A geo-spatial study on spatio-temporal growth of brackish water aquaculture along the coastal areas of West Bengal (India)

Abstract

The present study seeks to identify the landuse changes occurring due to haphazard growth of brackish water fisheries along the coastal areas of West Bengal through remote sensing and GIS techniques. High resolution multi-temporal Google Earth images were used for detecting spatio-temporal changes of two blocks of Contai sub-division located in Midnapore district of West Bengal. Also, the area was surveyed with GPS and the digitized maps were verified using the information collected from the aquaculture farm owners. It is evident from change detection analysis that a significant amount of area under agricultural land has been converted into aquaculture farm and also a large number of pre-existing ponds have been converted into brackish water fisheries. Remote sensing derived statistical information on inland fisheries of Contai II and III blocks reveals that area under brackish water fisheries has increased about 2950 acres within the period 2006 to 2011.

From rice fields to brackish water farms: changing livelihoods in agrarian coastal Bengal, India

“…The information collected from the field survey is not enough to quantify the exact change in land use. Thus, remote sensing technology coupled with GIS is used for generating the geodatabase to identify the land-use change (Dutta et al 2016 ). However, while monitoring the mushrooming growth of minute surface features like aquaculture farms here, coarse resolution multispectral Landsat data may not be a good selection, as these kinds of minor features are not easily discernible in the images (Dutta et al 2016 ).…”

“…Thus, remote sensing technology coupled with GIS is used for generating the geodatabase to identify the land-use change (Dutta et al 2016 ). However, while monitoring the mushrooming growth of minute surface features like aquaculture farms here, coarse resolution multispectral Landsat data may not be a good selection, as these kinds of minor features are not easily discernible in the images (Dutta et al 2016 ). Moreover, the Sentinel 2 satellite database cannot accurately predict these farms/ ponds because many of these farms in this study area have a lower area than its spatial resolution (i.e., 10 m × 10 m).…”

“…In this district, different coastal C.D. blocks such as Deshapran, Ramnagar I, II, Contai I, II, III, are already facing various positive as well as negative livelihood issues related to shrimp farming (Dutta et al 2016 ; Maiti 2019 ; Maity et al 2019 ; Rajakumari et al 2020 ). However, these coastal blocks are tide-affected and have minimal production in agriculture.…”

“…At the same time, it has to ensure that the growing population has access to adequate and sustainable food and shelter (Chougrani and El Amrani 2021 ). On the other hand, based on our possibilistic approach, we, the human beings, have always meant to modify the natural environment at the individual and communal levels to meet our growing societal and biological demands (Lawrence et al 2013 ; Dutta et al 2016 ). Therefore, collectively environmental exploitation is increasing day by day through the transformation and intensification of human activities (Belton et al 2020 ; Schmidt et al 2020 ).…”

“…To consider these vulnerabilities of such haphazard growth of shrimp aquafarm, it is essential to quantify the process of expansion. Since the majority of these brackish water fishing ponds are illegal/unauthorized, it is hard to obtain information about the altered land uses from land revenue and fisheries offices (Dutta et al 2016 ). Under this circumstance, remote sensing coupled with GIS can be a very useful tool.…”