World Aquaculture - December 2023

WWW.WAS.ORG • WORLD AQUACULTURE • DECEMBER 2023 43 India has vast floodplain wetland resources (0.8 million ha) distributed across the various river basins in the country. The Wetlands of Eastern and NorthEastern States - Assam, West Bengal, Bihar, Uttar Pradesh, Odisha, Arunachal Pradesh and Manipur - are among the most important from a fisheries point of view and account for 7.50 lakh ha of wetland water surface area (National Fisheries Development Board 2019). These wetland resources deliver a number of goods and services to resourcepoor fishers and nearby inhabitants as they harbor rich biodiversity and breeding grounds for different types of shellfishes and fin fishes. Simultaneously, these wetlands provide natural habitat for a large number of small indigenous fish species that support livelihoods and nutritional requirements of populations around them. Wetlands are known for being among the most productive fisheries resources, with production potential around 1500–2000kg/ha/year. But in general, fish yields from floodplain wetlands has been observed as comparatively low: 400-800 kg/ha/year (National Fisheries Development Board 2019). Studies show that climate change and other environmental factors and anthropogenic activities have rapidly reduced the productivity of these wetland ecosystems, which is a severe threat for the livelihood of the dependent fishers. Bihar state is surrounded by both small and large rivers, canals, reservoirs and floodplain wetlands as well as innumerable water bodies. Because of recurrent flooding in Bihar and its devastating intensity, this state has faced huge economic loss. In the year 2016, 15 out of 38 districts and 3459 villages in the state were affected by a flood outbreak that inundated 6006 km2 of land, impacted 8.82 million people, and caused damages worth US$ 73.99 million (Das et al. 2016). However, while on hand this flooding creates huge damage very year, on the other it also generates a vast scope of aquaculture within flood-prone ecosystems. These water-bodies are seasonal in nature and created by submergence of large and small areas of land during the monsoon/ rainy season (June-September). The total flood-prone area in Bihar is 26,073 km2 which is 27.7 percent of the total geographical area (Figure 1). Of the total flood-prone areas in Bihar, about 75 percent is in north Bihar. Areas of Bihar with 50 to 100 percent flood water inundation in every year are shown in Figure 2a, where Gandak, Bagmati, Kamla, Koshi and Mahananda (Figure 2b) are the major rivers responsible for flood outbreaks. These high flood-prone areas mostly fall in the districts of Purba Champaran, Sitramarhi, Muzaffarpur, Darbhanga, Madhubani, Samastipur, Saharsa, Khagaria and Katihar (Figure 1). The depth and duration of flooding in these areas varies from 0.75 m to 2.5 m and 20 to 90 days, respectively, depending on the rainfall received by the catchments of the rivers. Large floodplain areas are popularly known as chaurs in Bihar, India. Chaurs are mainly found in the basins of Kosi-Gandak river systems of North Bihar. A chaur is typically inundated with flood water during June/July to September with 2.5 - 3.0 m of water and 0.8 - 1.0 m of water during September to January every year (Kumar et al. 2015). The landowners of the chaurs become landless during flooding, as growing of any agricultural crop becomes difficult as a result of water logging during the monsoon season (June to December). These Community-based Aquaculture in Floodplain Wetlands of Eastern India Rohan Kumar Raman, Vivekanand Bharti, Dhiraj Kumar Singh, Jaspreet Singh and Akram Ahmed FIGURE 1. Flood affected crop in at Khagaria, Bihar (CONTINUED ON PAGE 44) FIGURE 2. Flood affected area in Bihar mapped based on average flood prone area during 2001 to 2010