WWW.WAS.ORG • WORLD AQUACULTURE • JUNE 2017 47 Coastal Bangladesh has the most commercially important species of mud crabs Scylla spp., from the family Portunidae (Macintosh et al. 2002). They dig and inhabit burrows in mangrove swamps and shallow, softbottom intertidal waterbodies (Quinitio et al. 2008). Mud crabs spend most of their life in estuaries and coastal environments that have mud or detritus, debris of leaves, branches, roots and enough shelter materials or places to hide to avoid cannibalism or to molt. Mud crabs are also known commonly as green crabs or mangrove crabs (Shafi and Quddus 1982). Mud crabs are omnivorous or scavengers, feeding on dead animal and plant matter. The 734-km long coastline of Bangladesh, with the world’s largest mangrove forest, is a hotspot for diverse aquatic organisms, including mud crabs, providing suitable breeding, feeding and nursery grounds. In recent years, mud crab farming has increased dramatically in the coastal regions of Bangladesh as a means to improve food security and provide livelihood options for coastal people who are highly vulnerable to natural calamities, including climate change impacts. Initially mud crabs naturally invaded fish and shrimp ponds as an unwanted secondary species. However, shrimp farming in Bangladesh collapsed in the 1990s because of disease outbreaks (Karim and Stellwagen 1998) and environmental degradation. During this crisis, mud crab was considered as an incidental product, providing some marginal return to farmers who were losing their investments in shrimp culture. This coincided with increasing international demand and the price obtained for Bangladeshi Mud Crab Aquaculture and Fisheries in Coastal Bangladesh Md. Mojibar Rahman, M. Ashraful Islam, Shahroz Mahean Haque and Abdul Wahab mangrove crabs. Within the next few years, many shrimp farmers deserted traditional shrimp farming and gradually switched to crab culture (Fig. 1). Presently mud crab has emerged as an alternative livelihood, a source of income and nutrition and an innovative way of helping vulnerable littoral communities adapt to a changing climate. Mud crabs have already gained popularity among coastal communities in greater Khulna and Chittagong regions (Azam et al. 1998) and are being recognized as a candidate species for culture in brackishwater environments (Ballao et al. 1999). There are about 300,000 people directly or indirectly connected with mud crab farming activities. In 2013-2014, Bangladesh exported 7707 t of hard-shell live crabs to international markets and earned US$ 21.1 million, as compared to US$ 6.7 million in 2010-2011 (DoF 2015). Unlike other fish and shellfish commodities, there is not a big demand for crab in the domestic market for local consumption because of religious restrictions on crab consumption. Over the last ten years, production from mud crab fisheries has increased gradually, mainly related to more coastal people becoming interested in crab farming. Technological developments, along with efficient capacity building, trained human resources, holistic uses of water resources, credit facilities, adequate support services, market demand and fetch will further augment the production. A healthy environment with suitable water quality and biological characteristics of coastal waterbodies are advantageous to productive (CONTINUED ON PAGE 48) FIGURE 1. Mud crab farming ponds/ghers in Shyamnagor, Satkhira, Bangladesh. Photo: Md. Mojibar Rahman. In recent years, mud crab farming has increased dramatically in the coastal regions of Bangladesh as a means to improve food security and provide livelihood options for coastal people who are highly vulnerable to natural calamities, including climate change impacts. Initially mud crabs naturally invaded fish and shrimp ponds as an unwanted secondary species. However, shrimp farming in Bangladesh collapsed in the 1990s because of disease outbreaks and environmental degradation.
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