Reservoir Fishing Gears

Rangoon net

A typical Rangoon net is a length of 50 metres and a hung depth of 3.9 metres. The hanging coefficient is 0.5 and the mesh size 50 mm bar. The net has a head rope with floats. To increase the entangling capacity, there is no foot rope.  Eight to ten such units are operated at a time. The nets are usually laid in the evening and the catches removed next morning. Rangoon nets exclusively used for Catla are known as 'Thoppa valai' and have a mesh size ranging from 100-130 mm. bar. A net of smaller mesh size (40 mm bar), known as 'Kenda valai,' is used for Cirrhina cirrhosa in Mettur reservoir.

Udu valai

It is an indigenous gear used in reservoir fishing. This net is also of the entangling type but having only a comparatively reduced fishing height and usually operated in shallow marginal areas for small varieties of fish. The average size of the net is 40 metres length and 6 meshes of 35 mm bar in depth. The material used is nylon twines of specification 210D/l/3. Both head rope with floats and foot rope with sinkers are present. Five to six such units normally constitute a fleet. The nets are operated during the twilight hours in the morning or the evening.

Gill net

The fishing depth, mesh size and length of the fleet varies according to the depth of the ground, fish and extent of the area. Mesh size of this net is also dependent on the species; 20 - 40mm is used for minor carps, catfishes and other small fishes and 75 - 120mm is used for carps and large catfishes. Polyamide multifilament and monofilament are the common fishing gear material. Typical gill nets have a head rope and the use of foot rope is optional. In some cases, the head rope is substituted by a row of large meshes of thicker twines. These nets are operated in the night, setting done before sunset and hauling by morning. However, operation during daytime is common during the migratory period of the fish and flood months.

Details of gill net in different centres

Gill net design operation and details for the Thirumoorthy reservoir is as follows.

• the length of the gill net is about 300m, which is constant.
• the number of the mesh ranges between 3000 to 4500 which is based on the mesh size of 100 to 280mm. Typically, the smaller mesh size gill net is used for catla (30 and 35mm) than those of the rohu, mrigala, and common carp net (50mm) with a horizontal hanging coefficient of 0.5 and vertical hanging coefficient of 0.86.
• The operational depth of the gill net is ranged between 5 to10 m, this diverse range is due to natural habit and target of the species. The maximum depth of 10 m is required to operate the mrigala and common carp net with a thickness of 0.3 to 0.4 mm and minimum of 5 m for catla. This variation is to avoid breakages of meshes by more strengthened fishes including Catla.
• 15 pieces of thermocole (20 grams) are used as floats while 60 numbers of cement stones or led beads (5 grams) are used as sinkers. Polypropylene twines are used as head rope, footrope and for rigging purpose.

Gill nets are operated either from a saucer shaped bamboo coracles or FRP coracles. Each coracle or boat is operated by one fishing unit consisting of two fishermen and each gill net unit is composed of five-gill nets. Nets are kept in soaking condition throughout the day and lifted for the collection of fishes twice in a day one at about 5 am and another at about 7 pm. Night catches are iced for selling on next day morning and day time catches are directly sold without icing. If any damages are observed in fishing nets then the net is hauled from reservoir and mending is carried out by fisherwomen of the concerned fishing unit.

Cast net

The net is fabricated with 0.5 mm Polyamide monofilament webbing with a mesh size of 75 mm. About 1.25 kg of monofilament webbing is typically used to make this net. The bottom circumference of cast net covers 6m² with the total height of the net being 3.5m. A 5m long and 5mm thickness of Polypropylene rope is used as hauling line which spilt into 30 lines through the webbing up to the bottom to facilitate the casting and hauling. About 250 pieces of iron rings each weighing about 20 g typically is attached to the foot rope of the cast net to facilitate quick sinking of gear to the bottom. The dry weight of a cast net along with all of its accessories is about 6.5 kg.

Hook and line

This is one of the common gear in reservoirs and lakes. This is used mainly to capture the predatory fishes. This gear initially was made of cotton twine and later replaced by nylon twine. It has a main line and many branch lines hung from the main line. At the end of the branch line, hooks are attached. Hook nos 11 – 20 are most common. The main line will be a thicker twine, and the branch line is of thinner twine. This gear vary according to the area of operation. Small fishes, earthworms, prawns and algae are normally used as baits.

Drop line

This gear is employed for the capture of scale and catfishes. It consists of the main line and many hooks of the same specifications attached to the end. The length of the line is either equal to or a little more than the depth of the fishing area. At the upper end of the line, a float is attached. The length of the main line is adjusted by winding the extra length of the main line on the float so that the bunch of hooks remains just above the bottom during the fishing operation. This type of fishing is done only in the day time as a constant vigil on the line has to be kept for retrieval and recovery of fish and line. This gear is effective during winter for the capture of scale fishes viz L.rohita, L.calbasu and catfishes.

Sources

• Dawson 2000. Fishing gear for reservoir and inland fisheries.
• George, V.C. 1971. An account of inland fishing gear and methods of India
• George V.C. 2002. Inland Fishing Methods. Central Institute of Fisheries Technology, Kochin.
• Kuriyan G.K. 1973. Fishing gears in freshwater reservoirs of India. Fishery Technology. 10: 1-5.
• Velmurugan R, Neethiselvan N, Sundaramoorthy B, Rayan X. P, Radhakrishnan K, Kalaiarasan M. 2016. Gill net selectivity and fishing pressure on Indian Major Carp in Thirumoorthy Reservoir, Tamil Nadu. Current World Environment. 11: 554 – 559