Reverine Fisheries

India is blessed with vast inland water resources in the form of rivers, estuaries, natural and manmade lakes. The Inland water bodies have been divided into five riverine systems and their tributaries extending to a length of about 29,000 km in the country – Indus, Ganges, Bramhaputra, East flowing riverine system and West riverine system. All these rivers, their tributaries, canals and irrigation channels have and area of roughly 13000km. These water bodies harbor the original germplasm of one of the richest and diversified fish fauna of the world comprising 930 fish species belonging to 326 genera. The major river systems of India on the basis of drainage can be divided broadly into two major rivers systems. They are (i) Himalayan rivers system (Ganga, Indus and Bramhaputra) and (ii) Peninsular river system (East cost and West coast river system).

Ganges River System:

It is the largest river systems of the world, having a combined length (including tributaries) of 12,500 km. It originates from Gangotri in the Himalayas at a height of about 3129 km above the sea level. After origin it drains the southern slopes of the central Himalayas. Ganga passes through UP, Bihar, some parts of Rajasthan, M.P. and west Bengal and finally joins to the Bay of Bengal. It has a large number of tributaries and ‘Yamuna’ river is one of the major tributaries of this system, which is about 1000 km long. The other tributaries are – Ram Ganga. Gomti, Ghaghra, Gandak, Kosi, Chambal, Betwa and Ken. Further more; it has numerous lakes, ponds and Jheels, both perennial and seasonal areas. It has a total catchment area of 9.71 lakh sq. km and receives an annual rainfall of 25-77 inches.

Physico-Chemical Characteristics:

i) Temperature range  - 16.70C in January – 31.50C in June to sept.
ii) PH - 7.4 during June to August and Maximum 8.3 during January to May.
iii) Turbidity - 100 ppm in January; 1100-2170 ppm during July to September.
iv) Do2 - 5.0 to 10.5 ppm during January to February while in monsoon 2.00ppm (July-Sept.)
v) Co2 - 0.6 ppm -10.0ppm
vi) Chloride - 4.0 -35.4 ppm
vii) Phosphate - 0.05-021ppm
viii) Nitrates - 0.08-0.22ppm
ix) Silicates - 4.0-20.3ppm
x) Carbonates - 1.0 – 12.0 ppm

Common Phytoplanktons:

Phytoplanktons are generally poor during the monsoon and autam months. Common phytoplanktons found in Ganga river system are – (i) Members of Bacillariophyceae like Amphora, Asterionella, Cymbella, Navicula and Synedra etc. (ii) members of Chlorophycace like, Chlorella, Closterium, Denticula, Pandorina and Spirogyea etc.(ii) members of Myxophyceae like Anabaena, Nostoc, Oscillatoria etc.

Common zooplanktons:

Rattulas, Rotaria, Keratella, Filuia, Notops, Monostyla etc.

Fisheries of Ganga river systems:

The Ganga river system supports a large number of commercially important fish species including major carps (Labeo. rohita: L.Calabasu, Catla catla and Cirrhinus mrigala), minor carps ( Labeo fimbriatus; L.bata; Cirrhinus. reba), catfishes (Wallago. attu ; Mystus. aor; M.tengara, Clarias. batrachus; Heteropneustes fossilis), cluipeiods, murrels (Channa species), feather backs (Notopterus. notopterus; N.chitala), mullets (Mugil corsula), fresh water eel (Anguilla) and prawns (Macrobrachium malcolmsonii; Palaemon. Lamarii). Apart from these fishes, the others like Pangasius; silonia silondia; Gudusia chapra; Bagasius. bagasius; Eutropichthys. vacha are also found in the river system.

The commercial fisheries in this zone are non-existing due to spares population, inaccessible terrain and poor communication between fishing grounds and landing centers. The fish yield has been declined over the years due to 1) sandification of the river bed (upto Patna) which reduced the rivers productivity due to blanket effect, (2) marked reduction in the water volume on account of increase sedimentation, (3) increased water abstraction and (4) irrational fishing.
In spite of this, the Ganga river system is contributing nearly about 89.5% of the total fish seed correlation of India.

Fishing gears used :

The principal gears used in Ganga river system are dragnets, cast nets and bag nets.

Godavari River System:

It originates in Doolai hills near Nasik in North Western Ghats. This river system is a part of East coast of pennensular river system, with a length of 1465 km covering the states like Maharastra, Andhrapradesh and Madhyapradesh. It has the primary tributaries like manjira, Wainganga; Subtributaries like paingunga and wardha and minor tributaries like maner and sabari. It drains into Bay of Bengal. It has a total catchments area of over 315,980 sqkm.

Physico-Chemical characteristics:

i) Temperature     -          27.5 to 36.40C
ii) PH                   -          7.2 to 8.3
iii) Do2 mg/L      -          1.26 -18.2
iv) Co2                -          0.0 – 6.6 ppm
v) Bicarbonates   -          45.8 -192-2ppm

Fisheries of Godavari River System:

The head waters harbour a variety of game fishes but don’t support the commercial fisheries. The commercial fisheries consist of carps (major caps, Labeo fimbriatus), large cat fish (Mystus spp., Wallago attu; Bagarius bagarius) and fresh water prawn (Macrobrachium rosenbergii). Hilsa formed lucrative –fisheries and the Indian major carps uplanted in the river in the beginning in 19th century are thriving well and contributing to the commercial fisheries.

Fishing gears used:

The principle gear used in Godavari river system are falls under two categories viz. gill nets, which include setgill nets, drift nets, drag gill nets (Benduvala) and the barrier gillnet (Katu vala). Seines include shore seine (Jaruguvala), Large seine (Allui vala) and dragnet castnets are also employed for fishing.

Krishna river system:

The originates in Western Ghats region, south of Poona and finally drains into East coast, with an a length of 1401km covering the state like Maharastra, Karnataka and Andhrapradesh. It has the main tributaries like Bhima (Annual) and Tungabhadra (Perennial). This river system has an total catchments area of 2,33,229 sq km. The physico-chemical characteristics, fish fauna and the fishing gears used similar to the Godavari river system. In general, the physiographic and fish fauna resembles the Godavari river systems. The head waters support rich fishery when compared to mid-stretch, which is rocky and inaccessible. No information is available on its present fishery and catch statistics.

Cauveri river System:

This river system originates from Brahmagiri hills on western ghat, with an elevation of 1340 m extending to a length of 800 km. this river system covering the states the Karnataka and Tamil Nadu finally drains into Bay of Bengal in Thanjavur district of Tamil Nadu. It has the tributaries like Bhavani, Noyil and Amaravathi. This river system has an total catchment area of 4,70000 sq km. The water resources of the river are extensively exploited as numerous reservoirs, anicuts and barrages have been built on the river.

Physico-Chemical characteristics:
i) Temperature – 26 to 30.90C
ii) PH - 7.6 to 8.5
iii) Do2 mg/L - 1.26 -18.2
iv) Co2 - 0.0 – 6.6 ppm
v) Bicarbonates - 45.8 -192-2ppm

The Cauveri river system exhibits substantial variations in its fauna - nearly 80 species of fish belong to 23 families have been reported from this river system. Its fish funa differs significantly from Godavari and Krishna river system. The fishes like Acrossocheilus hexagonolepis ; Tor. Putitora; Barbus carnatus; B. dubius; Labeo kontius; L. ariza; Cirrhinus cirhosa; Mystus aor; Mystus seenghala; Pangasius pangasius; Wallago attu; Silonia silonida; Glyptothorax madrapatanus; Gangetic carps such as Catla catla; Labeo rohita; Cirrhinus mrigala and the exotic species Cyprinus carpio and Osphronemus goramy have been transplanted in Cauveri river system. The game fish Tor khudri and T mussullah are found all along the river length except the deltaic stretch.

West coast river system:

The west coast system comprises the river Narmada and Tapti, both of which flow in westernly direction of the country and drain the narrow belt of peninsular India, west of the western ghats further in the north the system forms basins of Narmada and Tapti and the drainage of Gujarat.

Narmada river system :

This river system originates in Amarkantak hills of Madhya Pradesh, at an elevation of 1,057 m above the sea level. The length of the river is 1280 km, covering Madhyapradesh and Gujarat states and finally drains into gulf of Cambay in Gujarat. The effective catchments area of this river system is 94235 sq. km and 6330 sq. km of its all tributaries. This river system comprises of total 18 tributaries, of which 16 in Madhya Pradesh and 2 in Gujarat. This river system receives and annual rain fall of 12” – 115”.

Fishery of Narmada river system:

Narmada river harbors 84 fish species belonging to 23 genera. The contribution of carps in commercial fishery is of the order of 60.4%, followed by catfishes of 34.1 % and miscellaneous fishes of 5.5%. The carp fish groups are Tor tor; Labeo. frimbriatus; L.calabasu; L.bata; L.gonius; Cirrhinus. reba; Puntius. sarana etc, cat fish groups such as Mystus senghala ; M.aor ; M. cavasius; Wallago. Attu ; Clupisoma garua; Ompak bimaculatus and miscellaneous fish groups like Channa spp, Mastacembalus spp; Notopterus notopterus. Cast nets, gill nets and longlines are the fishing gears that are generally used in these waters.

Tapti River System:

This river system originates in Mount Vindhya of Satpura range at an elevation of 670 –100m above the sea level, with a total length of 720 km. This river system covers the states like Maharastra, Madhya Pradesh and Gujarat and finally drains into Arabian Sea at Dumas near Surat in Gujarat. The total catchments area of this river is 48,000 sq.km and annual rainfall is more or less similar to the Narmada river system.
Not much information of fish stock composition and fish yield is available. The main fisheries of this river system are Tor. tor; Mystus. seenghala; M.aor; Wallago attu; Labeo calabasu; L. fimbriatus; Puntius sarana; Cirrhinus mrigala; C. reba, Chupisorna garna; Channa spp; Mastacembalus. armatus.
Cast nets, gillnets and long lines and also Mahajal is used as the fishing gear in these

Factors influencing fish yield from rivers:

The intensity of fishing, nature of exploitation and species orientation are the characteristics of the artisan riverine fisheries and are governed by
i) Seasonality of riverine fishing activity
ii) Unstable catch composition
iii) Conflicting multiple use of river water
iv) Cultural stresses leading to nutrient loading and pollution.
v) Lack of understanding of the fluvial system and infirm data base.
vi) Fragmentary and out molded conservation measures lacking enforcement machinery.
vii) Inadequacy infrastructure and supporting services
viii) Affordability and playability and
ix) Socio- economic and socio-cultural determinant.

An intelligent management strategy has to take cognizance of key parameters such as hydrology, fish stocks and dynamics of their population together with regulatory measures for fishing. Observance of closed seasons and setting up of fish sanctuaries has proved their efficacy in the faster recovery of impaired fisheries.

(Source: http://www.fao.org/docrep/003/v5930e/V5930E01.htm#ch1)