Climate change effects on aquaculture: A case study from north western Bangladesh

Abstract

The present research was carried out to elucidate the impacts of climate change on aquaculture in north western part of Bangladesh. Primary data including fish farmer’s perceptions on climatic change and its impact on their farming practices were collected through face to face interview with 120 fish farmers, 30 from each upazila of Rajshahi district and secondary data of air temperature, rainfall and evaporation were collected from Bangladesh Meteorological Department. Present findings indicated that in last 44 years (1971-2014) mean annual air temperature has been increased by nearly 1.1 °C, while the mean annual rainfall has decreased from 148mm to 112 mm. In addition, mean evaporation showed the increasing trends over the Rajshahi division by 0.50mm/year. As the indicators of the climatic variability, on an average 47% fish farmer mentioned that annual temperature has increased followed by decrease of annual rainfall (about 14%), water quality variability (about 8%) and prolonged drought (7%). Near about 6% of the fish farmer also stated that recently they have experienced with more disease outbreak in fishes as well as lowering groundwater layer. Almost 100% of medium and large scale fish farmer mentioned that they completely depends on groundwater supply to culture fish. Moreover, a substantial percentage of the fish farmer perceived that the growth rate of the cultured fish has decreased and mortality of the fry and fingerlings due to heat shock and disease resulting in decrease in overall total fish production. In addition, farmers also experienced with excessive fish farming cost, most likely to manage the water quality of the ponds (33.33%) and to control diseases outbreaks (25.8%). Majority concluded that they are not interested in involving their family members in fish farming practices because of less marginal profit compared to before and searching for new alternatives to sustain and develop their livelihood status.