chapter vii reservoir fisheries estelar -...

Reservoir Fisheries………?-223-

Chapter VII

Reservoir Fisheries

Freshwater resources are one of the most precious

commodities for the living beings and especially to human beings.

Aquatic resources of water should be assessed on the basis of abiotic

and biotic parameters in order to provide the complete spectrum of

information for the conservation, assessment of fish diversity and

better fish-management and sustainable utilization. Rapid industrial

growth in the post-independent India resulting in deforestation,

unscrupulous exploitation of river water for irrigation, siltation of

river beds and reservoirs, unattended fish catches by the untrained

fisherman, destructive fishing, damming, habitat fragmentation, loss

of habitat, predation, diseases, etc. has drastically decreased the fish

diversity in the natural waters (Mudgal, 2007).

India being the fourth largest producer of fish in the world and

second in inland fish production, its share in the world production of

fish is about 4.6 %. Fisheries sector has been recognized as a

powerful income and employment generator as it stimulates growth

of a number of subsidiary industries and is a source of cheap and

nutritious food. At the same time, it is an instrument of livelihood for

a large section of economically backward population of the country.

More than 8.0 million fishers in the country directly depend on

fisheries and aquaculture for their livelihood (Chauhan, 2004;

Ayyappan et al. 2006).

Aquaculture in India is almost synonymous to carp culture,

since the latter alone contributes to more than 80 % of the total

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aquaculture production of the country. The carp culture mainly

involves three Indian major carps viz catla (Catla catla), rohu (Labeo

rohita) and mrigal (Cirrhinus mrigala) and three domesticated exotic

carps viz silver carp (Hypophthalmichthys molitrix), grass carp

(Ctenopharyngodon idella) and common carp (Cyprinus carpio)

Ayyappan et al. (2006). Reservoirs are generally stocked with

fingerlings of Indian major carps and indigenous medium sized carps

to augment their fish production. World’s major concerns are the

aquatic resources as the rapidly increasing human population is

resulting in tremendous pressure on food security. By 2010, an

additional 40-50 million tones of fish is expected to be required to

maintain the present global per capita availability of food fish.

However, the gap between production and per capita requirement is

still very large.

According to Chauhan (2004) India is reckoned to be self-

sufficient in carp fish seed to meet the demand of aqua farming. The

present carp seed production is about 17,000 million fry and it is

envisaged to achieve a target of 25,000 million fry by 2009-10. The

only alternative is to strengthen and sustain fish farming and culture

based capture fisheries by employing better management practices

and ensuring enhanced fish production as well as the environmental

sustainability. World Fish Center (2003) has also envisaged major

growth in fish farming in Asia particularly in India, where it is

expected to increase by 67 % by 2020.

Reservoirs are important water resources in Asia; the

reservoirs are diverse and therefore the strategies to be adopted for

optimizing yields are also different (Bhukaswan 1980; Cowx, 1996;

De Silva, 2001). The fish production from reservoir depends on

nutrients, biomass, and the quantity of stocked fingerlings.

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There is a common belief that fish yields of reservoirs tend to be high

in the initial few years after impoundment, and then begin to

stabilize at a lower level (Van & Luu, 2001). As indicated by

Bernacsek (1997) fish catch per unit effort is quite low in large

reservoirs, mainly due to the low productivity of pelagic water.

Recently, reservoir fisheries resources have tended to be

overexploited (Coates 2002; Cowx, 2002). First of all this is caused

by ineffective or inappropriate management measures. Open access

may be an important cause of over fishing, and lack of knowledge on

fisheries resources may lead to or results in over fishing (Coates,

2002).

Sharma et al. (1986) and Joshi (1987) reported the induced

breeding of Labeo gonius in Rajasthan having warm climatic

condition. Labeo rohita is the important commercial fish species,

most favoured by consumers of India, fetching a high price of Rs. 40

to 50 per kg for the marketable size. It is column feeder and mainly

feeds on decaying plants and detritus. It likes artificial feed and has

a good capacity to convert it into flesh. Usually low temperatures are

harmful for growth and reproduction of fishes (Popma and Lovshin,

1996).

The fishery of Indian reservoirs is comprised of both

indigenous and stocked fish populations. Among the former, the

Gangetic major carps occupy a prominent place in north Indian

reservoirs both as 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 catla,

Cirrhinus mrigala, Labeo rohita, L. calbasu, L. bata, Puntius sarana, P.

chagunio, C. reba, Mystus. aor, M. seenghala, Wallago attu, etc.

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Reservoir fishery is an important component of the inland

fisheries in South and South-East Asia. In India, the total water

spread area under all categories of reservoirs is estimated to be

about 3.0 million ha, which constitutes about 50 % of total reservoir

area in South-East Asia (Singh, 2001). Indian reservoirs, being in

tropics, have a high primary productivity and have the capacity to

produce more fish yield. Minor reservoirs are amenable to more

effective fisheries management than the large reservoirs (Jhingran

and Sugunan, 1990; Devi, 1997; Piska, 1999 and 2000; Chavan,

2006 and Vass, 2006). According to Kang (1992) the average fish

production of India is 20 kg/ha whereas that of Thailand is 47

kg/ha; Sri Lanka 283 kg/ha and China 150 kg/ha. Thus India is at

the bottom of the list though the scientific man-power in fisheries

sector of India is very high. The Chinese treat reservoir fishery as

“culture” fisheries. The hydrobiology is considered as the key to

fishery management.

Length-weight relationship for any fish species gives its

performance and well being in relation to habitat and helps in

monitoring the status of fish stock for obtaining optimum yield.

These relationships may vary from time to time in the same water

body due to alterations in water quality and fish stocks. Most of the

fishes compete for food with carps tending to reduce the overall fish

productivity of the reservoir (Ayyappan et al., 2006). The general

concept of length-weight relationship is that the weight of fish varies

as the cube of its length. But as the specific gravity and shape or

body outline of the fish is subjected to changes, the cube law is not

always applicable (Rounsefell and Everhart, 1953). Various workers

have studied the length-weight relationship of different fishes like

Labeo calbasu (Pathak, 1975), Notopterus notopterus (Kalita and

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Rath, 1998), Catla catla (Jhajhria, 2003), Cyprinus carpio (Saran and

Mohan, 2004) Clarias gariepinus (Nath et al., 2006), and Puntius

sophore (Shendge, 2008).

Observations

(A) Fish fauna of the reservoir

The fish fauna of Baigul reservoir has been studied during the

present investigation. Baigul reservoir has a rich assemblage of both

naturally occurring and stocked fish species. The reservoir is leased

to a contractor for 3-5 years for fishing and the fishing season

extends from October to June. The contractor employs various

parties of fishermen for fish catch. There is only one landing centre

where all catches are brought together. The assembled catches after

local consumption in fresh condition are transported to the other

markets. In addition to the fresh trade, smaller varieties of fish

(Puntius spp., Gudusia chapra and Prawns spp.) are also dried and

supplied to other places (U.P., Delhi etc.) (Table 7.1).

The fish fauna is comprised of major carps, cat fishes, minor

carps and a large population of trash fishes. A total of 36 species of

fish belonging to 13 families were identified in the reservoir. Among

13 families Clupideae, Notopteridae, Cyprinidae, Siluridae,

Channidae and Bagridae were the most common. The fish species

such as Labeo calbasu, Catla catlaL. gonius, L. rohita, Puntius sp.,

Cirrhinus mrigala, C. reba, Mystus tengara, M. seenghala, Nandus

nandus Gudusia chapra, N. notopterus, Wallago attu, Xenentodon

cancila and M. armatus etc. were quantitatively the main components

of the fishery of the reservoir (Plate 13 and 14).

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Table 7.1 : Fish fauna of the baigul reservoirS. No. Families Species Local name Abundance

1 Clupideae Gudusia chapra Suhia ANotopterus notopterus Patra A2 NotopteridaeN. chitala Moya SCyprinus carpio Common carp LTor tor Mahaseer SB. bendelisis Bhola SPuntius sophore Sidhari LP. sarana Sidhari MCirrhinus mrigala Mrigal/Nain MC. reba Raia MLabeo gonius Kursa AL.bata Bata LL. rohita Rohu LL. calbasu Karaunch MOxygaster bacaila Chilwa L

3 Cyprinidae

Catla catla Katla LMystus seenghala Dariai tengar LM. cavasius Sutahawa

tengaraL

M. vittatus Tengara SM.oar Dariai tengar S

4 Bagridae

M.tengara Tengara M5 Heteropneustidae Heteropneustus fossilis Singhi L

Ompak pabda Pabda M6 SiluridaeWallago attu Padhani/Lanchi S

7 Claridae Clarias batrachus Magur L8 Belonidae Xenentodon cancila Kauwa M

Channa gachua Changa MC. marulius Saur AC.punctatus Girai A

9 Channidae

C. striatus Saur A10 Anabantidae Colisa fasciatus Khosti S11 Centropomidae Chanda ranga Chanari M12 Nandidae Nandus nandus Dhebari M

Mastacembelus armatus Baam MM. pancalus Malga/Patya L

13 Mastacembelidae

M. aculeatus Malga/Patya LA = Most abundant, M = Moderately abundant, L = Less abundant, S = Seasonally

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Labeo rohita Gadusia chapra

Notopterus notopterus Cirrhinus reba

Labeo calbasu Cirrhinus mrigala

Plate 13 : Different species of fishes recorded from Baigulreservoir

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Labeo gonius Catla catla

Mystus tengara Xenentodon cancila

Nandus nandus Puntius sp.

Plate 14 : Different species of fishes recorded from Baigulreservoir

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Fish and Fisheries

The findings have revealed that the Baigul reservoir harbours a

variety of fish fauna. The results of the present study have been

presented in two parts. The first part deals with the collection and

identification of collected specimen and enlisting of the fish species

recorded during the study period; while the second part deals with a

comprehensive discussion based on the present fish production data

obtained from State Fisheries Department, Uttarakhand.

(B) Catch composition

In the Baigul reservoir, the commercial fishing is started in

October and continued up to June. Almost immediately after the fish

are brought to the shore, these are grouped into three classes viz.,

class-A, class-B and class-C according to their respective market rates.

In the present investigation the monthly data on fish catch from

January to December are presented in a systematic manner. The

species wise data are divided into 4/5 groups: The first group, major

carps which comprises of Labeo rohita, Catla catla, Cirrhinus mrigala

and Labeo calbasu, while the second group includes cat fishes: Mystus

sp. and Channa striatus. The third group includes minor carps such as

Labeo gonius and Notopterus notopterus. The fourth group includes

other fishes and the fifth is weed fishes including, Gudusia chapra, etc.

(Plate 15 and 16). Total catch composition of Baigul reservoir was

199393 kg during the study period (Table 7.2 Fig. 7.1 and 7.2).

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Plate 15 : Haul of Labeo gonius , the dominant fish of Baigul

Plate 16 : Fish haul with majority of weed fishes

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Table 7.2 : Total catch composition (in Kg.) of Baigul reservoir (2005)

Months A class B1 class B2 class B3 class C class Total

Jan 1001.0 965.0 3818.0 2573.0 26611.0 34968.0

Feb 462.0 608.0 14128.0 3448.0 9384.0 28030.0

Mar 661.0 725.0 14719.0 3043.0 2266.0 21414.0

Apr 836.0 708.0 12686.0 1175.0 434.0 15839.0

May 3184.0 1386.0 13180.0 513.0 5.0 18268.0

Jun 5652.0 1498.0 16288.0 1700.0 0.0 25138.0

Jul 0.0 0.0 0.0 0.0 0.0 0.0

Aug 0.0 0.0 0.0 0.0 0.0 0.0

Sep 0.0 0.0 0.0 0.0 0.0 0.0

Oct 256.0 739.0 8315.0 564.0 5615.0 15489.0

Nov 187.0 849.0 7443.0 572.0 8170.0 17221.0

Dec 576.0 1464.0 6996.0 1191.0 12799.0 23026.0

Total 12815.0 8942.0 97573.0 14779.0 65284.0 199393.0

Percentage 6.43 4.48 48.94 7.41 32.74 100.0

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128158942

97573

14779

65284

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

Fish

pro

duct

ion

(kg)

A class B1 class B2 class B3 class C class

2005

Classwise total

Fig. 7.1 : Classwise total fish production in Baigul reservoir

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6.434.48

48.947.41

32.74

A class B1 class B2 class B3 class C class

Fig. 7.2 : Classwise per cent contribution of total fish production in Baigul reservoirEste

lar


Class wise monthly variations in fish production

Class - A:

The monthly variations in the fish production of class A are

presented in the Fig. 7.3. It was observed that the highest production

(5,652 kg) of class-A was found during June followed by 3,184 kg in

May. Lower production was recorded in the month of November

(187.0 kg). Production of this fish showed increasing trend from

March onwards till June. Further, the total production of this fish

category recorded during January to December was (12,815.0 kg).

The class-A contributed only (6.43 %) to the total fish production of

Baigul reservoir (Fig. 7.2 and 7.3).

Class – B1

The share in production by this category is depicted in Fig. 7.3.

The highest production (1498.0 kg) was found during June followed

by May (1386.0 kg); while the lowest production was found in the

month of February (608.0 kg). Irregular trends in production

category II were observed during the present investigation. The total

production of class-B1 was 8,942.0 kg (Fig. 7.3). This category

contributed 4.48 % to the total fish production. Another notable

feature observed in the present study showed that share of this class

has increased relatively than in earlier years.

Class – B2

The fluctuations in production by class-B2 are depicted in

Fig. 7.4. It is apparent that the highest production (16288.0 kg) of

class–B2 was recorded during June followed by 14719.0 kg

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1001

462661

836

3184

5652

0 0 0256 187

576

0

1000

2000

3000

4000

5000

6000

Fish

pro

duct

ion

(kg)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

A class

965

608

725 708

1386

1498

0 0 0

739

849

1464

0

200

400

600

800

1000

1200

1400

1600

Fish

pro

duct

ion

(kg)


Months (2005)

B1 class

Fig. 7.3 : Monthly fish production of A & B1 Classes in Baigul reservoir

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production in March. The data also depicted that production in the

months of February (14128.0 kg) and March (14719.0 kg) was

almost similar; while the production was least (3818.0 kg) in the

month of January (Fig. 7.4). The total production of class-B2 was

97573.0 kg. It is obvious from the catch data that with high share in

the total fish catch, this class was most dominant.

Class – B3

The monthly variations in the production of class-B3 are

depicted in Fig. 7.4. It is evident that the highest production 3,448

kg of class-B3 was recorded during February followed by 3,043 kg in

March. The data also showed that production in the months of

October (564.0 kg) and November (572.0 kg) was close to each other;

while the least production was observed in the month of May (513.0

kg). A decreasing trend in the production was observed from

February to May. A total of 14,779 kg fish production was recorded

from January to December. The class-B3 contributed (7.41 %) to the

total fish landings.

Class - C

Small fish of low commercial value are included in this class-C.

The catch data of this category are depicted in Fig. 7.5. The highest

production (26,611 kg) of this category was found during January

followed by December (12,799 kg). The lowest production was found

in May (5.0 kg). A decreasing trend in fish production was observed

from February to June. The total production of this category was

65,284 kg. Further class-C contributed (32.74 %) to the total fish

production.

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3818

1412814719

1268613180

16288

0 0 0

83157443 6996

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

Fish

pro

duct

ion

(kg)


B2 class

2573

34483043

1175

513

1700

0 0 0

564 572

1191

0

500

1000

1500

2000

2500

3000

3500

Fish

pro

duct

ion

(kg)


Months (2005)

B3 class

Fig. 7.4 : Monthly fish production of B2 & B3 Classes in Baigul reservoir

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26611

9384

2266

4345 0 0 0 0

5615

8170

12799

0

5000

10000

15000

20000

25000

30000

Fish

pro

duct

ion

(kg)


Months (2005)

C class

Fig. 7.5 : Monthly fish production of class C in Baigul reservoir

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(C) Important food fishes (species wise)

Major carps are highly esteemed as food fishes in this region

because of good taste. Among the cat fishes, Mystus sp. has a good

demand in this area, because of high quality flesh. The principal food

fishes of Baigul reservoir in order of importance are given below:

SI. No. Groups Species

(A) Major carps Labeo rohita, L. calbasu, Catla catla andCirrhinus mrigala

(B1) Cat fishes Mystus tengara and Channa striatus

(B2) Minor carps Labeo gonius, and Notopterus notopterus

(B3) Weed fishes Gudusia chapra

(C) Other fishes Heteropneustes fossilis, Nandus nandus andMastacembelus armatus etc.

I. Major carps: These contributed 6.43 % to the total production.

Labeo rohita

The total monthly fish landings are shown in the Fig. 7.6. The

production of L. rohita varied from 13.0 to 2412.0 kg during the

present investigation. The highest fish production of 2412.0 kg was

recorded during June followed by 1200.5 kg production in May. The

data also depicted that catch in the month of April (159.5 kg) and

December (105.5 kg) were almost same; the lowest fish catch of 13.0

kg was observed during November. The total production 4,336.0 kg

was recorded during January to December. L. rohita contributed 2.17

% to the total landings from this reservoir (Fig. 7.7).

Catla catla

The monthly variations of Catla catla are presented in Fig.

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34968

28030

21414

15839

18268

25138

0 0 0

1548917221

23026

0

5000

10000

15000

20000

25000

30000

35000

Fish

pro

duct

ion

(kg)


Months (2005)

Monthwise total

Fig. 7.6 : Monthwise total fish production in Baigul reservoirEstelar


2.17 0.58 2.09 0.68

40.83

7.921.222.86

7.41

29.53

Rohu Catla Mrigal Karuanch Kursa

Patra Tengan Saur Others Gudusia

Fig.7.7 : Per cent contribution of important fishes to total fish production in Baigul reservoirEste

lar


7.8. The highest production (676.0 kg) of C. catla was recorded

during June followed by 168.0 kg production in May. On the

contrary, the recorded production was least in the month of

February (7.0 kg). The total production recorded from January to

December was 1156.0 kg. C. catla contributed about 0.58 % to the

total landings in Baigul reservoir (Fig. 7.7).

Cirrhinus mrigala

The monthly variations in the production of C. mrigala are

depicted in Fig. 7.9. The highest production (1427.0 kg) was found

during June followed by 936.0 kg production in May. The lowest

production was recorded in November (142.6 kg). A gradually

increasing trend in production was observed from March to June;

decreasing trend in production was observed from October to

November. A total 4177.1 kg fish production was recorded from

January to December. The fish contributed about 2.09 % to the total

production landing from Baigul reservoir (Fig. 7.7).

Labeo calbasu

The production of L. calbasu varied between 13.5 and 330.0 kg

in the Baigul reservoir. The monthly fish landings are shown in Fig.

7.9. The highest fish production of 330.0 kg was recorded during

May. The catches during February - March were 126.0 - 127.0 kg

and that during May- June were 317-330.0 kg. The lowest fish catch

of 13.5 kg was observed during October. The total production from

January to December 05 was recorded as 1,346.0 kg. L. calbasu

contributed about 0.68 % to the total landings during the present

investigation (Fig. 7.7).

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251

71.5 97159.5

1200.5

2412

0 0 0 26 13105.5

0

500

1000

1500

2000

2500

Fish

pro

duct

ion

(kg)


Labeo rohita

92

7 13.530

168

676

0 0 0 17 7.5

145

0

100

200

300

400

500

600

700

Fish

pro

duct

ion

(kg)


Months (2005)

Catla catla

Fig. 7.8 : Monthly fish production of Labeo rohita and Catla catla in Baigul reservoir

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392.5

206.5

321378

936

1427

0 0 0

177 142.6196.5

0

200

400

600

800

1000

1200

1400

1600

Fish

pro

duct

ion

(kg)


Cirrhinus mrigala

192.5

127 126

203.5

330317

0 0 0 13.5 1422.5

0

50

100

150

200

250

300

350

Fish

pro

duct

ion

(kg)


Months (2005)

Labeo calbasu

Fig. 7.9 : Monthly fish production of Cirrhinus mrigala and Labeo calbasu in Baigul reservoir

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Cat fishes

The contribution of cat fishes was 4.48 % to the total fish

landings of Baigul reservoir.

Mystus tengara

It is evident from the monthly variations that the highest

production (485.0 kg) was found during June (Fig. 7.10). The lowest

production was recorded in the month of March (101.0 kg). A total

production of 2,434.0 kg was recorded during the study period. M.

tengara contributed about 1.22 % to the total fish landings from this

reservoir (Fig. 7.7).

Channa striatus

The monthly production of C. striatus varied from 367.0 to

1031.0 kg. The total production of this fish was 5697.0 kg during the

study period (Fig. 7.10). The highest production (1031.0 kg) was

noted during December followed by 960.0 kg in the month of June.

The lowest production was recorded in the month of February (367.0

kg). Irregular trends in fish production were observed throughout the

study period. C. striatus contributed about 2.86 % to the total

landings from this reservoir (Fig. 7.7).

Minor carps

Minor carps contributed about 48.94 % to the total fish

production.

Labeo gonius

The production of L. gonius varied from 2676.0 to 15155.0 kg.

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393

167

101

226

432

485

0 0 0

169 169

292

0

50

100

150

200

250

300

350

400

450

500

Fish

pro

duct

ion

(kg)


Mystus tengara

446

367

492

419.5

894.5960

0 0 0

486

601

1031

0

200

400

600

800

1000

1200

Fish

pro

duct

ion

(kg)


Months (2005)

Channa striatus

Fig. 7.10 : Monthly fish production of Mystus tengara and Channa striatus in Baigul reservoir

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The monthly fish landings are shown in Fig. 7.11. The highest fish

production of 15155.0 kg was observed in June followed by 13477.0

kg production in March; while the lowest fish catch of 2676.0 kg was

recorded during January. The total production recorded form

January to December was 81406.0 kg. L. gonius dominated the

fishery followed by Notopterus notopterus in the minor carps group.

L. gonius contributed about 40.83 % to the total landings from this

reservoir (Fig. 7.7).

Notopterus notopterus

The monthly variations in the production of N. notopterus are

depicted in Fig. 7.11; it is evident that highest production of 2346.0

kg was observed during April followed by 2140.0 kg production in

December. The minimum production was recorded in the month of

June (1124.0 kg). The total annual production was recorded as

15784.0 kg. N. notopterus ranked second in the catches followed by

L. gonius in the minor carps group. N. notopterus contributed about

7.92 % to the total production from Baigul reservoir (Fig. 7.7).

Weed fishes

The contribution of weed fishes was 32.74 % to the total fish

landings of Baigul reservoir.

Gudusia chapra

The production of G. chapra varied from 5.0 to 24578.0 kg. The

highest production (24578.0 kg) was obtained during January (Fig.

7.12). The production of G. chapra was almost similar in the month

of February (8432.0 kg) and November (8170.0 kg). The fish was not

recorded in catches during April and June. The total production of

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2676

12032

13477

1034011258

15155

0 0 0

62405372

4856

0

2000

4000

6000

8000

10000

12000

14000

16000

Fish

pro

duct

ion

(kg)


Labeo gonius

1142

1762

1242

2346

1922

1124

0 0 0

20352071

2140

0

500

1000

1500

2000

2500

Fish

pro

duct

ion

(kg)


Months (2005)


Fig. 7.11: Monthly fish production of Labeo gonius and Notopterus notopterus in Baigul reservoir

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2573

3448

3043

1175

513

1700

0 0 0

564 572

1191

0

500

1000

1500

2000

2500

3000

3500

Fish

pro

duct

ion

(kg)


Others

24578

8432

5880 5 0

0 0

4730

8170

12378

0

5000

10000

15000

20000

25000

Fish

pro

duct

ion

(kg)


Months (2005)

Gudusia chapra

Fig 7.12 : Monthly fish production of Other fishes and Gudusia chapra in Baigul reservoir

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this fish recorded during present investigation, was 58881.0 kg. It

contributed 29.53 % to the total annual fish landings (Fig. 7.7).

Other fishes

These fishes shared 7.41 % to the total fish production in

Baigul reservoir. Monthly contribution by the other fishes is depicted

in Fig. 7.12. It is evident that the highest production (3448.0 kg) was

observed during February followed by March (3043.0 kg); the lowest

production was recorded in the month of May (513.0 kg). The data

further show variability in the production during different months.

The total production of this group of fishes recorded from January to

December was 14779.0 kg.

(D) Gear wise fish production

Fishing methods

The contractors mostly use traditional fishing methods in

Baigul reservoir for harvesting the fish catch. The commonly used

gears are gill net (Fansla jal); hooks and line (Dori), drag net (Chatti

jal), triangular net (Fautta or Jhinga jal), cast net (Ghagaria jal) and

rod and line (Bansi) (Plate 17 and 18).

Gill net

Like other reservoirs, gill net is the most common fishing gearemployed in Baigul reservoir throughout the year. The net is made ofnylon cord which is about 40 to 60 m long. Mostly 3 types of mesh

sizes, viz, 15×15 mm, 45×45 mm and 75×75 mm are used forcatching minor carps, major carps and cat fishes etc. The upper edge

of the net is attached with a series of floats, whereas sinkers aresuspended at the bottom edge of the net. The net is vertically

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Drag net with 1 × 1 mm mesh bar

Gill net with 15 × 15 mm mesh bar

Plate 17 : Drag net and gill net used for fishing in Baigul reservoir

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Plate 18 : Gill net of different mesh bars used for fishingin Baigul reservoir

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suspended in water with the help of boats. The fishing operation

starts in the evening and the catch is hauled in the subsequent

morning. The operating unit usually comprises of one small boat and

two fishermen. The fishes commonly caught with this device include,

Labeo spp., Catla catla, Mystus seenghala, M. tengra, M. vittatus and

Wallago attu (Table 7.3).

Table 7.3: Class wise and gear wise fish production of Baigulreservoir

A class B1 class B2 class B3 class C class Total Percentage

Gill net 7073 3230 55740 8626 15425 90094 45.2

Triangularnet

1660 990 7450 1169 958 12227 6.1

Drag net 2280 1942 20585 2336 35471 62614 31.4

Cast net 1507 2110 11380 2043 11430 28470 14.3

Hook line 0 0 0 0 2000 2000 1.0

Line androd net

295 670 2418 605 0.0 3988 2.0

Total 12815 8942 97573 14779 65284 199393 100.0

Triangular net

Triangular nets are conical in shape and made of bamboo

pieces of about 1.2×1.2 ×2.0 m size. The length of the net may also

vary between 1.0 and 2.5 m. The posterior end of the net where the

catch is collected is known as ‘Bhog’. In the operation of this net the

fishermen dip the front edge of the net in shallow water and capture

small prawns and weed fishes like Puntius spp. and Chanda sp. The

mesh sizes of 5×5 mm to 5×10 mm are recommendable for capturing

commercially important fish species. If the net is to be used in

deeper waters, a small boat is of great help.

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Drag net

Drag net is very large in size which horizontally covers an

enormous area in length (350 to 400 m) and width (3 to 4 m). One

large and two small boats with 24-30 fishermen form one operational

unit. The mesh size of the net is about 1x1 mm. The head rope of

this net is supported by a strong cord and is provided with a large

number of wooden or plastic floats, whereas the food rope is tied

with a number of sinkers to keep the net suspended in water in

vertical position. The operational principle involves handing over one

end of the net to one party of fishermen standing on the reservoir

bank. The net is then spread out in water in the semicircular fashion

with the help of boats to encircle the fish shoal from all directions.

The operational boats then turn to hand over the other end of the net

to the second party of fishermen standing at another distant place on

the shore. The net is operated in the month of May and June to

catch the fishes like Heteropneustes fossilis, Channa spp.,

Mastacembelus spp., Chanda spp., Puntius spp. etc.

Cast net

The cast nets are also occasionally used for fish harvest from

the reservoir especially in the shallower regions. The use of this gear

is not very common owing to the vastness of the reservoir.

This net is circular in shape, which opens like an umbrella.

The bottom rope of the net, fitted along its opening, is usually

fastened with a number of weights which facilitate an easy

suspension of the net in the water. The recommended mesh size of

the net is 5×5 cm to 8×8 cm. The fisherman throws the net towards

the expected shoal site by keeping in hand the string at its apex in

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such a manner that it falls over the water body in a circular fashion.

The net suspends easily in water due to the presence of attached

weights. Subsequently, the fishermen haul the net by slowly pulling

the string and closing its circumference. The varieties of fishes

usually captured by the cast net include Labeo spp., Catla sp.,

Cirrhinus spp., Mystus spp., Wallago attu and other large size species

of food fishes present in the water.

Hooks and line

Hooks and line is another important fishing gear commonly

operated in Baigul reservoir during post monsoon and summer

months when the transparency of water is low. This device is usually

used to harvest cat fishes and murrels. Lines are made of long cords

of cotton or waste silk tied with 100 to 200 country made iron hooks.

The common baits used on the hooks comprise trash fishes, small

prawns, earthworms etc.

Line and rod

Lines and rods are also sometimes used for capturing fish by

the fishermen in summers. For this purpose, earthworms are used

as the common bait for capturing fishes such as Mystus spp. Wallago

attu and Channa spp.

Catch Statistics in relation to the nets- gears used

Gearwise distribution of catches in Baigul reservoir has been

computed during the study period (Table 7.3). Gill net is the most

common fishing gear employed during the study period in the

reservoir. The total catch by gill net was 90094 kg or 45.2 %. Out of

total catch the catch of class-A fishes (Labeo rohita, L. calbasu, Catla

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catla, Cirrhinus mrigala etc.), was 7073 kg. The total catch of B1

class (Mystus sp., Channa sp. etc.) was 3230 kg; B2 class

represented by minor carps (L. gonius, Notopterus notopterus etc.)

was 55740 kg; catch of other fishes was 8626 kg and whereas the

total catch of weed fishes (Gudusia chapra, Chanda ranga etc.) was

calculated as 15425 kg. It was observed that minor carps were the

major component (55740 kg) whereas minimum catch was of cat

fishes (3230 kg).

The total catches by triangular net was 12227 kg or 6.1 % of

the total catch comprising of A class fishes 1660 kg, was B1 class

(990 kg), minor carps (7450 kg), B3 class (1169 kg), and C class (958

kg). It was observed that the maximum catch (7450 kg) by triangular

nets was of minor carps and minimum catch (958 kg) was of weed

fishes (Table 7.3).

The total catch of drag net was 62614 kg or 31.4 %. Out of

total catch, 2280 kg was A class; 1942 kg was B1 class; 20585 kg

was B2 class; 2336 kg was B3 class and 35471 kg was C class in the

Baigul reservoir (Table 7.3). It was noted that the maximum catch of

35471 kg by drag net was of weed fishes and minimum catch of

1942 kg was of B2 class cat fishes.

The total catch of cast net was 28470 kg or 14.3 %, out of this

1507 kg was A class; 2110 kg was B1 class; 11380 kg was B2 class;

2043 kg was B3 class and 11430 kg was C class. The maximum

catch of 11430 kg by cast net comprised of weed fishes and

minimum catch of 1507 kg was of major carps (Table 7.3).

The total catch by hooks and line was 2000 kg or 1.0 %. Major

carps, cat fishes, minor carps and other fishes were not caught by

hook nets and only weed fishes were caught by hook nets (Table 7.3).

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The total catch of line and rod was 3988 kg or 2.0 % from which 295

kg was of major carps; 670 kg was of cat fishes; 2418 kg was of

minor carps and 605 kg was of other fishes. Line and rod was not

used to catch weed fishes (Table 7.3).

(E) Fish productivity of the reservoir

The fish catch statistics available from 2001-2005 were used to

estimate the fish yield for different years. On the basis of water

spread area of 2693 ha, the yield rates from the reservoir were

estimated to be 43.84 kg/ha (2001), 52.74 kg/ha (2002), 37.82

kg/ha (2003), 28.27 kg/ha (2004) and 74.04 kg/ha (2005) (Fig.

7.13). The reservoir, therefore, can be placed amongst the moderately

productive reservoirs. The catch/ha estimated for different years is

as follows:

Year Total catch (kg) Kg/ha

2001 118068 43.84

2002 142028 52.74

2003 101845 37.82

2004 76131 28.27

2005 199393 74.04

(F) Length-weight relationship of some important fishes

The regression equations describing length-weight relationship

in case of important fish species of Baigul reservoir are presented in

Table 7.4 and 7.5 as well as Figs. 7.14 to 7.17. Accordingly, the

coefficient of correlation ®, coefficient of determination (r2) and the

levels of significance (P) for the relationship between length and

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0

2000

0

4000

0

6000

0

8000

0

1000

00

1200

00

1400

00

1600

00

1800

00

2000

00

Kg

2001

2002

2003

2004

2005

Year

Fig.

7.1

3: T

otal

fish

pro

duct

ivity

(kg)

of l

ast f

ive

year

s in

Bai

gul r

eser

voir

A c

lass

B1

clas

sB

2 cl

ass

B3

clas

sC

cla

ss

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weight for Labeo rohita, Catla catla, Cirrhinus mrigala, Channa

striatus, Labeo gonius, Notopterus notopterus, Gudusia chapra and

Puntius sarana have been worked out.

Table 7.4: Equations describing length-weight relationship indifferent fishes

Fish Length weight equation

Labeo rohita Log W = -2.9945+1.7415 log L

Catla catla Log W = -3.3732+2.0561 log L

Cirrhinus mrigala Log W = -3.2783+1.8639 log L

Channa striatus Log W = -3.2949+2.0577 log L

Labeo gonius Log W = -3.0586+1.7138 log L

Notopterus notopterus Log W = -1.9404+0.9779 log L

Gudusia chapra Log W = 0.8005+0.1936 log L

Puntius sarana Log W = -1.7255+0.8609 log L

Table 7.5: Coefficient of correlation; coefficient ofdetermination and level of significance related withlength-weight relationship in different fishes

Fish No. ofspecies

Coefficient ofcorrelation

(r)

Coefficient ofdetermination

(r2)

Level ofsignificance

(P)Labeo rohita 45 0.908 0.824 <0.01

Catla catla 55 0.933 0.870 <0.01

Cirrhinus mrigala 58 0.957 0.915 <0.01

Channa striatus 45 0.876 0.767 <0.01

Labeo gonius 48 0.954 0.910 <0.01

Notopterus notopterus 60 0.871 0.758 <0.01

Gudusia chapra 52 0.888 0.789 <0.01

Puntius sarana 50 0.912 0.831 <0.01

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Labeo rohita

The length-weight relationship of L. rohita (Fig. 7.14) can be

expressed by the following equation:

Log w = -2.9945 + 1.7415 log L

r = 0.908

It is obvious from the above equation that the relationship

between length and weight is not perfectly linear (r = 0.908). Besides,

the value of coefficient of regression is also very low (1.7415), which

is indicative of the fact that this fish becomes more slender with the

increase in body length. A fairly high value of coefficient of

determination (r2 = 0.824) was obtained (Table 7.4 and 7.5).

Catla catla

In case of C. catla, the logarithmic regression equation

obtained was as follows:

Low w = -3.3732 + 2.0561

r = 0.933

It is evident that the length-weight relationship of C. catla is

comparatively more fairly high (r = 0.933). A relatively high value of

coefficient of regression (2.0561) revealed that this fish also acquired

a slender form (Table 7.4 and 7.5, Fig. 7.14).

Cirrhinus mrigala

In case of C. mrigala, the logarithmic regression equation


Low w = -3.2783 + 1.8639 log L

r = 0.957

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Labeo rohita

y = 55.143x - 987.4R2 = 0.824

0

500

1000

1500

2000

2500

3000

3500

4000

0 10 20 30 40 50 60 70

Length (cm)

Wei

ght (

g)

Catla catlay = 113.79x - 2362R2 = 0.870

0

500

1000

1500

2000

2500

3000

10 15 20 25 30 35 40 45

Length (cm)

Wei

ght (

g)

Fig. 7.14 : Length-weight relationships of Labeo rohita and Catla catla in Baigul reservoir

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It is, therefore, evident that the length-weight relationship of C.

mrigala (Fig. 7.15) was comparatively fairly high (r = 0.957) than the

L. rohita and C. catla (Table 7.4 and 7.5).

Channa striatus

The length-weight relationship of C. striatus can be expressed

by the following equation:

Log w = -3.2949 + 2.0577 log L

r = 0.876

The graphical presentation of this relationship (Fig. 7.15)

revealed a linear relationship in length-weight parameters although

this fish also did not gain required weight as it grows in length. It is

obvious from the above equation that the relationship between length

and weight is perfectly linear (r = 0.876) (Table 7.4 and 7.5).

Labeo gonius

In case of L. gonius the logarithmic regression equation


Low w = -3.0586 + 1.7138 log L

r = 0.954



this fish also did not gain required weight as it grows in length

(r = 0.954). It is obvious from the above equation that the

relationship between length and weight is perfectly linear (r = 0.954)

(Table 7.4 and 7.5).

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Cirrhinus mrigalay = 73.104x - 1898.1R2 = 0.915

0

500

1000

1500

2000

2500

3000

3500

20 30 40 50 60 70

Length (cm)

Wei

ght (

g)

Channa striatusy = 114.2x - 1972.3R2 = 0.767

0

500

1000

1500

2000

2500

3000

3500

10 15 20 25 30 35 40 45

Length (cm)

Wei

ght (

g)

Fig. 7.15 : Length-weight relationships of Cirrhinus mrigala andChanna striatus in Baigul reservoir

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Labeo goniusy = 51.737x - 1144.5

R2 = 0.910

0

200

400

600

800

1000

1200

20 25 30 35 40 45

Length (cm)

Wei

ght (

g)

Nonopterus notopterusy = 9.5055x - 87.172R2 = 0.758

0

50

100

150

200

250

300

10 15 20 25 30 35 40

Length (cm)

Wei

ght (

g)

Fig. 7.16 : Length-weight relationships of Labeo gonius and Notopterus notopterus in Baigul reservoir

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The regression equation for N. notopterus was estimated to be

as follows:

Log w = -1.9404 + 0.9779

r = 0.871



this fish also did not gain required weight as it grows in length (Table

7.4 and 7.5). Besides, the value of coefficient of regression is also

very high (0.9779), which is indicative of the fact that this fish

became more slender with the increase in body length.

Gudusia chapra

In case of G. chapra the length-weight relationship is presented

by the following equation (Fig. 7.17).

Log w = 0.8005 + 0.1936 log L

r = 0.888

It is obvious that the variation in weight on account of its

growth in length does not conform to the cubic formula for length-

weight relationship (Table 7.4 and 7.5).

Puntius sarana

The length-weight relationship of P. sarana (Fig. 7.17) can be

expressed by the following equation:

Log w = -1.7255 + 0.8609 log L

r = 0.912

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Gudusia chapray = 1.5617x + 6.3171R2 = 0.789

0

5

10

15

20

25

30

35

40

45

50

10 12 14 16 18 20 22

Length (cm)

Wei

ght (

g)

Puntius saranay = 7.2599x - 53.148R2 = 0.831

0

20

40

60

80

100

120

140

160

180

10 15 20 25 30

Length (cm)

Wei

ght (

g)

Fig. 7.17 : Length-weight relationships of Gudusia chapra and Puntius sarana in Baigul reservoir

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It is, therefore, evident that the length-weight relationship of P.

sarana was more linear (r =0.912) with a fairly high value of

coefficient of determination (r2 =0.831) (Table 7.4 and 7.5).

(G) Strategies for the fisheries management of thereservoir in relation to plankton food web

The present investigation confirms the observations made by

Sugunan (1995) that effective stocking of seed is a prerequisite for

the higher production of fish from the reservoirs. Katiha (2002) found

that higher productivity was the direct outcome of optimum stocking

measures adopted through pen culture.

Fish yield in impoundments depends not only on geo-

morphological and physico-chemical characters, but much more on

manner and level of exploitation (Sugunan, 2000). Considerable work

has been carried out on the fisheries and management of water

bodies in India (Welcomme and Henderson, 1976; Jhingran and

Sugunan, 1990; Cowx, 1994; Sugunan, 1995, 2000; Sugunan and

Sinha, 2000; Sugunan and Katiha, 2004 and Pillay and Katiha,

2007).

The indigenous fish stock levels of Baigul river system are not

adequate to realize the yield potential of the reservoirs. Hence, it is

absolutely necessary to stock the Baigul reservoir with fingerlings of

suitable fish species to maximize production at a sustainable level.

The objectives of stocking are besides aiming at maximizing yield, to

take care of preservation of the biodiversity of the system. Stocking

programme in Baigul reservoir appears to be judicious with stocking

of Indian major carps (rohu, catla and nain (mrigala). Sporadic

occurrence of common carp has been recorded in the catches. The

present yield of reservoirs is moderate.

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According to Das et al. (2002), catla should form the dominant

component of stocked fishes. The performance of rohu in reservoirs

especially in oligotrophic ones has not been very encouraging; the

growth of rohu has been found to be impressive in old reservoirs with

rich periphytic flora and fauna. The presence of aquatic vegetation is

particularly suitable for the growth of rohu in Baigul. The reservoir

also contains huge amount of detritus which is a good food resource

for nain. Hence, Indian major carps (rohu, catla and nain) should

form the dominant component of stocking in Baigul reservoir (Plate

19 and 20).

The length of fish seed at the time of stocking is critical in a

reservoir ecosystem to enhance their survival. A length of 10 cm and

above is ideal for quick growth and better survival. About 200-300

fingerlings per hectare may be stocked in large reservoirs and 300-

400 fingerlings in medium and small reservoirs. Average area

[(FRL+DSL)/2] or 60 % of the full reservoir area may be considered

for computing the stocking (Das et al., 2002).Stocking should be

done preferably during post-monsoon (September-October), when the

water level stabilizes and a spurt in zooplankton production occurs.

The Baigul reservoir is stocked with only 4-5 cm fry/fingerlings of

Indian major carps and perhaps it is the main reason for low

recovery of Indian major carps in the catches.

According to Pillay and Katiha (2007), natural breeding and

recruitment of stocked species varies from reservoir to reservoir.

Breeding is no guarantee for successful recruitment, as survival

depends on many factors. In general, natural recruitment is not

dependable in reservoirs, especially in those formed on tributaries,

which warrants stocking on a continuing basis.

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Plate 19 : Fishermen spreading drag net forharvesting in reservoir

Plate 20 : Fishermen with the catch

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The effects of water-level fluctuations on the reproduction of

fishes and the effectiveness of spawning in reservoirs are reported by

several investigators. The fluctuations of water level in reservoirs are

not always injurious; a deliberate drawdown is sometimes used as a

management tool in reducing stocks of undesirable fishes. Otherwise,

it may be used to establish favorable spawning and feeding areas for

desired species in the impoundments by a practical application of

managed fluctuations. Yakovleva (1969) stated that the fluctuations of

water level at specific periods possibly improve conditions and

increase the breeding efficiency of the fishes. A reduction of water

level in Volgorad reservoir, USSR, 1.5 m to 2.0 m from normal

preserve level in summer led to improving the breeding conditions of

fishes throughout the reservoir in the spring. Allen (1970) has

suggested that the water level in reservoirs must be maintained or

slightly increased during the spawning activity of desirable fishes. A

level between reasonable limits is maintained for about two to three

weeks or until the spawning is completed. This will avoid exposing the

eggs to an extreme low level with a risk of standing, or submerging the

eggs in too deep water. During summer season there is a large draw

dawn of water for irrigation purposes exposing a huge bottom area of

the lake. This season also corresponds with the development of the

brood stock. It is therefore suggested proper maintenance of the water

level in Baigul is very essential.

Though there is a system of mesh regulation, it is not generally

enforced. Strict mesh regulation should be enforced to prevent

exploitation of small sized species. Small-meshed nets could

however, be operated in certain seasons and in certain areas to

exploit the minor carps and minnows under supervision. The best

season for such operation would be the period of low water levels.

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The reservoir is leased to a contractor for a period of 3-5 years

for fishing. The highest bidding contractor is required to deposit 25

% of the money immediately and rest is deposited within specified

time given by the Department. The fishermen co-operative societies

taking part in bidding are given preference with 25 % concession.

As the reservoir is surrounded by several villages and colonies,

large scale poaching is a common feature. Attempts to prevent illegal

fishing by the fisheries personnel manning the reservoir or by the

contractor are violently resisted by the poachers. Therefore the

prohibition of destructive methods of catching fish, such as

explosives, poisons, snatches, fishing traps and the taking of fish in

places where at times they congregate has to be strictly avoided.

The fishermen are not the permanent residents of Tarai region,

but they are hired by the contractor from the eastern parts of Uttar

Pradesh, Bihar and West Bengal. They from small parties while

fishing and the income accruing as a result or total fish catch is

distributed among them. The monthly income of a fishermen ranges

between Rs. 2000 to Rs. 3000 per month.

The fishes caught at the reservoir reach different markets such

as, Kichha, Rudrapur, Pantnagar, Haldwani and Baheri through

various retailers-cum vendors. During the peak seasons, however,

the surplus quantity of fish catch, including the trash fish and small

prawns (dried), are transported to the distant markets.

In order to augment fisheries in Baigul reservoir, the state

department has also established a fish-seed production farm of

about 4 ha in the vicinity of this reservoir. The farm has the capacity

to produce 40 lac fish fry/fingerlings per year.

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Discussion

Reservoir fisheries are of considerable economic importance in

view of its vast resources, potential employment opportunities and

significance as a source of animal protein in our diet. According to

Jhingran (1989), the average fish yield from the reservoirs has been

extremely low during the last decade or so. This is obviously because

of the prevalent unscientific management practices resulting from

inadequate knowledge of the ecology and production biology of the

reservoir. The fish fauna of Baigul reservoir mainly consists of a rich

assemblage of minor carps and forage fishes, residual cat fishes and

some amount of major carps.

Fish fauna of Baigul reservoir comprised of 36 species of major

carps, minor carps, cat fishes, other fishes and weed fishes. Deorari

(1993) reported 35 fish species belonging to 21 genera of major

carps, minor carps, cat fishes and weed fishes in Dhaura Reservoir.

Balai (2007) recorded 40 species (28 genera) belonging 13 families

representing 5 orders in Jaisamand reservoir. Pathani and Joshi

(2007) identified 39 species of fish belonging to 14 families in Nanak

Sagar reservoir. Deorari (1995) recorded 49 fish species belonging 15

families from Nanak Sagar reservoir.

Rose et al. (2006) reported 22 species belonging to 7 families

contributing to the commercial fisheries of water bodies of Ajmer,

besides the large sized major carps, cat fishes and murrels in

substantial members. Singh et al. (2006) recorded 53 different

species belonging to 7 orders, 18 families and 34 genera from

Mahanadi River. Mohite (2006) recorded 31 species of fishes

belonging to 11 families in reservoirs of Solapur District,

Maharashtra. Sakhare and Joshi (2002) reported the

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occurrence of 20 fish species belonging to 4 orders in Bori reservoir

in Osmanabad district of Maharashtra.

Sultan et al. (2005) reported that the fishes of category A and B

representing major carps of all size groups behaved as a sub-

population; initially major carps were 10.62 % and 0.89 % for the

royalty regime. Category C fishes constituted nearly 38.71 % and

category D (49.77 %) in royalty regime. According to Balai (2007),

fishes of category-I contributed only (4.87 %), category-II (36.44 %),

category-III (15.92 %), category-IV (5.65 %), category-V (24.73 %) and

category-VI contributed (12.38 %) to the total fish production of

Jaisamand reservoir. In the present study class-A contributed

(6.43%), class-B1 (4.48 %), class-B2 (48.94 %), class B3 (7.41%) and

class-C (32.74 %).

Singh and Sharma (1991) have also recorded a large

population of weed fishes (40 %) in Nanak sagar reservoir. Deorari

(1993) recorded that the contribution of weed fishes ranged from

42.1 to 56.6 % in Dhaura reservoir in tarai region. Similarly, the

weed fishes contributed about 57 % of the total fish catch from

Tumaria reservoir in Udham Singh Nagar district (Rawat, 1991). The

weed fishes were also the most important component of reservoir

fishery in Baigul reservoir contributing 32.74 % to the total catch

during study period. The highest catch of weed fishes during winters

in Baigul may be attributed to low temperature in which these fishes

become more sluggish and caught easily. During summer, due to low

water level with high temperature, the fish catch was also high. The

aquatic weeds present in these reservoirs give better place for the

shelter of the weed fishes. Labeo gonius is most dominant fishery of

this reservoir which contributed 40.83 % in Baigul to the total catch.

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In the present investigation, the contribution of important

fishes/groups to the total fish production was calculated as follows:

Catla catla (0.58 %), Cirrhinus mrigala (2.09 %), Labeo rohita (2.17

%), Channa striatus (2.86 %) and other fishes (7.41 %). Balai (2007)

recorded monthly fish production of Catla catla as 49.59%, Cirrhinus

mrigala (6.74 %), Labeo rohita (1.68 %), Wallago attu (1.34 %),

Channa marulius (0.09 %) and other fishes (36.66 %) in Jaisamand

reservoir; major carps contributed 58.01 %, cat fishes 5.33 % and

other fishes 36.66 %. In the present study major carps contributed

6.43 %, cat fishes (4.48 %), minor carps (48.94 %) and weed fishes

(32.74 %).

As per the report of Sakhare and Joshi (2003) the potential

yield in the reservoirs of the districts of Maharashtra was estimated

at 5432.28 tones based on stocking level of 9733 lakh fish seed.

Deorari (1993) have observed the limnological features of the

Dhaura reservoir and indicated the possibility of a better yield of

fish. The moderate temperature of water (15.5ºC to 34.5°C) is

favorable for good growth of plankton. Similarly the pH values (7.2 to

8.6) are also favorable for a high rate of production. Baigul reservoir

with almost similar limnological profiles appears to be a favorable

habitat for fish growth. Rawat (1991) has reported an average fish

production of 21.30 kg/ha for Tumaria reservoir whereas Singh and

Sharma (1991) reported a production of 10-14 kg/ha for Nanak

Sagar reservoir; both reservoirs are located in the tarai region.

Development of fisheries in a particular reservoir directly

benefits a large number of people engaged in different activities. But

the fish production from these reservoirs is currently much below

than their potential. In Indian reservoirs, the fish yield ranges from a

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minimum of 2.5 kg/ha/yr to a maximum of 120 kg/ha/yr (Jyoti et

al., 2004). Some of the reasons for low yield are lack of

understanding of reservoir ecology, paucity of indigenous fish fauna,

faulty stocking and over exploitation. Sugunan and Sinha (2000)

emphasized that the fish productivity is related to morphometric,

hydrological and ecological features of particular water because the

yield is partly a function of biotic and abiotic factors influencing

production process of that ecosystem. The low fish production (28.34

kg/ha) from Baigul reservoir in 2004 could be attributed, among

other factors, to inadequate stocking, and irrational exploitation. In

Baigul reservoir the dominance of weed fishes might have interfered

with the growth of major carps. Besides competing for food and

space, the weed fishes provide a forage base for predatory cat fish

populations which in turn affect the recruitment potential of

economic carps as well.

The commercial fishing in Baigul is carried out mostly from

October to June, using traditional types of gears viz., gill net, hooks

and lines, drag net, triangular net, cast net and rod and line. The

fishing methods are designed to suit the local conditions and the

availability of different fishes in the reservoir. Some of the gears are

very specific and are designed for a particular species although most

of them take multispecies catches. The gill nets of different sizes

were effectively used during the periods of maximum water level to

capture valuable fish species like minor and major carps and at

fishes. Simultaneously, the hooks and lines were also used.

Drag nets were frequently used during May and June in

shallow areas with maximum catch efficiency. The majority of fishes

trapped by the drag net were weed fishes. Because of a very low

market price of the weed fishes caught by the drag nets, this gear is

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economically less viable. The highest catches of fishes (62614 kg)

were obtained by drag net during present investigation. The

contribution of drag net was 31.4 %. Triangular and cast nets were

operated in both the years, to catch small prawns, weed fishes,

major carps, minor carps and cat fishes. The contribution of cast

and triangular net was 14.28 % and 6.13 % and total catch was

28470 and 12227 kg in the Baigul reservoir. The use of rod and lines

were occasionally observed in summer for catching cat fishes. The

total catch of line and rod and hook line was 3988 and 2000 kg

during study period. The contribution of these nets was very low.

The majority of carps are omnivores feeding on plankton.

However, during larval stages zooplankton constitutes the main food

of all carps. Large populations of weed fishes must be depleting the

zooplankton population in the Baigul reservoir. Consequently the

lack of adequate zooplankton feed in the reservoir could be the major

factor for the low population of major carps in general, and Catla

catla fishery in particular as the latter is a zooplanktophagous fish.

Standing water bodies support a wide range of indigenous fish

species in the dry season and make a crucial contribution to fishery

production (Hoggarth et al., 1999 and Craig et al., 2004), with G.

chapra an important element of the catch. A similar observation was

found in the present investigation.

The causes of success or failure of particular fish or groups of

fishes in man-made reservoir are many. The changed,

ecomorphological features, availability of food, spawning success,

survival and recruitment of young to the fishable stock, employment

of suitable gears, season of fishing etc. are some of the factors that

contribute to the success or failure of the fishery. Bhatnagar (1963)

and Rajagopal (1969) have observed that the decline of fishery in

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Tungabhadra reservoir could be attributed to elimination of the

juveniles by the non-selective gears like shore seine and intensive

exploitation of natural stock by gill nets.

Jhingran (1991) has suggested that minimum mesh size

permitted for gill nets should not be less than 30 mm. According to

David and Rajagopal (1978) the gill nets with mesh sizes of 40, 50

and 70 mm were found to be more effective for commercial fishing in

Tungabadhara, Govind sagar and Hirakund reservoirs.

Krishnamurthy et al. (1964) pointed out that in Mettur and

Krishnarajsagar reservoirs, nets of larger mesh sizes (> 50 mm) were

used to catch the commonly occurring carps and cat fishes. Similar

patterns of use of gill nets have been observed in Baigul reservoir.

Deorari (1993) pointed out that in Dhaura reservoir, gill nets of

larger mesh sizes (> 50 mm) were used to catch the commonly

occurring commercial fishes viz. carps, cat fishes and some weed

fishes. Similar patterns of use of gill nets (50 – 75 mm mesh size)

have been observed in Baigul reservoirs.

In the present investigations, a sharp decline in water level

could have reduced the fishing season and lead to concentrated

fishing in summer, resulting in a total exploitation of the fishery. The

average size of carps and cat fishes, therefore, dropped below the

marketable size and the catch per unit effort was reduced. Thus,

fishery in the Baigul reservoir predominantly yielded small-sized

herbivorous forage fish and weed fish. The small fish are sun- dried

and marketed while the larger ones are transported to the nearby

markets.

Phytoplankton population in Baigul reservoir is represented by

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the extensive blooms of blue green alga, Microcystis aeruginosa

which is not directly utilized by the existing fish species. Obviously,

it does not enter the food chain as a result of which the zooplankton

population in Baigul reservoir is low.

The major aims of the stocking program in the reservoir are

biological control and balancing a depleted fish population.

According to Luu (1998) and Luong et al. (2004), development of

these stocked species relies on natural food within the reservoir

being ecologically sound and most likely more sustainable.

Consequently, the stocking needs to compensate for recruitment over

fishing, and to maintain the fisheries productivity of a water body at

the highest possible level (Welcomme, 1998). The findings of this

study and results of fish stocking in the reservoir are positively

related to changes in population.

The perusal of Table 7.4 and 7.5 reveals that relationship

between length and weight differed significantly (r = 0.871 to 0.957);

P < 0.01 in different fishes. Based on the coefficient of determination,

more than 90 % of variations in weight in Cirrhinus mrigala and

Labeo gonius and more than 80 % in Catla catla were attributable to

the variation in length in Baigul reservoir. Similar results were also

reported by Rao et al., (1991), De and Dutta (1990), Reddy and Rao

(1992), Singh (1994), Ujjania and Sharma (1999), Ujjania (2003) and

Rose et al. (2006) reported such relationship in certain freshwater

fishes. Ujjania (2003) also calculated them and observed ‘b’ values

from 2.853 to 4.06 and V values of 0.458 to 0.947 (length range 25

to 75 cm) from Surwania dam (small water) body of Banswara,

Rajasthan. Reddy and Rao (1992) reported growth parameters in

freshwater fishes. The results obtained in the present study are

comparable to those obtained the above studies.

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The growth exponent values of present study of Labeo rohita

were found comparable to those reported by Singh (1994) from lake

Jaisamand, Udaipur and Ujjania (2003) from Surwania Dam,

Banswara. The values of regression coefficients (0.1936 to 2.0577)

indicated that the growth rates of the fish were lesser than the cube

of their length. There are also reports of significant deviation of

length-weight relationship from the cube law in the fishes (Sultan,

1981; Gowda et al., 1987; Sivakami, 1987; Kulshreshta et al., 1993;

Pandey, 1995; Mitra, 2001 and Nath et al. 2006). Agarwal and

Saxsena (1979) recorded the value of 2.18 for Catla catla. Basheer et

al., (1993) observed ‘b’ value for Channa punctatus to be 2.9419.

Hasmana and Lal (1993) reported that the value of ‘b’ ranged from

2.5 to 3.9.

The fishery of Baigul reservoir is mainly comprised by medium

sized carp Labeo gonius. Weed fishes, catfishes and minor carps

comprise the rest of the fishery. Major carps contribute only 6.43 %

to the total fish catch. The dominance of weed fishes and the

presence of catfishes in reasonable amount are apparently the major

factors in preventing the development of major carps in sizeable

numbers. It is recommended that L. gonius should be stocked in the

reservoir to increase its production as it has good recruitment rate.Estelar

chapter vii reservoir fisheries estelar -...

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