60 SEPTEMBER 2012 Dhaka is the eighth largest city in the world, with a population of about 17.6 million, accounting for about one-third of Bangladesh’s urban population. By 2025, assuming current population growth trends, the Dhaka metropolitan area will have a population of more than 20 million, and may be the fourth largest city in the world. In Dhaka, specifically the metropolitan area administered by Dhaka City Corporation (DCC), the population density is one of the highest in the world, at more than 20,000 people/km2. About 10 million people live in slum areas, and it is estimated that up to 55 percent of Dhaka residents live below the poverty line (Bunting and Lewins 2006). Feeding the large number of people is a key issue for this megacity. Fish is the main source of protein for the people of Bangladesh. Bangladesh has vast areas of surface water in the form of ponds, dighis, lakes, streams and rivers, coastal areas, natural depressions and estuaries covering 4.56 million ha (DoF 2011) where fish can be cultured profitably. Fisheries are diverse with fish and shrimp in the fresh and marine waters of Bangladesh that play a major role in nutrition, employment and foreign exchange earnings with about 12 million people are associated with the fisheries sector. About 400,000 ha of ponds/ditches and more than 900,000 households are involved in aquaculture (ADB 2005). Varieties of cultural, socioeconomic and institutional settings, together with a diversified set of aquatic species and farming practices, has given a multidimensional identity to the aquaculture sector. The rapid growth of aquaculture production has made the sector important to Bangladesh. Shrimp and prawns, the most prominent products from aquaculture in international trade, has been the major force behind increased aquaculture production in the country. Since the late 1980s, aquaculture has acted as a stabilizing factor for this industry (Barua and Sarker 2011, Barua et al. 2011). Intensively managed aquaculture in urban and periurban areas is being developed by entrepreneurs in several countries. Less land is required per unit production for intensive as compared to semi-intensive production (Bunting and Lewins 2006), investment costs associated with establishing intensive systems are comparatively high and dependence on external inputs, such as feed and energy, are greater. With intensively managed farms, operators can exert greater control, better regulation of production factors such as water quality, feed delivery and stock management. More intensive, less open systems offer the producer greater control over biosecurity related to public, animal and environmental health hazards. However, because capital and operating costs are high, it is usually only feasible to produce high-value products often destined for export or niche markets. Production from urban and periurban aquaculture in Bangladesh and West Bengal, India is not differentiated in national or state level statistics. Consequently it is difficult to assess the scale and extent of such activities. The assessment of periurban aquaculture reported in this article is based on interviews and secondary information from sub-district (upazila) fisheries offices. The urban area of Dhaka considered in the assessment is that under the jurisdiction of Dhaka City Corporation (DCC) and the periurban area is that under the Dhaka Metropolitan Development Plan (DMDP) by RAJUK (Table 1). Inland Capture Fisheries Dhaka is surrounded by rivers that are interconnected with canals, which have always formed a lifeline for city residents. In the last 30 years, a convergence of unregulated industrial expansion, rural to urban migration, encroachment of rivers, overloaded infrastructure, confusion about institutional responsibility for the quality of Dhaka’s waterbodies, and ineffective enforcement of environmental regulations have taken their toll on surface water quality. The one wastewater treatment plant (at Pagla) is currently operating below capacity because of sewerage system failures. Few industries operate effluent treatment systems. Almost all the waste from humans, industry, and millions of farm animals, along with tons of pesticides and fertilizers, make their way into Dhaka’s surface water untreated. As a result, many sections of the rivers and canals in the city and surrounding areas, especially the Buriganga and Sitalakhya, are biologically dead during the dry season. In the past decade a wide range of changes affecting fisheries have taken place, including very large increases in fish production from all forms of pond aquaculture, declines in most capture fisheries, encroachment and degradation of natural assets, rapid urbanization, infrastructure investments that have negatively affected fisheries, and increased pollution. A major constraint to fish production is reduced dry season surface water flows in the Buriganga Sitalakhya and other rivers. Production from the capture fishery has declined, caused by the continuing losses of floodplain habitat from flood control/management structures, siltation, industrialization and urbanization, lost connections along critical fish migration pathways, major reductions in dry season riverine flows, overfishing, and degradation of water quality resulting from rapidly increasing industrial, human and agricultural pollution. Production from the more than 57,000 ha of seasonal floodplains, including beels and rivers in and around Dhaka, is by far the most important component of the capture fishery. Fisheries and Aquaculture in Urban and Periurban Areas of Dhaka, Bangladesh Prabal Barua 1 *, Chaiti Barua 2 and Jewel Das 3
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