The fishing industry uses several different methods to catch large numbers of fish. They mostly involve the use of nets. Trawling uses a cone-shaped net towed behind the fishing boat (known as a trawler). Purse-seining involves surrounding a school (group) of fish with a net and drawing the net lines together. Drift nets may be as long as 95km (60 miles). Left to drift in the water, they can catch many millions of fish at once.
Fishermen use a wide range of gear to land their catch. Every type has its own effects on the ocean. By selecting the right gear for the right job, the fishing industry can help minimize its impact on the environment.
Here are some methods and types of fishing, some more, some less popular:
Noodling is fishing with hands practiced in South of the United States. Fishermen catch catfish by sticking hand into a catfish whole where this fish lives.
Flounder tramping is a method of fishing practiced in Scottish village of Palnackie on every August. People compete in catching the flounder (which is a species of flatfish) by stamping on them.
Spearfishing is fishing with ordinary spears or with their variants like harpoons, tridents, arrows, Hawaiian slings, and superguns.
Netting is method of fishing which uses fishing nets. There are many types of nets for different uses and different fish. Cast net (or throw net) is a smaller round net with weights on it edges. Gillnet is placed in water vertically (using combination of weights and floats) and catches fish which try to pass through it. Trawl net is large, conical a dragged by ship.
Dredges
Dredges are metal-framed baskets that are dragged across the seafloor to collect clams, cockles, mussels, oysters, scallops and sea cucumbers. Towed dredges scrape or dig into the substrate with rakes or teeth to about a foot in depth. Mechanized dredges are used to dig and wash out mussels that have buried into the seabed. There are also hand-held dredges. This fishing method can have significant impacts on sensitive seafloor habitat and bottom-dwelling species. One way to limit these harmful effects is to limit the areas where dredging can occur.
Gillnets
Gillnets are walls of stationary or drifting netting that are almost invisible to fish, so species like cod, perch, salmon, sardines and trout swim right into them. Set, drift and trammel gillnet use different configurations of floats and weights to suspend the netting more or less vertically. Encircling gillnets are set in shallow waters, and noise or another means is used to entangle the fish in the netting. Fix gillnets are stretched between two or more stakes that are driven into the seabed in the intertidal zone. Gillnets can accidentally catch vulnerable ocean animals like sea turtles, marine mammals and sharks. These impacts can be reduced by setting the gillnets deeper in the water column to allow room for animals to swim over and adding gear like pingers, which warn passing marine mammals.
Pole-and-Lines
Pole-and-lines are poles with a single line, hook and bait that are used to catch a variety of fish ranging from open-ocean swimmers like tuna to bottom-dwellers like cod. They can be hand-operated or mechanized when operating in deep waters. Pole-and-line gears have very low catch of unwanted marine life because fishermen catch one fish at a time and they can release unwanted species.
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