Crab culture potential in southwestern Bangladesh: alternative to shrimp culture for climate change adaption

Abstract

Outbreaks of disease, price increases, international competition and impact of climate change has setback shrimp culture in the coastal region of Bangladesh. In this changing environment, crab has emerged as a potential exportable commodity in the country. Farmers are transferring to crab farming as it is less susceptible to disease, resistant to adverse environmental conditions and has a good market price. This paper highlights the application of remote sensing and GIS for crab culture potential. The paper discusses the imminent capabilities of satellite imaging technology and Multi criteria evaluation (MCE) module in GIS environment for development of sustainable crab aquaculture consisted physical, environmental and socioeconomic data to evaluate coastal land based criteria for mud carb farming based on water quality, water availability, salinity, risks of flooding, soil types, topography, land use/land cover; infrastructure, inputs, seed sources, market and support services. All the layers with associated attribute data were digitally encoded in a GIS database to create thematic layers. The database was verified to remove the inconsistency if any. The expert opinions were combined into the model by assigning weights of relative importance to evaluate crab farming and land suitability was categorized as very suitable, moderate suitable, marginal suitable and currently not suitable by implementing the logical criteria. MCE identified a range of suitable land parcels with unique characteristics. The resultant map reveals that a considerable amount of land (28.33%) fell under very suitable category which is situated in the northwest and southwestern part of the area. On the other hand, majority of the land parcel (62.22%) fell within the moderately suitable group that is scattered throughout the area and approximately 9.45% of land was only marginally suitable for crab culture. However, there is no land parcel designated as unsuitable in the present study for crab culture. The suitability output is replicable within the study area and transferable to other areas for other cultured species