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INLAND FISHERIES RESOURCES OF INDIA

Dr. Subhendu Datta Sr. Scientist

CIFE, Kolkata Centre

Inland fish production As against 0.24 million tonnes of fish produced in 1950-51, the production of inland fish

in the country during 2003-04 was at 3.4 million tonnes, and this increase in the fish production has placed the country on second largest producer of inland fish. Even with vast increase in production over the years it is able to provide about 8 kg/caput to the present populace (taking 56% as fish eaters) against the nutritional requirement of 11 kg. The projected domestic requirement of the country by 2020 AD is estimated at 12 million tonnes, more than ¾ of which has to come from inland sector. Inland fish production by State/UTs is given in Table 1.

Table 1. Inland Fish production by states/union territories (1990 to 2002-03)

Inland water resources The river system of the country comprises 14 major rivers (catchments >20,000 km

2), 44

medium rivers (catchments 2,000 to 20,000 km2) and innumerable small rivers and desert

streams (catchments area <2,000 km2). Different river systems of the country, having a

combined length of 29,000 km, provide one of the richest fish genetic resources in the world. The floodplain lakes are primarily continuum of rivers Ganga and Brahmaputra. These are in the form of oxbow-lakes (Mauns, Chaurs, Jheels, Beels as they are called locally), especially in Assam, Manipur, West Bengal, Bihar and eastern Uttar Pradesh (212.213 thosand ha). They occupy important position in the inland fisheries of India because of their magnitude as well as their production potential. Besides, the resources under ponds and tanks have been estimated at

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2.254 million ha and in the coastal area 1.2 million ha has been identified as potential resource for finfish and shellfish farming.

Riverine resources of India

The inland water resources harbour the original germplasm of one of the richest and diversified fish fauna of the world, comprising 930 fish species belonging to 326 genera, out of 25,000 total fish species recorded world-wide. The major river systems of India on the basis of drainage can be divided broadly into two-(i) Himalayan river system (Ganga, Indus and Brahmaputra), and (ii) Peninsular river system (East coast and West coast river system). State-wise distribution of riverine resources of India along with their lengths is depicted in Table 2 and the details of the area and potential fish yield of the major rivers are furnished in Table 3.

Status of riverine fishery

The rivers of India are being subjected to considerable stress and accordingly the adverse effects are being manifested in poor fish landing, both in terms of quality and quantity. The prized fisheries such as Indian major carp have either collapsed or are at the threshold of collapse.

1. GANGA RIVER SYSTEM:

It is one of the largest river systems of the world, having a combined length (including

tributaries) of 12,500 km. After originating from Himalayas, it drains into the Bay of Bengal

after traversing a distance of 2,225 km. The Ganga river system harbours about 265 fish species,

out of these 34 species are of commercial value including the prized Gangetic carps, large

catfishes, featherbacks and murrels. In mountainous region, from source to Hardwar the fisheries

are dominated by Schizothorax spp., catfishes, mahseer and Labeo spp. The commercial fisheries

assume importance in 1,005 km middle stretch of the river (Kanpur to Farakka). The mainstay of

fishery is the species belonging to cyprinidae (176 species) and siluridae (catfishes).

Table 2. The profile of various river systems in India River system Name of main river Approximate

length (km)

State

Ganga Ganga 2,525 Uttar Pradesh, Bihar, West Bengal

Ranganga 569 Uttar Pradesh

Gomti 940 Uttar Pradesh

Ghaghra 1,080 Uttar Pradesh, Bihar

Gandak 300 Bihar

Kosi 492 Bihar

Yamuna 1,376 Punjab, Haryana, Delhi, Uttar Pradesh

Chambal 1,080 Madhya Pradesh, Uttar Pradesh, Rajasthan

Tons 264 Uttar Pradesh

Son 784 Uttar Pradesh

Ken 360 Madhya Pradesh

Brahmaputra Brahmaputra 4,000 Arunachal Pradesh

Dibang, Siang, Assam

Lohit, Manas, Nagaland

Duri, Dihang, Sikkim

Dhansri, Koppili Manipur

Indus Jhelum 400 Jammu and Kashmir

Ghenab 330 Jammu and Kashmir, Himachal Pradesh

Beas 460 Himachal Pradesh, Punjab

Sutlej Himachal Pradesh, Punjab

Ravi Jammu and Kashmir, Himachal Pradesh, Punjab

East Coast Mahanadi 851 Orissa, Madhya Pradesh

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Godavari 1,465 Maharashtra, Andhra Pradesh

Krishna 1,401 Maharashtra, Andhra Pradesh, Karnataka

Cauvery 800 Karnataka, Tamil Nadu

Bhima 861 Karnataka

West Coast Narmada 1,322 Maharashtra, Gujarat, Madhya Pradesh

Tapti 720 Gujarat, Madhya Pradesh

Mahi 583 Gujarat

Source: CIFRI, Barrackpore, W.B.

The important species are: Gangetic major carps, catfishes, murrels, clupeids and featherbacks,

besides migratory hilsa. On an average, fish yield has fluctuated in the stretch between a high of

230 tonnes to a low of 12.74 tonnes during 1958-1995 and yield of major carps on kg/ha/year

basis from 83.5 to 2.55 during the above period. The mean annual landings are given in Table

1.13.

Table 3. Potential fish yield from Indian rivers based on their length and basin area

River Length

(km)

Basin Area

(million km2)

Catch

Area based

(tonnes)

Stream based

(tonnes)

Himalayan Rivers

Ganga 2,525 0.88 17,443 17,142

Yamuna 1,376 0.37 5,243 8,588

Brahmaputra 800 0.19 1,782 3,958

East Coast Rivers

Krishna 1,401 0.26 5,434 5,365

Cauvery 800 0.09 1,791 1,917

Mahanadi 800 0.14 2,088 2,943

West Coast Rivers

Narmada 1,312 0.10 4,844 2,124

Tapti 720 0.06 1,454 1,294

Mahi 533 0.02 802 446 Source: CIFRI, Barrackpore, W.B.

Table 4. Estimated mean annual landings (metric tonnes) at different centres in Ganga

Centres 1959-66 1973-81 1981-89 1989-97

Allahabad 207.17 129.63 128.46 67.55

Buxar 65.85 43.59 25.65 NA

Patna 81.93 85.5 70.84 NA

Bhagalpur 108.86 NA 62.45 37.79 Source: CIFRI, Barrackpore, W.B. NA = Not available

2. BRAHMAPUTRA RIVER SYSTEM: Brahmaputra river originates from a glacier (Kubiangiri) in Tibet and has a combined

length of 4,025 km including its tributaries. The upper sector of the river is not having

commercial fishery of any significance. This segment harbours coldwater fishes such as Tor tor,

T. putitora, T. mosal, T. progenius, Neolissocheilus hexagonolepis, and large catfish, Bagarius

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bagarius. A total of 126 fish species belonging to 26 families out of which 41 are of commercial

importance have been reported.

The average catch at 4 important landing centres was estimated at 847 tonnes in 1970's.

The fisheries in the upper, middle and lower stretches of the river are dominated by catfishes. In

the upper middle stretch miscellaneous fishes dominate (54.14%), followed by catfishes

(28.40%) and major carps (17.46%) while in middle stretch catfishes (28%) have replaced the

miscellaneous fishes followed by major carps (26%) and hilsa (18%). Fisheries of lower mid-

stretch is again dominated by miscellaneous group (34%), followed by catfishes (24%), minor

carps (20%), major carps (11 %) and hilsa (7%). Prawn contribution in the total landing of the

mid-stretch is restricted to only 4-7%.

3. INDUS RIVER SYSTEM:

The major portion of Indus river system lies within Pakistan but its 5 tributaries, viz. Jhelum, Chinab, Ravi, Beas and Sutlej originate from the western Himalayas. In headwaters of these rivers, commercial fisheries are absent. The common fish species inhabiting are Salmo trutta fario, Oncorhynchus mykiss, Tor tor; T. putitora, Schizothorax spp., Labeo dero, Gara gotyla, Botia spp. and Nemacheilus spp. The Beas and Sutlej contain indigenous carps and catfishes akin to the Ganga river.

The Jhelum in Jammu and Kashmir is reported to support commercial fisheries. The species caught are Schizothorax spp., Labeo dero, L. dyocheilus, Crossocheilus latius, Puntius conchonius, Cyprinus carpio (C. carpio communis and C. carpio specularis), loaches and Glyptothorax spp. 4. PENINSULAR RIVER SYSTEM:

This system may be broadly categorized into (i) east coast river system, and (ii) west coast river system

. EAST COAST RIVER SYSTEM.

The combined length of the 4 rivers which constitutes this system, viz. Godavari, Mahanadi, Krishna and Cauvery is about 6,437 km with a total catchments area of 121 million ha.

Godavari:

The headwater harbours a variety of game fishes but do not support commercial fishery. It has been observed that during 1990 the river was maintaining a fish production of 1 tonnelkm/annum. However, the commercial fisheries consist of carps (major carps and L.fimbriatus), large catfishes (Mystus spp., Wallago attu, Silonia childreni and B. bagarius) and freshwater prawn (M. malcolmosonii).

Mahanadi River:

The upper reaches harbour game fishes but commercial fishery is non-existent due to inaccessible terrain. The ichthyofauna is similar to that of the Ganga river with addition of peninsular species. Hilsa is confined to lower reaches and together with major carps and catfishes forms lucrative fishery. Data on fish production and catch per unit effort (CPUE) is not available.

Krishna River:

Several dams have been constructed on this river, which have altered the ecology of this river.

Cauvery River:

The water resource of the river is extensively exploited as numerous reservoirs, anicuts and barrages have been built on the river. The game fishes like Tor khudree and T. mussullah are

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found all along length of the river except the deltaic stretch. The commercial fisheries comprise carps (Tor spp., Barbodes carnaticus, B. dubius, Neolissocheilus wynaadensis, Puntius pulchellus, Labeo kontius) and catfishes (Glyptothorax madraspatanum, Mystus spp., P. pangasius, W attu, S. childreni and Silurus wynaadensis).

WEST COAST RIVER SYSTEM The main westward flowing rivers are Narmada and Tapti.

Narmada River:

Narmada river harbours 84 fish species belonging to 23 genera. The contribution of carps in commercial fishery is of the order of 57 .47-62.4 % (mahseer 23.7-27%, Labeofimbriatus 18.2-19.2%, L. calbasu 5.2-6.4%), followed by catfishes, 24-38% (Rita spp. 12-14%, M. seenghala, 7.8-9.8%, M. aor 4.7-5%, Wallago attu 7.4-8.2%, M. cavasius 0.5-0.8%) and miscellaneous fishes 4-5% (Channa spp., Mastacembelus spp., N. notopterus and minnows).

Tapti River:

Not much information on fish stock composition and fish yield is available. About 2.6

tonnes of fish/day is captured from the river. The commercial fishery mainly consists of Tor tor;

Labeo fimbriatus, L. boggut and L. calbasu among carps followed by catfishes such as Mystus

spp. and W attu.

RESERVOIR FISHERIES OF INDIA

Reservoir resources Reservoirs constitute the single largest inland fishery resource, both in terms of resource

size and productive potential. There are various estimates on the total area under reservoir in India. The National Commission on Agriculture (NCA, 1976) has estimated the total area under reservoir at 3 million ha during the mid-sixties and projected its growth to 6 million ha by 2000 AD. A detailed study made by the FAO in 1995 has estimated a total of 19,370 reservoirs in the country with a total area of 3.1 million ha.

Table 5. Distribution of Different reservoirs in India Small Medium Large Total

Number 19,134 180 56 19,370 Area (ha) 1,485,557 527,541 1,140,268 3,153,366

Source: Sugunan, Reservoir Fisheries of India, FAO Fish tech. Paper No. 345, FAO, Rome

The reservoirs in the country are distributed under divergent geoclimatic, morphometric and edaphic environments. Reservoirs are generally classified as small (<1000 ha), medium (1000-5,000 ha) and large (>5000 ha). The distribution of small, medium and large reservoirs in India is given in Table 5.

India, being a country of continental proportions, its reservoirs are spread over various types of terrains and soil types exposed to diverse climatic conditions and they receive drainage from a variety of catchment areas. Fish production from different categories of reservoirs like small, medium and large has been estimated at about 50 kg/ha/year, 12.3 kg/ha/year and 11.5 kg/ha/year, respectively, the average being about 20 kg/ha/year. This production is very low in comparison to countries such as Thailand (65 kg/ha/year), Russia (88 kg/ha/year) and Sri Lanka (100 kg/ha/year). The present low levels of production from the reservoirs is on accounts of many reasons such as lack of fish seed production and stocking, inappropriate gears and crafts, poor landings and marketing channels, absence of closed-season and other inadequate

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management measures like weak cooperatives, stranglehold of middle-men, etc. Reservoir fish stocks and fisheries

The fisheries of Indian reservoirs are constituted of both indigenous and stocked fish populations. Among the former, the Gangetic major carps occupy a prominent place in north Indian reservoir both a naturally-occurring and stocked species. In addition to this, they also harbour many species of common carps, major and minor catfishes and miscellaneous species. The important species accounting for major parts of the catch are catla, rohu, mrigal, calbasu, L. bata, P. sarana, P. chagunio, C. reba, M. aor, M. seenghala, W attu, etc.

In peninsular reservoirs, the indigenous fishes forming the commercial fisheries are Cirrhinus cirrhosa, C. reba, Labeo kontius, L. fimbriatus, Labeo dussumieri, Puntius dubius, P. sarana subnasutus, Barbodes carnaticus, P. kolus, P. hexagonolepis, Tor tor, Thynnichthys sandhkhol, Osteobrama vigorsii, W attu, Aorichthys seenghala, Silonia silondia, S. children ii, P. pangasius, Pseudeutropius mitcheIIi, Horabagrus brachysoma, Mystus vittatus, etc.

Indian reservoirs also harbour a sizeable population of trash fishes like Ambassis nama, Esomus danricus, Aspidoparia morar, A. mola, P. sophore, P. ticto, Oxygaster bacaila, Laubuca laubuca, Barilius barila, Osteobrama cotio, Gadusia chapra, etc.

Most of the fishes compete for food with carps tending to reduce the overall fish productivity of the reservoir. Present yield and production potential from reservoirs is shown in Table 6.

Table 6. Present yield and potential of production from different categories of reservoirs in

India Category

Total

available

area

(ha)

Present Potential

Average

production

(kg/ha)

Fish

production

(tonnes)

Average

production

(kg/ha)

Fish

production

(tonnes)

Small 1,485,557 49.90 74,129 100.00 148,556

Medium 525,541 12.30 6,488 75.00 39,565

Large 1,140,268 11.43 13,033 50.00 57,013

Total 3,153,366 29.70 93,650 77.70 245,134

Source: CIFRI, Barrackpore, W.B.

FLOODPLAIN WETLANDS

What is floodplain?

A floodplain is a plain land formed along the course of a river by the deposition of

sediment, typically dropped by a river during periodic floods. Floodplains are the flat land or low

lands bordering rivers that is subjected to periodic flooding which tend to be most expansive

along the lower reaches of rivers. They are either permanent or temporary water bodies

associated with rivers that constantly shift their beds especially in the lower stretches.

Floodplains contain such features as levees (river embankments built by deposition as the river

floods), backswamps (are located in depressions close to the raised levee banks), delta plains (A

deposit of clay, silt, and sand formed at the mouth of a river where the stream loses velocity and

drops part of its sediment load. Due to the resemblance with triangular shape of the letter delta

'∆', the Greeks gave the name delta to such an island.), and oxbow lakes. Rivers with extensive

floodplains are the Nile, Ganges, Danube, and Po. Floodplains are generally very fertile, thus

making them rich agricultural lands.

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What is wetland? Wetlands, as defined by Ramsar convention, include areas of marsh, fen, peatland or

water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water, the depth of which at low tide does not exceed six meters. In simpler terms, wetlands occupy the transitional zone between permanently wet and generally dry environments. They share the characteristics of both the environments, and yet cannot be classified exclusively as either aquatic or terrestrial (Maltby, 1991).

Types of Wetlands: • MARSHES - Reeds, rushes, grasses and sedges growing in shallow water along the edge of lakes and rivers.

• FRESHWATER SWAMP FOREST - herb species forests, growing on saturated or flooded soils, normally in a

zone along the lower reaches of rivers.

• PEATLAND - spongy waterlogged land formed as a result of slow decomposition of plant materials.

• FLOODPLAIN - flat land or low land bordering rivers that are subject to periodic flooding.

• MANGROVE - wood trees growing along muddy estuaries of large rivers and sheltered coastal areas.

• LAKES - standing bodies of water occupying large basins or small depressions.

• ESTUARINE, MARINE AND COASTAL ZONE WETLANDS - Estuaries are the contact areas between

freshwater and marine environments. Marine zone wetlands consist of permanent shallow water habitats less than

six metres deep at low tide.

• MAN-MADE WETLANDS - such as fish and shrimp ponds, paddy fields, reservoirs, examining lakes, gravel pits

and sewerage farms and canals.

There are 8 different categories of wetlands in India, differentiated by region:

• The reservoirs of the Deccan Plateau in the south, together with the lagoons and the other wetlands of the southern

west coast;

• The vast saline expanses of Rajasthan, Gujarat and the gulf of Kachchh;

• Freshwater lakes and reservoirs from Gujarat eastwards through Rajasthan (Kaeoladeo Ghana National park) and

Madhya Pradesh;

• The delta wetlands and lagoons of India 's east coast (Chilka Lake); the freshwater marshes of the Gangetic Plain;

• The floodplain of the Brahmaputra ;

• The marshes and swamps in the hills of north-east India and the Himalayan foothills;

• The lakes and rivers of the mountain region of Kashmir and Ladakh;

• The mangroves and other wetlands of the island arcs of the Andamans and Nicobars.

The Convention on Wetlands (at Ramsar, Iran, 1971) - called the "Ramsar Convention" - is an

intergovernmental treaty that embodies the commitments of its member countries to maintain the ecological

character of their Wetlands of International Importance and to plan for the "wise use", or sustainable use, of all of

the wetlands in their territories. 2nd

February in each year is World Wetlands Day. It marks the date of the signing of

the Convention on Wetlands on 2 February 1971, in the Iranian city of Ramsar on the shores of the Caspian Sea.

Wetlands of international importance are given the status of ‘Ramsar site'. India has 25 Ramsar sites e.g. Chilika

lake (Odisha), East Kolkata wetlands (W.B), Bhoj wetland (M.P.), Deepor beel (Assam), Harike lake (Punjab),

Kolleru lake (A.P.), Loktak lake (Manipur), Wular lake (J. K.), Sambhar lake (Rajasthan), Rudrasagar lake

(Tripura), Ashtamudi wetland (Kerala), Bhitarkanika Mangroves (Odisha), Keoladeo National Park (Rajasthan) etc.

What are floodplain wetlands?

Wetlands situated on floodplains of major rivers can be designated as floodplain wetlands which cover a variety of water bodies in India such as beels, jheels, mauns, pats, anoas, boars, hoars, bowrs etc.

The floodplains of the Ganga and Brahmaputra rivers have the distinction of nurturing

some of the finest wetlands of the country, which perform a variety of social functions. These natural ecosystems have intimate relationship with mankind since their inceptions both directly (fisheries, irrigation, portable water, recreation, water for industries, etc.) as well as indirectly (recharge of groundwater, floor protection, regulation of local climate, aesthetic values, etc.). An

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estimated 2,013,213 ha of floodplain lakes is available where fish and fisheries remain a traditional economic activity with tremendous socio-economic impact in the rural sector (Table 7).

Table 7. Distribution of wetlands under Ganga and Brahmaputra valleys

State River basin Area (ha)

Assam Brahmputra and Barak 100,000 Bihar Gandak and Kosi 40,000 West Bengal Ghaghra and Ichhamati 42,000 Arunachal Pradesh Kaneag, Siang, Lohit, Tira, etc. 2,500 Manipur Iral, Imphal, Thoubal 16,500

Tripura Gumti 500 Meghalaya Someshvari, Jinjiran 213

Uttar Pradesh Ganga, Ghaghra 11,000

Assam: In India, Assam has maximum area under floodplain wetlands associated with

Brahmputra and Barak valleys. The distribution of floodplain lakes (beels) in different parts of

Assam is given in Table 8.

Table 8. Distribution of floodplain lakes (beels) in different parts of Assam

Regions No. of

beels Area (ha) River valley/lakes

Central Assam 342 31,080 Brahmputra Valley

Lower Assam 352 29,000 Brahmputra Valley

Upper Assam 376 23,000 Brahmputra Valley

Bagia border Bangladesh 322 800 Barak Valley

The beels of Assam have indicated very high fish yield potential in the range of 476-2,324 kg/ha. The Assam beels have showed the pre-dominance of small fish species (Puntius spp., Chanda spp., Mystus vittatus, Nandus nandus, A. mola). Carnivorous catfish (W attu, A. coila, O. bimaculatus), air-breathing species (H.fossilis, A testudineus), murrels (c. punctatus) and featherbacks (N. notopterus) also dominate these waters. The beels of Assam are one of the prime sources of natural capture fishery dominated by small fish species including many species of ornamental Importance. The yield rates range between 14.0 and 488 kg/ha/year. The beels, however, lack scientific fishery Barak management except in a few stray cases (Boiya beel, Hailakandi and Kalpa beel, Barpeta) (Table 9). Table 9. Production of some beels of Assam

Name of beel Average fish production (kg/ha/yr)

Brahmaputra Dogra 116 Dighali 36 Siligujan 418 Ghorajan 14 Barak Sone 97 Barchumati 488 Average production (Assam)

172

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West Bengal: There are more than 150 beels in West Bengal, with an estimated water spread area of 42,000 ha. The beel ecosystem of the state largely been dominated by very rich endemic fish species. However, certain exotic species like Hypophthalmicthys molitrix, Ctenopharyngodon idella and Cyprinus carpio have also been introduced in these water bodies. A total of 24 endemic fish species have so far been recorded from the West Bengal beels and amongst them Puntius spp., A. mola, Channa spp., Nandus nandus, Gadusia chapra, L. bata and the Indian major carps are important. Status and yield of some productive beels are depicted in Table 10.

Table 10. Status and yield of some productive beels of West Bengal

District Beel Area

(ha)

Depth

(m)

Type of

beel Macrophyte

infestation level

Fish

(kg/ha/

year)

Fishery

information

Hooghly Dekole 117.6 1.0-1.8 Closed;

lake like

Weed

choked 13-36

Capture fishery;

closed season

(January-April)

Cooch

Behar Gorai

chara 50.0 4.0-6.8

Open

(R. Dharala);

ox-bow lake Moderate 325

Stocking,

Indian major

carps

Bardhaman Bansdaha 26 1.7-6.5 Closed

(R.Bhagirathi),

ox-bow lake Moderate 1100

Stocking,

Indian major

carps, G. chapra

24-Parganas Gopalpur

(Beribaor) 131.0 4.5-12.6

Closed (R.

Ichhamati) (U-

shaped cutoff

meander)

Low 420-

771

Stocking, Indian

major carps, grass

carp, silver carp,

Gudusia chapra.

Catch quota 15

kg/day/person

The fish potential of West Bengal beels indicated poor to moderate status from 43.8 to 320

kg/ha/year. The North Bengal beels with alkaline pH showed better potential as compared to

South Bengal beels with acidic pH. However, fish yield of various beels has increased

substantially with the adoption of various management practices.

Bihar: The North Bihar (the Gandak and Kosi Basins), due to its geo-morphological features

and geographical locations is bestowed with an estimated area of 50,000 ha under floodplain

wetland resource. The state has oxbows (mauns) and tectonic (chaurs) types of lakes. These

water bodies in Bihar have been studied in detail.

Ox-bow lakes (Mauns): Chaurs and Mauns (or Mans) are formed by the shifting of river course which remains

waterlogged for best part of year. Chaurs are natural tectonic depressions and Mauns (or Mans)

are Ox-bow lakes, which are the cutoff portions of river meanders. Oxbow lake is a crescent-shaped lake (U-shaped or like the shape of oxbow) that is formed when a wide

meander from a stream or river is cut off from the main channel to form a lake.

It is of two types:

(1) The 'Live' or 'open' lakes

(2) ‘Dead' or 'closed' lakes

Open lake has connections with river and a dead lake has lost its all connections with

the river.

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As estimated, 4,735 ha area under ox-bow lake is available in the Bihar with major

congregation in East and West Champaran Districts followed by Muzaffarpur, Begusarai and

Samastipur (Table 11). Ox-bow lakes and abandoned river courses are one of the prime

resources of fish protein in North Bihar. These lakes are in very poor state owing to high degree

of eutrophication as reflected by the massive infestation of aquatic weeds, besides other

indisciplined human interference. Most of the lakes are choked with weeds to the tune of 50-

100%, hence, they are in the advance state of swampification. The prized economic fishes,

Indian major carps in particular, have either completely been eliminated or their population has

dwindled to an alarming proportion. Fishes of less economic value have occupied the niche on a

large-scale along with the dominance of predators.

Table 11. Distribution of Ox-bow lakes in North Bihar

Location/District Area (ha)

East Champaran 2.076

West Champaran 1,951

Muzaffarpur 748

Begusarai 220

Samastipur 40

In spite of the fact that the ox-bow lakes of Gandak basin exhibited relatively high

diversity of fish fauna, the medium-size like Notopterus spp., Mystus cavasius, Clarias

batrachus, Chana gachua, Mastacembelus armatus, Mastacembelus pancalus, and big fishes

like Wallago attu, Channa marulius and C. straitus dominate the fishery up to 35%. Shrimp

fishery is very common in these lakes as indicated by the extensive use of a large number of

traps especially during the summer months.

Tectonic lakes (Chaurs): The northeast part of Bihar has a long stretch of floodplains in Gandak and Kosi basins.

This part has a distinct tract of depressed landmass, the region of tectonic lakes. The series of

shallow lakes locally known as chaurs exist in these areas to the tune of about 46000 ha. These

water bodies support a rich biodiversity, but are biologically sensitive and fragile in nature. The

major lake areas under this resource are used for fish culture are: Kabar Tal area (Begusarai),

Kusheswarasthan area (Darbhanga), Sirnri Baktiarpur area (Saharsa) and Gogabeel areas

(Katihar). In addition to these, Barila chaur area under Vaishali district is also important.

Stocking density, however, does not seem to have been arrived at on any rational basis.

Funds available at the disposal of the managers and seed availability generally govern the

stocking density, hence stocking rates are highly variable. In Bhornra beel stocking density

varied between 97 and 171 kg of fry/ha, in Akaipur beel, density varied between 59 and 253

kg/ha, in Kola beel the stocking rate was between 84 and 356 kg/ha and in Gopalnagar it varied

between 110 and 259 kg/ha. The fish yield rate from these beels indicated differential response.

Yield varied between 307 and 937 kg/ha in Bhornra, 633 and 915 kg/ha in Akaipur, 534 and

3,020 kg/ha in Kola, and 719 and 2,124 kg/ha in Gopalnagar beel.

In these water bodies of the culture-based fishery, growth of fish is density dependent

and mortality is size dependent. Thus, it is very important to generate advice on size at stocking

and stocking density. Unfortunately, no beel is maintaining sufficient data on the size and

number of fishes stocked species-wise. There is no clue on the survival rate of fishes as well.

The quality and amount of data available at the beels in this regard are not sufficient to make any

sound scientific findings on stocking-yield relationship.

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Estuarine fisheries

The fisheries of estuaries of India are above the subsistence level and contribute significantly

to the production. The important estuarine fisheries resources of the country with their

production levels are detailed in Table 12.

Table 12. Important estuarine fisheries resources in India Estuarine system Estimated area level (ha) Production (tonnes) Major fisheries

Hooghly-Matlah 234,000 20,000--26,000 Hilsa, Harpodon, Trichiurus,

Lates, prawn etc.

Godavari estuary 18,000 c.5,000 Mullets, prawns

Mahanadi estuary 3,000 c.550 Mullets, Lates, sciaenids,

prawns

Narmada estuary 30,000 c.4,OOO Prawn

Peninsular estuarine

systems (Vasista,

Vinatheyam, Adyar,

Karuvoli, Ponniar, Vellar,

Killai, Coleroon)

- c.2,000 Mullets, prawns,

Chilka lagoon 1,036,000 c.4,000 Prawns, mullets, catfishes,

clupeids, perohes, threadfins,

sciaenids

Pulicat lake 36,900 760--1,370

(20.6-37.2 kg/ha)

Prawns, mullets, Pearchs,

Crabs, clupeids Vembanad lake and Kerala

backwaters

50,000

14,000--17,000 (fishes)

(280--366 kg/ha)

88,000 (live clams)

170,000 (dead shells)

Prawns, mullets, Lates, pearl-

spot, Chanos

Wetlands of West Bengal

(a) Freshwater bheries

(b) Saline bheries

9,600 33,000

10--14 (1,258 kg/ha) c.25,500 (775 kg/ha)

Prawns, mullets, tilapia Lates

Source: CIFRI (ICAR), Barrackpore.

Estuarine fisheries resources The east-coast estuaries intermingling in the Bay of Bengal have diverse fisheries

potentialities. Of all the individual species, Hilsa (=Tenualosa) ilisha has remarkably high abundance contributing 32.5 to 38.6% and 16 to 25% of the annual landings in Hooghly and Mahanadi estuarine systems, respectively. The species contributes 1 to 5% of the yearly landings in other estuaries mainly in Andhra Pradesh and Tamil Nadu. This lower abundance in Hilsa ilisha is attributable to geomorphological and hydrobiological conditions unconducible for breeding migration of the species to the freshwater zones of these estuarine systems. Monsoon catch of Hilsha illsha alone contributes 70-80% of the total annual landings in Hooghly as well as Mahanadi estuaries. The landings of Hilsha ilisha mainly comprises second to fifth year age groups.

Mullets form an important group of fishes in all the estuarine systems with maximum contribution of 134-250 tonnes/year in Mahanadi estuary, followed by 122-150 tonnes/ year in Godavari, 53 tonnes/year in Hooghly and 1.5 - 4.2 tonnes/year in Adyar estuary. The dominant species are Mugil cephalus, Liza parsia, Valamugil cunnesius, Valamugil speileri, Liza subviridis, Liza macrolepis and Liza melinoptera. Other than mullet and Bilsha ilisha, the commercially important species in east coast estuaries are Setipinna spp., Pama pama, Trichiurus spp., Coilia spp., Sillago spp., Leiognathus spp., Lutianus spp., Barpadon nehereus, Polynemus spp., Lates calcarifer, pomfrets, etc. About 150168 species of finfishes are available in the estuaries of the east coast region.

Prawns comprising mainly Metapenaeus monoceros, Fenneropenaeus (Penaeus) indicus, Penaeus monodon, Metapenaeus dobsonii, Metapenaeus affinis, Metapenaeus brevicornis, Parapenaeopsis stylifera and Penaeus sculptilis, are also equally important in the estuarine

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annual landings. Godavari has the maximum prawn catch of 5,000 tonnes/year and Adyar estuary 2.1 to 3.8 tonnes/year. These fish fauna can be broadly divided into 3 categories:

1. Marine species migrating upstream and spawning in freshwater areas of the estuary like

Bilsha ilisha, Polynemus paradise us, Sillaginopsis panijus and Pama pama. 2. Freshwater species which spawn in saline area, viz. Panagasius pangasius and

Macrobrachium rosenbergii. 3. Marine forms coming to saline zone of the estuary for breeding like Arius jella,

Osteogeneiosus militaris, Polynemus indicus and Polynemus tetradactylus. Estuarine fisheries of Mahanadi:

Owing to lower tidal impact extending up to 42 krn only, the Mahanadi estuary does not have much variation in the species distribution pattern within the system. However, Bilsha ilisha fmd their way to the system for upstream breeding migration and eventually they form about 30 to 40% of the total estuarine landings. The other important groups, the mullets, threadfins, perches, sciaenids and catfishes constitute 30, 5.4, 3.7, 4.9 and 1.9% of the annual landings, respectively, besides prawns offer about 12.4% of the total estuarine catch. Estuaries of the Peninsular India:

Godavari estuary, the major estuary in Peninsular India has an area of about 18,000 ha. Goutami is the main source of the estuarine complex in which tidal influence extends only up to 40--50 km upstream from the mouth region. Formation of sand bars in the estuarine mouth restricts the entrance of tidal water like Mahanadi estuarine system. The total production from this estuary is estimated to be about 5,000 tonnes. Mullets and prawns form the major catch of the system. Metapenaeus monoceros, M. dobsonii, M. affinis, M, brevicornis, Penaeus monodon and Fenneropenaeus (Penaeus) indicus are the important prawn species available in the lower reaches of the estuary.

Backwaters of Kerala/Kayal:

One of the peculiarities of the Kerala coastal zone is the presence of a number of

backwaters or estuaries locally known as kayal. The kayals are blessed with natural resources

and support a variety of flora and fauna. The brackish water fisheries generate a lot of

employment opportunities and earn considerable amount of money through export. In Kerala, the

tourism industry to some extent depends on the backwaters. Even though there are efforts to

preserve these economically important wetlands but indiscriminate reclamation is on the increase

to cater to the needs of growing urbanization. The most prominent among the Kerala estuaries is

the Vembanad estuary located east of the Cochin-Alleppey coastal plain. Morphologically, the

paddy fields (Kuttanad region) south of Vembanad estuary seems to be an extension of

Vembanad estuary. This reclaimed parts form a very important wetland category and a type

locality for Kerala coastal wetlands.

Estuaries of the northwest coast: Gujarat, the western most part of India, has the longest shoreline (1,600 km) among the

maritime states of India. The Gulf of Cambay is characterized by a number of large and small estuaries. All major estuaries like Tapi, Narmada, Mahi, Sabarmati, Mik and Dhadhar are marked by flared outlines and tidal meanders, except the Narmada estuary. The Narmada estuary is classified as a salt-wedge estuary where freshwater flow predominates. The Tapi, Narmada, Mahi and Sabarmati estuaries bifurcate around island and have appreciable in-filling and hence are called estuarine delta.

River Narmada is having an estuarine stretch of about 120 km which ends in Gulf of

Cambay. Gradual decline in tidal ingress is being observed due to development of sand bars at

the mouth region of the estuary. From 10 years records during 1973-82, the average annual

production of the estuarine system has been estimated to be about 4,000 tonnes in which as

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group hilsa predominates (40-45%, average 1,662 tonnes), followed by mullets (15-20%,

average 687 tonnes) and prawns (5-8%, average 287 tonnes). Miscellaneous species contributed

30-38% (average 1,520 tonnes) of the total landings. The fishing potential estimated in a survey

during 1986-87 indicated that 2,884 fishermen are actively engaged in fishing activities in the

system with 103 boats (non-mechanized) and about 28,000 nets. Gill nets are in maximum use

(26,414 nos.) in the lower zone of lhe estuary. Hilsa forms the major catch of these gills nets (80-

85%). Cast nets are mainly used for prawn fishing. Besides these, the seedlings of freshwater

giant prawn (Macrobrachium rosenbergii) form an important fishery resource in mixo-

oligohaline and limnetic zones of the system.

Coldwater fisheries

The ecological conditions of the fishery resources of the upland areas namely coldwater

streams, brooks, rivers, natural and man-made lakes are quite different from that of the plains.

There are 2 types of streams namely snow-fed and spring-fed. These streams are characterized

by rocky and gravelly bottoms, high transparency, low temperature, high oxygen level due to

high velocity and continuous water flow and their primary and secondary productivity are low.

Temperature plays a crucial role in the occurrence and distribution of fishes in these areas. The

other factors, which play key role in the distribution of fishes, are swiftness of current, nature of

substratum and availability of food. The fishes of the upland water-bodies have either strong

power of locomotion (mahseer) or have developed special organ of attachment (Garra and

Glyptostemoids) in the fast turbulent streams. These fishes are of small size in contrast to the

warmwater fishes. On the basis of temperature tolerance, the fishes of the upland areas are

classified into eurythermal type (wide range of temperature tolerance i.e. Schizothorax and

Barilius) and stenothermal type (narrow range of temperature tolerance i.e. exotic trout). The

common fishes inhabiting the upland streams of Kashmir, Himachal Pradesh, Uttaranchal, North

West Bengal, Sikkim, Arunachal Pradesh, Nagaland, Meghalaya and Nilgiris, Kodai hills and

Munnar high range of the Peninsular Indian rivers are presented in Table 13. The estimated

coldwater fisheries resources are shown in Table 14.

Table 13. Common coldwater fishes of upland areas of the Himalayas and Peninsular plateau Group Family/sub-family Fish species

Indigenous fish stocks

Mahaseer

Cyprinidae/Cyprininae Tor putitora, T. tor, T. khudree, T. mosal, Tor

malabaricus,Neolissocheilus hexagonolepis, N.

wynaadensis

Snow trout

Cyprinidae/Cyprininae Schizothorax plagiostomus, S. progasrus,

Schizothoraichthys scurvifrons, S. niger

Brails Cyprinidae/Rasborinae Barilius bola, B. barila, B. vagra

Minor carp Cyprinidae/Cyprininae Labeo dero, L. dyocheilus

Loaches Cobitidae Botia spp., Nemacheilus spp.

Catfishes

Sisoridae Glyptothorax pectinopterus, Glyptosternum

venticulatum

Exotic fish stock

Trout

Salmonidae Salmo gairdenri (Oncorhynchus mykiss),

Salmo trutta fario, Salvelinus fontinalis

Common carp

Cyprinidae Cyprinus carpio communis, C. carpio

specularis, C. carpio nudus

Trench Cyprinidae Tinea tinea Source: NRC-CWF (ICAR), Bhimtal.

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Table 14. Coldwater fisheries resources of India

Resources

River length

(Upper reaches of 16 big and small rivers in Himalayan

and Peninsular region)

8,243 km

Natural lakes

(Nearly 30 high mountain and valley lakes both in Himalayas

and Peninsular region)

20,500 ha

Reservoirs (man-made)

(Nearly 12 located in Himalayan and Peninsular region)

2,65,000 ha

Source: NRC-CWF (ICAR), Bhimtal.

The population pressure has adversely affected the fragile upland ecosystem. The

resource ecology, the aquatic habitat and their biodiversity are all under grave stress due to felling of forest trees, damming of rivers and streams. To add to the malaise, the natural calamities of rock-falls, landslides, avalanches, cloudbursts worsen the situation. As a result, the ecosystems such as the valley lakes in Kashmir, Kumaon lakes, Doty lake in the Western Ghats and Loktak Lake in Manipur have reached higher tropic levels and as such can not sustain fish species which they used to earlier. Approximate resources of coldwater region in India are given in Table 15.

Table 15. Area-wise list of different kinds of natural water-bodies in the Indian uplands

Particulars of water-body Stream length/area

Himalayan and Deccan Plateau river system 8,310 km

1. Brackishwater lakes (above 3000 msl) 2,390 ha

2. Freshwater natural lakes (1,500-2,000 msl) 18,150 ha

3. Kashmir high mountain lakes (above 3000 msl) 400 ha

4. Valley wetland ecosystems 3,000 ha

5. Shiwalk Himalayan lakes 74 ha

Central Himalaya

1. Freshwater lakes of Kumaon 355 ha

Himalayan manmade lakes and reservoirs 43,770 ha

Peninsular zone

1. Natural lakes 85 ha

2. Man-made lakes and reservoirs 4,400 ha Source: NRC-CWF (ICAR), Bhimtal.

***