3. Rural Aquaculture System

3.1 Production Systems, Facilities and Species
3.2 Extent of Rural Aquaculture
3.3 Socio-economic Aspects
3.4 Environmental Issues

3.1 Production Systems, Facilities and Species

Unlike the development of mono-culture of common carp (Cyprinus carpio) in Europe and elsewhere, culture of Indian major carps originated automatically as polyculture of catla (Catla catla) rohu (Labeo rohita) and mrigal (Cirrhinus mrigala). This was mainly because culture operation was entirely depended on the wild mixed seeds of carps, which were collected from the rivers during monsoon when they bred and farmers had no means to segregate them. Over the years, farmers learnt better husbandry practices. Scientific research and extension services further improved upon the package of culture practices.

Introduction of three other Asiatic carps namely grass carp, (Ctenopharyngodon idella) silver carp, (Hypophthalmicthys molitrix) and common carp in India as the component of Composite fish culture (Polyculture of Indian and Chinese carp) has resulted in enhancing the productivity of rural aquaculture (Sinha 1972, Sinha et. al 1973, Sinha and Ramchandran 1985). Carps are the main out put of freshwater pond aquaculture production system, which is photosynthesis dependent, most suited to poor resource farmers. The other most prevalent system is trapping and holding system in paddy field, which results in carp, catfish, prawn and shrimp harvest. Integrated production system of crop-livestock-fish has been very old but because of lack of good management skill and ready market of all the products it has not developed as expected.

The Table 6 gives a general picture of different aquaculture systems prevalent in rural India, the rate of production is directly dependent on the extent of input supply and the degree of management (Sinha 1990).

In order to enhance the natural productivity, pond water is fertilized with organic and inorganic fertilizer or wastewater is fed to the pond. Sometime biogas slurry is put in the water. The fish is normally fed with rice bran and oil cake. Formulated feed is given for higher production and pond water is also aerated or changed to support a very high biomass. But normally feeding with formulated feed or aerating the water are beyond the means of common farmers. Polyculture of Indian major carp alone or together with exotic carp as Composite Fish Culture are most popular which are undertaken as with or without fertilization and feed based systems.

Package of practices has been standardized for wastewater-based system, biogas slurry based system, and aquatic weed-based system (Ayyappan, Personal Communication). Cage culture, Pen culture, Running water fish culture are still in the infancy.

Table 6. Systems of production with varying input and degree of management and range of production (estimated)

S.No.	System	Species	Prevalence	Seed	Feed	Fertilizer	Aeration	Production range (kg/ha/yr)
1	Polyculture	Indian major carp	Very common	Fry	-	-	-	100-300
2	“	“	Very common	“	-	Little	-	300-600
3	“	“	Common	Fingerling	-	-	-	600-1000
4	“	“	“	“	-	Little	-	1000-2000
5	“	“	“	“	Rice bran and oil cake	“	-	2000-3000
6	“	“	“	“	“	Adequate	-	3000-5000
7	Composite fish culture	Asiatic carp	“	“	“	“	-	3000-10000
8	“	“	Not common	“	“	“	Plenty	10000-15000
9	Air breathing fish culture Mono or polyculture	Anabus testudineus Clarias batrachus & H. fossilis	Not common	High rate of fry stocking	Rice bran oil cake fish meal etc.	“	-	1000-2000
10	Prawn culture Mono Culture	M. rosenbergii M. malcomsonii	“	Post larva	Formulated Feed	“	At times	1000-2000
11	Carp and prawn polyculture	“ Asiatic carp and prawn	“	Carp fingerling and prawn post larvae	Rice bran and oil cake	“	-	300-500 of prawn 3000-5000 of fish
12	Rice-fish Culture in freshwater	Carp or/and catfish	“	Wild	-	-	-	100-300 of fish 1-10% increase of rice
13	Fish and livestock	Carp and pig	“	Fingerling 30-40 pig/ha	-	-	-	5000-6000 of fish and 1500-2000 of pork
14	Fish and bird	Carp and duck	“	Fingerling and Duckling 200-300/ha	-	-	-	3000-4000 of fish and 18000-18500 eggs and 500-600 kg of duck meat
15	Rice-fish culture in brackish water	Prawn and mullet and other brackishwater fish	Common	Wild auto Stocking	-	-	-	70-900 of fish and prawn
16	Shrimp culture	P. monodon P. indicus	Common	Post larva	Little	Little	-	1000-1500
17	“	“	Increasing number	“	Adequate formulated feed	Adequate	Adequate	3000-4500
18	“	“	Not common	Very high-density	“	“	Plenty	10000-20000

Culturable Species

The fresh water aquaculture resources in the country comprise of 2.25 million hectares of ponds and tanks, 1.3 m. ha of bheels and derelict waters, 2.09 m of lakes and reservoir as also 0.12 m km of irrigation canal, and 2.3 m. ha. of paddy field. Similarly, brackishwater resources are also vast and varied. The country has a number of lakes, most important of which are the Chilika and Pulicat Lakes and Vemband backwater. An estimated potential area of 1.42 million ha is available for brackishwater aquaculture. In addition, nearly 2 million ha salt affected soils exist, having a potential to be used for aquaculture.

Indian major carps catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala), kalbasu (Labeo calbasu) and Chinese carps like grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmicthys molitrix) and common carp (Cyprinus carpio) are the major fish species which are cultivated. Other less important and minor carps such as Labeo fimbriatus, Labeo gonius, Labeo bata, Oxygaster spp, Rasbora spp, Cirrhinus cirrhosa, Puntius kolus Puntius carnaticus, Puntius pulchellus, Puntius sarana, Puntius sophore, Puntius ticto, and Amblypharyngodon mola are also candidate species for culture since they have regional demand. But availability of seed, is yet a major constraint since the farmers do not know how to produce their seed. Similarly, Wallago attu, Mystus seenghala, Mystus aor, Pangasius pangasius, Rita pavimentata have regional demand in north and north western states but their seed production technology is yet to be perfected. Clarias batrachus, Heteropneustes fossilis and Anabas testudineus are in great demand in eastern and northeastern states. Culture of freshwater prawns Macrobrachium rosenbergii and M. malcolmsonii is getting highly popular under monoculture or polyculture along with carp and at times with Clarius or Heteropneustes.

The tiger prawn Penaeus monodon is the major contributor to the brackishwater aquaculture. Others such as P. indicus, P. merguiensis P. semisulcatus, Mugil cephalus, Liza parsia, Liza tade, Liza macrocephalus, Chanos chanos, Etroplus suratensis, Lates calcarifer are the prime candidate species for aquculture in brackishwater.

3.2 Extent of Rural Aquaculture

As the old saying goes “as you sow so you reap” appears quite apt for aquaculture. The whole system of production is a continuum and it is very difficult to strictly divide in different categories like extensive, semi-intensive and intensive culture systems mainly on extraneous feed supply or off-farm agro-industrial inputs. Similarly, it is difficult to segregate rural aquaculture from entrepreneurial aquaculture, which normally concerns with the intensive cultivation. In fact, many farmers who have been involved in subsistence level production increased their production over the years, with more inputs and better management skill, resulting in enlarging their resource base and gradually becoming entrepreneurial. For example, a farmer who used to stock fry in unprepared pond because of not knowing the technique of pond preparation and usefulness of fingerlings stocking, when came to know, followed the technique strictly and got better harvest and more income. Thus over a period of few years he could afford more inputs and intensified his management and became entrepreneurial. In fact, it is most desirable that the rural aquaculture should be evolved ultimately into entrepreneurial aquaculture and make the resource poor farmers entrepreneurial farmers. Such evolution is already taking place in rural India particularly in freshwater sector.

Shrimp aquaculture in India shows two distinct types of entrepreneurship, one comprised of resourceful farmers and small entrepreneurs another of large entrepreneurs or commercial enterprises. The former practices shrimp farming at low level of intensity which is not very capital intensive or input intensive but the latter undertakes complex commercial aquaculture requiring extensive facilities and management skill with reliable supply of seed and feed to achieve high production. Very high stocking density needs a considerable amount of freshwater and oxygen. It also requires sophisticated infrastructure to ensure that the products reach the markets in form and quality required by the consumers.

Thus, as per the definition of Edwards and Demaine (1997), fresh water aquaculture and shrimp farming under traditional and extensive systems only should be strictly viewed as rural aquaculture in India.

The status of rural aquaculture in various states is as follows:

Fresh water aquaculture

· Andhra Pradesh

Although the state has the distinction of possessing one of the oldest fish farms in the country at Sunkeshula, not much of rural aquacultural activities existed before seventies. However, persistent efforts of the state government, supported by the efforts of the ICAR through its All India Coordinated Research Project on Composite Fish Culture, under CIFRI and later supplemented by the Central Institute of Fisheries Education, resulted in development of entrepreneurial aquaculture in the state and within a very short period it has become the most economic farming practices in the state. The estimated production from aquaculture in the state is about 1,80,000 t. with some farmers producing as high as 5-7 t/ha/yr. and FFDA ponds showing an average production of 3500kg/ha/yr. But the FFDA has covered an area of about 4120 ha only of the total water area available in the state of about 5,17,000 hectares.

· Assam

The state is very rich in inland fisheries resources such as ponds, beels, oxbow lakes and derelict water bodies but people were more interested in fishing than fish culture. However, the efforts of the state government, and the work under All India Coordinated Research Project on Composite Culture, helped rural aquaculture to make great progress. Some of the farms started producing fish mainly carp @ 3-4 t/ha/yr. Derelict water is also getting gradually used for airbreathing fish culture, which are also preferred species in the state. In fact, this is partly because of the effort of the All India Coordinated Research Project on Air breathing Fish Culture.

About 23,000 ha of water area is available under ponds and tanks in the state of which 2930 ha has been covered under FFDA, with an average rate of production of about 1885 kg/ha/yr.

· Bihar

The state has a long tradition of rural aquaculture. The estimated production presently is about 130,000 tons of fish. It possesses about 95,000 ha of water area under tanks and ponds. The FFDA has covered about 23,343 ha with an average production @ 2075kg/ha/yr, producing about 1/3 of the total fish production from the state.

· Gujarat

The state has very little experience or tradition of rural aquaculture. However, it has picked up in recent years. Gujarat, which possesses about 71,000 ha of water area under ponds and tanks, has already covered 36,983 ha under FFDA producing on an average @ 1,225 kg/ha/yr. The total production is about 45,000 tons of fish.

· Haryana

The state had no tradition of rural aquaculture. However, through the persistent efforts and the right strategy of the state, backed by the All India Coordinated Research Project on Composite Fish Culture and then by CIFE, fish culture sector has done exceedingly well. The state has the distinction of becoming one of the most important states of India for freshwater aquaculture. This is by and large entrepreneurial aquaculture.

It is remembered that when WFP/FAO launched a rural development project in collaboration with the state at Mahendragarh district in 1984, it was difficult to convince the farmers to undertake fish culture. In those days fish was not supposed to be touched or cultured by many people in the state.

Now the FFDA farmers have achieved an average rate of production of 2,953 kg/ha/yr, which is one of the highest in India. The state possesses about 10,000 hectares of water area under ponds and tanks. Of which the FFDA has already covered 6807 ha. It is expected that the state will further intensify the aquaculture production.

· Himachal Pradesh

The state has hardly about 1,000 hectares of water area available for aquaculture. The FFDA farmers have covered about 300 hectares with an average production of 2 t/ha/yr. The state has no rural aquaculture a few decades ago, however, it is now getting popular and more and more farmers are taking up aquaculture.

· Jammu and Kashmir

The state is having a water spread area of about 17,000 hectares as ponds and tanks. But it had no tradition of rural aquaculture before. The FFDA has covered about 3,000 hectares with an average production of 2.5 t/ha/yr.

· Karnataka

Although Karnataka has 414,000 hectares of water resources mainly in the form of large tanks, rural aquaculture activity did not exist much before. However, persistent efforts of the state have resulted into FFDA covering an area of about 28,000 hectares with an average production of 1330 kg/ha/yr producing a total of 38,000 tons of fish. The future of aquaculture development will depend on extensive fish culture in large water bodies. Pen culture and cage culture systems need to be immediately popularized.

· Kerala

Fresh water aquaculture is becoming an important economic activity in recent years, however, the state has the distinction of being the cradle of rice-fish aquaculture in the country. The FFDA has covered an area of 2,309 hectares of about 3,000 total hectares available under ponds and tanks. The average production has gone up to 1,650 kg/hectare/yr. and thus producing a total of about 3,809 tons of fish.

· Madhya Pradesh

The state possesses 1,19,000 ha of water area under ponds and tanks. It has been deeply involved in popularizing rural aquaculture for a long time. It has the distinction of pioneering “bundh breeding” of carp in wet bundh. Through the persistent efforts of the state government and of the ICAR institute (CIFE) Powerkhera, the fish culture activity has been intensified and the state is now poised to take a great leap forward in rural aquaculture.

· Maharashtra

Rural fresh water aquaculture was not in vogue in the state. However it has been trying to popularize the same for the past three or four decades. In fact the state has the distinction of producing 10t/ha/yr. in early 70s under AIRCP on Composite Fish Culture at Hadapsar farm at Poona. The results of the project had a conducive effect on the popularization of fresh water aquaculture. The FFDA has already covered an area of 15,071 ha of the total of about 50,000 ha available as ponds and tanks in the state. The farmers are producing an average of 1240 kg/ha/yr.

· Orissa

The state has approximately 113634 hectares of water area available as ponds and tanks and has the tradition of freshwater aquaculture. The farmers are also very responsive to improve the management techniques. The FFDA has already covered 27,230 hectares of water area with an average production of 2,105 kg/ha/yr, contributing a total of about 57,319 tons of freshwater fish. The state has always had the best R&D support of the ICAR institute since the establishment of the pond culture division of the CIFRI in 50s, followed by the FARTC in late 70s and then from CIFA since 1986.

· Punjab

The state has no tradition of rural aquaculture but has emerged in recent years as one of the most advanced in the sector. The aquaculture production in the state is showing the highest average production in the FFDA ponds touching to about 4,100 kg/ha/yr. The FFDA has already covered 7,148 ha and it appears that there is practically no more fallow water left in the state. The total production of the state is about 29,306 tons of fish. The state has very good potential for further growth.

· Rajasthan

The state possesses 180,000 hectares of water area under ponds and tanks, but they are mostly large water bodies. It has no tradition of rural aquaculture but the FFDA has been able to cover 2424 hectares of water area, which is producing on an average @ 2030 kg/ha/yr totaling 4,920 tons of fish.

· Tamil Nadu

The state has rich resource of water available as ponds and tanks, which comprises a total of 224,000 hectares. Rural aquaculture has not done very well yet, although it has been giving emphasis for its development. The ICAR has supported the state efforts through its AICRP on Composite Fish Culture at Bhavanisagar during 70s. In recent years it has taken up a vigorous program of aquaculture development. Presently 5114 hectares have been covered under FFDA program with an average production of 1240 kg/ha/yr. totaling 6341 tons of fish.

· Uttar Pradesh

There has been an increase in rural aquaculture activity in recent years, although the state govt. has initiated its efforts in the late 60s. Big farms were established by the state administration and with the collaboration of ICAR, the AICRP on Composite Fish Culture and Seed Production was started in 1971 at one of the largest fish farms of the state located at Gujartal. The project was engaged in R&D activities and organized training programs for farmers and extension workers. The farm has the unique distinction of breeding grass carp and silver carp for the first time in the state in 1973 from the brood stock from composite fish culture pond. Presently, 80452 hectares of a total of 162000 ha have been covered under FFDA, which has shown an average of 2320 kg/ha/yr. with a total production of 186,648 tons of fish.

· West Bengal

The state has a long history of both freshwater and brackishwater aquaculture and its activities are being progressively intensified. Persistent efforts of the state government and supplemented by R&D support provided by ICAR in 70s through AICRP on Composite Fish Culture at Kalyani, Operational Research Project on Composite Fish Culture at Krishnanagar, National Demonstration Centres, and also though IDRC supported Rural Aquaculture Project, have gone a long way in successful development of rural aquaculture in the state. The state became surplus in fish seed production and farmers are becoming entrepreneurial. Presently, the FFDA has covered about 23,343 ha water area of the total available of 2,76,000 ha with an average production @ 3t/ha/yr and thus producing a total of 305,205 tons of fish.

· Northeastern States

Tripura has a long history of aquaculture but now all the Northeastern states have been giving considerable emphasis on the development of rural aquaculture.

These states have about 72,000 hectares of water spread under ponds and tanks and the FFDA has covered about 6,849 ha. The average production rate of the states is 1,928 kg/ha/yr. The total production is 1,328 tons of fish.

Brackishwater rural aquaculture

As it is clear from the tables 4 and 5, very little brackish water resources have been yet utilized, for example, Gujarat with 376,000 ha. of potential brackish water area suitable for aquaculture, is currently utilizes only 700 ha., leaving an unutilized resources to the extent of 98%. Similarly, utilization is very low in Maharastra (3%), Goa (3%), and West Bengal (8%).

3.3 Socio-economic Aspects

Access to public water bodies

Generally, landless and rural poor do not have the physical access to infrastructure facilities to undertake fish culture nor have the economic access to procure inputs. It is important that the government should formulate and implement legal framework for water rights and rights to water based resources so as to allow access and user rights to rural poor to undertake aquaculture in such bodies, which are by and large under public domain.

Subsidy and bank loan

They have also practically no asset to offer for collateral as security for obtaining institutional finance, which howsoever directed toward social goal of raising the lots of poor, serves by and large a commercial concept of lending and capital growth. It is therefore necessary to evolve mechanism to provide institution finance without physical collateral. Perhaps farmers´ certificate of successfully completion of training in fish culture from a government institution or their actual knowledge of fish culture may act as collateral.

Under the FFDA scheme the subsidy for tank reclamation and inputs, farmers get 25% subsidy whereas banks give 75% loan. But the amount of subsidy and loan are inadequate and farmers normally do not have the means to do adequate improvements or to buy required inputs. Procedural delay in obtaining this amount also creates problems to the farmers and at times they get frustrated and discouraged. The financial institutions also require that the Government release the subsidy before they release the loan and any delay in releasing the subsidy also delays the sanction of the loan and thus adversely affects production.

Lease of water bodies

Short duration lease of water bodies has been one of the main constraints. A study made by the IMA, Ahmedabad (1991) has shown that at the All India level 87.5% of the ponds were leased out for 5 to 10 years and 9.4% for less than 5 years. Merely 3% of ponds were leased out for more than 10 years. Individuals (30%) and partners (70%) took lease. Uncertainty attached in short duration lease discourages the farmers to undertake major renovation of the ponds and in the last year of the lease they normally do not spend on the inputs also. Banks normally hesitate to lend money in such cases.

Insurance

Insurance scheme is available in certain states, the IMA study (1991) showed that although the percentage of fish farmers who suffered is high, the percentage of farmers taking insurance and claiming for damage is vary small. This is mainly because of the hassles involved in keeping proper record, complexities of preparing claim certification and processing of the claim.

Marketing

It is interesting to note that during 1970s carps from Bangladesh were seen being sold in Calcutta markets but now fish from Andhra Pradesh is said to be sold in Bangladesh. Indian major carps are sold in the U.K markets particularly to those places where Indian population is sizable. However, secondary and tertiary markets are emerging for carps all over India. Yet, strictly speaking poor farmers have to sell their produce in the local market at a very cheap price or to middlemen. Proper mechanism is still inadequate to collect and disseminate information about the prices and markets. Wholesalers and commission agents have the key role in marketing fish for the farmers. However, the farmers share some time as high as 88% of the sale price in the local sale though, it is much lower in the outstation price. In the outstation sale the producers get about 60% of what consumers pay.

It is important that proper infrastructure is created for efficient marketing of aquaculture products. Government should invest more and also encourage private sector investment in market infrastructure development serving farmers and entrepreneurs.

Also creation and expansion of small-scale credit and saving institutions are necessary to facilitate development of aquacultural trading, transportation, and processing enterprises.

3.4 Environmental Issues

Loss of productivity and of water from freshwater ponds

Loss of productivity and of water from fallow ponds is of great concern. With the influx of adequate sunlight, aquatic ecosystem has the potential for a sustained rate of assimilation as high as 4 to 8g biomass/m2/day or about 30 tones of dry weight/ha/yr. If this productivity is not optimally utilized through aquaculture, it disrupts the aquatic environment and with continued nutrient run off from the catchment, results into eutrophication of the ecosystem, giving rise to algal bloom and water hyacinth and other obnoxious weed infestation. It is important to note that animal waste in the form of urine and excreta of 186 million cattle, 77 million buffalo, 45 million goats, 10.8 million pigs and 258 million poultry, continually find their way to aquatic ecosystem.

Aquatic ecosystem shows first sign of disruption when the amount of its oxygen production does not keep pace with its requirements. Scientific fish culture management improves the oxygen imbalance, otherwise, reduction stage sets in the ecosystem and considerable amount of hydogen sulphide and methane are produced.

Gradual appearance of the aquatic weed from submerged to emergent variety normally shows highly distressed condition of the ecosystem. Because of such weeds, increasing amount of silt is trapped, adversely affecting the total volume of the ecosystem and its carrying capacity. The most noxious weed like water hyacinth (Eichhornia crassipes) starts flourishing. In India 60-70% of inland water is presently infested with aquatic weed predominantly by water hyacinth.

Considering the capacity of growth and regeneration of water hyacinth, loss of water from the ecosystem is enormous. It registers 5% gain in weight every day. Two parent plants produce about 30 offspring in 23 days resulting in 12000 plants, with a total weight of 470 tons in 4 months (Barrett 1989). At least 80% of the plant body constitutes water i.e., 376 tons of water is contained in 470 tons of water hyacinth. Added to this, loss through transpiration is also considerable and many folds than normal evaporation from the aquatic ecosystem.

Although India is not among the 26 countries of the world which have been declared water stressed, it cannot afford to loose such an amount of freshwater from the ecosystem. In fact, it faces the challenges of water scarcity, the per capita availability of water in the country is 1/3 compared to two decades ago. Also in many places the water table has gone down from 8 meters to 48 meters now.

Thus, because of poor productivity management and eutrophication, aquatic ecosystems to a large extent are stressed and disrupted in the country. Wherever fish culture is taken scientifically, it improves and maintains the oxygen balance which is the lifeline of the ecosystem like that of any plants and animals. Thus fish is to be viewed as a major ecological player and fish culture as a major tool to improve and restore the aquatic ecosystem.

Environmental consequences of brackishwater aquaculture

Loss of mangrove

A great concern has been shown towards loss of mangrove in India because of shrimp farming. A rough estimate indicates that in Andhra Pradesh, the maximum loss of mangroves towards shrimp farming is 8,000 ha, accounting about 40%. Whereas Orissa and Tamil Nadu have lost respectively about 4,000 ha (26%) and 4,000 ha (26%). In West Bengal, a total of about 5,000 ha out of a total of 420,000 ha i.e., about 1.25% of true mangrove areas in the Sundarbans have been cleared for shrimp farms.

Loss of biodiversity

The shrimp culture industry initially relied heavily on wild seed, which resulted in a very serious threat to the natural populations of fish and shellfish in estuaries and rivers. It has been estimated that 18 post larvae of other species of shrimp and fish are sacrificed for every post larva of P. monodon collected from the wild. In West Bengal total annual harvest of wild shrimp seed was around 400 million, causing destruction of billions of other fish and shrimps. This is a colossal loss of biodiversity. However now the situation is improving fast because of the establishment of shrimp hatcheries.

Conversion of agriculture land

No detailed survey is yet undertaken to see the trend of conversion of agricultural land. But a rough estimate indicates that in Andhra Pradesh, about 4,000 ha (about 1.5%) of paddy fields have been converted into shrimp farms. This is followed by 2,000 ha (0.5%) in Orissa and 800 ha (0.8%) in Tamil Nadu (Babu Rao, Personal communication). The trend of such conversion is not very desirable, however it should not be viewed as an alarming situation particularly when the total coastal saline soil of the country amounts to 3.1 million ha. Further, there are reports that about 800-1,200 ha of salt pans have also been converted into shrimp farms in the State of Andhra Pradesh (Sinha 1996)

Salinization of portable water

Salinization of fresh water has been reported because of heavy consumption of ground water for shrimp farming. Freshwater wells have been reported to have turned saline in Nellore. Krishna and west Godavari districts in A.P.

Nutrient loading

Nutrient loading is yet another problem which has been encountered in semi intensive and intensive culture mainly because of high protein food. As much as 7.5% of N and 80% of P from feed are wasted and enter the environment. A rough estimate puts it as one ton of P. monodon production results in a loading of 57.31-2 kg of N and 13.0-24.4 kg of P in the pond, causing unmanageable self pollution.

Study undertaken by the National Environmental Engineering Research Institute (NEERI), Nagpur on the socioeconomic of the farmers in Andhra Pradesh and Tamil Nadu, suggested that the cost of the ecological and social damage has exceeded the benefits that have accrued to the farmers due to adoption of shrimp aquaculture activities. The validity of the findings needs proper evaluation. Many seriously doubt such inference. Thakur, Reddy and Prakash (1997) clarified many of the points raised regarding pollution being caused by shrimp farming. However, Government of India acted immediately and formulated the guidelines for sustainable aquaculture and also created a regulatory and monitoring body known as Aquaculture Authority of India to regulate and oversee the desirable development of aquculture (Yadav, Personal Communication).

It is important to note that paddy-shrimp culture and extensive system of shrimp farming are environmentally compatible. The problems start with intensification and multiplication of the farms without giving serious thought of the implications.

Loss due to sub-optimal production

Loss due to sub-optimal production becomes very important in the context of rural aquaculture. It should be viewed seriously and all attempts should be made to improve the productivity under traditional culture. For example, about 33,000 ha. in West Bengal is under the traditional method of shrimp cultivation, with a production range of 70-215 kg/ha/yr., averaging 186 kg/ha/yr. This is about 714 kg/ha/yr less than the production obtained in Kerala under traditional culture i.e., 900 kg/ha. Considering the total bheri area available in West Bengal this low average production amounts to loss of 23,562 tons equal to financial loss of Rs. 4,712 million.

Similarly, in the States of Karnataka, Maharashtra, and Gujarat the average production is in the range of 100-340 kg/ha/yr. Taking into account the area available in three States (Tables 4 and 5), the production/revenue loss is very significant. Thus, there is a strong justification to raise the shrimp production level under the traditional culture system in these states, so as to reach 900 kg/ha/yr as in Kerala.

Environmental Impact Assessment

As per the constitution of India, the aquatic resources management and exploitation except marine resources are under the state control. The Central Government however, provides overall guidance and suggestion for impact analysis of all the projects having an impact on the natural resources or on people’s habitat. Aquaculture projects should not violet any customary right and rights guaranteed by the constitution particularly about water resources. The people can challenge the execution of projects on grounds of violation of fundamental right guaranteed under Article 19(1) (g) of the constitution (Sinha 1996). Environment assessment (EA) is not yet mandatory for all aquaculture projects. The Ministry of Environment, Government of India on a case basis examines individual project on its merit to determine whether EA will be required. Certain states have Land Use Board or their own Environment Department, which review the project environmentally. But the Aquaculture Authority of India requires the EA of larger aquaculture projects. However it is important that mitigating plans must be made for any possible adverse impact.

Table 4. Status of state-wise shrimp farming in India

State	Production system (ha)	Resource	Water flow	Total area (ha)	Suitable area for shrimp	Salinity (ppt)	Stocking density (000s/ha)	Feeding	Cycle	Yield (kg/ha/yr)
West Bengal	Extensive (traditional)	Wetland bheries, seasonal & perennial	Saline tidal waters from estuaries	32,930 low saline (9,944 ha)	32,930	1-10	40-50	No feeding	2	70
				medium (15,613 ha)		10-20				214
				high (7,472 ha)		up to 37				84
Orissa	Confined and tidal gheries (extensive)	Wetland gheries of 2-50 ha each with constructed embankment	Saline tidal waters from estuaries	31,600	31,600	15-20	10-12	Natural food	2	250-450
	Confined ponds (semi-intensive)	0.2-0.5 ha ponds around Chilka lagoon	Monsoon - runoff			L-0-15 M-10-20 H - 20-32	20-25	MOC + rice bran. crushed land snail	2	730-1,025
	Intensive (case study) Paradeep	In two 0.33 ha well fertilized, manured & aerated ponds	Brackish water canal				15-30	Protein rich supplementary food (imported)	One (116 days)	3,000-5,000
Andhra Pradesh	Extensive (traditional areas 1-5 ha each)	Low-lying	Estuaries	63,663	17,006	L-0-15 M-10-30 H-15-32	15-30	Natural	2	250-500
	Semi-extensive	Slightly elevated areas, 1-2 ha	estuaries			15-20	30-75	Natural 50% Artificial 50%	2	500-1,500
	Semi-intensive	Elevated area, 0.5-1.0 ha each	Estuaries				80-300	Mainly artificial	2	1,500-3,000
	Semi-intensive (case study)	5 well aerated & fertilized ponds of 0.8 ha each	Creek			20-25	250-280	Artificial	2	4,000-5,000
Tamil Nadu	Extensive (traditional)	Backwaters lagoons & mangrove swamps	Pump fed tidal water	56,000	15,000	10-20	10-20	Natural	2	500-600
	Semi-intensive	- do -	- do -			20-45	40-50	Natural+ supplementary	2	500-1,500
	Intensive	- do -	- do -			20-45	200-300	Imported	2	3,000-8,000
Pondicherry	Semi-intensive to intensive (under developmental stage)	Brackish-water area	Estuarine tidal water	800	456	15-20		Supplementary
Kerala	Extensive (traditional)	Backwaters, perennial & seasonal paddy fields	Estuarine	12,987	12,987	5-20	Natural ingress from tidal water	Natural	2	839-903
	Intensive (case study) Kannur	0.12 h well aerated pond (fertilized, manured & limed)	Pump-fed estuarine waters			15-20	280	Imported	1	3,000
Karnataka	Extensive (traditional)	Khar & low-lying land	Tidal water	8,000	4,200	10-20	Natural ingress	Natural	1	340
Goa	Extensive (traditional)	Khazan paddy fields	Tidal water	18,000	12,500	15-18	- do -	- do -	1
Maharashtra	Extensive (traditional)	Salt pans	- do -	80,000	14,555	20-25	- do -	- do -	1	325

Table 5. State-wise details of shrimp farming in India

State	Estimated potential area (ha)		Year
			1990-91	1991-92	1992-93	1993-94	1994-95@
West Bengal	4,05,000	A	33,815	33,918	34,050	34,150	34,400
		P	12,500	13,800	16,300	16,500	25,00
Orissa	31,600	A	7,075	7,417	7,760	8,150	8,500
		P	4,100	3,800	4,300	3,300	4,800
Andhra Pradesh	1,50,000	A	6,000	8,100	9,500	19,500	34,500
		P	7,350	9,700	12,800	26,000	26,000
Tamil Nadu	56,000	A	250	480	530	1,050	2,000
		P	450	700	1,100	2,000	3,000
Pondicherry	800	A	Neg.	Neg.	Neg.	Neg.	Neg.
		P	Neg.	Neg.	Neg.	Neg.	Neg.
Kerala	65,000	A	13,000	13,145	1,3000	13,860	14,100
		P	8,925	9,500	9,750	11,500	12,000
Karnataka	8,000	A	2,500	2,542	2,570	2,600	3,500
		P	1,000	1,100	1,150	15,000	2,500
Goa	18,500	A	525	525	550	575	600
		P	245	300	350	400	450
Maharashtra	80,000	A	1,800	1,869	1,980	2,180	2,400
		P	800	920	1,050	300	400
Gujarat	3,76,000	A	125	231	360	475	700
		P	125	170	200	500*	700
Total	11,90,900	A	65,100	68,227	70,700	82,540	1,00,700
		P	35,500	40,000	47,000	62,000*	74,850

	*	Apart from this 3,000 tonnes of freshwater prawns are produced from the farm in Gujarat State.
	@	Estimates
	A	Area under culture
	P	Estimated production

Source: MPEDA