Please note that this page is no longer being updated and it is available for historical reference only

Mangroves and coastal aquaculture

Numerous statements have appeared in the aftermath of the tsunami on how the large-scale conversion of mangroves to shrimp ponds in the past exacerbated the damage by the tsunami.

To what extent are mangroves and aquaculture competing land uses? How should different land use options be reconciled and what should be done to ensure that future developments in coastal aquaculture become sustainable land use options?

Several types of coastal aquaculture (the farming of aquatic animals and plants) exist including:
  • Bottom culture (where no enclosures are used) e.g. of the blood cockle and of seaweed (typically in open bays)
  • Floating cage or pen culture of fish - e.g. groupers, red snapper, milkfish and sea bass (typically in estuaries and creeks)
  • Rafts, poles, lines and cultch used for culture of oysters, mussels and seaweeds (in bays, creeks and estuaries)
  • Pond culture, e.g. of shrimp and milkfish (in the intertidal or supratidal zone)
  • Shore based fish and shrimp hatcheries (not usually in or close to mangrove areas due to need for clear seawater)
Many types of coastal aquaculture are practiced within or close to mangrove areas. Many of these have no or very limited adverse effects on mangroves and have been practiced for hundreds of years providing livelihoods to thousands of rural families.

Although there may be issues of localized water pollution/eutrophication arising from intensive cage culture of fish, the main concern for mangrove areas and their associated creek systems is related to the construction of shrimp and fish ponds, particularly where these involve the clearing of existing mangroves.

The principal tsunami-affected areas with aquaculture ponds in inter-tidal zones are found in Aceh, Indonesia. However, no information is currently available on the extent of damage (degree of destruction, losses) of such pond facilities. There is also evidence from elsewhere in Indonesia and in Thailand that aquaculture cages in creeks and estuaries within or adjoining mangrove areas have been damaged, displaced, or their stocks lost, as a result of the tsunami.

Traditional tidal ponds - known as ┬┐tambaks┬┐ - have a long history in Indonesia. Coastal dwellers constructed these ponds as trap ponds in mangrove areas. Subsequent further construction or conversion of ponds in mangrove areas for more intensive forms of shrimp aquaculture has taken place. Not only are the coastal waters in mangroves rich in nutrients and stocked with wild post-larvae and juvenile shrimps of commercial species, which may help small scale operators stock their ponds, but mangroves are also located in the sheltered and shallow estuarine areas, which sometimes, but not always, are suitable for pond culture. It is well known that acid sulphate soils in such zones are generally not suitable for pond aquaculture.

Due to an increased awareness of the important roles mangroves play in the marine food web and in providing wood and non-wood forest products and coastal protection, most countries in the region have long since restricted or banned the conversion of inter-tidal mangrove into pond culture.

Where the demand for land for agriculture or aquaculture (e.g. to increase production of rice and fish for local consumption) or for infrastructure development necessitates the conversion of mangrove areas, the decision should be based on the results of a thorough environmental impact assessment - including a valuation of all the direct and indirect benefits mangroves provide. And proper measures should be taken to minimize the damage to the mangrove ecosystem as a whole.

A wide range of environmental issues in coastal aquaculture have been studied and discussed extensively. A number of related international technical, policy and legislative guidelines have been published, which are also addressing problems of aquaculture developments in mangrove areas. These may be of use in the post-tsunami rehabilitation phase. (See below)

Needs for action

  • Establishment of a strategic planning mechanism and institutional framework involving local, provincial and national levels authorities in forestry, agriculture, fisheries and rural development and other stakeholders (communities, NGOs, private sector, funding and technical agencies) in the affected areas to provide advice on land use options within an integrated coastal area management framework.

General mangrove management considerations and recommendations

Not all areas of mangroves need to be protected and mangrove resources are often heavily utilized for wood and other products. Where the demand for land for agriculture or aquaculture (e.g. to increase production of rice and fish for local consumption) or for infrastructure development necessitates the conversion of mangrove areas, the decision should be based on the results of a thorough environmental impact assessment - including a valuation of all the direct and indirect benefits mangroves provide. And proper measures should be taken to minimize the damage to the mangrove ecosystem as a whole.

Guidelines for Sustainable Coastal Aquaculture Development

A wide range of environmental issues in coastal aquaculture have been studied and discussed extensively. A number of related international technical, policy and legislative guidelines have been published, which are also addressing problems of aquaculture developments in mangrove areas. These may be of use in the post-tsunami rehabilitation phase.

Special reference is made here to a specialized web site providing significant information on shrimp aquaculture and the environment, based on the outputs of a joint effort by the World Bank, the Network of Aquaculture Centres in Asia-Pacific (NACA), WWF and FAO. This site contains a wide range of thematic, regional and country case studies related to the promotion of better management of shrimp aquaculture.

Further, the World Bank, the International Society for Mangrove Ecosystems (ISME) and Centre for Tropical Ecosystems Research (cenTER Aarhus) of the University of Aarhus produced:
In addition, FAO has published guideline documentation in support of sustainable shrimp culture:
GESAMP, an UN interagency scientific advisory expert panel, has produced guidelines and tools for the planning and management of coastal aquaculture development. These guidelines are available at:

Further information

FAO Forestry Department Mangrove Webpage

FAO Fisheries Department Tsunami Relief Webpage

FAO Fisheries web site

FAO Code of Conduct for Responsible Fisheries:
http://www.fao.org/fi/agreem/codecond/codecon.asp and http://www.fao.org/DOCREP/005/v9878e/v9878e00.htm

FAO Fisheries Department, 1997. Aquaculture development. FAO Technical Guidelines for Responsible Fisheries No.5. FAO, Rome. 40p

FAO. 1996. Integration of fisheries into coastal area management. FAO Technical Guidelines for Responsible Fisheries. No. 3. Rome, FAO. 17p.

World Bank, NACA, WWF and FAO. 2002. Shrimp Farming and the Environment. A World Bank, NACA, WWF and FAO Consortium Program .To analyze and share experiences on the better management of shrimp aquaculture in coastal areas. Synthesis report. Work in Progress for Public Discussion. Published by the Consortium. 119 pages.
Also available at http://www.enaca.org/Shrimp

Lewis, R.R. III, M.J. Phillips, B. Clough and D.J.Macintosh. 2003. Thematic Review on Coastal Wetland Habitats and Shrimp Aquaculture.Available here Report prepared under the World Bank, NACA, WWF and FAO Consortium Program on Shrimp Farming and the Environment. Work in Progress for Public Discussion. Published by the Consortium. 81 pages.