Fishermen could not do their work without ropes, lines and lines. They use nets made of string, strings for harpoons, fishing lines with hooks and many other types of ropes and lines.
Before going to sea, fishermen repair nets so that there are no holes through which caught fish can escape.
There are fishermen who use ropes that are many kilometers long. They are made to pass over the edge of a huge net, which is called seine or trawl. When they are on the high seas, they pull this rope to close the net and catch the fish.
To fish for tuna they use hooks and lines. Sometimes it takes three fishermen to hoist a large tuna. All lines are tied to a single hook.
In some eastern countries, fishermen tie certain birds called cormorants to a rope. They dive into the water and catch fish. But they can't swallow them because they have a metal bow around their neck.
To catch a big swordfish, the fisherman throws with great force, he shoots him, a spear called a harpoon. This is tied to a long rope with a floating mark that indicates where the fish is going, after being injured. Whales are not fish, but the whalers catch them the same way.