Lars Hein is an environmental
officer in the Project Advisory
Unit of FAO's Investment Centre
Division.
The rapid expansion of shrimp aquaculture on India's flat coastal lands has
been an important cause of conversion of mangroves in the past decade,
generating environmental concern.
Shrimp aquaculture ponds constructed in sparse mangrove forest in the Godavari delta, Andhra Pradesh, India
- L. HEIN
In the past decade, Indian shrimp aquaculture has experienced rapid growth. Total aquaculture shrimp production increased from 30 000 tonnes in 1990 to 102 000 tonnes in 1999. The expansion was driven by the high profitability of shrimp farming and attracted a wide range of investors, ranging from individual farmers converting paddy fields to multinational companies investing in large-scale semi-intensive and intensive shrimp farming. The economic significance of the shrimp sector is large in terms of export earnings (currently about 1.6 percent of the value of Indian exports is from shrimps produced in aquaculture) and employment (involving an estimated 200 000 employees).
Yet the development of shrimp aquaculture in India has been controversial. Among the substantial environmental and social problems - including water pollution, salinization of drinking-water wells and paddy fields, destruction of fry of wild fish and crustacean species and various social conflicts related to land conversion - a critical outcome has been the conversion of mangroves to shrimp farms.
The conflicts generated by these problems culminated in a Supreme Court decision banning non-traditional shrimp aquaculture in India's coastal zone in 1996, followed by the 1997Aquaculture Bill which partly deviated from the Supreme Court decision and allowed existing shrimp farms in the coastal zone to continue operations under a number of conditions. Currently, the debate between the Ministry of Agriculture, the Ministry of Environment and Forests, the shrimp farming industry and the various environmental and social NGOs is still ongoing.
The states of India's East Coast
The Sundarbans delta extending over the coastal areas of West Bengal and Bangladesh contains one of the largest remaining mangrove forests in the world. Other mangroves of the East Coast are found in the deltas of the Godavari, Krishna Mahanadi and Kollidam rivers (see Figure below) and in smaller patches along the coast. As in many parts of the world, mangroves play a vital role in the coastal environment as a cyclone protection belt, as a habitat for juvenile fish and crustacean species and through the supply of a variety of products (e.g. shellfish and wood) to the local population.
Large areas of mangroves have been destroyed in India since the beginning of the century; the Sundarbans mangroves are believed to have covered almost twice the current area in the early 1900s (Government of India, 1990). Causes for the degradation of mangroves include land conversion, timber and fuelwood collection, grazing and natural causes such as cyclone damage (Chaudhuri and Choudhury, 1994; Krishnamoorthy, 1995).
An overview of the mangrove cover of the four states of the Indian East Coast is presented in Table 1. Different studies show a general decline in mangrove area, but there are large variations among the estimates. These variations are the result of different mapping techniques and application of different minimum crown coverage for classification as mangrove forest. The figures from the Indian Forest Resources Assessments suggest that the rate of destruction of mangroves decreased in the period 1988 to 1994; however, this is not confirmed by other sources (Jagtap, Chavan and Untawale, 1993; Chaudhuri and Choudhury, 1994; Andhra Pradesh Remote Sensing Application Centre, 1999).
TABLE 1. Mangrove areas by state (km2) | ||||
State |
Sidhu (1963) |
Blasco (1977) |
India Forest Resources |
India Forest Resources Assessment (1987-1989) |
Andhra Pradesh |
184 |
100 |
400 |
380 |
Orissa |
120 |
50 |
200 |
210 |
Tamil Nadu |
26 |
15 |
50 |
20 |
West Bengal |
4 189 |
2 000 |
2 120 |
2 120 |
Total East India |
4 519 |
2 165 |
2 770 |
2 730 |
Sources: Sidhu, 1963; Blasco, 1977; Government of India, 1991a, 1997. | ||||
Four major types of shrimp farms are used in India, ranging from traditional to intensive systems (see Box). The rapid growth of the shrimp aquaculture sector induced a large increase in the total area under shrimp farming (see Table 2). This increase was mainly attributable to the expansion of extensive and semi-intensive systems. Traditional shrimp aquaculture on a significant scale has only been practised in the states of West Bengal and Kerala (Alagarswarmi, 1995). Most of the shrimp farms present in the other states in 1990 were extensive and semi-intensive farms developed in the 1980s.
TABLE 2. Areas under shrimp cultivation, by state (ha) | |||
State |
1990 |
1994 |
1999 |
Andhra Pradesh |
6 000 |
34 500 |
84 269 |
Goa |
525 |
600 |
650 |
Gujarat |
125 |
700 |
997 |
Karnataka |
2 500 |
3 500 |
3 540 |
Kerala |
13 000 |
14 100 |
14 595 |
Maharashtra |
1 800 |
2 400 |
970 |
Orissa |
7 075 |
8 500 |
11 332 |
Tamil Nadu |
250 |
2 000 |
2 670 |
West Bengal |
33 815 |
34 400 |
42 525 |
Total |
65 090 |
100 700 |
161 570 |
Sources: 1990, 1994: MPEDA in James, 1999; 1999: India Hatcheries Organization, unpublished data, 1999. | |||
Based on Alagarswami (1995), ADB/NACA (1998) and James (1999), it is estimated that currently about 50 000 ha are under traditional aquaculture systems, some 90 000 ha under extensive systems, about 20 000 ha under semi-intensive farming and some 1 000 ha under intensive shrimp farming.
Since the mid-1990s, the shrimp aquaculture sector has been suffering from the so-called white spot disease, a viral disease that was introduced to India in 1994, most likely with broodstock imported from Southeast Asia. The disease spread rapidly throughout the subcontinent and caused a 50 percent decline in shrimp production from aquaculture by 1997 (FAO, 1999). Although no treatment for the disease is available (apart from prevention), recent production data suggest that shrimp production is increasing again (India Hatcheries Organization, unpublished data, 1999; FAO, FAOSTAT regional fisheries statistics, unpublished, 2000).
Types of shrimp farms TRADITIONAL SYSTEMS These include a variety of polyculture systems, usually with a large component of miscellaneous fish and a small component of shrimps. In these systems, ponds are filled with tidal water with no control over quality and quantity of stocking. Average production is low and ranges from 200 to 500 kg per hectare per year (mixed species and sizes). In improved traditional systems, the traditional ponds are stocked with wild shrimp seed (in particular from the tiger shrimp, Penaeus monodon), increasing overall yields by some 100 to 200 kg per hectare per year and increasing the shrimp component to about one third of the total crop (Alagarswami, 1995). EXTENSIVE SYSTEMS Extensive systems apply monoculture and usually supply water through pumping from canals, creeks or the sea. Farmers use locally prepared feeds and, under good management, are able to harvest up to some 700 kg per hectare per crop with one or two crops per year. In modified extensive systems, ponds are prepared with tilling, liming and fertilization, which enables the application of higher stocking densities (up to 10 per square metre) and increases the potential yield to some 1 000 kg per hectare per crop. SEMI-INTENSIVE SYSTEMS These are more recent pond systems, up to 1 ha in size, with regular supply and drainage canals, controlled water exchange and higher stocking densities (in the order of 15 to 30 per square metre). The farms are usually located in estuarine areas and dilute estuarine water somewhat with fresh water to maintain optimum salinity levels. Imported pellet feeds are used, and application of drugs and chemicals (such as disinfectants, piscicides, fungicides and antibiotics) is common. Average annual yields of semi-intensive farms in India are about 2 200 kg per hectare with an average of 1.2 to 1.5 crops a year (ADB/NACA, 1998). INTENSIVE SYSTEMS The ponds are 0.25 to 0.5 ha in size with four aerators per pond and a central drainage system to remove accumulated sludge. Feeding with pelletized food takes place a number of times per day and the stocking density increases to 30 to 80 per square metre. Yields of over 8 000 kg per hectare are possible, but the actual average annual yield in India is about 4 500 kg per hectare in 1.6 crops per year (ADB/NACA, 1998). Although this system is very common in Thailand and Taiwan Province of China, it is not frequently used in India (James, 1999). |
The fast development of the shrimp sector required the conversion of flat, coastal lands to shrimp ponds. Part of the shrimp pond construction took place in mangroves, and shrimp aquaculture has been an important cause of the conversion of mangroves in India in the last decade (Lakshmana Rao, Mahapatra and Subba Rao, 1994; Holmgren, 1994; Alagarswami, 1995; Krishnamoorthy, 1995; James, 1999). A recent survey by the aquaculture sector found that about 5 percent of the shrimp aquaculture farms in India have been constructed in former mangrove areas (ADB/NACA, 1998) (Table 3). Mangrove conversion has been undertaken by both small-scale extensive farms and by larger-scale semi-intensive and intensive farms (Vivekanandan, Muralidharan and Subba Rao, 1997; ADB/NACA, 1998).
TABLE 3. Prior land use of shrimp farms (%) | ||||
Production system |
Mangroves |
Intertidal wetland |
Rice farming land |
Other, including fallow land |
Traditional and extensive |
3 |
20 |
32 |
45 |
Semi-intensive |
7 |
8 |
5 |
80 |
Totala |
5 |
14 |
18 |
63 |
a 966 farms, with a total surface of 3 560 ha. | ||||
In order to determine the significance of the destruction of mangroves by aquaculture in relation to other factors having an impact on mangrove ecosystems, a case study has been carried out for the Godavari delta, Andhra Pradesh, by the Andhra Pradesh Remote Sensing Application Centre. The results of the classification of the images are presented in Table 4.
From the remote sensing images it is apparent that in the Godavari delta area, about 14 percent of the aquaculture farms have been constructed on mangrove lands. Shrimp aquaculture is responsible for about 80 percent of the conversion of mangrove land. Shrimp ponds are often located in sparse mangrove forests (see Maps). The decrease in the area of sparse mangrove cover is partly reversed by the conversion of dense into sparse mangroves, probably through fuelwood collection and grazing.
TABLE 4. The impact of shrimp aquaculture in the Godavari delta (ha) | ||||||
Land use |
Land use area |
Converted to shrimp farms | ||||
1989 |
1997 |
1999 |
1987-1997 |
1997-1999 |
1989-1999 | |
Crop land |
4 543 |
2 324 |
6 903 | |||
Fallow land |
3 149 |
1 327 |
4 497 | |||
Dense mangrove |
16 586 |
15 987 |
15 318 |
433 |
471 |
1 137 |
Sparse mangrove |
4 530 |
3 786 |
3 199 |
604 |
666 |
1 030 |
Total mangroves |
21 116 |
19 773 |
18 517 |
1 037 |
1 137 |
2 167 |
Other |
2 281 |
1 493 |
3 714 | |||
Aquafarms |
2 006 |
13 032 |
19 239 |
|||
Total |
17 281 |
6 251 |
17 281 | |||
Source: Remote Sensing Images from the Andhra Pradesh Remote Sensing Application Centre, 1999. | ||||||
The rate of conversion of mangroves into shrimp ponds increased in the period 1997 to 1999, suggesting that shrimp pond construction started in fallow and crop lands but then encroached on mangroves in the absence of suitable fallow land. Policy regulations banning the conversion of mangroves to shrimp ponds and the protected status of the Godavari forest have not been able to prevent the conversion of mangroves into shrimp ponds.
In February 1991, the Ministry of Environment and Forests issued a notification under the Environment (Protection) Act, 1986, which declared all coastal stretches of seas, bays and estuaries up to 500 m from the high tide line on the landward side as the Coastal Regulation Zone (CRZ). The notification placed a number of restrictions on industrial activities in the CRZ and on the extraction of groundwater, and requested the coastal States to prepare coastal zone management plans (see Box).
In response to the various social and environmental conflicts that arose from the fast development of the shrimp aquaculture sector, social workers and environmentalists filed a petition with the Indian Supreme Court in 1994. The petition sought a ban on non-traditional aquaculture farms in the CRZ through the enforcement of the 1991 CRZ Notification. At the request of the Supreme Court, the National Environmental Engineering Research Institute investigated the social and environmental costs of shrimp farming in 1995. It was estimated that these costs far exceeded the economic benefits of aquaculture farms1 and in December 1996, the Supreme Court responded by placing a number of stringent restrictions on shrimp farming in the coastal zone, including the following.
Coastal zone management plans For regulation of development activities, the coastal states were requested to prepare coastal zone management plans through the 1991 CRZ Notification. The Coastal Zone Management Plans require the classification of all coastal land within 500 m landwards of the high tide line into four categories: CRZ-I includes ecologically sensitive areas, including parks and mangroves and areas between the high tide line and the low tide line. In this zone no new construction is permitted landwards of the high tide line. Between the low tide line and high tide line the only construction activities permitted are those pertaining to facilities for carrying treated water discharge into the sea, facilities for carrying seawater for cooling purposes, oil, gas, etc. CRZ-II includes areas that have already been developed, e.g. with housing or infrastructure facilities, up to or close to the shoreline. In this zone buildings were not be permitted on the seaward side of existing roads or existing authorized structures. CRZ-III includes relatively undisturbed areas, including rural areas, essentially free of houses and infrastructure. CRZ-IV includes coastal stretches in the Andaman and Nicobar and other small islands except those designated in other categories. In CRZ-III and -IV, the area up to 200 m from the high tide line is appointed as a no-development zone, although agricultural activities, forestry and salt mining are permitted. From 200 to 500 m above the high tide line, construction of buildings is allowed, with some extra specifications for CRZ-IV (Government of India, 1991b). In the years directly following the CRZ Notification, none of the state governments actually prepared the coastal zone management plans, and awareness of the Notification did not spread widely outside the state departments of environment and forests. Only after the various appeals were made to the Supreme Court on the basis of the 1991 Notification, did the states start to prepare Coastal Zone Management Plans. In general, the plans record current land use, point out threats to the coastal environment and include general guidelines for coastal zone management. Because of a lack of enforcement, the plans have had, to date, only limited impact on the construction of shrimp farms. |
Full enforcement of the Supreme Court judgement would have had major implications for the shrimp aquaculture sector. The aquaculture lobby accordingly filed a petition in 1997 seeking review of the judgement. The court responded by extending the implementation date of the order, and provided a new interim order on 19 August 1997 which stated that the farms that were to be demolished as per the 1996 judgement will not be demolished until further order, but that no fresh seeds could be put in these farms.
Following the Supreme Court judgement, the Ministry of Agriculture formulated the Aquaculture Bill which was enacted in 1997. The bill specified the organization and the mandate of the Aquaculture Authority (that was to be constituted following the Supreme Court judgement), and provided a number of directives for shrimp aquaculture in the coastal zone. All aquaculture farms were to obtain a licence within six months of the notification of the bill, and no licence was to be granted for aquaculture farming proposed within 200 m from the high tide line or within the CRZ in relation to creeks, rivers and backwaters. However, this restriction on eligible locations did not apply to aquaculture farms in existence on the day of establishment of the Aquaculture Authority, thus providing a deviation from the initial Supreme Court judgement.
The regulation system for coastal zone management enacted with the 1991 CRZ Notification was not capable of mitigating the environmental and social conflicts that arose from the rapid expansion of the shrimp aquaculture sector. With the 1996 Supreme Court order and the 1997Aquaculture Bill, new legislation was put in place, but the current permission and regulation system for shrimp farming is still deficient in a number of aspects, which relate in particular to its enforcement.
The state level committees of the Aquaculture Authority are responsible for the implementation of the permission system. Part of the apparent lack of environmental and social considerations in the permission system can be explained by the limited influence of the state departments of environment and forests in these committees. Although the departments of environment and forests are represented, the state level committees of the Aquaculture Authority are generally controlled by the state fishery departments. In addition, as there is little field monitoring of existing or proposed aquaculture farms and as there is no clear obligation for existing shrimp farms to apply for a licence, shrimp farmers often have little awareness of these regulations.
Comparison of land use and land cover in the Godavari delta in 1989 and in 1999, showing the encroachment of shrimp farms on mangrove land
|
|
Various studies indicate that shrimp aquaculture has contributed to the overall degradation of mangroves in India's East Coast in the last decade. For example, in the Godavari delta, shrimp farms have been responsible for some 80 percent of mangrove conversions in the last decade.
In addition to the conversion of mangroves, shrimp aquaculture contributed to a number of other environmental and social conflicts. Protests from local villagers, supported by various social and environmental NGOs, culminated in the 1996 Supreme Court judgement and the 1997Aquaculture Bill which established a regulatory framework for shrimp aquaculture in India.
The economic benefits of shrimp aquaculture, in particular foreign exchange earning and provision of employment, are highly important to the Indian economy, but there is a need to minimize further its social and environmental costs, in particular through more effective enforcement of current regulations. When shrimp farmers gain more experience with the prevention of the white spot disease, the number of shrimp farms may further increase and effective enforcement will be critical in avoiding further conflicts.
A number of policy measures are recommended to increase enforcement and to decrease the environmental and social costs of shrimp aquaculture in India. These measures have a focus on mangrove protection; additional measures would be required to address other environmental and social issues.
Bibliography
ADB/NACA. 1998. Aquaculture sustainability and the environment. Report on a Regional Study and Workshop on Aquaculture Sustainability and the Environment. Bangkok, Thailand, Asian Development Bank and Network of Aquaculture Centres in Asia and the Pacific.
Alagarswami, K. 1995. India country case study. In Regional study and workshop on the environmental assessment and management of aquaculture development (TCP/RAS/2253). NACA Environment and Aquaculture Development Series No. 1. Bangkok, Thailand, Network of Aqua-culture Centres in Asia and the Pacific.
Andhra Pradesh Remote Sensing Application Centre (APRSAC). 1999. Environmental management and monitoring of shrimp culture project, East Godavari District, Andhra Pradesh - land use/land cover. Hyderabad, India.
Blasco, F. 1977. Outlines of ecology, botany and forestry of the Mangals of the Indian subcontinent. Oxford, Elsevier Scientific Publishing Company.
Chaudhuri, A.B. & Choudhury, A. 1994. Mangroves of the Sundarbans. Vol. 1. India. The IUCN Wetlands Programme. Bangkok, Thailand, IUCN.
FAO. 1995. Code of conduct for responsible fisheries. Rome.
FAO. 1996. FAO technical guidelines for responsible fisheries. No. 3. Rome.
FAO. 1999. Aquaculture production statistics 1988-1997. Rome.
Government of India. 1990. Conservation of mangroves in India. New Delhi, Ministry of Environment and Forests.
Government of India. 1991a. The State of Forest Report, 1991. Forest Survey of India. New Delhi, Ministry of Environment and Forests.
Government of India. 1991b. Coastal zone notification. In Gazette of India, February 1991. New Delhi, Ministry of Environment and Forests.
Government of India. 1997. The State of Forest Report, 1997. Forest Survey of India. New Delhi, Ministry of Environment and Forests.
Government of India. 1998. Guidelines for adopting improved technology for increasing production and productivity in traditional and improved traditional systems of shrimp farming. New Delhi, Ministry of Agriculture, Aquaculture Authority.
Holmgren, S., ed. 1994. An environmental assessment of the Bay of Bengal Region. Swedish Centre for Coastal Development and Management of Aquatic Resources, March 1994. Bay of Bengal Programme, Madras, India.
Jagtap, T.G., Chavan, V.S. & Untawale, A.G. 1993. Mangrove ecosystems of India - a need for protection. Ambio, 22(4): 252-254.
James, P.S.B.R. 1999. Shrimp farming development in India - an overview of environmental, socio-economic, legal and other implications. Published on line by Aquaculture Magazine, December 1999. (www.ioa.com/ãquamag).
Krishnamoorthy. 1995. Remote sensing of mangrove forests in Tamil Nadu Coast, India. Faculty of Civil Engineering, Anna University, Madras. (thesis)
Lakshmana Rao, M.V., Mahapatra, K. & Subba Rao, D.V. 1994. The coastal zone of Orissa.
Sidhu, S.S. 1963. Studies on mangrove, p. 129-136. Vol. 33b, Part 1. National Academy of Sciences,.
Vivekanandan, V., Muralidharan, C.M. & Subba Rao, M. 1997. A study on the marine fisheries of Andhra Pradesh. As supported by BILANCE, 1997. (draft report).
1 However, although it was generally agreed that these social and environmental costs were substantial, the estimate itself was widely questioned as the calculations were based on limited data and disputable calculation methods (Vivekanandan, Muralidharan and Subba Rao, 1997: James, 1999).
