What are the major fishing techniques used in the oceans?

There are several major fishing techniques used in the oceans, each tailored to target specific species and environments. Some of the most common fishing techniques include:

1. Trawling: This method involves dragging a large net, called a trawl, along the ocean floor or through the water column. Trawling can be done at different depths and is used to catch bottom-dwelling species like shrimp, cod, and flatfish.

2. Longlining: Longlining involves setting a long line with baited hooks, either near the surface or on the ocean floor. This technique is commonly used to catch species such as tuna, swordfish, and halibut.

3. Purse seining: Purse seining is a method where a large net is deployed around a school of fish, and then the bottom of the net is drawn closed, forming a "purse." This technique is often used to catch schooling fish like sardines, anchovies, and tuna.

4. Gillnetting: Gillnets are vertical panels of netting that are set in the water to entangle fish by their gills. Fish swim into the net and get caught by their gill covers. Gillnetting is commonly used to catch species such as salmon, herring, and cod.

5. Pot/trap fishing: This technique involves using baited traps or pots to attract and capture species like lobsters, crabs, and shrimp. The traps are typically left on the ocean floor and periodically checked by fishermen.

6. Handline fishing: Handline fishing is a simple method where a single fishing line with a baited hook is held by hand or attached to a pole. This technique is often used by small-scale fishermen to catch a variety of species.

7. Trolling: Trolling involves dragging baited lines behind a moving boat. This technique is commonly used to catch pelagic species like tuna, marlin, and mackerel.

It is important to note that while these fishing techniques are widely used, some of them can have negative impacts on marine ecosystems if not properly managed. Sustainable fishing practices, such as using selective gear and avoiding overfishing, are crucial to maintain healthy ocean ecosystems and ensure the long-term viability of fish populations.