty Images
Experts say that encouraging pole and line fishing would be better for the environment, but this method isn't widespread because it's labor-intensive, requiring manpower, skill and time.
However, many Maldivians aim to keep the tradition alive. "When you are out at sea for about a week, I don't think much about it, because I am passionate about it," Abdallah says. "My heart and soul is in this."
"Now we have a lot of young people showing interest in fishing," he adds. "I love it because it is what my father and forefathers did."