Annex II Country Reports

Annex II-5 INDIA (Cont.)

IV. Tamil Nadu

In Tamil Nadu, there are extensive backwaters, lagoons and mangrove swamps covering an area of 56,000 ha. A macro-level survey has indicated that about 15,000 ha of low-lying areas adjacent to brackishwater areas may be suitable for shrimp farming. Tidal amplitude is less than one metre and hence, the farmers are adopting pump-fed systems. The concept of brackishwater aquaculture underwent a change when private companies and the corporate sector entered into shrimp farming in Tamil Nadu, pumping seawater directly from the sea and not from the estuaries or creeks. This boosted the potential for shrimp farming in the state. The Tuticorin region in the villages of Taruvaikulam, Pattanamaruthur and Ottapidaram in V.O. Chidambaranar District has become an area of intense activity based on the seawater pumping system. An Aquaculture Estate of about 120 ha is planned in the Taruvaikulam area by the Government of Tamil Nadu. Already more than 200 ha have been brought under intensive culture, mostly for P. indicus but also for P. monodon, by the private and corporate sectors. Production rates in these farms range from 3–8 tonnes/ha/crop. The Government of Tamil Nadu has also decided to develop a total of 1,000 ha in different districts for shrimp culture for the benefit of the socio-economically weaker sections of the society.

Table 13. Economics case study TASPARC farm for 2 crops in 1 year.

Another region of expanding shrimp farming activity is the coastal area of South Arcot and Nagapattinam-Qaid-e-Millet Districts. In this region extensive and semi-intensive farming are practised with P. monodon and P. indicus and production rates range from 0.5 to 1.5 tonnes/ha/crop. Some of the scientifically managed farms have obtained more than 4 tonnes/ha/crop of P. monodon, even under adverse salinity (45 ppt) conditions. Qaid-e-Millet District is expected to overtake other areas in Tamil Nadu shortly as a number of companies are presently establishing farms. The other coastal districts in Tamil Nadu are also witnessing development. With a 1,000 km coastline and relatively stable sea conditions, except for occasional cyclones, Tamil Nadu will be making fast strides in coastal shrimp farming. It is estimated that as at present about 2,000 ha have been developed for shrimp culture along the Tamil Nadu coast.

V. Pondicherry

It has been estimated through a macrolevel survey that the potential brackishwater area available for shrimp farming is about 456 ha (out of a total estimated area of 800 ha) in the Pondicherry and Karaikal region. The estuary in Yanam has permanent access to sea throughout the year. An experimental brackishwater shrimp farm at Chinnaveerampattinam on the Chunambar estuary with an area of 4 ha has been constructed by the Department of Fisheries. Similarly, another experimental farm of 4 ha has been constructed at Karakalacherry in Karaikal region. Karaikal region has relatively large areas of suitable land for shrimp farming as compared to Pondicherry. More than 100 ha has already been developed in Karaikal region. Dykes were constructed to prevent seawater intrusion into land, but now seawater is pumped into the ponds crossing the dyke.

At Yanam, near Kakinada, 50 ha of brackishwater land has been taken up for shrimp farming and 22 ponds of 1 ha each will be constructed by the Government and leased to fishermen and marginal farmers. In addition, the District Rural Development Agency (DRDA) is developing about 14 ponds of 1 acre each, to be leased to trainees covered under TRYSEM (Training of Rural Youth for Self Employment) programme.

VI. Kerala

Traditional shrimp culture has been practised in the low-lying backwater areas of Kerala since time immemorial. The system is of two types: (i) perennial fields where shrimp/fish culture is practised throughout the year, and (ii) seasonal fields where paddy is cultivated during the monsoon months (July-October) and the fields are inundated with saline water for shrimp/fish culture for the rest of the year. The area under culture is shown in Table 14.

Table 14. Area under traditional shrimp culture in Kerala State.

There has been a steady growth in the area of culture from about 4,000 ha in 1960 to 13,000 ha in 1990, and 81.6% of the total shrimp culture area at present is in Ernakulam District. Vypeen Island near Cochin accounts for a very large concentration of both perennial and seasonal fields. Soon after the paddy harvest in October (the variety is called “Pokkali”, and hence the fields are called Pokkali fields), the bunds of the fields are strengthened and sluices are installed. The fields vary in size from less than 0.5 ha to more than 10 ha. While the paddy crop is grown by the agriculturist owning the land, the field is subsequently leased out to shrimp farmers for a period of 5 months, from mid-November to mid-April. The lesee prepares the fields by repairing the bund and fixing a sluice gate for regulating flow of tidal water. The paddy stumps and straw left behind in the field are not removed, but allowed to decay there to form a good organic manure for shrimp culture. Stocking is done by letting tidal water and juvenile shrimp into the fields at high tide. They are attracted to the field by keeping a light at the sluice gate during the night. When the tidal water starts receding during low tide, a closely tied screen made of split bamboo is inserted across the sluice gate and water alone is let out trapping the juvenile shrimp in the field. This type of entrapment is continued at every high tide throughout the period of operation.

Harvesting starts from mid-December. This is done during the low tides by operating a conical net fixed at the sluice gate. Sluice net operation is done at dawn and dusk for 5–8 days around every new moon and full moon during which the maximum tidal amplitude is experienced. The final harvesting locally known as “Kalakkipiditham” or “kettu kalakkal” is done at the end of the season by sluice net, cast net and hand picking.

The perennial fields, which are deeper and not suitable for paddy cultivation, are used for shrimp culture throughout the year. The methods of stocking and harvesting are similar to those adopted in the seasonal fields. The fields range 2–75 ha each in area. The area under the perennial system is only 15.8% of the total area under traditional culture. The average annual production of shrimps is 903 kg/ha in the seasonal fields and 839 kg/ha in the perennial fields. Higher catch rates are generally observed in the January-March period. The species of shrimps caught are Metapenaeus dobsoni, M. monoceros, P. indicus and P. Monodon. M. dobsoni contributes more than 50% of the catch.

Almost all of the brackishwater lands in Kerala are privately owned. Some interest is being shown now to improve production through scientific farming by stocking desired species, generally P. indicus and P. monodon, and supplementary feeding, with some pumping of water from the canals. Experimentally, higher production rates have been shown. The major problem in changing the traditional system into semi-intensive culture is the land use policy of prohibiting agricultural lands for other uses, except for the present licensing system for using the “Pokkali” fields for shrimp filtration, ownership pattern and leasing of lands. The estimated shrimp production from the traditional system is 9,500 tonnes/annum. A case study for shrimp culture in Kannur, Kerala is shown in Table 15.

Table 15. Case study: Shrimp farming in Kannur, Kerala.

Note: Final harvest data not available.

VII. Karnataka

Karnataka has two coastal districts, the Uttara Kannada and Dakshina Kannada, together having a coastline of 300 km. The total area of brackishwater land is 8000 ha, of which 4200 ha has been found suitable for shrimp farming (Table 16).

Table 16. Area suitable for shrimp culture in Karnataka State.

Karnataka has a traditional system of brackishwater aquaculture similar to the practices in Goa. The Khar lands are low-lying areas inundated during high tides, bunded and provided with sluice gates for the exclusion of saline water during high tide, so the lands can be used for agriculture during southwest monsoon. For paddy cultivation the lands get flushed with rainwater and the sluice gates are closed preventing entry of salt water. After the harvest of paddy, these lands are leased to private entrepreneurs who take up shrimp farming from December to April. The sluice gates are opened to allow entry of tidal water during high tides and closed during low tides. The shrimp and fish juveniles enter the fields and are harvested at intervals during low tides after they attain substantial growth. The annual yield of fish and shrimps in these Khar lands is 400 kg/ha/season, of which shrimps account for about 340 kg. The total production of shrimps and fish from these fields amount to about 600 t/year. P. indicus and P. merguiensis are the two main species in the region.

Since the availability of the Government land for leasing to the private entrepreneurs is limited, the Government has to make some policy decisions to amend certain Acts and Rules to enable use of agricultural lands and mangrove areas for shrimp farming. The Government is also taking steps to encourage private land owners to take up shrimp farming with the policy decision to set up hatcheries. Modern shrimp farms are being established at a very slow pace.

VIII. Goa

Goa has a coastline of 104 km and about 250 km of waterways formed by the major rivers Tirakol, Chapora, Mandovi, Zuari, Sal, Talpona and Galgibag. The State has around 18,000 ha of low-lying paddy fields or “khazan” lands which are located all along the sides of tidal rivers. Out of the 18,000 ha, about 2,000 ha are used for 2 crops of paddy, 12,500 ha for a single crop of paddy and about 3,500 ha are lying fallow without much productive use. In the 12,500 ha, paddy cultivation is carried out during June/July to October/November, and during the rest of the year the fields are lying idle. If such fields are flooded with tidal waters (as is done in Kerala “pokkali” fields) after the harvest of paddy in December, a fairly good harvest of shrimp is possible around April. The existing rules of land use do not permit inundation of these fields by tidal brackishwater but, a small portion of such land is flooded with salt water every year with due approval of the Government. The Goa Government has recently passed an Act to permit shrimp farming in khazan lands. The 3,500 ha of fallow, marshy land is available for conversion to shrimp farming. The North Goa District has 1,066 ha and the remaining area in South Goa District. Goa has had a traditional system of brackishwater farming since time immemorial and about 500 ha with maximum concentration in the taluks of Bardez, Tiswadi, Salcete and Ponda, is occupied by this system. The systems can be considered under following categories:

1. Permanent farms (Traditional): These are situated very close to the estuaries or creeks. Wild stocking with all varieties of fish and shrimp is carried out using tidal waters. Harvesting of marketable size shrimps is a continuous process.

2. Shrimp infiltration in “khazan” lands: The khazan farm consists of a narrow or wide strip of land alongside the river or creek, protected from the tidal water by embankment bunds. Sluice gates are provided on these bunds to control the inflow and outflow of water from the farm. The sluice gate consists of 1, 2 or multiple collapsible doors which automatically close when there is a rise in water levels outside the farm and open when there is a rise of water inside. This enables prevention of an undesirable flow of water into the farm during high tides and draining of pond water into the river during low tides. There are numerous drains inside the farm which are used for raising fish and shrimps. Fishing is mostly carried out using the sluice gate net during spring tide periods. In certain khazan lands, after the paddy is harvested, the entire field is flooded for raising fish/shrimp and harvest takes place in April.

3. Salt-cum-fish production: Salt curing in salt pans takes place during February-May. During the remaining part of the year, fish/shrimps are raised in these fields partly by natural stocking and partly by supplementary stocking.

The Government has a 5 ha estuarine farm at Ela Dhauji for technology demonstration. A larger pilot farm each at Choraon Island (80 ha land area) was proposed but shelved due to environmental problems.

In the private sector a number of semi-intensive shrimp culture farms are under various stages of development. About 100 ha has been brought under shrimp farming.

IX. Maharashtra

The coastal marshy land in Maharashtra is estimated to be about 80,000 ha, of which 14,555 ha has been found to be suitable for shrimp farming. This area is distributed in different coastal districts as follows:

These are Government-owned lands and a policy has been enunciated to lease these lands for shrimp farming. Although there has been no traditional system of farming in Maharashtra, there have been sporadic efforts to impound tidal waters in salt pans and whatever shrimp and fish seed is trapped, is allowed to grow for 2–3 months. About 1800 ha of land is so far utilised and shrimp production is about 200–250 tonnes per annum at a low rate of 100–150 kg/ha. The Government has a pilot farm of 4.02 ha area at Ratnagiri where P. merguiensis culture is demonstrated to local farmers. A semi-intensive culture farm of 8 ha area exists at Asangaon in Thane District. A number of semi-intensive shrimp farms have been developed north of Bombay, adjoining Valsad District of Gujarat.

X. Gujarat

Gujarat has a coastline of about 1600 km and vast stretches of estuarine and brackishwater areas are formed by the perennial rivers Narmada, Tapti, Mahi, Ambica and Purna and several seasonal rivers. It has an estimated extent of 376,000 ha of coastal land. However, surveys have shown that suitable areas for brackishwater aquaculture are of the order of 7,500 ha, especially in South Gujarat in Valsad, Surat and Bharuch Districts. North Gujarat, Saurashtra and Kutch areas are not favourable for direct utilisation for shrimp culture at present. There is very little development of shrimp farming at present in Gujarat, except for a few small farms in Valsad District and the Government farm of 10 ha at Matwad. However, several training programmes for farmers and farm women have been orgainsed to instil an interest in shrimp farming. This has resulted in farmers and entrepreneurs applying for leases of Government land. As of 1991, 294 farmers had applied for land in Valsad District, of whom 51 have been allotted a total extent of 290 ha of land. The development was also hampered due to non-availability of seed, there being no commercial hatcheries in the State.

Rivers like the Par and Kolak in Valsad District, and Sena creek in Surat District are highly polluted by effluents discharged from the industries in Atul, Pardi, Vapi and Olpad which makes the ecosystem unsuitable for shrimp farming purposes. There is need to enforce proper treatment of these effluents before they are discharged into the rivers. The Government of Gujarat is engaged in preparation of master plans for vast areas in Baruch and Valsad Districts.

XI. Lakshadweep

A few brackishwater bodies are available in the island. Almost all the ponds are seasonal, except one at Kavaratti Island which has an area of 0.2 ha. The pond is used for retting coconut husk for the coir industry. The depth of pond varies from 0.5–1.0 m. It is proposed to stock the pond with P. indicus, P. semisulcatus and P. monodon seeds. No shrimp seed has so far been reported from Lakshadweep Islands. The experimental transport of wild seed (P. monodon and P. indicus) from Machilipatnam in Andhra Pradesh to the islands was taken up in 1988.

In March 1993, it was reported that a joint venture project on cage culture of Mediterranean seabass and seabream with imported seed will be taken up at Agathi, initially with 20 cages with a production rate of 50 tonnes/cage. In subsequent years, breeding of the above two exotic species will be taken up at Agathi itself for supply of seed for cage culture. It is understood that the Central Marine Fisheries Research Institute will monitor the project.

XII. Andaman and Nicobar Islands

A model shrimp farm of about 10 ha has recently been established under Government of India Ocean Development programme in Port Blair. It practises semi-intensive culture of P. monodon, transporting seed by air from the mainland of India.

5.1.5 World Bank Project

Since 1992–93, the Government of India has been implementing the World Bank assisted IDA credit project on Brackishwater Aquaculture and Inland Fisheries in the states of West Bengal, Orissa, Andhra Pradesh, Bihar and Uttar Pradesh. The brackishwater shrimp component is located in the coastal regions of the states of West Bengal, Orissa and Andhra Pradesh, situated in about 13 sites covering a land area of about 6,000 ha with a net waterspread area of about 3,800 ha. These sites are Bhairavapalem (150 ha), Interu (300 ha), P.T. Palem (690 ha), Impure (200 ha) and C.G. Palem (650 ha) in Andhra Pradesh; Bidelpur (490 ha), Narendrapur (400 ha) and Jagatjore and Banpada (450 ha) in Orissa, and Dadanpatra (300 ha), Digha (135 ha), Meendwip (1420 ha), Canning (300 ha) and Dighirpai (175 ha) in West Bengal. The inland fisheries component is situated in the states of West Bengal, Orissa, Andhra Pradesh, Bihar and Uttar Pradesh. The project includes over 130 reservoirs (Andhra Pradesh-51, Orissa-60 and Uttar Pradesh-22) covering about 46,000 ha, and about 60 ox-bow lakes in Bihar, Uttar Pradesh and West Bengal covering about 5400 ha.

The total annual production of shrimp from the project is estimated to be about 7,600 tonnes. Fish production is estimated to increase to about 7,800 tonnes (38% from ox-bow lakes and 62% from reservoirs). Employment and higher income would be provided for over 5,200 families in the brackishwater areas and for nearly 9,000 households in over 200 fishermen co-operatives. The development of shrimp culture area would be in clusters, using a model of 50 ha water area for each cluster. A total of not less than 70% of total water area would be ponds of 0.5 ha each, and the remaining 30% would be divided into ponds of 1 ha each. Each 0.5 ha pond would be leased to one family from the weaker socio-economic sections of the society. The remaining 1 ha ponds would be leased in block to one (possibly two) entrepreneur (s). While each pond would be managed by the respective lessee, the common areas and activities including water exchange and maintenance would be managed by the respective District level Brackishwater Fish Farmers Development Agencies (BFDA) on the basis of an annual service charge.

The inland fisheries project would provide the necessary finance for stocking and feed, and would introduce features that would improve the quality of co-operative functions, provide training and technical assistance through the District-Level Fish Farmers Development Agencies (FFDA). It would also promote association with NGOs which would be willing to work with selected co-operatives. Under the World Bank project, Environmental Assessment was performed during May-June 1990 and subsequently during June-July 1991. The positive and negative potential impacts were assessed as follows.

1. Brackishwater aquaculture development:

2. Ox-bow lake development

Based on their Environment Assessment, the World Bank project has incorporated a comprehensive Environmental Action Plan to establish (i) an Environmental Monitoring Plan to provide baseline information on the impacts on the environment, and (ii) an Environment Management Plan which would describe the management interventions that are necessary to directly mitigate possible negative environmental impacts from the project activities.

Some of the mitigatory actions proposed are:

1. A programme of mangrove afforestation to compensate for the forest cover that would be lost to pond and infrastructure in Meendwip Island in West Bengal.

2. A study on the hydrology of the lagoon of the Interu site in Andhra Pradesh in the likely context of its eutrophication due to daily water exchange and discharge of residual pond effluents; if the study proves the seriousness of the threat to the lagoon, consideration to be given to: (a) construction of a farm discharge canal between the lagoon and the sea; and (b) the construction of wet lands within the lagoon to act as nutrient sink for excessive organic load.

3. Construction of sluice gates to allow the drainage of agricultural water through the shrimp farm dykes at the Biderpur site in Orissa in order that construction of fringe bunds may not block irrigation drainage from agricultural lands.

4. In the case of impact relating to eutrophication of ox-bow lakes, mitigation would involve periodical removal of sediment from the lakes.

5.1.7 Environment's influence on shrimp culture

Please refer to Section 4.1.2 of this report for basic information.

i. Impacts of typhoons, sedimentation and other physical changes

Sedimentation has been shown to be a major problem in the entire traditional system and in the new system which draws water from creeks which carry a heavy sediment load brought by the river system. Sediment trapping has not been effective due to very fine silt load carried by the rivers and creeks. Sedimentation tanks are prescribed for such areas. De-silting of ponds is beset with problems of proper disposal as the disposed of earth is likely to be washed back into the ponds during the next rains.

Cyclones with heavy rainfall and gusty winds exceeding 100 km/hour cause damages to estuaries, inventories and standing stocks. The north east monsoon and associated depression affect the South Andhra and Tamil Nadu coast. The south west monsoon and associated cyclones affect the North Andhra, Orissa and West Bengal coasts. Cyclones are infrequent along the west coast, but floods due to heavy rainfall in the south west monsoon would affect the farm structures from Kanyakumari to the Gulf of Cambay. Closure of barmouths of almost all the estuaries in South Andhra and Tamil Nadu coast restricts tidal flow into the backwater system to a few months. Farmers have had to contend with drastic salinity fluctuations and temperature rise.

ii. Impacts of pollution

Shrimp farms are largely located in the neighbourhood of agricultural lands or in the drainage basin of watershed areas. Although no effect of pesticides on aquaculture has come to light, it may be a cause of concern in future. Coastal waters are by far cleaner, except for some hot spots like Bombay and Madras. Cochin has shown potential for industrial pollution both atmospheric (acid rain?) and aquatic (Periyar river). Sewage discharge from all major cities is of concern. Calcutta has developed an unique system of using city sewage via Kulti estuary for raising crops and for fish culture. In this city, the waste water reuse spreads over an area of over 5,000 ha - the largest of its kind in the world. The Salt Lake swamp of Calcutta is one of the best examples of a sustainable sanitation pattern that has largely expunged the conventional waste water treatment plants (WWF, 1992).

iii. Economic losses associated with the above

No report is available. The economic loss caused by the November 1991 cyclone in Nellore District, Andhra Pradesh is shown in Table 17.

Table 17. Shrimp farms affected by the cyclone in November 1991.

The May 1990 cyclone that hit Andhra Pradesh affected shrimp farms to the extent of 326 ha in East Godavari, 145 ha in West Godavari and 2203 ha in Krishna Districts. Economic loss data are not available.

iv. Legal provisions preventing environmental impacts (legislation, zoning, conservation rules)

No separate legal provision to mitigate the environment's influence on aquaculture exists. General legal provisions under The Water (Prevention and Control of Pollution) Act, 1974 and the Environment (Protection) Act, 1986 would also apply to the aquaculture farms.

v. Farm management measures used to reduce impacts

Very little action has gone into this. The waterways (brackishwater canals and creeks) are a common property resource and withdrawal of water from and discharge of wastes by the farms on either side into the same waterways is a common practice. This generally leads to environmental degradation. Cyclone protection dykes and peripheral dykes are constructed to avoid flooding of ponds. The peripheral dykes are not high enough, due to cost factors, and hence flood damages occur. Sedimentation tanks and long supply canals have been designed in some farms in Gujarat to reduce sediment load in grow-out ponds.

vi. Government measures (now and in future) to reduce impacts (survey, monitoring, enforcement etc.)

The Government is not at the moment concerned with any specific issues connected with the impact of environment on aquaculture, apart from enforcing the rules under the Acts on Water (Prevention and Control of Pollution) and Environment (Protection), which would indirectly help the aquaculture environment. Projects such as the World Bank aided one have built in cyclone protection dykes. Mangroves are not to be touched, but where some part of the project site has to be disturbed, an equal area is to be replanted. In respect of Government lands, some states (e.g. Gujarat) are preparing master plans which would take care of environment's influence on shrimp farming.

5.1.8 Environmental impacts related to shrimp farming

i. Description of environmental impact of shrimp hatcheries/shrimp larval collection

Shrimp hatcheries tend to concentrate in a few ideal locations. For example, in a distance of about 40 km near Madras, seven shrimp hatcheries are located. The hatcheries of the World Bank aided project are also proposed to be on a cluster basis in some cases. All commercial hatcheries use antibiotics as a routine prophylactic measure. EDTA is used as chelating agent. Chlorination of water is also carried out. The effluents of hatcheries would contain residues of the above, besides metabolites and organic load. Algal culture uses nutrient media both in axenic and mass culture.

Shrimp fry collection from the wild and large-scale by-catch destruction has already been referred to in this report. The commonest gear used for fry collection in West Bengal is the Medinipur type of shoot net (behundi jal) which is operated both from the shore and from boats. Drag nets and barrier nets are also used. Nazat in North 24 Parganas District is considered the biggest tiger shrimp seed market in the country. Thousands of persons belonging to the fisherfolk and agricultural communities have found gainful employment in fry collection and trade. It is reported that about 900 million tiger shrimp fry are collected annually to meet the demand for the extensive and semi-intensive farms located mainly in North 24-Parganas District (Nielsen and Hall, 1993). The CIBA study estimated the destruction of shrimp fry by-catch to be almost 407 million in Nazat, 62 million in Harwood Point and 2,592 million in Ramnagar (Banerjee and Singh, 1993). The percentage contribution of by-catch to the total catch was 64.0% in Harwood Point, 98.5% in Nazat and 99.4% in Ramnagar. A total of 49 species of finfish and 11 species of crustaceans formed the by-catch.

The pressure on seed resources in West Bengal, Orissa and Andhra Pradesh is on the increase to meet the demands of shrimp farms. The by-catch destruction is alarming. The shrimp trade is a significant economic activity for thousands of families, including traders and transporters. It is likely to have an adverse effect on estuarine ecology and fisheries, and may have an impact on recruitment to coastal fisheries. There is no regulation on shrimp fry collection and trade. Management measures which have been suggested are educating the fry-catchers, establishing a fry bank, reducing stocking densities of tiger shrimp fry in bheries, using hatchery fry as stocking material and transporting fry under oxygen packing (Banerjee and Singh, 1993). The study of Nielsen and Hall (1993) showed the feasibility of cage rearing of shrimp fry with techno-economic analysis.

ii. Description and diagnosis of environmental impacts related to removal of mangroves for shrimp pond culture

Utilisation of mangroves
With new developments in shrimp farming, some areas in Godavari and Krishna mangroves have been converted. A proposal to convert Chorao Island mangroves in Goa to shrimp farms has nearly been shelved. The World Bank aided project has built in a programme of mangrove afforestation to compensate for the forest cover that would be lost to pond and infrastructure development in Meendwip Island in West Bengal.

Ecological impacts of mangrove utilisation
Destruction of mangroves leads to removal of shelter and would result in tidal water reaching far inland and the salinisation of agricultural land.

Legal provisions preventing the environmental impacts
Legal provisions are derived from various Acts, particularly The Wildlife (Protection) Act, 1972; The Water (Prevention and Control of Pollution) Act, 1974 and subsequent Amendments to the Act; and The Environment (Protection) Act, 1986 and the Rules, Amendments and Notifications subsequently issued thereunder, more specifically the Notification dated 19th February 1991 of the Ministry of Environment and Forests, Government of India.

Farm management measures used to reduce impacts
Farmers are concerned with environmental impact, particularly in crowded areas where influent and effluent waters of all farms have the same source. This is evident in Kandleru creek farms in Andhra Pradesh, but practically nothing is done to reduce the impacts. Similar situations exist in seawater based farms where continuous rows of farms are located along the coastline. The stocking densities in semi-intensive farms are upward of 20 post-larvae/m² which necessitates use of high energy feeds, drugs and chemicals. There is no system of monitoring at farm level or at State level, except for the research on environment impact being carried out by the Central Institute of Brackishwater Aquaculture.

Government measures (now and in future) to reduce impacts
The Union Ministry of Environment and Forests insists upon the imperative need to undertake detailed environmental impact assessments of large scale aquaculture projects. The EIA should include: (i) physical resources; (ii) biological resources; (iii) hydrology and water quality; (iv) socio-economic aspects and human use values; and (v) legal aspects. All activities including shrimp farming, with investment exceeding Rs 50 million, will require environmental clearance from the Ministry of Environment and Forests, Government of India. Shrimp farming activities with less than Rs 50 million investment will require to be regulated by the State Government as per Coastal Zone Management plans of the State approved by the Central Government in the Ministry of Environment and Forests. The Pollution Control Boards at State level are in the process of developing standards for aquaculture effluents for implementation.

iii. Description and diagnosis of environment impacts related to the discharge of shrimp pond effluent

No data available. A study has been initiated recently in some shrimp farming areas in Andhra Pradesh and Tamil Nadu by the Central Institute of Brackishwater Aquaculture.

iv. Description and diagnosis of environmental impacts related to land use for shrimp farming

Description of land use types for shrimp farming
Generally, elevated lands adjoining the banks of estuaries, brackishwater creeks and canals, backwaters are used for semi-intensive shrimp farming. This facilitates drawing in water by use of pumps and draining by gravity. Seawater based farms are located along coastline in lands irrespective of soil texture. The traditional farms are located largely in the waterbody itself by construction of embankments and taking in and letting out water through the sluices according to tides (bheries, gheries, pokkali fields, perennial fields).

Changes in land use patterns related to shrimp farm development
Paddy fields are being converted to shrimp farms, as in some parts of Andhra Pradesh (e.g. Bhimavaram). Some paddy lands along the fringe of Chilka Lake have been lost to shrimp farming. The rainfed confined shrimp pond system utilises soil salinity and rain water to build up brackishwater (15–20 ppt) for 2 crops in a year. Permission is given for shrimp farming in some salt pan areas during the lean (rainy) season when salt production is not possible.

Ecological, social and economic problems related to changes in land use for shrimp farming
The major ecological problems feared and voiced is salinisation of agricultural land and ground water sources. Economically, shrimp farming yields a much higher rate of return on investment and profits, compared to other uses. This may bring about social conflicts due to large differences in income between those who stick to traditional production systems and those who switch over to shrimp farming. Those who cannot afford to go in for moderate to heavy investment for shrimp farming will be isolated from the changing trend.

Legal provisions preventing the environmental impacts
The Indian Fisheries Act, 1897, was essentially an enabling Act, giving powers to state Governments to enact state Acts and make rules and regulations for fishery management. The Act specifically prohibited the use of dynamite or other explosive substance in any water, including seawater, within a distance of one marine league of the seacoast, to catch or destroy any fish, including shellfish. This Act also prohibited the use of any poison, lime or noxious material into any water with intent thereby to catch or destroy fish. The Act empowered making rules which may prohibit or regulate all or any matters concerning erection and use of fixed engines (fixed or stationery gear), construction of weirs, use of nets and fishing in any specified water for a period not exceeding two years. Thus, legal provisions were made on fisheries matters in India nearly a century ago.

There followed Acts and Rules from the states as can be gleaned from the following example:

• The Punjab Fisheries Act, 1914; Punjab Fisheries Rules, 1966.

• The Himachal Pradesh Fisheries Act, 1976; Himachal Pradesh Fisheries Rules, 1979.

• The Madhya Pradesh Fisheries Act, 1948.

• The Manipur Fisheries Act, 1988.

• The Meghalaya Fisheries Rules, 1980.

• The Nagaland Fisheries Act, 1980.

• The Rajasthan Fisheries Act, 1953.

• The Indian Fisheries (Tamil Nadu Amendment) Act, 1927.

• The Tripura Inland Fisheries Bill, 1986.

• The U.P. Fisheries Act, 1948.

• The Andaman and Nicobar Islands Fisheries Regulation, 1938.

• The Indian Fisheries (Pondicherry Amendment) Act, 1965.

• The Goa (Brackishwater) Fish Farming Regulation Act, 1991.

A number of maritime states passed Marine Fishing Regulations Acts/Rules in the 1980s. Although the Acts/Rules are primarily concerned with regulating fishing in public as well as private waters through a system of licensing by Government authorities, they are also concerned with resources and ecology. The Goa Act is specific to brackishwater aquaculture.

Exclusive concern for the environment as a whole became legalised with the Wildlife Act, 1972, the Water Act, 1974, the Air (Prevention and Control of Pollution) Act, 1981 and the Environment Act, 1986. The main characteristics of the present policy on development of coastal lands include the implementation of Coastal Regulation Zone (CRZ) rules, protection of forests including mangroves, protection of biological diversity, prohibiting industrial type activity and regulating other activities as per approved zonation and development plans.

Each State Government has a land use policy which is implemented by a single Authority or a Land Use Board. In West Bengal, the State Department of Environment has had long involvement in the review of land use projects through their participation in the Land Use Board. In Andhra Pradesh, there is no Land Use Board, but the Department of Environment possesses the Statutory authority to request environmental impact statements from Fisheries Development projects.

Farm management measures used to reduce impacts
Some corporate sector farms which purchased vast areas are presently using only part of them and claim that environmental impact, if any, is contained within the extent of their own land. This is a short-sighted view. Secondary aquaculture (oysters, mussels, seaweeds etc.) in effluent treatment ponds to settle suspended solids and remove nutrient/organic loads is under consideration and awaiting development of appropriate technology.

Government measures (now and in future) to reduce impacts This will develop with CRZ rules implementation and aquaculture zonation in Coastal Zone Development plans of the states. Once the Pollution Control Boards evolve permissible levels of pollutants in aquaculture effluent water, these will have to be monitored. Most likely, the larger farms will have to have their own effluent treatment ponds as part of their shrimp farm complex.

v. Future management strategies for farms and Government in resolving any conflicts or environmental problems

As shrimp farming is developing fast, the following strategies have been developed for avoiding problems which have arisen in other countries (or reducing their impact):

1. India needs to boost production of shrimp through aquaculture with environment and development as a unified motto.

2. Since the area available is vast, this can be achieved by application of environmentally-friendly technologies for optimal production rates against maximum production rates.

3. Sustainable development of shrimp aquaculture should be guided by the principles of social equity, nutritional security, environmental protection and economic development with a holistic approach to achieve long-term benefits.

4. New definitions and parameters of extensive, semi-intensive and intensive culture systems as suited to Indian conditions and Government policies rather than copying models of other countries (particularly those which have rushed and suffered) and the development of guidelines thereof.

5. Diversification of species among shrimps and to integrate fish wherever possible to suit the different agro-climatic and aquatic zones of the country.

6. Careful development of Coastal Zone Management Plans under CRZ to meet the requirements of coastal aquaculture development plans with some flexibility (as required) for specific areas.

7. Identification of aquaculture zones or careful consideration and provision of buffer zones against possible impact on other land uses; also intermediate buffer zones within aquaculture zones.

8. Consideration of the living, social and vocational needs of local people in villages/towns in aquaculture plans in order to avoid conflicts.

9. Development of sets of regulations on use/ban of drugs and chemicals, including antibiotics, in hatcheries and farms; on abstraction of groundwater and salinisation problems.

10. Development of standards for effluent discharge as applicable to local conditions.

11. Development of viable technologies for secondary aquaculture to gainfully utilise nutrient enriched farm effluents and encourage farmers to adopt such technologies with the necessary support.

12. In view of the fact that coastal farms are located generally in remote areas and cannot be monitored by external agencies on a reasonably effective basis, farmers/group of farmers should equip themselves with facilities to monitor possible important parameters at periodic intervals and maintain such records for their own benefits and for production to inspecting agencies.

13. Brackishwater Fish Farmer Development Agencies to be strengthened in all respects, including environmental management and disease diagnosis, prevention and control, through appropriate training and setting up district level laboratories for essential analytical and diagnostic work.

14. Manpower development at managerial and technician level.

15. Research-extension-farmer group meet for appropriate technologies and feedback.

16. Effective monitoring and enforcement of regulations.

vi. Environmental perspectives of shrimp farming along Kandleru creek, Andhra Pradesh

Kandleru is a 34 km long brackishwater creek in Nellore District, Andhra Pradesh (Figure 2). It is essentially a drainage canal of the watershed of the region and maintains a permanent opening to the sea (Bay of Bengal). It commences its course near Gudur and its confluence with the sea is at Krishnapatnam. The total length of the creek is 45 km, of which 11 km is in freshwater regime and 34 km in the brackishwater regime. The width of the creek varies from 20 m to 200 m and the depth from 1 m to 12 m. The salinity profile is from freshwater situation during November-December (N.E. monsoon) to about 25 ppt in May-June (summer), with 10–18 ppt range in other months. The tidal amplitude is about 1.0 m. The creek traverses through four villages namely Venkata-chalam, Manubolu, Chillakuru and Muthukuru mandals.

A total area of about 2,300 ha of brackishwater land is available for shrimp farming along both sides of the creek. About 600 ha of this has already been developed and is under shrimp culture. Another 500 ha (approximately) is presently under construction. About 500 ha private land will come up shortly under shrimp culture. About 700 ha of Government lands have been allotted variously for the World Bank project (100 ha), and beneficiaries.

All the shrimp farms draw water from the Kandleru creek and drain effluent water into it. Thus the effluent water gets pumped back into the ponds for culture purposes and the cycle is repeated in all farms. Semi-intensive and modified extensive farms coexist, and the latter has more area now. A detailed study of environmental factors during one production cycle at six farms has recently been conducted by the Central Institute of Brackishwater Aquaculture and the report is under preparation. The study also included three farms which are seawater based, located in Nellore District. The Kandleru data showed that there is factoral concentration of all water quality parameters in the ponds and the effluent water shows far higher concentration than the influent water during the harvest time.

Figure 2: Kandleru Creek in Nellore District, Andhra Pradesh, a centre of active shrimp culture activities.

Nutrients, ammonia, COD and suspended solids show higher values in the discharge water. A proposal to construct a separate drainage canal along the entire length (34 km) of creek to facilitate separate drainage for all the farms and finally into the sea was considered. An engineering feasibility study on the proposal showed technical difficulties, logistical problems and very high cost; hence the proposal has been dropped as not feasible. However, a general pollution abatement programme for the entire area will be prepared shortly with larger responsibilities given to the farmers themselves with technical guidance, to maintain the health of the creek to ensure sustainable development of shrimp farming in the 2,300 ha area along side the creek.

5.2 Carp culture in India, with special reference to Kolleru lake

5.2.1 Introduction: extent, history, economic importance of carp culture

Traditional systems of freshwater fish culture in India, involving the collection and transportation of carp seed from the rivers and stocking in the ponds, were in vogue mainly in Bengal, Bihar and Orissa. The then composite Madras Presidency played a notable role in stocking the ponds and tanks under State control, which led to similar steps by other states. The establishment of the Central Inland Fisheries Research Institute, Barrackpore in 1945, led to development of technologies for increasing productivity on a scientific basis and for breeding major carps in confinement to increase seed availability. The breakthrough on breeding of Indian major carps by administration of pituitary hormone came in 1959. Availability of carp seeds through hatcheries made it possible to extend fish culture all over India. The exotic species of Chinese origin like silver, grass and common carps enlarged the scope through composite fish culture. Integrated farming with duck/poultry/pigs/crops was taken up on the Chinese model. The starting of Fish Farmers Development Agencies (FFDA) at the district level in 1973 was a landmark in the history of fish culture in India. As of 1991, the country had 365 FFDAs, covering a water area of 271,000 ha with an average productivity level of 1,895 kg/ha/year. Experimental carp culture at research level at the Central Institute of Freshwater Aquaculture has yielded production rates of 15 tonnes/ha/year. The technology is spreading fast among the agriculturists who have converted large areas of paddy fields into fish ponds. Corporatisation of aquaculture (inland and coastal) is being encouraged (Dehadrai, 1992).

5.2.2 Types of technology

All over the country, composite fish culture with Indian major carps and exotic carps is practised. The choice of species depends on demands of the consumer market. In large public ponds, stocking alone is usually done. Since these ponds continue to be used for varied purposes in the villages, fertilisation and feeding is not done due to resistance from the public. The farmers provide supplementary feeding in smaller ponds to enhance production. In exclusive ponds dug for fish culture, pond preparation, liming, manuring and fertilisation (basal dose in the beginning and maintenance dosages during culture), nursery rearing, scientific stocking and supplementary feeding, fractional stocking and harvesting based on market situation, are practised.

5.2.3 Management and legal regime for access to carp culture sites

No details are available. For obtaining electrical connection, the farmers are required to apply to the State Electricity Boards for aquaculture pump service. The FFDAs register the farmer beneficiaries for subsidies and monitoring.

5.2.4 Description of Kolleru Lake environment

Kolleru Lake is a shallow freshwater wetland, a natural depression, the bed level being 3 ft below MSL, between the Godavari and Krishna deltaic systems in Andhra Pradesh (Figure 3). The lake is located between 81°05'E-81'20'E longitude and 16°32'N-16°51'N latitude. The total area of the lake is 95,400 ha at +10.7 feet contour and 13,500 ha at +3.0 feet contour. The water depth is 2.57 m at maximum, 0.22 m at minimum and 0.84 m on average. The high flood depth is more than 3.0 m and at this depth the lake spread is 86,000 ha.

Figure 3: Kolleru Lake in Andhra Pradesh, an advanced centre of carp culture.

Budameru, Tammileru and Ramileru are the inflowing rivers into the lake. Besides, 15 channels from the deltaic system and 15 drains join the lake. The lake is connected to the Bay of Bengal by the outflowing canal Upputeru which is 72 km long. Ecologically, the lake is divided into three zones: Zone I (the lake proper) which is purely a freshwater zone, extending from Mangaluru, Sripparu on the west to Kaikalur on the south and Pandiripalligudem on the east; Zone II, the transitional zone, extending from Pandiripalligudem on the west to Kottada on the east, receiving freshwater from the western and northern regions and tidal waters from Upputeru river from the south; and Zone III (the tidal zone) which is subject to the tidal oscillations (Rao, et al., 1987). In the lake there are 46 island villages and 76 shoreline villages. The main occupation of people is agriculture. There are 42,000 fishermen engaged in capture fishery in the lake. About 120 species of fish and 12 species of shrimps have been recorded from the lakes, of which 35 are from the tidal zone of Upputeru canal region. The annual average production from capture fishery is 3,200 tonnes (1987–90). The main species of the fishery are Metapenaeus monoceros, Heteropneustes fossilis, Channa striata and Anabas testudineus, which together contribute 70% of total production.

Aquaculture was introduced into this predominantly agriculture and fishing based economy of the lake by the Government of Andhra Pradesh in 1977 for the Fisheries Co-operative Societies. Since then, seeing the success of the programme, the private sector has come into aquaculture in a very large way, not only in production but also packaging, long distance transportation (to Calcutta) and marketing. A large number of fish seed hatcheries have been established.

Rao and Raju (1989) estimated the total waterspread area of fish ponds in the lake at 3,500 ha, the individual pond size ranging 2–16 ha. The agricultural lands in the +3 to+5 ft contours have been converted into fish ponds during the peak 1983–89 period. All farmers practise composite carp culture. The highest production rates reported are 10–12 tonnes/ha/year.

5.2.5 Environmental constraints to carp culture in Kolleru Lake

The resources, production activities and environmental problems in Kolleru Lake were discussed at the National Workshop on “Kolleru Lake Environment Information System” organised by the Centre for Environment, School of Environment, Water Resources and Remote Sensing, Jawaharlal Nehru Technology University, at Hyderabad in October 1991. The major issues of environmental degradation considered are as follows:

1. The lake is losing out due to large-scale reclamation of land for agriculture and construction of a network of fish ponds and roads.

2. The lake is subjected to increasing pollution load by industrial effluents from sugar factories, distilleries, tanneries, agro-chemical factories, paper mills and rice mills.

3. There is dumping of sewage effluents from municipal and urban agglomerations.

4. The large duck population contributes an annual droppings of 37,000 tonnes.

5. The lake is heavily infested with macrophytes.

6. The lake is undergoing a process of eutrophication and the peripheral region has been found to be hyper-eutrophic as observed by certain abiotic factors.

7. Dominance of blue-green algae (Oscillatoria sp., Spirulina sp.), diatoms (Diatoma sp., Melosira sp.) and green algae (Spirogyra sp.) is considered as a biological indicator of pollution.

8. Thousands of tonnes of organic matter in the form of hay and paddy dust is let into the lake.

9. Residues of about 18,000 tonnes of inorganic fertilisers from paddy fields drains into the lake.

10. Mass scale decay of hydrophytes lead to severe problems.

11. The lake is threatened by accelerated sedimentation.

12. Depletion of dissolved oxygen is often observed in the lake due to obstruction to free flow of water and occasional release of metabolite-loaded wastes from fish ponds.

13. All varieties of fish contained toxic metals (mercury, lead, cadmium, zinc and copper) although within tolerance limits.

14. The lake has been subject to more drastic changes from 1984 onwards as compared to previous periods.

15. Finally, it was urged that the Kolleru Lake Development Authority created by the Government will organise such steps as would ensure the resuscitation of the lake, habitations etc. preserve the ecosystem, and preserve and enrich the aquatic fauna of the lake.

16. The WWF (1992) report took note that the Kolleru lake has lost 34,000 ha of wetland area to agriculture and stated that the noise created by irrigation pumps was considered to be one of the causes for the disappearance of large breeding colony of pelicans from the lake in the 1960s.

6. PRIORITIES FOR DEALING WITH ENVIRONMENTAL PROBLEMS

This section considers the “cure” and “prevention” of the environmental problems presented above, including shrimp and carp farming.

6.1 CURE: Aquaculture units suffering the effects of changes to their environment

6.1.1 Carp culture:

6.1.2 Shrimp culture

6.2 CURE: Individuals suffering the effects of changes to the environment arising from aquaculture activities

6.2.1 Carp culture

No major problems at present. These might arise in future with intensification. In Kolleru Lake, the environmental changes brought about by carp culture have been one of the reasons for loss of land, disappearance/reduced appearance of some species of migratory birds, and obstruction of waterways.

6.2.2 Shrimp culture

6.2 PREVENTION

(i) Aquaculture units causing harmful changes to the environment; and

(ii) Non-aquaculturists from modifying the environment to the detriment of aquaculture production units.

1. Enforcement of legal provisions under the relevant Acts of the Government.

2. CRZ regulations to consider specific needs of aquaculture as an expanding production activity and the Coastal Zone Management Plans of the states/Union Territories to carefully plan taking into consideration present situation and future needs.

3. Early development of regulations on permissible levels of most significant parameters of water quality keeping in view the limited intervention of aquaculture for promoting growth of stock in the medium.

4. Environment Impact Assessment (EIA) and Environmental Monitoring Plan (EMP) to be insisted upon for larger units and self assessment/monitoring for smaller units, subject to verification at inspection.

5. Zonations and appropriate siting of farms; not to proliferate indiscriminately but to develop in a planned manner for sustaining production (Alagarswami, 1991).

6. More hatcheries to be encouraged and supported to meet seed demands to reduce pressure on wild seed resources.

7. Feed mills to maintain quality of feeds and to ensure water stability as required; self/external inspection mechanism to be introduced to maintain specific standards.

8. Mangrove forests not to be touched for aquaculture purposes.

7. FUTURE AQUACULTURE DEVELOPMENT

7.1 Environmental implications of future development

Aquaculture in India has emerged, during the last 10 years, as one of the major sectors of fisheries development, thanks to the liberal Government policies and support to the enterprising efforts of the farmers. The area expansion has been steady but slow, largely due to inadequate infrastructure facilities. Shrimp culture, as compared to carp culture, is tracing a higher rate of growth at present. The 100,000 ha target for shrimp culture fixed for the year 2000 AD may be easily achieved. The export target for the marine products, which is around Rs 20,000 million per year as of now, is fixed at Rs 50,000 million by the end of the VIII Five-year Plan, that is in 1996–97. Shrimp culture, from this point of view, is in the “Extreme Focus” category and, hence, there is a vigorous promotion and support effort by Government and public finance sectors. With the recent liberalisation and opening up of the nation's economy with import facilitation and export incentives to be competitive at the global level, coastal aquaculture and to an extent freshwater aquaculture will boom.

It is a healthy sign that, concomitant with the development, there is an awareness of environmental issues involved in aquaculture. India has the ancient wisdom and tradition of safeguarding the environment for sustainable growth and development as can be seen from the traditional practices of agriculture. The active participation of India in the UNCED meeting at Rio has fortified this principle. There have been oral and written presentations in meetings and in the media on environmental issues connected to aquaculture. India has sufficient legal provisions under various Acts on Wildlife, Water, Air and Environment to ensure environmental security of all activities. The CRZ regulations will look after the coastal zone, of which aquaculture is a part. The country is fully aware of the catastrophes witnessed in the shrimp culture industry of some countries and would like to have “preventive” action rather than “curative” action. The policy for shrimp farming has been clearly spelt out to encourage semi-intensive systems. The World Bank project on shrimp culture has a target of 2 tonnes/ha/year. This could be the national average, the country would like to achieve and maintain.

There exists an intensive system which takes a yield of up to 10 tonnes/ha/year, but in terms of area occupied by this system it is very small, at present at around 500 ha. The environmental impact assessment plans should be more specifically addressed to this enterprise and stricter controls exercised so that its future development and growth is carefully regulated. The disease problems so far faced are more in this enterprise than in the other systems.

Preliminary environmental studies have shown that factoral concentration of water quality parameters are very high, particularly in respect of suspended solids, nutrients, ammonia and COD. In some of the shrimp farming centres, the pesticide market is doing an active business with gullible farmers without any “malady-remedy” analysis. These are some of the factors to be concerned about and regulated. Salinisation is a perceived threat which has to be contained by the principles of zonation. Threats to biodiversity do not exist at present, except in the case of Kolleru Lake, but could become important with the growth of the industry. The problem of external factors of floods and sedimentation could be viewed inevitable but mitigatory action could be considered while preparing the master plans for zones/sites and in the overall Coastal Zone Management Plans of the states under CRZ.

7.2 Recommendations

Research

1. A close and critical examination of traditional systems of aquaculture and improvements thereof for increasing production, productivity and returns.

2. Aquaculture systems research on a holistic basis.

3. Focus on environmental impact on a representative basis of ecosystems, technologies, production systems and regions to generate reliable data to understand interactions.

4. Research on need for and judicious application of drugs and chemicals where necessary, residual effects, withdrawal time, safe environment and safe products.

5. Research on feeds and feed technology vis a vis environmental health.

6. Research on so-called enhancers of pond water and soil quality such as minerals and bacterial enzyme products.

7. Research on pre-disposing factors of diseases, diagnosis and preventive and control measures, with early warning system.

8. Farm effluent treatment and secondary aquaculture.

9. Genetic and biotechnology interventions for stock and production improvement which might relieve pressure on environmental impact.

10. Research on disease-free and disease-resistant stocks.

11. Comparative economics with environmental audit of different culture systems.

12. Mechanisms for surveillance, monitoring and control of production systems with environment in focus for pollution indicator parameters.

13. Application of Remote Sensing Data in land use planning for aquaculture.

Training

1. Institutionalisation of training for aquaculture and industry as in vogue for agriculture and industry.

2. Training of scientists in specific disciplines and specialisations, as well as interdisciplinary training.

3. Training of planners, developers and managers of aquaculture.

4. Training of technicians in specialised fields.

5. Imparting training skills in trainers.

6. On-site training of farmers.

Information exchange

1. Strengthening institutional infrastructure for information exchange.

2. Use of satellite communication system on a regional basis.

3. Preparation of compendium of regional information on important aspects such as regulations, permissible levels of pollutants, legal framework etc.

4. Regional Aquaculture Review on a periodic basis in print form.

5. Strengthening and improving scientific publications/journals in the Region.

REFERENCES

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Alagarswami, K. 1991. Aquaculture: Ensuring sustainable growth. The Hindu Survey of Indian Agriculture, 1991, pp. 222–226.

Alagarswami, K. 1993 (Ms). Changing pattern of fragile aquatic systems under threat in India. Paper for presentation at the International Workshop on Conservation of Fish Germplasm Resources and their Habitats, National Bureau of Fish Genetic Resources, Allahabad.

Anon, 1988–89. Annual Report, Central Inland Capture Fisheries Research Institute, Barrackpore, India.

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WWF, 1992. India's wetlands, mangroves and coral reefs. World Wide Fund for Nature India, New Delhi, for the Ministry of Environment and Forests, Government of India, New Delhi, 61 pp.