Evaluation of Land Suitability for Crab Culture: A Methodological Study using GIS
Salam, M. A.
Assistant Professor, Department of Aquaculture,
Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.
Phone: +88 091 55695-7/2282, Fax: +88 091 55810
Ross, Lindsay G and Beveridge, C. M. Malcolm
Institute of Aquaculture, Stirling University, FK9 4LA, Scotland, UK.
Aquaculture has benefited significantly from the use of Geographical Information Systems (GIS) and Remote Sensing in recent years and these techniques have jointly showed their capabilities in the evaluation and assessment of suitable sites for a variety of culture systems. A GIS is a combination of computer hardware and specialised software, which is used to store, manipulate and analyse data of diverse kinds with a common geographical base. With such automation, reporting can be in the form of tabular data, graphics, and most importantly maps (Burrough, 1986).
GIS have been developed rapidly in the past decade and begin to be used for aquaculture and fisheries development studies. To date, GIS has been applied to regional, country wide or sector studies for aquaculture, where human resources, specific site, economics, markets and socio-cultural resources were used (Kapetsky et al.,1988; Meaden and Kapetsky,1991). On a large scale, a number of sector studies have been made, for example, in the African continent (Kapetsky, 1994), on the Gulf of Nicoya, Costa Rica (Kapetsky,1987), on Johor, Malaysia (Kapetsky,1989), on Louisiana state, USA (Kapetsky et al., 1990) and on Ghana (Kapetsky et al., 1991). Species related GIS for catfish culture was developed by Kapetsky et al., (1988), salmonid cage culture by Ross et al., (1993) and white prawn modelling by Scott et al., (1998).
Although there is considerable potential for shrimp culture in South-western Bangladesh, aquatic resources management in the region have not to date been fully integrated with the rural economy. These resources have great potential and could be further developed to help meet the increasing demand for fish and shrimp in the area. This is best done rationally, establishing a structured decision making and planning scheme, which would play a vital role as a promoter of efficient development.
In this paper focus has been given to using Geographical Information Systems to locate, inventory and compare areas suitable for crab culture at a regional level.
Materials and Methods
The study area is located 300km Southwest of the capital city of Dhaka, Bangladesh, and bordered with India. The area is situated on the vast coastal plain at the apex of the Bay of Bengal and encompasses approximately 14,000 km2 (Figure 1). The area lies between 21030' and 23015' North longitudes and 89000' and 90000 East latitudes and includes the world’s largest continuous mangrove forest, the estuarine marshlands and numerous rivers, canals and their tributaries (Viju, 1995 and Giri and Shrestha 1996). The terrain is relatively flat with elevation ranging from sea level to 5 m above the mean sea level.
The region is one of the most promising areas for aquaculture due to two major factors. Firstly, it’s fresh and coastal water resources are the most abundant in the country. Secondly, the world’s largest continuous mangrove forest is situated in the region, which provides a food source and nursery for the offshore fishery, protection of the coasts from storm surges and cyclones, domestic and commercial products, recreation and tourist services, habitat for various fin fishes, crustaceans and molluscs. It is also the habitat for the Royal Bengal tiger and other national heritage. Culture of fresh and marine water fish, shrimp and other crustacean species are highly important as they can be easily integrated with other activities such as agriculture and livestock rearing.