Background

Background and description of project

In Bangladesh, prawn and shrimp farming is the second largest export industry (after garment) with an export of USD 433 Million in 2017. Prawn farming is a core industry in the coastal belt of Bangladesh where a total of 35 million peoples and 833,000 farmers are engaged in the industry. Thus, the prawn industry plays a vital role in export earnings, food production and livelihood opportunities, but is also a crucial element in poverty alleviation. Prawn farming requires feeds or algal-stimulating fertilizers to feed the  prawns, but the intensive breeding negatively affects the water quality by build-up of organic matter in the ponds. Microbial activity causes a high production of CO2 and methane gasses from the ponds. The release of these gasses from Bangladeshi prawn farms is estimated to be 2 to 6fold higher than from prawn production in China and Vietnam. To reduce these emissions, IMTA is implemented at prawn farms by adding local snails and aquatic plants to the ponds. Snails have been shown as efficient consumers of organic matter in ponds and can after harvest be used as a protein-rich ingredient in feed for fish or prawns. Thereby, organic matter is removed and recycled for new production with a low climate effect. CO2 emissions is further reduced by adding floating plants, e.g., Azolla or duckweed, to the ponds to assimilate CO2. Together, snails and floating weeds is expected to cause a major reduction of organic matter and reduce CO2 and methane emissions for the benefit of both climate and prawn producers. During cyclones, prawn farmers often experience intrusion of saltwater. In addition to climate change, a major reason for the saltwater intrusion is a reduced freshwater level, which has occurred after construction of the Farakka Barrage in 1975. Today, water supply from the Ganges to West Bangladesh has declined significantly, and draughts have led to intrusion of saltwater into rural, coastal regions. Salinity has further spread from empty marine shrimp ponds. These conditions all negatively affect farming of freshwater prawns. Almost 97% of prawn farmers express concern due to salinity changes that increase the prawn mortality due to a reduced tolerance to pathogenic bacteria, causing severe diseases. However, some bacteria, named probiotic bacteria, are beneficial and disease-preventing to prawns, and they can boost their immune defense to better resist microbial infections. Certain locally produced probiotics are already used in fish farming in Bangladesh, but not in prawn farming. As supplement to probiotic bacteria, a novel phage therapy that involves virus for killing of specific pathogens will also be tested.

Climate-friendly and climate-resilient prawn farming in Bangladesh

Economic feasibility of both IMTA and adaptation measures to resist prawn diseases following salt intrusion in Bangladesh will be analyzed. For reducing greenhouse gas emissions and increase sequestration in the ponds, Ecoprawn study whether IMTA pay off economically and is socially acceptable. The best economic strategy of prawn farmers in adapting to salt intrusion is identified and the effectiveness of IMTA in reducing greenhouse gasemissions analyzed. Governance of the purchaser-driven value chain of prawns from Bangladesh to Europeis analyzed taking the greenhouse gas emission all through the lifecycle into account. The possible role of co-management in mitigating and adapting to climate change is considered. Bangladesh is the partner country due to the huge potential to become one of the world’s largest producers of eco-friendly farmed prawns. For now, the farmers need knowledge and technology to reduce greenhouse gas emissions and adapt to salt intrusion.