As a Matter of Fact ...
Commercial fishing results in bycatch which is a large contributor to sea turtle deaths.
Commercial fishing is an activity of catching fish and seafood for commercial profit. It employs different methods to effectively catch large variety of species. The fishing gear includes nets, which comprise trawls and dredges, hook and line, traps, grappling devices, and stupefying devices. The gear used while fishing impacts the marine environment in different ways and to different degrees which is why one should be careful while choosing the fishing gear.
Common Types of Fishing Nets
While some commercial fishing enterprise would solely depend on hand-casting nets and a few pot traps, another fishing enterprise could have a huge fleet of trawlers that process tons of fish on a daily basis.
Gill nets are made using a single piece of netting hung between a float line and a lead line. The netting itself can either be monofilament or multifilament. Depending on the species of fish that you intend to catch, you will find gill nets in different lengths, mesh sizes, and depth. Choosing the right net mesh size works because the mesh size allows fish of the proper size to get caught in the nets. What happens is the fish gets gilled or stuck by its gills when it attempts to pull itself out of the net.
Cast nets are small, round nets, and when thrown in, open up to its full diameter. These nets have weighted edges which cause it to sink and trap fish inside. The net is pulled back on the boat with the help of an attached line.
Seine nets are made using a single piece of small mesh netting hung between a float line and a lead line. These nets are used as a barrier or a wall to encircle and entrap the fish within.
Hoop nets are elongated cylindrical nets supported by one or more hoops. These nets are fitted with valves or funnels that allow the fish to enter into the net and get trapped. Bait bags are loaded into the net to attract the fish into the net.
Trawl nets are conical-shaped nets that allow it to be towed along the bottom of the sea. The trawl is pulled through water with the help of one or two boats. This method of fishing, however, results in a lot of bycatch and ends up damaging the sea floor.
Trammel nets are three-layered nets attached between a lead line and a float line. The outer layers form a wall that trap the fish into the smaller mesh net that forms the inner layer. The outer layers are made of nylon, while the inner layer is made of either monofilament netting or multifilament netting.
Commercial fishers employ largely on the technology that they are provided with, thus, resulting in varied fishing methods. The fishing technique, however, varies not only from region to region but also from the species being fished for.