Differences in Fishing Methods

   To address the different habits and habitats of various fish species, fishermen have invented a variety of fishing techniques. Among them, light fishing and trawling are two highly representative methods. Light fishing is a "luring" tactic, utilizing the fish's phototaxis to attract them before catching them; while trawling is an "active sweeping," dragging a huge net across the water or seabed, catching everything in its path.

Light Fishing

1. Attracting Fish: At night, fishing vessels turn on high-intensity fish-attracting lights installed on or underwater. These lights are extremely powerful; some large fishing boats can illuminate a radius of 1 kilometer as if it were daytime, thus attracting scattered schools of fish to the illuminated area.

2. Attracting Fish: By adjusting the depth and intensity of the lights, or by moving the light-up vessel, the fish are further concentrated in specific water layers and locations suitable for fishing.

3. Catching: When the fish are sufficiently concentrated, the appropriate fishing gear is quickly activated to catch them. The most common method is light-attracting purse seine, which involves encircling a school of fish and a light source together with a purse seine before hauling in the net.

Trawling

1. Setting the Net: After arriving at the fishing grounds, the fishing vessel lowers the net and attachments (such as net boards and sinkers) into the sea via a stern slipway.

2. Towing: The fishing vessel moves forward at a certain speed (usually 3-5 knots), towing the net. For single-vehicle trawls, the net boards on both sides of the net are crucial; they generate tension under the action of the water current, opening the large opening of the net horizontally like wings.

3. Lifting the Net: After towing for several hours, the fishing vessel begins to haul in the winch, using a slipway or winch to pull the net bag (the last part of the net, where the catch is collected) onto the deck, where the catch is emptied.