A gill net is a type of fishing net that is prorogued in a vertical direction into the water to trap fish by their gills into the net. This net is not visible to the fish. When he fish head is stucked in the net they get entangled in it and are caught. Rare species of fishes such as Cod, ling, hake, flatfish, dogfish etc are trapped using the gill net. Long panels of nets are set into the depth. The depth of these panels can be set at any levels just below the surface of the water or on the sea bed.
There are many types of gill nets. Some of them are as follows
Flag net: Gill net is the cheapest of all the other nets. Single sheet of net is used to make flag nets. A string is attached at the top which is used to release it in water. Since there is no bottom rope attached to this net it gets rolled up in the wind or current. To avoid this Monofilament netting should be used instead of nylon netting.
Leaded Gill: The leaded gill is similar to flag gill. The only difference between the two is that leaded gill has a top and bottom rope as well as float rope and lead. There are many disadvantages of this type of gill. It can be majorly used for saltwater fishes.
Tie down gill net: It is one of the types of oldest net that was used by freshwater fishermen in 1960's. This is one of the best type of gill nets that are available. It is generally same like leaded gill but in Tie down gill net every 6ft a string is attached till the bottom of the net. This reduces the depth of the net. It is also referred as hobble net or goose net.
Trammel net: It is the most expensive gill net. It has three layers of net. A lighter net is placed between two larger nets. If a fish gets trapped in this type of net, it gets entangled between the nets and cannot back of for release itself from the trap. It is used by commercial fishermen to catch huge quantity of fish. They use a bigger size net for this purpose.
Disadvantages of gill nets
Unintended catch: The fishermen use these types of net to catch a huge quantity of fishes. But many a times other species like dolphins, turtle. Sharks etc are trapped in the net and die.
Ghost fishing: When the gill nets get loose or cut in the sea due to any reason will continue to trap fish .Many unintended species may also get trapped in this free floating net. When other big fish come to get this trapped fish they too get caught in the net and eventually they all die or hurt themselves very badly.
Risk for rare species: Gill nets are banned in some areas however it is still being used in many regions .Many rare species of fishes and other water animals have died due to this practice. Many sea birds and other mammals have also died trapping in the gill nets. This has adverse affects on the tourism of the region too.