Sustainability of Aquaculture in BangladeshIntroduction

Aquaculture and fisheries currently is one of the most important potential sectors of the national economy, accounting to 5% of gross domestic product and 6% of foreign export earnings. Labor employment in this sector has been increasing by 6% approximately. No other sector in Bangladesh illustrates development potential more clearly than fisheries. The total fish production in Bangladesh in 2011 was estimated at 2.8 million tons, of which 1.14 million tons (41%) were obtained from inland aquaculture, 1.08 million tons (38%) from capture fisheries and 0.58 million tons (21%) from marine fisheries (DoF, 2011).

Of all the global food production systems, aquaculture is widely perceived as an important weapon in the global fight against poverty and hunger. Aquaculture production, especially pond aquaculture may be a dependable source of obtaining increased fish production in order to supply and feed the ever increasing population of the world (FAO, 2010).

What is Sustainable Aquaculture?

Sustainable aquaculture is a dynamic concept and the sustainability of an aquaculture system will vary with species, location, societal norms and the state of knowledge and technology. Several certification programs have made progress in defining key characteristics of sustainable aquaculture.

Aquaculture system to be truly sustainable, it must have:

Environmental sustainability — Aquaculture should not create significant disruption to the ecosystem, or cause the loss of biodiversity or substantial pollution impact.

Economic sustainability — Aquaculture must be a viable business with good long-term prospects.

Social and community sustainability — Aquaculture must be socially responsible and contribute to community well-being.

Several certification programs have made progress in defining key characteristics of sustainable aquaculture. Some essential practices include:

Environment practices: Mangrove and wetland conservation; effective effluent management and water quality control; sediment control and sludge management; soil and water conservation; efficient fishmeal and fish oil use; responsible sourcing of bloodstock and juvenile fish; control of escapes and minimizing biodiversity and wildlife impact.

Community practices: Establish well-defined rights, aquaculture zones and

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responsibilities for aquaculturists; regulatory compliance and effective enforcement; community involvement; worker safety, fair labor practices and equitable compensation.

Sustainable business and farm management practices: Effective biosecurity and disease control systems; minimal antibiotic and pharmaceutical use; microbial sanitation; maintain global standards for hygiene; efficient and humane harvest and transport; accountable record-keeping and traceability; profitability.

Sustainable Livelihoods Approach (SLA)A livelihood comprises the capabilities, assets and activities needed for a means of living (Scoones, 1998). A livelihood is sustainable when it can cope with and recover from stresses and shocks, and maintain or enhance its capabilities and assets, both now and in the future, while not undermining the natural resource base (DFID, 1999). According to Scoones (1998), five key indicators are important for assessing sustainable livelihoods:

1) Poverty reduction, 2) Well-being and capabilities, 3) Livelihood adaptation, 4) Vulnerability and resilience, and 5) Natural resource base sustainability.

The SLA is prominent in recent development programs that aim to reduce poverty and vulnerability in communities engaged in small-scale aquaculture and fisheries (Edwards et al., 2002; Neiland and Bene, 2004). The livelihoods approach seeks to improve rural development policy and practice by recognising the seasonal and cyclical complexity of livelihood strategies (Carney, 2002; Allison and Ellis,2001).

Fig: The sustainable livelihood framework (source: DFID, 1999, Adato and Meinzen Dick, 2002)

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Sustainability assessment framework

The term and concept of sustainability in the agricultural field has received much at -tention since the late 1980s, when it became a part of the long-term perspective on economic growth (Franceschi and Kahn, 2003). There are many definitions of sus-tainability in the literatures from various disciplines. Pretty et al. (2008) stated that re-silience and persistence, in addition to economic, social and environmental out-comes, need to be considered with respect to sustainability of agriculture systems. Ecologists define ‘a sustainable agricultural (aquaculture) system with a non-nega-tive change in the stock of natural resources and environmental quality over time’ and economists define ‘a sustainable agricultural (aquaculture) system with a non-negative trend in productivity’ (Leung and El-Gayar, 1997).

Background of Coastal AquacultureShrimp aquaculture in Bangladesh began its expansion in 1971. The export oriented shrimp industry took off in the 1980s, when large-scale shrimp aquaculture in higher income countries such as Thailand, Indonesia, China, the Philippines and Taiwan began to suffer from environmental and social damage (Ito 2002). Increased fishingPressure on natural marine shrimp stocks and maximum harvesting in all available areas fuelled the initiation of large-scale shrimp farming in coastal areas. From the early 1980s, the government of Bangladesh has supported the improvement of shrimp farming (Islam and Wahab 2005). Shrimp farming rapidly expanded in the coastal districts, including Shatkhira, Khulna, Bagerhat, and Cox’s Bazar, and Bangladesh is now one of the major exporting countries of P. monodon and M. rosenbergii in the world (New 2005). Currently, there are about 16,237 brackish water shrimp (P. monodon) farms covering about 148,093 ha and 36,109 fresh water shrimp (M. rosenbergii) farms covering about 17,638 ha

Sustainability IssuesThe environmental and social impacts of shrimp farming include large-scale degradation of mangroves, alteration of wetlands, land subsidence, salinization of ground and surface water, pollution of agricultural lands and coastal waters by pond effluents and sludge, introduction of exotic species or pathogens into coastal environment, loss of wild larvae and subsequent loss of goods and services generated by natural common property resources.

Mangroves and Wetlands DestructionMangroves and wetlands are important ecosystems, both ecologically and economically (Baran and Hambrey 1998; Nickerson 1999; Islam and Wahab 2005). Globally, more than a third of the mangrove forests have disappeared in recent decades, and shrimp culture is by far the greatest cause of this. If losses attributable to fish farming are included, mariculture is responsible for more than half of the losses of mangroves (Valiela and others 2001). Most of the shrimp farms in Southeast Asia, including Thailand, the Philippines and Vietnam, are derived from

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mangroves and coastal wetlands (Flaherty and Karnjanakesorn 1995; Primavera 1995; Be´land and others 2006). In Bangladesh extensive coastal lands have been converted to shrimp farms, but the direct contribution to mangrove destruction has rarely been quantified. One study reported that the loss of approximately 9,734 ha of mangrove in the southeastern part could be directly attributed to shrimp culture (Shahid and Islam 2003). The mangrove ‘Chakaria Sundarbans’ has disappeared due to various anthropogenic interventions which include fuelwood collection, human settlement, salt production and shrimp farming (Hossain and others 2001; Islam and Wahab 2005).

Soil AcidityAquaculture ponds in mangrove areas give rise to highly acidified soils as a result of exposure to air. This results in low pH of pond water and high levels of dissolved aluminum in a form that is highly toxic to aquatic animal life. The stress caused by high acidity makes the cultured animals susceptible to diseases and parasites and may even cause death. In Bangladesh several shrimp disease outbreaks and production losses have been linked to acid sulfate soils (Deb 1998). Many shrimp farms of coastal zones in Southeast Asia including Taiwan, Thailand and Indonesia have been abandoned due to acid sulfate soils and associated problems (Lin 1989; World Bank and others 2002).

Salinization of Soil and WaterThe use of large volumes of underground freshwater to generate brackish water for shrimp culture led to the lowering of groundwater levels, emptying of aquifers, land subsidence and salinization of adjacent land and waterways in Taiwan and other Southeast Asian countries (Primavera 2006). The discharge of saltwater from shrimp farms also causes salinization in adjoining rice and other agricultural lands. In southwestern Bangladesh, saltwater intrusion has caused problems in terms of severely decreased supplies of potable freshwater, which again has led to increase of gastrointestinal infections as well as loss of diversified crops, poultry and fodders (Ali 2006).

Loss of Fry and Wild StockHarvesting of wild PLs is highly wasteful in terms of mortality of PLs and discarded bycatch, and ecologically destructive (Primavera 1998; Bhattacharya and Sarkar 2003). In Bangladesh approximately 2,000 million shrimp fry are collected annually from wild sources. For fresh water shrimp (M. rosenbergii) more than 90% of the total PL is derived from natural sources and for black tiger shrimp (P. monodon) it is more than 50% (Banks 2003). Approximately 40% of the collected seed die before stocking in culture facilities due to poor handling and transportation (Brown 1997) and the amount of discarded bycatch is staggering. Hoq and others (2001) estimated that about 12–55 post larvae of other shrimp species, 5–152 larvae of finfish and 26–1636 other macro-zooplankton organisms are discarded in the collection of a single P. monodon post larva.

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Demand for Fish Meal, Fish Oil and Trash Fish for AquacultureFish meal and fish oil made from low value trash fish are still used primarily by poultry and swine industries, but aquaculture, including shrimp, has the fastest growing demand for these commodities. The proportion of fish meal supplies used for aquaculture rose from 10% in 1988 to 17% in 1994, 33% in 1997 and 65–68% in 2002 (Tacon 2005). Larsson and others (1994) estimated that more than 80% of the primary production required to feed the shrimps is derived from external ecosystems, and furthermore, a semi-intensive shrimp farm needs a spatial ecosystem support ‘the ecological footprint’ that is 35–190 times larger than the surface area of the farm. In Bangladesh shrimp farmers traditionally use apple snail (Pila globosa) meat to feed farmed shrimp. The estimated harvest of snails from various wetlands, canals and paddy fields in 1999 was 365,849 m (Chowdhury 1999). The demand for snails intensified with the expansion of ghers. As a results P. globosa disappeared from many wetlands of southwestern region (Williams and Khan 2001).

A sustainable future for shrimp production in BangladeshIn recent years aquaculture has become more and more important for Asia, particularly in Bangladesh. It represents the second largest export industry for Bangladesh a!er garments with 97% of the shrimp produced being exported, contributing about 4% to national GDP and employing approximately 1.2 million people for production, processing and marketing activities. Including their families, this sees approximately 4.8 million Bangladeshi people directly dependent on this sector for their livelihood. However, while the Bangladeshi shrimp industry grows, it has also drawn some controversy. Some groups argue in favour of the industry, asserting that it produces nutritious food, releases the pressure on our overfished oceans and meat production, and contributes to the income of poor farmers who have no other possibilities for improving their situation. Others warn against buying these shrimps and accuse the industry of a variety of abuses, ranging from environmental degradation, to endangering local food security, to social considerations of low salaries, insecure work and bad working conditions.

These diverse aspects are all the more important considering that Bangladesh is the country with the highest population density in the world, is one of the most threatened by climate change, and has a large number of people below the poverty line. Consumers in countries importing Bangladeshi shrimp must navigate different one-sided perspectives and rarely have a balanced opportunity to weigh advantages and disadvantages, to help them judge what ethical and sustainable aquaculture production and consumption should look like.

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Indicator-based sustainability assessment of shrimp farming

Fig: Selected indicators for sustainability assessment of shrimp farming in Bangladesh

Fig: The three-dimensional conceptual framework for sustainability assessment of shrimpfarming

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Sustainable aquaculture in small water bodies While human-made pressure on the natural fish production system has been accelerated by the construction of flood control and irrigation dams, and overfishing has caused the production from capture fisheries to decline sharply over the years, innumerable waterbodies in the form of ponds, ditches and natural depressions still remained fallow or underutilized in Bangladesh. Efforts to introduce aquaculture technologies to bring these untapped resources to productive use will definitely be an additional source of cash income for the farm household. Experiences of adoption of improved aquaculture technologies that have been developed through on-station and on-farm research to suit the farmers' conditions suggest that the decline in capture fisheries production can be supplemented with fish production by utilizing these waterbodies. The technologies that were tested were low cost and based on farm generated resources and by-products which enabled farmers to be less dependent on credit and commercial inputs. Farmers were able to realize four times the pre-extension production level. Moreover, integration of aquaculture into the farming system has raised the possibility of more efficient use of on-farm resources as well as increase the on-farm supply of fish for household consumption. The implications for adoption by resource-poor farmer and sustainability of aquaculture practices were discussed in the context of equity and benefits to target groups.

What are the main problems with aquaculture? 

Unsustainable aquaculture can devastate our oceans and the environment and im-pact on local people's food and security.

Some examples include:

The extraction of marine species from oceans, including wild juveniles vital for future stock growth, increasing the burden on wild fish stocks and having ma-jor food security implications;

Fishmeal and so-called 'trash fish' used for feed production - often the main food for local people - taken for use in aquaculture ponds;

The release of organic wastes (that, for instance, act as plant nutrients for harmful algal blooms) and toxic effluents into the oceans;

The destruction of coastal ecosystems, displacement of coastal communities and depletion of fresh water sources to build aquaculture ponds.

What kind of aquaculture is sustainable?   

There are no species that are sustainable as such. The sustainability of a species depends on its feeding and lifecycle habits, as well as the farming operation. Only species that are plant eaters, who can breed in captivity, and whose farming does not produce high levels of nutrient output can be cultivated sustainably.

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There are a number of conditions an aquaculture operation must adhere to in order to be sustainable. Among other things, an aquaculture operation can only be re-garded as sustainable if it:

Is continually moving towards plant-based feeds originating from sustainable agriculture;

Does not use fishmeal or fish-oil-based feeds from unsustainable fisheries and does not represent a net loss in fish protein yield;

Does not use wild-caught juveniles; Only cultivates species that are native in open water systems, and then only

in bag nets, closed-wall sea-pens or equivalent systems (if there is cultivation of non-native species, it must be restricted to land-based tanks);

Does not result in negative environmental impacts in terms of discharges and effluents to the surrounding areas;

Does not result in negative effects to local wildlife (plants as well as animals) or represents a risk to local wild populations;

Does not use genetically engineered fish or feed; Uses stocking densities that minimize the risk of disease outbreaks and trans-

mission; Does not deplete local resources, for example, drinking water supplies and

mangrove forests; Does not threaten human health; Supports the long-term economic and social well-being of local communities.

ConclusionAquaculture in developing countries can improve the sustainability of small-scale farms provided that it isfully integrated with other enterprisesand household activities so as to allow farm families and communities to manage their natural resources effectively. Aquaculture, in common with all other food production practices, is facing challenges for sustainable development. Most aqua-farmers, like their terrestrial counterparts, are continuously pursuing ways and means of improving their production practices, to make them more efficient and cost-effective. Awareness of potential environmental problems has increased significantly. Efforts are under way to further improve human capacity, resource use and environmental management in aquaculture.

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Reference

Azad, A.K., Jensen, K.R. and Lin, C.K. (2009) ‘Coastal aquaculture development in Bangladesh: unsustainable and sustainable experiences’, Environmental Management, Vol. 44, No. 4, pp.800–809.

Barbier, E.B. (1987) ‘The concept of sustainable economic development’, Environ-mental Conservation, Vol. 14, No. 2, pp.101–110.

Boyd, C.E. (2003) ‘Guidelines for aquaculture effluent management at the farm-level’, Aquaculture, Vol. 31, No. 1, pp.101–112.

Braaten, R.O. and Flaherty, M. (2001) ‘Salt balance of inland shrimp ponds in Thai-land: implications for land and water stabilization’, Environmental Conserva-tion, Vol. 28, No. 4, pp.357–367.

Bray, R.H. and Kurtz, L.T. (1945) ‘Determination of total, organic and available forms of phosphorus in soils’, Soil Science, Vol. 59, No. 1, pp.39–45.

ADB. 2005 An evaluation of small-scale freshwater rural aquaculture development for poverty reduction. Asian Development Bank (ADB), Manila, Philippines. 35 pp.

Ahmed, N., Wahab, M.A. and Thilsted, S.H. 2007. Integrated aquaculture-agriculture systems in Bangladesh: potential for sustainable livelihoods and nutritional se-curity of the rural poor. Aquaculture Asia., 12(1): 14-22.

Allison, E.H. and Ellis, F. 2001. The livelihoods approach and management of small-scale fisheries. Marine Policy., 25: 377-388.

Allison, E.H. and Horemans, B. 2006. Putting the principles of the sustainable liveli-hoods approach into fisheries development policy and practice. Marine Pol-icy., 30:757-766.

Carney, D. 2002. Sustainable livelihoods approaches: progress and possibilities for changes. Department for International Development (DFID), London, UK. 33 p.

Chambers, R. and Conway, G. 1992. Sustainable rural livelihoods: practical con-cepts for the 21st century. IDS Discussion Paper 296, International Develop-ment Studies (IDS), Brighton, UK. 19 p.

DFID. 1999. Sustainable livelihoods guidance sheets. Department for International Development (DFID), London, UK. 35 pp.

DoF. 2011. Fishery statistical yearbook of Bangladesh 2009-2010.Fisheries Re-sources Survey Systems, Department of Fisheries, Dhaka, Bangladesh.113 pp.

Scoones, I. 1998. Sustainable rural livelihoods: a framework for analysis. IDS Work-ing Paper 72, Institute of Development Studies (IDS), Brighton, UK. 38 p.

Shang, Y.C. 1990. Aquaculture Economic Analysis: An Introduction. The World Aquaculture Society, Baton Rouge, Los Angels, USA. 21 pp.

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