Assessment of aquaculture habitat suitability of Gazipur district using geo-spatial technology based multi-criteria modeling

Abstract

The aim of this study wasto develop a method using integrated habitat suitability index approach to produce geo-referenced ecological information about the habitat requirements of different species. A habitat suitability framework has been developed for cultured species of Gazipur districtcomprising five (5) upazilas, named- GazipurSadar, Kalikair, Kaliganj, Kapasia and Sreepur. The degree or magnitude of habitat suitability depends on different parameters such as (i) river connectivity (ii) good spawning ground (iii) water quality (temperature, pH, DO, BOD) (iv) soil pH (v) water pollution (vi) food availability (vii) livelihood status of fishermen, etc. Both the primary and secondary data are used for this study. Primary data were collected through semi-closed questionnaire interview, key informant interview and cross-check interviews. Gazipur Sadar and Kapasia Upazilas have been identified as the highest and lowest habitat suitability for beel and floodplain respectively. In case of KaliakairUpazila, highest habitat suitability has been identified for beel and lowest for pond habitat; in KaliganjUpazila highest suitability for pond and lowest for floodplain; in Sreepur Upazila highest suitability for pond and lowest for beel fish habitat. The present study using multiple regression model has revealed that habitat characteristics, regarding connectivity among existing water bodies, water availability and spawning ground condition, are moderately correlated with habitat suitability at 95% significant level. The present condition of water depth indicates that it is not the major cause for maintaining habitat suitability for culture fish production in the study area. Phytoplankton availability may not play more important role in maintaining habitat suitability due to using artificial feeding for culture fish production in the selected upazilas of Gazipur district. The present condition of water quality is the major causes for maintaining habitat suitability for both the capture and culture fish production in the study area. The present condition of soil quality indicates that it is one of the major causes for habitat suitability for both the capture and culture fish production in the study area. However, water pollution has not been identified as the major causes for regulating habitat suitability Furthermore, increasing indiscriminate fishing activities, like brood and fry fishing and unregulated use of gears, with increasing standard livelihood pattern of full time commercial fishermen resulting in decreased habitat suitability particularly for the capture fish habitats (beel and floodplain).