Impact of water salinity on livelihoods around Sundarban mangrove forests in Bangladesh: A socio-scientific study

Abstract

Sundarbans, the largest mangrove forests in the world occupy 10,000 sq.km and are located in Bangladesh (60%) and India (40%). Sundarban forests are being affected not only by climate change but also by their own inhabitants as they either are forced by climate change to use Sundarbans natural resources or as usual practice of their livelihoods. Sea level rise as one of the impacts of Climate Change brings saline water to the Sundarbans and also to the farms. Farmers are losing their cultivation because of water and soil salinity increment. They have to either change their livelihoods or migrate from their own village seasonally sometimes even permanently. One of the replacement options to their livelihoods can be Sundarbans as it is easily accessible. This study has been done to see the impact of seasonal changes affected from climate change on livelihoods of people nearby Sundarbans, their adaptation all year round while seasons are changing and peoples’ knowledge on climate change and also what they have experienced in their life in this regard. Two villages where lost many farms and declined agricultural crops because of salinity were selected by site visit and also by the help of local authorities. They are located next to Sundarbans, in east part of Bangladesh Sundarbans. Totally 80 people, 40 people from each village were randomly selected with age of more than 18 years old. They were questioned by the pre-prepared and tested questionnaires during the six seasons, throughout a year. The questionnaires included personal details, their livelihoods, respondent knowledge on climate change and the impact of climate change on environment as they experienced in their life. More than 90% respondents of both villages perceived that climate change is happening very rapidly than ever before. Around 50% of respondents feel climate changes in their daily life. Respondents strongly believe that the cultivation land, number of wild animals, and forest areas were decreased very much recently. 80% of them experienced the sea and river level rise. One of the interesting outcomes is that more than 50% could not see any changes in the number of cyclones. It was found that there is no relationship between the age and the trend of water and soil salinity increment. Aged and young people, both are suffering from salinity increment and can recognize it clearly. Young generation is interested to leave the village than changing their job to stay back as they can notice how their family is suffering. They explained 9 ways to understand the salinity grade of soil and water meanwhile they could recognise 8 sources for soil and water salinity in which the main source is saline water from sea by high tides and sea level rise. Respondents requested different supports from Government and Non-Government Organisations for instance Micro Credit from NGOs and infrastructures from GOs. All Physicochemical specifications of Water and Soil samples which were collected from rivers, canals, ponds, tube wells and soil of the study area during the seasons, all year round were analysed. It was found that there were statistically significant at level of 1% (most cases) and 5% (all cases) of changes, which indicates that there were remarkable changes during different seasons for pH condition, Electrical Conductivity (EC), Salinity, content of Potassium, Sodium, Chloride, Calcium, Magnesium, Bicarbonate concentration, Sodium Adsorption Ratio (SAR) and impacts are visible. It was also found out the salinity of tube well water is much higher than other samples. The salinity and EC increase during dry seasons, late autumn and winter. Comprising of the data collected from field interview and collected from water and soil laboratory analysis shows that the livelihoods of dwellers change while the salinity is changing during the seasons and their dependency on Sundarbans is increasing too. Also it shows that during the high salinity months, people who are losing their job due to the water or soil salinity, they are migrating to other places either seasonally or permanently for sustaining their livelihoods. Finally, positive significant relation was found for F-test and t-test and they were within ranges of 1 to 5% significant level for all the cases of environment parameters changes within themselves and with socio-economic parameters of dwellers of study area.