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CONSERVATION OF AQUATIC

ENVIRONMENT

INTRODUCTION:

What is a resource?

Resource may be defined as a basic or primary material of the earth’s environment,

which neither is manufactured nor processed product. Natural resource is often considered as a

cultural appraisal. Because of the heterogeneity of human cultures, the value of resource may

vary considerably in time and space.

Categories of resource:

Two categories of natural resources are renewable and non-renewable.

(1) Renewable resources are living or biotic resources and other such as air, water and soil

which are closely associated with and affected by living organisms.

(2) Non-renewable resources are the non-living materials, minerals, fuels and similar things.

The basic inherent distinction between these categories of resources is that renewable resources

are able to reproduce or replace themselves or increase. For the renewable resources,

management involves, as a minimum, practices that will result in a sustained yield. With proper

forest management, trees can be cut every year, and yet there will always be trees in the future.

With good soil management, land will always be able to grow agricultural crops. One can leave a

breeding stock of a renewable resource and expect that with proper care it will generate the

original supply. Improper use will results in impairment or exhaustion with adverse socio-

economic consequences to man. Renewable resources are very much interrelated. For example,

if a forest is cut and proper management practices are not followed, not only the timber is

affected but also soil, climate, water regime, stream flow, fish life in water and animal life in

Dr. Subhendu Datta

Sr. Scientist

CIFE, Kolkata Centre

India

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land are adversely affected. Virtually living resources are so intimately connected together

forming a system that when you touch one you touch them all.

The non-renewable resources can neither regenerate nor replace themselves. Once these

are used, they are gone and there is no hope for replacement. In such cases either we will have to

find a suitable substitute or do without it. For non-renewable resources, good management is

chiefly wise use with the avoidance of waste. It is possible to string out the supply for a longer

period and to use the resource only for worthwhile purposes, but if it is used at all, it will

eventually disappear.

A broad environmental approach to conservation is a necessity because physical

environment, biotic resources and the people form the whole.

What is conservation? From the foregoing discussion, conservation is thereby defined as the management of

human use of the natural resources so that it may yield the greatest sustainable benefit to present

generation while maintaining its potential to meet the needs and aspirations of future generations.

Conservation embraces preservation, maintenance, sustainable utilization and restoration of

natural environment.

NEED FOR CONSERVATION OF FISHERIES RESOURCES (threats to aquatic biodiversity)

The aquatic ecosystems have been subjected to various forms of environmental stress,

during the past few decades. Most of such environmental problems are man induced and not

normal. Some of such problems are discussed below:

(1) Anthropogenic activities: Increased human activities in the catchment area of the various

aquatic systems have affected the natural processes of the systems adversely thereby threatening

the normal growth of biotic communities. This is the main cause of all other problems. Changing

land use patterns with increasing demographic pressure has been identified as a potential threat

to natural resources including aquatic systems.

(2) Water abstraction: Encroachment or abstraction of natural water bodies for various usage

such as agriculture, urban expansion, industrial growth and so on has become the order of the

day (Pl. see table 1).

Table 1. Water use (India) 2000 AD (in million cubic meter/year)

Uses Taken Consumed Returned

Irrigation 869 783 86

Power 150 5 145

Industry 35 10 25

Domestic 38 8 30

Total 1092 808 286

(Available water 1900 million cubic meter/year)

(3) Siltation: Siltation in natural water bodies is one of the major problems affecting the

biodiversity. Deforestation, intensive agriculture and other anthropogenic activities have

accelarated the pace of soil erosion causing higher rates of siltation. The resultant impact of (2)

and (3) is shrinkage in effective water area, both in terms of physical extension and water depth,

leading to stress on fish abundance and biodiversity. The original germplasm is available only in

river. Higher sedimentation of Ganga riverbed up to Patna from Haridwar due to deforestation in

the catchment areas reduces the productivity. The denuded catchment washing are responsible

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for textural deformities. Wetland ecosystems in the country are the worst sufferer and may be

cited as the best example. Siltation also results in destruction of natural spawning/breeding and

feeding grounds.

(4) Pollution: Water pollution has assumed a serious proportion in recent years affecting the

aquatic resources adversely, both physically as well as biologically. The natural water bodies

have been subjected to an indiscriminate ingress of domestic sewage, factory effluents, oil

spillage, waste heat and solid wastes. Agricultural runoff containing fertilizer and pesticides has

added to the complexities. The net out comes of such developments ends up in excessive nutrient

enrichments leading to Eutrophication and as a result impairment in biotic growth. Pollution also

affects adversely the migration, behaviour, many physiological processes, life cycle, disease

incidence, nutrition, food chain and genetic make up. It also affects fishing and fishery products.

Emergence of algal blooms or massive invasion of macrophytes is some of the symptoms

indicating habit imbalance and creation of unfavourable aquatic regime, non-conducive for

normal distribution of biota.

(5) Weed infestation: Presence of aquatic macrophytes in reasonable quantity provides stability

to an ecosystem. However, its excessive colonization assuming the status of weed is highly

detrimental to ecological balance and hence the aquatic biodiversity and fish abundance. In each

ecosystems locking of necessary nutrients in the hydrophytic chain takes place and the

phenomenon of survival for the fittest operates as a result of which many sensitive and fragile

organisms are either eliminated completely or at least become endangered.

(6) River course modification: Fish and their habitats are considerably affected by river valley

projects. The problems, which arise for fishery due to the construction of a reservoir, are

unfavourable physico-chemical conditions of water, unavailable food and feeing areas,

restriction of fish migration, destruction of spawning grounds, excessive growth of aquatic weeds

and change in the species composition of fish. The decline of hilsa fishery above Farakka barrage

is due to the higher pollution level in the middle stretch of Ganga and impaired migration due to

Farakka barrage.

(7) Irrational fishing: The fishery resource of riverine sector is being subjected to intensive

exploitation by traditional fishermen and other communities with disastrous consequences to the

biodiversity and fish abundance of the system. Due to the over-exploitation of the fish stock, fish

production of many river systems has decreased considerably. This along with various

destructive methods of fish catching e.g. use of unselective gears, catching of juveniles and

brooders, poisoning, dynamiting, electro fishing have resulted decreased fish abundance in the

conventional fishing grounds in inland open waters.

Example-1: Huge quantity of both commercial and non-commercial prawn and fish seed is being

destroyed (9139.5 to 19294.5 million in five months from February to June) during selective

collection of Bagda seed (P. monodon) from Sunderbans region. It is recorded that Bagda seed

constitute only 5-10% of the total catch of the nets.

Example-2: The indigenous carp L. fimbriatus and large catfish (M singhala and S. childreni),

which together contributed about 70 tones in 1963 reduced to insignificance due to over fishing

in Godavari river system.

(8) Introduction of exotic fish species: About 300 species of fishes have been introduced into

India for the development of sports and cultural fishery, control of weeds and aquatic insects and

for recreation. However, exotic fish species have been reported to affect the native fish fauna

adversely either directly or indirectly.

Direct effects:

Through predation: Example 1: Brown trout (Salmo trutta fario) introduced in Beas river

affected the snow trout (Scizothorax plageostomus) by predation, which was used to be major

fishery of the river.

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Example 2: In Punjab, Gambusia affinis, has reduced the population of many species as it has

natural tendency to feed on fish eggs and hatchlings.

Through competition for niche: Example 1: Introduction of silver carp in the Govindsagar dam is

responsible for drastic decline of catla catla, both being plankton feeder.

Example 2: Cyprinus carpio has also affected the Cirrhina mrigala due to common feeding

habit.

Example 3: In the Dal lake of Kashmir, C. carpio is attaining predominance over valuable

endemic mahseers and Schizothoracids, due to its early maturity, prolonged spawning period and

higher fecundity.

Example 4: Tilapia mosambica has wiped out most of the naturally occurring fishery of Puntius

spp, in the Amaravatty reservoir in Coimbatore district.

Both common carp and Tilapia spp also affect the culture fishery (in composite fish culture) due

to their prolific and wild spawning.

Indirect effects: (Through parasitism, niche modification and hybridization): Introduced fish

species may transfer and spread parasitic disease across the countries. In the lake Victoria, fish

introduction is reported to result in change in fish community, which ultimately caused

Eutrophication and algal bloom. Hybridization between exotic and native species has profound

effect on the genetics of original fish species.

(9) Insufficient legislation and willingness from Government: Legislations limiting effort,

declaring closed seasons and sanctuaries, regulation of mesh size and minimum size for catch

have not made any impact. Enforcing legislations in riverine fisheries is a daunting task for

obvious regions. Many fishermen communities are migrating with families from one place to

another in search of good fishing. Without the willing co-operative of fishermen, implementation

of various conservatory measures is extremely difficult. This is possible only with the

improvement of socio-economic conditions of fishermen community. They should be helped to

settle permanently at once place and weaned away from river fishing by providing alternate

avenues such as leasing the water bodies to them for reasonably long periods and developing

fisheries in tank and reservoirs. Present legislations on fisheries are not sufficient. For

management of fishery resources strong effective enforcement of existing regulation are needed.

However, most important is educating the user group of the resources and prosecutation should

be regarded as the best resort. The users of fisheries resources should be made familiar with

regulations and reasons for their imposition. However, all these things required good willingness

from Government, which is lacking at present.

All the above factors viz. water abstraction, deforestation leading to land and soil erosion,

pollution from domestic sewage and industrial effluents, intensive agricultural practices which

are responsible for sedimentation in river bed, weed infestation, eutrophication, destruction of

feeding and breeding grounds, river course modification, irrational fishing, insufficient

legislation and lack of willingness from legislator and politicians had led to the habitat

destruction of fishery ecosystem and thereby decline the fish abundance and fish production in

the conventional fishing grounds in inland open waters and pose severe threats to aquatic

biodiversity. All factors that are responsible for depletion of fishery resource are supposed to

intensify during 21st century. Such a scenario calls for proper management of fishery resources

without curtailing the economic growth. Hence, the need for conservation of fishery resources

arises.

CONSERVANCY MEASURES FOR RIVER AND RESERVOIR FISHERIES

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In view of the diverse nature of the perturbations causing degradation of inland fishery resources,

several strategies are adopted to stabilize the status of fisheries and to prevent their further

decline. These strategies include following measures:

1. Habitat manipulation

2. Fish population manipulation

3. Fishing regulation

4. Aquaculture

5. Research and monitoring

6. Public awareness

1. Habitat manipulation: It pertains to enhance the fish yield without actually increasing its

population or altering the community structure. It is required to provide favourable

environmental conditions in order to sustain fish life particularly of desirable species and to

increase the total carrying capacity of the water body. Habitat manipulation includes protection

and restoration/improvement of the habitat.

(a). Protection of the habitat: Native fish habitat can be protected by creating specific reserves

and refuges where habitat conditions are suitable for target species and which are protected from

further loss and degradation. Whenever possible, rivers should be protected from further

deterioration by checking development in the floodplains and catchment areas, dredging,

straightening and revetting of the banks of the main channels, siltation and disposal of untreated

sewage and industrial effluents.

(b). Restoration/improvement of the habitat: Lost or degraded habitat can be restored or

improved to increase fish abundance, diversity, and overall environmental quality. It involves the

management of water level and its flow, protection and improvement of water quality. In stream

habitat is improved by using devices that impound or modify the river flow (e.g. current

deflectors), provide cover and improve the spawning areas. Bank side environment (riparian

environment) of streams and rivers can be protected and restored by fencing the riverbanks to

prevent loss of vegetation through cattle grazing. Off channel habitats such as side channels,

back channels, ponds, marshes and wetlands, which are important habitat for fish, should be

recreated and restored.

Recreation of suitable hydraulic regime in the water bodies is also very important step for

the habitat improvement. In standing water bodies (ponds, lakes and reservoirs) water quality can

be improved by the application for fertilizers, control of aquatic vegetation, desiltation, aeration

etc. Large rivers are difficult to manage because of size, current and variations in discharge.

However, water quality can be improved through soil and water management in the catchment

area, treatment of domestic and industrial waters before their discharge and control of water level

by planned storage and release from reservoirs.

2. Fish population manipulation (Regulation of species): It pertains to the alterations in the

population density of fishes and their composition in the water body. It involves reduction of

existing population of undesirable fish species and stocking of individuals of new or already

established species.

(a). Population reduction: It is desirable when lake or pond becomes contaminated by species of

no value for angling or fish production. Even if this undesirable species are present in small

numbers, they are always a danger to the desirable fish species because of their prolific breeding

habits. Population of undesirable species is controlled through netting, trapping or electro

fishing. In cases, where these species are present in abundance and it is not possible to remove

them partially, then eradication of fish community is carried out by using toxicants, by draining,

or by both the methods.

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(b). Stocking: It is one of the most popular management techniques. It pertains to stocking or

introduction of fish in lakes and reservoirs where natural breeding has been restricted by dam

construction or where fishery are on the decline because of over fishing and poor water quality.

Stocking/introduction involves following practices:

Stocking of resident species to support existing stocks.

Introduction of species that might have been present but are threatened or eliminated by

anthropogenic activities.

Introduction of additional species native to the catchment area.

Introduction of additional species native to catchment area.

Introduction of exotic species to support or enhance its existing fishery

Creation of fish community in newly constructed or redeveloped water body.

Native fish translocation or introduction should be done carefully because it has adverse

ecological and genetic effects on the recipient native stock. No introduction should be carried out

where there is no apparent niche for the species. When a niche is vacant, the introduction of new

species can support large fisheries. In India, several indigenous fish species (Catla catla, Labeo

rohita, Cirrhina mrigala, Labeo kalbasu) have been transferred from one river system to another

in order to improve local fish fauna and to increase fish production.

3. FISHING REGULATION: Various methods are there to regulate the fishing such as:

(a). Mesh regulation: This implies the restriction on mesh size of the net. The use of mesh

selective gear usually entails a consideration of the mesh sizes to be adopted which can only be

viewed relative to the characteristics of the stock to be exploited. As has been described, the

fishing-up process usually involves a drift downwards in the mesh size, which needs

considerable enforcement of legislation to stop. If the objective of the fishery is to exploit only

the large species of the community, the imposition of mesh limits, which protect the immature

fish, is probably the only way to do it effectively. If the mesh size is lowered to take the

advantage of the smaller species, then almost automatically the larger ones will disappear. As

number of species caught increases progressively as the size of the mesh decreases. One possible

solution to the dilemma is the limitation of mesh size in major gears such as seine nets, gill nets,

etc. The minimum mesh size for nets permitted under Indian Fisheries act (1897) is 30 mm so

that smaller fish are not caught.

(b). Restriction on size of the fish to be caught: The minimum size of the fish to be caught

vary in different states from 225 to 305 mm so that every fish get a chance to breed at least once

in its lifetime. Restrictions are also imposed on the sale of undersized fishes.

(c). Restriction on types of gear (Gear regulation): Gear is often prohibited for reasons other

than those bearing directly on the fish stock. Long lines, for instance, are regarded with disfavour

by users of cast nets, which may become entangled in the hooks. Barriers, which completely

block the river channel, thus stopping fish migrations, are as likely to be removed for reasons of

navigation as for fisheries. However, there are restrictions on the type of gears to be used for

catching desirable individuals of commercial fishes. In Delhi, since 1948 restriction have been

imposed on fishing except with rod and line, hand line and long line from July 1 to August 30,

every year.

(d). Restriction on total catch: The total catch is related to the number of fishermen operating

on the river. Furthermore, the individual artisanal fisherman seems to have a limited fishing

power in that he is physically capable of removing only a certain quantity of fish from the system

in any one year. Because of this, the solution that seems most appealing in this type of fishery is

a simple restriction on the number of fishermen operating in a certain region. Such control of

access through licensing remains one of the most important managerial tools, particularly in

commercial or recreational fisheries. An allied technique, the fixing of catch quotas for

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individual fishermen poses enforcement problems in artisanal fisheries but may be practical

where industrialized practices which are more intensive are adopted.

(e). Closed season: This means restriction of fishing in certain periods. By nature, most river

fisheries have built-in closed seasons. In the floodplain this lasts from just after bank full on the

rising flood to peak floods when the fish population is too dispersed and individual fish are too

small in size for them to be readily available to the majority of methods of capture. In the

torrential upper reaches, flows are frequently too high for effective fishing during some of the

year. This effective closed season makes biological sense in that it allows the fish to reproduce

relatively undisturbed and for the young to grow to a reasonable size before they are exposed to

the fishery. However, restrictions on the overly heavy fishing of migrating adult fish to the

spawning grounds may be necessary in some places. Under Indian Fisheries act (1897), fishing is

prohibited during spawning season or during any season of poor quality of fish.

(f). Declaration of sanctuaries or protected waters: As fishing of the floodplain and river

channel in the dry season becomes more intensive, there is a risk of local over-exploitation of the

stock. For this reason, traditional fisheries have long been based on the designation of certain

floodplain depression lakes and reaches of the river as reserves, which remained unfished. In

larger systems, there are actually inaccessible areas, which from reserves as they are infrequently

exploited. As a management measure the conservation of certain areas is probably a wise move

and gains force when other pressure are being applied to the system. Under Indian Fisheries act

(1897), certain parts of the river and reservoirs, which constitute breeding and nursery grounds of

fishes are declared as sanctuaries and are closed for fishing for certain periods or all the year

round.

(g). Leasing of lakes and reservoirs in alternate years: This is done in order to give the fish

a chance to breed and to make up the natural stock of these water bodies.

(h). Prohibition on indiscriminate fishing: Fishing by means of fixed engines (fixed engine

means net, cage, trap or other contrivances fixed in the soil for tracing the fish) or construction of

weirs is prohibited.

(i). Ban on the use of explosives or poisonous substances: The restriction or complete

outlawing of fishing practices that are more destructive is most important. However, even such

methods may be appropriate in some circumstances. Poisoning of watercourse liable to damage

the stocks of fish when carried out in the main channel of the river, whereas its use for removing

fish from temporary floodplain pools or for eradicating undesirable species may be quite

permissible. Unfortunately was the use of poisons allowed in one habitat it would rapidly extend

to others. Under Indian Fisheries act (1897), for fishing use of explosives or poisonous

substances is prohibited [For details of the Indian Fisheries act (1897) and rules framed there

under in various states is given at the end of this chapter].

(4). Aquaculture: Aquaculture in lakes and reservoirs is the best way of utilizing the natural

resources, easing the pressure on capture fisheries and meeting the rising demand of fish.

(5). Research and monitoring: There is urgent need for more research on threatened fish

species to provide more information on their habitat needs, pattern of distribution and abundance

and various aspects of biology particularly breeding and developmental biology.

(6). Public awareness: Awareness should be created among general public, fishermen and

anglers about the value of native fishes, threats to fishes due to various human activities and

various adaptive measures to conserve the inland fishery resources.

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FISH BIODIVERSITY OF INDIA: PRESENT STATUS AND

CONSERVATION STRATEGIES

India is fortunate to possess vast and varied fish germplasm resources distributed widely in vivid

aquatic ecosystems. The aqua resources of the country include 2.02 million square Km area of

Exclusive Economic Zone (EEZ) of surrounding seas, more than 29,000 Km length of rivers,

about 1,13,000 Km of canals, about 1.75 million ha of existing water-spread in the form of

reservoirs, about 1 million ha in the form of tanks and ponds and about 0.6 million ha of

stagnant, derelict, swampy water-spread area.

What is biodiversity (Biological diversity)?

The most accepted definition, propounded at Rio Conference reads as:

“Biological diversity means the variability among living organism from all sources including

inter alia, terrestrial, marine and other aquatic systems and the ecological complexes of which

they are part; this includes diversity within species, between species and of an ecosystem”.

The definition in question suggests that biodiversity does not mean only the variability of

species and the conservation of threatened biota but it covers the whole range of natural

environment, from microbes to landscape. It is suggestive, therefore, that the conservation of

biodiversity must be viewed in its totality rather than restricting our observation to living ones

only.

Need for biodiversity: Maintenance of fish biodiversity along with the other biotic resources

can be viewed as prerequisite for the well being of even the human beings. While several reasons

can be ascribed to the need, there are four basic reasons for the maintenance of biotic resources:

1). Diversity or variability seems aesthetically pleasing in most environments. This is not only

true in general but often applies to the specific species frequently encountered by man.

2). There is often local pride in population or species that characteristic of an area. People often

become disturbed when some local form of animal is threatened by extinction and this concern is

an important region for conservation of at least some species.

3). It is generally agreed by ecologists and evolutionary biologists that species diversity and

genetic variability are necessary for the long-term maintenance of stable complex ecosystem and

species.

4). All the living being co-evolves for their mutual benefits during the evolutionary process in an

ecosystem. Any species getting extinct upsets the ecological balance to the detriment of each

species and community as a whole.

Indigenous fish biodiversity: About 2,200 finfish species have been recorded by the NBFGR

(National Bureau of Fish Genetic Resources), Lucknow form different ecosystems of India

which is 10% of the total fish species as more than 20,000 species (approx. 22,000 till date)

reported worldwide. Out of these 2200 species, about 400 species are commercially important

which includes cultured, culturable and wild species. The approximate break-up of fishes

inhabiting different ecosystems is given below:

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Table 2: Approximate break-up of fishes inhabiting different ecosystems

Ecosystems No. of fish

species

found

Percentage

of total

Examples

Cold water 73 3.32% Masheers, Trouts, Bolla, Kalabans etc.

Warm fresh water 644 29.27% Carps, Fresh water Catfishes,

Airbreathing fishes, Minnows etc.

Brackish water 43 1.50 % Mullet, Hilsa, Bhetki, Prawns etc.

Marine water 1440 65.45% Sardines, Marckerel, Bombay duck,

Tunas, Pomfrets, Marine water Catfishes,

Crustaceans, Molluucks, Pearl, Oysters,

Clams, Mussels etc.

Exotic fishes in Inland ecosystem: (a). Sport fishes: Brown trout, Rainbow trout, (b). Food

fishes – Mirror carp, scale carp, grass carp, silver carp, tilapia. (c). Ornamental fishes: gold

fishes, green sward fish etc., (d). Larvicidal fishes: mosquito fish, guppy etc.

ENDANGERED, THREATENED AND RARE FISHES:

The IUCN (International Union for Conservation of Nature and natural resources), the

major world agency for conservation of animals and plants, published lists of species globally in

the Red Data Book.

According to the classification followed in the Red Data Book the status of our vanishing

or vulnerable species of fish can be grouped under the following categories:

1. Endangered: Taxa in danger of extinction and whose survival is unlikely if the causal

factors continue operating.

2. Threatened: Taxa believed likely to move into the endangered category in the near

future if the causal factors continue operating.

3. Rare: Taxa with small populations that are not present endangered, but are at risk.

Present status: Due to various identified causative factors the fish genetic resources, in general,

have been suffering from stresses. Some of the conventional fishing grounds have been showing

dwindling trends, while some fish species are even endangered needing conservation. Based on

the deliberations during the National Seminar (April, 1997) and further sample surveys

conducted by NBFGR and other organizations, the Bureau has prepared a provisional of

Endangered (28) and Indeterminate (70) finfishes of India. The ecosystem wise status of their

germplasm resources as follows:

Table 3. A provisional list of Endangered and Indeterminate fishes of India

Number of species Ecosystems

Endangered Indeterminate Total

Cold water 6 13 19

Warm water 15 33 48

Brackish water 5 9 14

Marine water 2 15 17

Total 28 70 98

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The endangered fishes of India are listed below:

Coldwater fishes: Gymnocrypris biswasi,Schizothorax plagiostomus,S. progastus,S.

richardisonii, Tor putitora and T. tor.

Warm water fishes: Alia coila, Anguilla bengalensis, Bagarius bagarius, Eutropiichthys vacha,

Labeo dyocheilus, Notopterus chitala, Ompok bimaculatus, O. pabda, O. pabo, Pangasius

pangasius, Puntius sarana, Semiplotus semiplotus, Tenulosa ilisha (above Farakka),

Thynnichthys sandkhol and Tor khudree.

Brackishwater fishes: Etroplus maculutus, Lates calcarifer, odon-tamblyopus rubicundus,

Osteogeniosus militaris and Periophthalamus koelreuteri.

Marine water fishes: Rhiniodon typus and Platycephalus maculipinna.

Impact of stresses on fish biodiversity

Over-exploitation of the fisheries resources coupled with habitat destruction result in the

shrinkage of fish population. Due to these factors, a number of fishes in some conventional

fishing grounds are declining rapidly and some have become endangered too. As re-established,

genetic variation is the raw material in species populations, which enables them to adapt to the

changes in their environment. The number of relative abundance of alleles in a population, in

fact, is a measure of genetic variation or heterozygosity. Genetic variation, in turn, is a measure

of a population’s ability to adapt to environmental changes or stress and thereby to survive or in

other words, any loss of genetic variations leads to a poorer match of organisms to adopt to

environment, increasing the probability of their extinction. The associated severe genetic

problems in the small genetically effective population track the form of genetic bottleneck,

genetic drift and accumulation of homozygosity (Inbreeding depression).

Genetic bottleneck: Genetic bottlenecks effectively sample (although met necessarily randomly)

a few individuals from a larger gene pool resulting in a permanent population with less overall

genetic variability. Loss in genetic variability reduces the capacity of adaptation of the species in

the changing environment ultimately making it unfit to survive.

Genetic drift (Sewall Wright effect): Evolutionary changes in small populations produced by

random variation in allele frequencies and not by natural selection. The resulting mutant genes

generally confer no significant benefit on the organisms in which they occur and they may be

disadvantageous. It is a prolonged bottleneck leading to the repeated loss of variance until in

days ultimate form all loci are fixed with complete absence of genetic variance. It is seen that

longer the period of drift and smaller the population, greater will be the loss of variance.

Inbreeding depression: It is probably the most serious problem of endangered fishes with small

population sizes. Inbreeding is defined as the mating of individuals related to common ancestry,

that is, those that share more genes in common due to descent than individuals randomly selected

from the population. Inbreeding results in a predictable increase in homozygous genotypes

differentially affecting different traits.

CONSERVATION STRATEGIES FOR FISH GENETIC RESOURCES OF INDIA

Conservation of our entire fish genetic resources is a requirement and need of the hour. As far as

conservation of fish genetic resources is concerned, efficient and concrete strategies have already

been initiated in this direction at National Bureau of Fish Genetic Resources, Lucknow and a few

institutions which are being discussed under the following headings:

1. Checklist

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2. Catalogue

3. Endangered fish management

4. Germplasm characterization

5. Germplasm conservation

6. Androgenesis

7. Mass awareness programme

1. Check list: A checklist of Fish Genetic Resources of India consisting of 2,200 fish species

with information on taxonomy, habitat and distribution has been prepared by NBFGR and is

ready for publication.

2. Catalogue: A catalogue on Fish Germplasm Resources of India is being prepared. The

catalogue contains detailed information on taxonomy, distribution, bionomics, life history,

breeding behaviuor, fishery, aquaculture, genetics and conservation status.

3. Endangered fish management: The emerging field of endangered fish management has yet

to fully incorporate conservation genetics into recovery programme. Genetic aspects of small

populations must be considered at the outset of management programme in order to maximize

probability of their long-term survival and continued adaptability. Total genetic variance of a

species consists of within population genetic variance of a species consists of within population

genetic diversity and the differences found among populations, both types of variances should be

maintained to maximize adaptive flexibility of endangered fishes. Forces that erode genetic

variation include small population size, population bottlenecks, genetic drift, inbreeding

depression, artificial selection in captivity, and mixing of distinct genetic stocks.

Suggestions for genetically sound management of endangered fishes include genetic

monitoring of natural and captive populations, use of large numbers for captive breeding where

feasible, selective mating to avoid inbreeding where necessary, minimization of time in captivity

and separate maintenance of distance stocks.

4. Germplasm characterization: This includes ascertaining the characters that are polymorphic in

nature for inclusion in studies of genetic resources. Among the various cryogenic techniques,

NOR (nucleolar organizer region) banding of chromosomes has been useful in finding out

polymorphism between and within species. Distinct NOR patterns have been reported in seven

finfishes by NBFGR. A detailed chromosomal atlas of Indian fish species has also been

published by the bureau.

4. Germplasm conservation:

(a). In situ conservation: In situ conservation of fish as land races and wild relatives is useful

where genetic diversity exists and where wild forms are present. This is done through their

maintenance within natural or man-made ecosystem in which they occur.

Example: In Himachal pradesh, where the landing of prized mahseer fish is first declining, the

state Government has selected a few areas viz. Sedhpur and Machial in Mandi district, Renuka in

Sirmaur district and Baizanath in Kangra district where mahseer fishing is banned for its in situ

conservation.

In order to develop feasible strategies on in situ conservation of endangered mahseer (Tor

putitora and Tor tor), NBFGR has taken up studies along the Ladhiya River in Kumaon

Himalayas (U.P. hills). Population dynamics, the cause of decline in mahseer fishery and their

magnitudes are under investigation. The programme for ranching of artificially bred mahseer

fingerlings in the Ladhiya River is under way. A similar rehabilitation programme has also been

started by the CICFRI, Barrackpore for Hilsa (Tenualosa ilisha) in the Ganga river system.

(b). Ex situ conservation: In this. The species are conserved out side their natural habitats either

perpetuating sample population in genetic resources centers or in the form of gene pools of

gamete storage, germplasm banks (Gene Bank) etc. Establishment of gene bank by cryo

preserved milt, eggs and embryos assures further availability of genetic materials of threatened

12

categories and for intensive breeding programme of economically important species. Long-term

cryopreservation of milt of endangered as well as commercially important species like Tor

putitora, Tor khudree, Labeo rohita, Cyprinus carpio var communis and Salmo gairdneri

gairdneri has been achieved by NBFGR. How ever, work is in progress for the development of

technique for cryopreservation of egg and embryos of fishes. NBFGR is going to set up a gene

bank with cryopreserved milt of commercially important and endangered fish species during the

current five-year plan itself. Further, the Bureau is also going to establish resource centers to

cater the needs of marine, brackish water and cold water ecosystems where breeding strategies of

endangered species are envisaged.

(c). Entire biomass conservation: This implies the preservation of entire animals and plants of

a particular area. Marine ecosystems are being tempered with through commercial fishing,

navigation and technological advancement, which are detrimental to most habitats and

ecosystems. The National Marine Parks, which are being established in Indian islands of

Laccadive, Palk Bay and Kutch are in the line of entire biomass conservation and appears to be

the only pragmatic approach. This type of preservation will be extremely important in slowing

the rate of species extinction.

5. Androgenesis: It is sophisticated technique of biotechnology for production of the fish from

male genome only avoiding the maternal genetic contribution altogether. Androgenesis is done

by the destruction of female nuclear genome before fertilization and restoring diploidy by

temperature stock. Even if an endangered fish gets extinct and 9its milt is available in the gene

bank, it would be possible to reconstitute the fish from cryopreserved milt alone by employing

this technique. So far, androgenetic progeny has not been reported from any Indian fish. NBFGR

has, however, initiated work in this direction.

6. Mass awareness programme: The success of environmental protection and biodiversity

conservation efforts ultimately depend on the reaction of mass and participation of local public.

NBFGR has lunched massive mass awareness campaign along the Ladhiya river catchment in

U.P. hills for conservation of endangered mahseer. Three mahseer conservation committees have

been constituted in upper, middle and lower stretches of the river involving villagers, fishermen,

students, Yuvak Mangal Dals, Gram sabha members and officials. A series of lectures,

discussions and poster displays are being arranged by the Bureau in the Ladhiya and Sharda river

catchments (Kumaon Himalayas) from time to time.

LIMITATIONS OF THE CAPTURE FISHERIES

Constraints of the open systems:

An open ecological system is characterized by the continual inflow of energy and materials

which if balanced results in a steady-state condition. Therefore, availability of solar energy and

nutrients and an interaction between the two are primary constraints on a production system. The

factors, which limit the availability of energy and nutrients or modify it in various ways, are

climatic edaphic conditions, the former influencing the latter condition and together they

determine the nutrient availability and transport. Climate influences the length of the growing

season by affecting photosynthesis. Wind velocities determine the degree to which

autochthonous nutrients are recycled, and precipitation influences the degree of nutrient leaching

of the water body. Edaphic conditions govern the watershed in supplying nutrients and trace

elements in sufficient quantities for organic synthesis.

The fishing intensity along river courses varies from stretch to stretch depending upon a

variety of factors like current velocity, terrain of the river led, accessibility and the general

productivity of the water.

13

Factors influencing fish yield:

Many factors which influences the fish yield from inland capture fishery resources are described

below:

a) Biological and ecological studies have revealed that the fish communities are very sensitive

to flood regime because of their dependence on the seasonal floods to inundate the grounds

needed for feeding and breeding. Any change in the pattern and form of flood curves results

in the alteration of fish community structure.

b) Another characteristic feature of a river system is the nature of the input governing the

productivity pattern. In the upper stretch of the rivers, such inputs are mainly allochthonus

but in the potamon region encompassing the flood plains the major inputs are silt and

dissolved nutrients. There is a gap of knowledge on the relationship between these inputs

and energy flow and productivity trends in these systems.

c) The intensity of fishing, nature of exploitation and species orientation are the characteristic

of the artisanal riverine fisheries and are governed by:

i) Seasonality of riverine fishing activity

ii) Unstable catch composition

iii) Conflicting multiple use of river water

iv) Cultural stresses leading to nutrients loading and pollution

v) Lack of understanding of the fluvial system and infirm database

vi) Fragmentary and outmoded conservation measures lacking enforcement of machinery

vii) Inadequacy of infrastructure and supporting service

viii) Affordability and palatability

ix) Socio-economic and socio-cultural determinants

x) Inland fisheries was struggling to come out of the old fashioned style to a more rational

and scientific style

xi) Construction of dams has been the cause decline and damage to several regionally

important fisheries.

xii) Discharge from industrial establishment into Inland water bodies is polluting the water

in very serious apportions and is damaging the fish population tremendously.

xiii) Age-old practice of indiscriminate fishing of fingerlings and juveniles, supporting

local, seasonal fisheries, especially in breeding or nursery grounds, have been doing

enormous damage, and needed effective controls for conservation.

xiv) Likewise, time-old practice of sewage disposal into rivers was a menacing practice

causing heavy pollution.

xv) Great harm is also being done from agricultural wash coming to inland waters, which

brings to fish a very toxic principle of the numerous pesticides used in the agricultural

practices.

MANAGEMENT OF FISH STOCK

In principle, a fishery exploits a community, which in its unexploited state exists in some kind of

equilibrium with itself and with the environment. Under normal circumstances, such a

community may be assumed to tend to maximize its biological productivity and to continue to do

so when subjected to a reasonable level of exploitation. In such a situation, manipulation of the

community in all probability adds little or nothing to the yield of the fishery. There are two

14

circumstances, however, under which such interventions may be desirable. First, where the fish

community is lacking some element to exploit a food resource or habitat (i.e. a ‘vacant niche’) it

may be considered advisable to introduce one or more new species into the waterway. Second,

where the fish community as a whole, or some preferred element of it, is over fished a policy of

stocking may be adopted.

Introduction of New Species

In their unmodified condition, most rivers support fish communities that are sufficiently

diverse to fill most of the available trophic and spatial niches. Nevertheless some systems are

modified there is a tendency for certain indigenous species to disappear and for others to take

their place. This is most noticeable in impoundments where many rivers species, which are

adequately adapted to the new conditions are absent from the original fauna and to overcome this

additional species may have to be introduced from other river basins. In some cases,

introductions have been performed uncritically, and such species as the carp (Cyprinus carpio) or

Oreochramis mossambicus have themselves been blamed for degradation of the environment or

fish community structure. These and others, for instance Salmo gairdneri, have been implicated

in the elimination of sometimes delicate native resources, such as the unique faunal associations

of Northeast California or the endemic galaxiids and Protroctes oxyrhynchus from New Zealand.

Such cases often arise when there has been a contemporary disturbance of the environment,

which may have led to the elimination of the species in any case. The presence of introduced

species may thus be considered an advantage as they are able to colonise the disturbed habitats

and thereby maintain or increase species diversity. Fishes such as these, which are among the

main elements for intensive aquaculture, find their way into natural waters by accidental release

from farm ponds. Any introduction of anew species into the fish fauna of a river should,

therefore, be preceded by a very careful analysis of its anticipated impacts. The procedures for

such an analysis have been defined by EIFAC/CECPI (1983).

While widespread or impetuous transfer of new species is to be decried, the great success

of these same species under other circumstances points to the role of properly considered

introductions. Thus, most of modern aquaculture is founded on a comparatively small number of

introduced species, the tilapine cichlids have been invaluable in increasing the yield from Asian

reservoirs and the common carp supports fisheries in many highly eutrophicated streams.

Typical of such successful transfers is that of the Chinese carps into the Amu Darya river. A

combination of the macrophytes eating Ctenopharyngodon idella with the planktonophage

Mylopharyngodon piceus, Hypophthalmichthys molitrix, Aristichthys nobilis and Parabeamis

pekingensis colonised the system including the adjoining Kara Kum canal thereby laying the

basis for a rich fishery.

Stocking

Three main motives for stocking exist:

(a) Stocking to maintain production in the face of intensive exploitation

(b) Stocking to mitigate or compensate for adverse effects of some activity within the river

basin

(c) Stocking to increase production from individual components of the aquatic system,

usually through extensive aquaculture or ranching;

With the exception of trout streams and some sport fisheries in the temperate zones

systematic stocking of rivers to maintain and improve their fish stocks is not yet a

widespread practice. In fact, the tendency has been more for rivers to act as a source of

supply of juvenile fish seed for stocking into reservoirs and fish culture installations. The

15

requirements for successful stocking of salmonids have been extensively studied and rules of

thumb for numbers of fish and age of fish to be stocked have been derived for various waters

(EIFAC, 1982). The requirements and indeed the rationale for stocking with others species is

less well understood and in many cases, current practice appears arbitrary and

counterproductive. There is considerable room for the expansion of stocking as a tool for the

management of river systems.

WATER POLLUTION CONTROL LEGISLATION

The problem of water pollution has attached worldwide attention during recent past. Cases of

catastrophic water pollution can sensationalize the world and divert our attention from the subtle

effects of low-level water contamination, which is considered by many scientists as more

important. The control of water pollution has to be done at the source itself. Today we have the

technical means to reduce the level of pollutants in wastewater from point sources. In contrast,

pollutants from non point sources are difficult and expensive to control, because their

concentrations are normally low and their values enormous. These and other scientific, technical,

social, managerial and aesthetic problems pose great difficulty for legislating and administering

the control of water pollution. Yet, due to the worldwide awareness the concern for the

prevention and control of water pollution is reflected in the legislative activities all over the

world.

The United Nations conference on human environment held at Stockholm in 1972 was

the first attempt to echo the global concern about the environmental pollution and the

recommendations, of this conference are known as the Stockholm declaration. India has not

lagged behind in making legal safeguards for the control of pollution and protection of

environment. However, the Water (Prevention and Control of Pollution) Act, 1974, was the first

comprehensive legislation towards pollution control, there were plethora of many other

enactments dealing with the problems of environmental degradation especially the Water

Pollution. Some of our municipal and public health acts, particularly those for large cities,

conferred powers on our local bodies for controlling water pollution due to the industrial

effluents and for taking necessary enforcement action against the concerned industries.

Penal Provision

A substantial area of pollution is covered by the public nuisance, as defined in section,

268 of the Indian Penal Code. The Indian Penal Code provides three sections, namely Sections

268, 277 and 290 for the purpose of the control of water pollution directly or indirectly. These

provisions are quite inadequate to deal with the water pollution.

Criminal Procedure Code

The criminal procedure code, deals with the water pollution in a cursory manner.

Under section 133 of Cr. P. C., proceedings can be initiated to remove or to regulate pollution

amounting nuisance from a public place, public way, river or channel, which may be lawfully

used by public. Section 144 of Cr. P. C. empowers District Magistrate or any other Executive

Magistrate to issue a direction to prevent annoyance or injury to any person lawfully employed

or danger to human life, health or safety. Besides, municipal enactments also contain provisions

to deal with water pollution.

Under provision of the section 12 of the Factories Act, 1948 and rules framed there

under, the factories have to make proper arrangements for the disposal of effluents and State

Government can regulate it by making rules. It was experienced that several laws enacted earlier

to control pollution didn’t cover specific problems of water pollution. Therefore, the Prevention

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pf Water Pollution Bill, 1969 was introduced in the Rajya Sabha. Later on, this bill was replaced

by the Water (Prevention pf Water Pollution) Act, 1974. The Act tries to control pollution by

lying down, standards through the Central and State Boards for the prevention and control of

water pollution.

Structure of Boards

The Central and State Boards established by the respective Governments for

performing the functions assigned to them under the Act are autonomous corporate bodies.

Sometimes, pollution of some major rivers may require unified studies and operations in

different stretches falling under two or more states, the Act provides for the constitution of joint

Boards for such States or Union Territories in accordance to the agreement between the

respective Governments.

Function of the Board

The main function of the Central Board shall be to promote cleanliness of streams and

wells in different areas of the states and to plan and execute nation wide programme for the

prevention, control or abatement of water pollution. State Boards shall plan a comprehensive

programme for the prevention; control or abatement of pollution streams and wells in the states

and to secure the execution thereof. Apart from advising the Central Government on water

pollution matters, the Central Board has the overall responsibilities to:

a. Coordinate the activities of the state boards and resolve disputes among them.

b. Provide technical guidance to the state board and carryout research and investigation on

water pollution problems.

c. Organise the training of necessary technical personnel.

d. Prescribe standards for tolerance limits of the sewage and industrial effluents for a stream

or wells.

e. Organise, through mass media, a comprehensive programme, collect and publish statistical

data and prepare manuals codes etc. on matters relating to water pollution. The central

Board also performs the function of the Board in respect of Union Territories.

The field operations and the task of planning and enforcement for achieving the objectives of the

Act are primarily of the State Boards apart from advising the state Governments in this regard

are primarily, to:

i. Collaborate with the Central Board in organizing training programme, conduct of research

and collection and information relating to water pollution.

ii. Prescribe standards for sewage and trade effluents in the light of the quality of receiving

water.

iii. Evolve economical methods of treatment of these effluents having regard to the local

circumstances

iv. Evolve efficient methods of treatment, utilization and disposal of sewage and trade effluents

taking into account the tolerance limits of permissible pollution of a stream

v. Take enforcement action by requiring any person to construct new systems or modify

existing ones for disposal of sewage and trade effluents and prescribing effluent standards

to obtain information about the discharge of effluents into the stream, so as to perform its

functions.

The Board also has the power to take samples and have them analysed with or without notice to

the occupiers. The Board function is also to advise the State Government with respect to the

location of any industry likely to cause pollution. Both Central and State Boards are authorized

17

to established laboratories to enable them to perform their functions including the analysis of

samples of water or effluents. Thus, vast power has been given to the Boards to deal with various

aspects of water pollution problems.

Enforcements power and penalties: The act confers the following two categories of powers on

the state Board for taking action against the offences committed under the Act.

Enforcement Action

Under this action, a notice is issued to the owner by the Board requiring him to carry

out the specified work within the stipulated time. In case of non-compliance, the board can carry

out the work and recover the cost from the owner.

Penal Action

Under this action, the prosecution of the defaulter is carried out by the board in the

court of the presidency Magistrate or First Class Magistrate, getting him convinced for the

alleged offence and penalized through imprisonment or payment of fine.

The Water (Prevention and Control of Pollution) Cess Act. 1977

Though the Act confers powers and functions on the pollution Boards it is silent on

funds, which it leaves to state Governments. Due to the paucity of funds, the effective

enforcement of the Act was not possible by the state Boards, keeping this in view the

Government considered a proposal to impose a cess to meet the expenses of the Central and State

Boards. The water (prevention and control of pollution) Cess Act was passed in 1977 to help

augment resources and control of pollution.

The Environment (Protection) Act, 1986

The Environment (Protection) Act 1986 is a landmark legislation to provide a single

focus in the country for the protection of environment and to plug the loopholes in the existing

laws. The Act has come into force and rules under the Act were notified, from November 19,

1986. It is an ‘umbrella type enactment to ensure enforcement of several Acts and Regulations

already in existence concerning environmental pollution control and safety.

The Act confers powers on the Central Government to “take all such measures as it deems

necessary or expedient for the purpose of protecting and improving the quality of environment

and preventing, controlling and abating environmental pollution” Section 3(1). Section 5 of the

Act empowers the Central Government to issue directions for (a) the closure, prohibition or

regulation of any industry, operation or process and (b) the stoppage or regulation of the supply

of electricity or water or any other service. This can be done by the Central Government without

obtaining a court order. Section 6 of the Act empowers the Central Government to make rules for

the first time for: the standards of quality of air, water and soil for various environmental

pollutants (a) the maximum allowable limits of the concentration of various areas and purposes,

(including noise) for different areas (b) procedures and safe guards for the handling of hazards

substances (c) the prohibition and restrictions on the location of industries which are carrying on

the processes and operations in different areas (e) the procedures and safeguards for the

prevention of accidents which may cause environmental pollution and (f) for providing remedial

measures for such accidents.

It has now become mandatory for persons carrying on industry, operations etc. not to allow

emission or discharge of environmental pollutants in excess of the standards (Section 7 & 8).

Now the person responsible for the discharge of any hazardous substance in excess of the

prescribed norms will have to immediately intimate the concerned authorities (Section 9) and to

be bound, if called upon, to render all assistance, section 9(b). The penalties for defaulters in the

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Act are very stringent. Whoever fails to comply with or contravenes any of the provisions of this

Act, or the rules made or orders or directions issued there under, shall, in respect of each such

failure or contravention continues, which may extend to 5000 rupees everyday during which

such failure or contravention (Section 15(1). If the failure of contravention continues beyond a

period of one year after the date of conviction, the offender shall be punishable with

imprisonment for a term, which may extend to seven years.

The Ganga Action Plan

The Central Ganga Authority was constituted in February 1985 to evolve and oversee the

implementation of long term Ganga Action Plan for cleaning river Ganga. The Ganga project

Directorate has its regional offices at Lucknow, Patana and Calcutta. The types of schemes under

the Ganga Action Plan may broadly be classified as follows:

• Schemes for diversion of wastes waters including reservation/installation of interceptors and

pumping stations.

• Schemes for renovation or installation of sewage treatment plants including bio-energy and

other resource-recovering components as feasible.

• Other schemes for low cost sanitation facilities for river front development and biological

conservation.

To meet the objectives of the Ganga Action Plan, 250 schemes are to be taken up in 27 cities.

The focus in these schemes is on sewerage. The Ganga Project Directorate is also coordinating

the integrated eco-development research project in 18 universities.

FISHERIES LEGISLATION IN INDIA

BRIEF HISTORY OF INLAND FISHERIES LEGISLATION:

In India, the idea regarding the conservation of fisheries resources of the rivers was given

by Sir Arthur Cotton during sixties of the last century. He was in charge of a number of dams

and weirs being constructed at that tie on the rivers of South India. He feared that these structures

might adversely affect the local inland and coastal fisheries. The Government of India deputed

Dr. Francis Day (later Sir) in 1869, to investigate the freshwater fisheries and to draw up a

scheme with a view to institute a special and necessary legislation for better protection of the

fisheries of the country. Sir Francis Day, after a through investigation of many years published

two reports in 1873, viz, “Freshwater Fish and Fisheries of India and Burma”, and “The Sea Fish

and Fisheries of India”, in which he drew the attention of the Government to the widespread

slaughter of ripe fish, fry and fingerlings. He also pleaded the urgency to adopt legislative

measures to conserve the fisheries resources.

Nothing was done for many years. By 1888, the question again forced its way to the

front, and it was considered by the Agricultural Conference held at Delhi in that year. The

Government of India enacted the Indian Fisheries Act, which came into being in 1897 (as it

received the assent of the Governor General of India on the 4th

February, 1897).

RELEVANCE OF LEGISLATION IN INLAND FISHERIES:

The belief in the inexhaustibility of capture fishery resources has been belied since long.

Experience has shown that uncontrolled fishing and highly destructive devices of fish capture

19

deplete fishery resources and are followed by great economic distress. The purpose of fishery

regulations is to obtain maximum sustained yield of fish from waters and assure a recurring

bountiful harvest of fish without depleting the resources and wastage of fishing effort. The basis

of empirical regulations is the belief that every fish should be given a chance to breed at least

once. By way corollaries to this belief the following notions may be mentioned;

(i) that it is necessary to have a large number of spawners of a species;

(ii) that all smaller fish must be protected as the majority will mature and become

spawners

(iii) that it is very essential to protect fish during the spawning season.

INDIAN FISHERIES ACT OF 1897 AND RULES FRAMED THERE UNDER IN

VARIOUS STATES

The salient features of the Indian Fisheries Act, 1897 are as follows:

1. (i) This act may be called the Indian Fisheries Act, 1897.

(ii) it extends to the whole of (British) India, except Burma; and

(iii) it shall come into force at once.

2. Subject to the provisions of sections 8 and 10 of the General Clause Act, 1887, this Act

shall be read as supplemental to any other enactment for the time being in force relating to

the fisheries in any part of (British) India except Burma.

3. In this Act, unless there is anything repugnant in the subject or context –

(i) Fish includes shell-fish;

(ii) “fixed engine” means any net, cage, trap or/other contrivance for taking fish, fixed in the

soil or made stationary in any other way: and

(iii)“Private-water” means which is the exclusive property of any person, or in which the person

has for the time being an exclusive right of fishery whether as owner, lessee or any other

capacity.

Explanation:- water shall not cease to be “private water” within the meaning of this definition by

reason only that other person may have by custom a right of fishery therein.

4. (i) If any person uses any dynamite or other explosive substance in any water with intent

thereby to catch or destroy any of the fish that may be therein, he shall be

punishable with imprisonment for a term which may extend to two months, or with fine

which may extend to two hundred rupees;

(ii) in substance (i) the word “water” includes the sea within a distance of one marine league

of the sea-coast; and an offence committed under that subsection in such sea may be tried,

punished and in all respects dealt with as if it had been committed on the land abutting

coast.

5. (i) If any person puts any poison, lime or noxious material into any water with intent thereby

to catch or destroy any fish, he shall be punishable with imprisonment for a term which may

extend to two months, or with fine which may extend to two hundred rupees;

(ii) the local Government may, by notification in the official Gazette, suspend the operation of

this section in any specified area, and may in like manner modify or cancel any such

notification.

6. (i) The local Government may make rules for the purposes hereinafter in this section

mentioned and may by a notification in the official Gazette apply all or any of such waters,

not being private water, as the local Government may specify in the said notification;

(ii) The local Government may also by a notification, apply such rules or any of them to any

private water with the consent in writing of the owner thereof and of all persons having for

the time being any exclusive right of fishery therein;

(iii) such rules may prohibit or regulate all or any of the following matters, that is to say:

20

(a) the erection and use of fixed engines;

(b) the construction of weirs; and

(c) the dimension and kind of the nets to be used and the modes of using them.

(iv) such rules may also prohibit all fishing in any specified water for a period not exceeding

two years;

(v) in making any rules under this section the local Government may

(a) direct that a breach of it shall be punishable with fine which may extend to one hundred

rupees and, when the breach is continuing breach, with a further fine which may extend

to ten rupees for every day after the date of the first conviction during which the breach

is proved to have been persisted in; and

(b) provide for

(i) the seizer, forfeiture and removal of fixed engines erected, or used, or nets used, in

contravention of the rule; and

(ii) the forfeiture of any fish taken by means of any such fixed engine or net.

(vi) the power to make rules under this section is subjected to the connection that they shall be

made after previous publication;

(vii) (i) any police officer, or other person specially empowered by the Local Government in

this behalf, either by name or as holding any office, for the time being, may without an

order from a Magistrate and without warrant, arrest any person committing his view any

offence punishable under section 4 or 5 or under any rule under section 6 -

(a) if the name and address of the person are unknown to him, and

(b) if the person declines to give his name and address, or if there is reason to doubt the

accuracy of the name and address if given;

(ii) a person arrested under this section may be detained until his name and address have

been correctly ascertained.

It is in no doubt, that the implementation of the Indian Fisheries Act, 1897 proves to be an

essential criteria to preserve fish and fishery resources intact.

The Indian Fisheries Act, 1897, implemented in different states of India as follows:-

(a). Restriction on types of gear and Mesh: The minimum mesh size for nets permitted is 30

mm so that smaller fish are not caught. However, nets of smaller meshes are permitted to be used

in the in the marginal areas as in Tilaiya (Damoder Valley Corporation) and some reservoirs of

Andhra Pradesh and Tamilnadu. In Delhi, since 1948 restriction have been imposed on fishing

except with rod and line, hand line and long line or any other net less than 1.5 inch square mesh

from July 1 to August 30, every year. Mesh regulation is also observed in Manipur, Andaman

and Nicober Islands. In Assam, the sizes of gaps in bamboo fencing used for fishing have been

limited. Restriction have been imposed on the use of certain nets during specified parts of the

year, as well as on the mesh sizes of nets of Assam, Maharastra, M.P., Punjab etc. Form 1st April

to 15th

of June drag net of having mesh size of 2.2 inch are not allowed of any water body of

Assam.

(b). Restriction on size of the fish to be caught: Many states have prohibited the catching of

economical fishes having size below 25 cm (average) so that every fish get a chance to breed at

least once in its lifetime. Restrictions are also imposed on the sale of undersized fishes. In 1956,

Punjab state Government prohibited catching of rohu, catla, mahseer and mrigal smaller than

25.4 cm long. In Delhi, the capture and sale of these species below 20.4 cm in length has been

prohibited since 1948. The state of Uttarpradesh has prohibited, since 1954, the capture and sale

of fry and fingerlings of major carps, 5.1-25.4 cm in length from July 15 to sept.30 and of

breeders from June 15 to July 31 in the prohibited areas, except under a license issued by the

21

proper authority. In M.P. a size limit of 22.9 cm was imposed in 1953, for the capture of rohu,

catla, mahseer and mrigal.

(c). Closed season: Closed season is followed in Bihar, Madras, Jammu and Kashmir, M. P.,

Mysore In all large reservoirs, fishery is closed from June-July to end of September so that fishes

are not hampered during their spawning migrations and allowed to breed, at least, once. Fishing

is closed from 1st July to 15

th September in the entire state of Rajasthan. However, at Jaisamabad

(Rajasthan), there is no restriction with regard to mesh or the fish size and no closed season is

observed.

(d). Declaration of sanctuaries or protected waters: About 3.2 Km of river stretches below

the dams Mettur, Tungabhadra (Karnataka) and Gandhisagar (M. P.) have been declared as

sanctuaries. Sanctuaries have been declared in Assam, Bihar (river son above and below the

anicut at Dehri and Barun of the Shahabad and Gaya district) and Punjab (specified waters of

Gurdashpur, Hosiarpur and Ambala districts and near the specified bridges). Delhi, U. P., M.P.,

T.N., J& K, A.P. also observe restrictions on fishing in prohibited waters. In J & K, prohibition

has been imposed on the extraction of Hakreza, awter nuts, aquatic plants and gravel or stones

during the spawning season of fish in reserved and protected waters from November to February

except with the permission of authorities concerned. In Kerala, restriction has been imposed

against attracting prawn into private water except under license. In T. N. fishing is prohibited in

rivers Cauvery, Harangi, Sampaja and Barapole and their tributaries during the period march 15

to June,1. (In Cauvery river from Cauvery bridge to its confluence with Ellis Surplus channel). In

Haryana, conservation and developmental measures have been adopted in the portions of Uhl

river and Lambadug and their tributaries situated in the Mandi district, Pabar river (Rohru

upstream) and Bapsa river situated in the district of Mahasu.

(e). Leasing of lakes and reservoirs in alternate years: This is followed in Madhyapradesh.

(f). Prohibition on indiscriminate fishing: In M.P. Madras, Kerala, Haryana, Punjab and in

Delhi fishing by means of fixed engine or construction of weirs are prohibited.

(g). Ban on the use of explosives or poisonous substances: Various states such as U.P. (in

1948), A. P. (formerly Hyderabad, in 1956), Kerala (formerly Travancore-Cochin, in 1950), J &

K (1903), Karnataka (1931), Rajasthan (1953), Kerala (1950), Himachal Pradesh (formerly

Bilaspur, in 1951), Delhi (1948), Coorg (formerly Madras, in 1903) banned the use of poisons

and explosives for fishing. In Assam, the pollution of the water by retting of jute had been

prohibited since 1953.

Besides these, now some rules are enacted regarding prawn farming by Tamil Nadu

government. These are as follows:

(1). No shrimp farming can be done I the vicinity of the paddy field. The distance of shrimp farm

from the paddy field should be 2 Km.

(2). To monitor the aquatic pollution from all industries, “may be aquaculture”, Government of

Tamil Nadu has constituted monitoring committee at district level with collector as Chairman of

the monitoring committee and the members of the committee are from various department viz.

Agriculture, Forest, P.W.D., Fisheries and Pollution Control Board.

Constraints and suggestions:

(1). Fishing right: In some of the states fishing rights of notified water (river, canal, reservoir,

tanks, beels etc.) is not vested with the fishery department. These are based by other department

like reverine department (as in Assam state) and by irrigation departments as in Punjab and

Haryana). Fresh legislation should be made vide with fish rights of all these water bodies should

vested with states Fisheries department.

22

(2) Check at fish market: At present, there is hardly any legislation for the checking of sale of

rotten fish in the market. Fisheries department can be interested with the job of checking market

allowed on the sale good quality fish.

(3) Control of village ponds: At present, all the village ponds are under the control of village

Panchayat. Some times theses tanks are not leased out for fishery and they remain fallow. The

control of village ponds should be handed over to fisheries department and fishery official should

be made responsible for their development.

(4). Adoption of Fisheries legislations by all state Governments: Many of the states like West

Bengal (till recently) and other states in the North East region had no fishery legislation for the

conservation of the fishery resources. Some states have taken some measures but only in limited

area. All the state Governments should make laws and rules to conserve their fisheries resources.

(5). Creation of Fisheries legislation enforcement wing: States, which had adopted fisheries

conservation rules, are not in a position to enforce them for want of adequate enforcing staff.

Every state fishery department should create a separate fisheries wing in the department for

enforcing at least the existing rules and regulation. At present J & K and Punjab are perhaps the

only states that are having fisheries legislation enforcing wing.

(6) Replacement of the Indian Fisheries Act of 1897 by a new legislation: About a century ago,

the Indian Fisheries Act, was promulgated and introduced the country in 1897, for conserving the

fisheries resources. The act had a number of lacunae. It was applicable to notified public waters

but not to the private waters. The act never considered the social and economic conditions of the

fishing communities. The quarrel between the traditional boat fishermen and the trawler owners

in Goa in 1976 and in Kerala in early eighties resulted in considerable loss of life and property.

In inland areas, the recent dispute of traditional fishermen with feudal elements over fishing

rights of a stretch of river Ganga in Bhagalpur (Bihar) also led to many killings. The National

Commission on Agriculture of 1976 recommended the introduction of necessary conservation

and management measures and the replacement of the Indian Fisheries Act of 1897 by a new

legislation. However, nothing seems to have been done in this regard.

(7) Scientific management of aquatic environment: After Independence of the country, there is

huge increase in population, which led to rapid urbanization and industrialization in the bank of

river Ganga and other rivers. The indiscriminate discharge of domestic sewage and industrial

effluents without any treatment or with partial treatment in the rivers (Viz. Ganga), lakes,

reservoirs, coastal areas etc. has caused serious degradation of some of these ecosystems, so

much so that many rivers have become barren and support no fish life. Government of India and

some of the state governments have established Pollution Control Board and have introduced

antipollution laws but they are all toothless and ineffective.

Conclusion: It may be concluded that fisheries management is full of complexities. If one part of

the problem is tackled, its result may exacerbate the difficulties to other parts. However, there is

an immediate and urgent need to introduce appropriate legislative measures for the protection,

conservation and management of Inland fisheries resources of India based on latest biological

and ecological studies. Apart from these, the actual users of the resources, viz, the traditional

fishing communities must be consulted and their aspirations taken onto account before the

formulation of regulations. After all, when the fisheries legislation is viewed from the human

dimensions, there seems to be truth in the old axioms “ one does not manage fish, one manage

people”.

CONCEPT OF GENE , ALLELE, NUCLEOTIDE AND DNA

Purine and pyrimidine bases: Adenine (A) and guanine (G) are derivatives of purine (fig. 2) and thymine (T),

cytosine (C) and uracil (U) are derivatives of pyrimidine (fig 3).

23

Nucleoside: An organic compound consisting of nitrogen-containing purine or pyrimidine bases linked to a

pentose sugar (Ribose or Deoxyribose) e.g. adenosine, guanosine, thymine,uridine and cytidine.

Nucleotide: An organic compound consisting of nitrogen-containing purine or pyrimidine bases linked to a

pentose sugar (Ribose or Deoxyribose) and a phosphate group. (In short Nucleoside + Phosphate group), for

example, adenosine monophosphate (AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP).

Nucleic acid: A complex organic compound in living cells that consists of a chain of nucleotides. There are two

types: DNA (deoxyribonuleic acid) and RNA (ribonucleic acid) (fig 3).

Base pairing: For DNA, adenine pairs with thymine (for RNA adenine pairs with Uracil) and cytosine pairs

with guanine by hydrogen bonding. This is responsible for holding together the two strands of a DNA molecule

to form a double helix (fig 4).

Gene: In classical genetics a gene visualized as a discrete particle, forming part of a chromosome, that

determines a particular characteristic. A gene occupied a specific position (locus) on a chromosome. It may be

defined as the shortest length of chromosome that cannot be broken by recombination (by meiosis) or that can

undergo mutation. The gene as a unit of function may be defined as the sequence of nucleotides concerned with

a specific function, such as the synthesis of a single functional polypeptide chain or of, messenger RNA

molecule corresponding to a particular sequence of the genetic code. One or more of these structural genes,

coding for protein, may be associated with other genes controlling their expression.

Allele: One of the alternative forms of a gene. In a diploid cell, there are usually two alleles of any one gene

(one from each parent), which occupy the same relative position (locus) on homologous chromosomes. One

alleles is often dominant to the other (Known as the recessive), i.e. it determines which aspects of a particular

characteristic the organism will display within a population there may be several alleles of a gene; each has

unique nucleotide sequence.

Cistron: A length of DNA that contains the information for coding a specific polypeptide chain. A cistron

codes for a messenger RNA (mRNA) molecule; it does not include section of DNA. That may have noncoding

functions, code for ribosomal, or transfer RNA. In short, this is a unit of DNA or RNA corresponding to one

gene.

Nucleotide strands

Weak hydrogen bonds among the bases of two strands of nucleotides

Fig. 1. Backbone structure of nucleic acid

O

NH2

N

N

N HN

N

N H H2N N N

H

Adenine Guanine

Fig. 2. Purine bases

24

C

A

G

NH2

O

NH2

HN N HN

N N N

H H H

Thymine (DNA) Cytosine Uracil

Fig. 3. Pyrimidine bases

O - O

-

O- P O

-

- O P O

- Hydrogen

bonding

O

O

A T O CH2

CH2 O

H H H H

H

H H

H H H For DNA this hydroxyl group of ribose is deoxygenated and for RNA it is OH

O

O

-O P O

-

O

CH2 O G C

H H

H H

H

Fig.4. Backbone structure of DNA double helix

NOTE: Main activity of DNA is production of protein. Protein is made of amino acids. There are 20 amino acids.

According to the language of DNA the pattern or sequence of A. T. G. C., pairs in DNA determine the arrangements

of amino acids in a particular protein i.e. what kinds of protein will form. As the total number of amino acids is 20,

patterns or sequences of A. T. G. C. pairs in DNA are also 20. Therefore, the portion of DNA, which takes part to

produce a full protein that is called a Gene. Cells produce protein continuously through out the life period of man

and animals therefore, the importance of gene is enormous.

Findings of Human Genome Project: In the human body the structural map of DNA in all the 46 chromosomes of

a cell is called genome. There are 3 X 109 Crores of A-T-G-C base pairings in the whole genome. Different kinds of

genes in the DNA consist only 5% of the total genome. Rest is trash and called Junk DNA, which does not takes part

25

in the production of any kinds of protein. In this 5% area, there are 1-lakh genes. Again, within a gene, there are

trashes A-T-G-C base pairings or junk DNA. The difference between two people is due to difference in sequence of

A-T-G-C base pairings in a gene. This difference is not large, among 1000 base pairing 999 pairs are identical, and

this means two person are 99.9% identical in their genetic make up. They differs only in one base pairing out of

thousand i.e. for one person when it is A the other person may have G or C in that position and this makes the whole

difference. This difference is called SNP or Single Nucleotide polymorphism.

Reference books:

1. Conservation and production of natural waters. Eds R. W. Edwards and D. J. Garrod.

2. Environmental management handbook, IOS press, Seven-olof Ryding.

3. Ecology, Fisheries & Fish Stock Assessment of Indian Rivers. Eds. M. Sinha, M. A.

Khan and B.C. Jha. Bulletin No. 90, August, 1999.

4. Conservation of Natural Resources (2nd

ed) Gey-Harold Smith (ed)- John Wiley &

Sons. Inc. Chapt. 19. Fisheries for the future.

5. Environmental Conservation. R. F. Dasman, John Wiley & Sons. Inc. Chapt. 9. Water

and Fisheries.

6. B. K. Padhi and R.K. Mandal (2000). Section IV: Genetics in the management and

conservation of natural fish population. In : Applied Fish Genetics. p. 133-153. A

publication of Fishing Chimes.

7. W. S. Lakra (2000). Cryopreservation and biodiversity conservation. Part A. Chapter

9. In: Fish Genetics & biotechnology. p. 152-174. Publisher. CIFE, Mambai.

8. Kamaldeep Kaur and Asha Dhawan. (1997). Fisheries management and Conservation.

In Introduction to Inland Fisheries. Published by National Agricultural Technology

Information Centre, Ludhiana. p.221-232.

9. Kuldip Singh. (1989). Role of legislation in the conservation and management of

capture fisheries resources. In Conservation and management of Inland capture

fisheries resources of India. Jhingran, A.G. and Sugunan, V.V. (Eds.). Published by

Inland Fisheries Society of India. Barrackpore. p. 264 – 270.

10. P. Das. (1999). Fish biodiversity of India: Present status and conservation strategies. In

Ecology, Fisheries and Fish Stock Assessment in Indian Rivers. CIFRI Bulletin No. 90.

M. Sinha, M. A. Khan and B.C. Jha. (Eds.). Published by CIFRI, Barrackpore, August

1999. p.213-225.

11. V.G. Jingran. (1991). Regulation of population and exploitation. In Fish and Fisheries

of India. (3rd

edition). Published by Hindustan Publishing Corporatation (India), Delhi.

p.125-128.

Model Questions:

1. Write a brief assay on conservation of Inland fish genetic resources of India.

2. Discuss the Indian Fisheries Act of 1897 in relation to the conservation off fisheries.

3. Discuss the probable causes of decline of fish abundance in most conventional fishing

grounds in the Inland open waters of the country.

4. Explain how the fish genetic resources in general and the threatened fishes of India in

particular can be conserved for the benefit of the country.

5. Short notes: Closed season, Mesh regulation.

6. What are the various management measures to be taken for conservation of the fishery of

Ganga river system?

7. a). Describe in brief different threats to aquatic biodiversity.

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b). Write different fishing regulatory measures to conserve fishery resources.

c). What is androgenesis.

8. a). What are the impacts of stresses on fish biodiversity?

b). Write briefly different methods of germplasm conservation.

c). Describe the term endangared, threatened and rare species.

9. a). Describe in brief different conservancy measures for river and reservoir fisheries.

b). Describe the measures for management of fish stock.

c). Define biodiversity. What is the need for biodiversity?

10. Long Note on ‘Threats to aquatic biodiversity’.