Coastal Bangladesh Research Articles

Risks and adaptation dynamics in shrimp and prawn-based farming systems in southwest coastal Bangladesh

The shrimp industry in Bangladesh is an important economic sector with growing demand, export potential, and employment opportunities. However, the industry is threatened by external and local production and market risks. Risk management strategies can be implemented through farming systems modification developing of different types of shrimp and prawn-based systems, although the adaptive capacity and economic and socio-ecological impacts are unclear. This study evaluated risks, adaptation strategies, profitability, and socio-ecological dynamics in two shrimp-based (shrimp/shrimp/shrimp and wet season (WS) rice/shrimp/shrimp) and two prawn-based (prawn/dry season (DS) rice/prawn and prawn/DS rice/prawn/dike crops) farming systems. Data was collected using focus group discussions (n = 45), household case studies (n = 18), household surveys (n = 120), and key informant interviews (n = 20). Major risks identified included disease outbreaks, lack of tidal water, salinisation, heat extremes, irregular and reduced rainfall, and price fluctuations. Agronomic management (modifying production systems, adjusting farming operations, input applications, dike cropping) was the dominant adaptation strategy in addition to financial mechanisms (market update, selling live stocks and inputs credits), gher management (water management, excavation, dike management) and water management. Adverse socio-ecological impacts of shrimp farming included salinisation, biodiversity loss, soil and water contamination, and reduced crop and livestock production. In contrast, positive impacts of prawn farming included crop diversification and livestock production and decreased salinisation, soil degradation, and biodiversity loss. Despite higher production costs, prawn-based systems generated net income nearly three times higher (USD 3410 to 4470) as compared to shrimp-based systems (USD 1570 to 1790) because dike crops added about 25% extra income. A critical insight of the research is that the prawn-based systems (prawn/DS rice/prawn/dike crop and prawn/DS rice/prawn) were economically more viable (profitable and less risky) than the shrimp-based system. However, neither the shrimp nor prawn system is feasible in all locations. Improved and semi-intensive shrimp farming in high salinity areas with available tidal water and an integrated prawn-based farming system in low to moderate salinity areas can be a viable agricultural land use planning in southwest coastal Bangladesh. This research can contribute to sustainable land use planning for brackish water shrimp and fresh water prawns, and planning to increase the profitability, risk resilience and competitiveness of the shrimp- and prawn-based farming systems with less socioecological impacts.

Effect of Seedling Age on Growth and Yield of Local Aman Rice Varieties in the Low Land Area of Southwestern Coastal Bangladesh

Suitable variety and optimum seedling age are important agronomic decisions for better productivity of rice particularly in the low land area. A field experiment was conducted at the experiment field of Agrotechnology Discipline, Khulna University, Khulna, Bangladesh during aman season (monsoon) to investigate the effect of seedling age on growth, yield attributes and yield of different local aman rice varieties in the coastal low land area of southwestern Bangladesh. Four different seedling ages (15, 30, 45 and 60-days old) and three local rice varieties (Ranisalute, Jatai balam and Basful balam) were used as experimental treatments. The experiment was arranged in a factorial randomized complete block design and replicated thrice. Earlier age seedling (15 days) substantially influenced the growth parameters but yield attributes and yield were significantly higher with 30-days old seedlings yet no significant variation with 45-days old seedling. 30-days old seedling produced 8-32% more grain yield than other seedling ages. Among the varieties, the highest plant height, yield components and yield were achieved from Ranisalute yet the yield variation was only 3-5%. From the findings of this experiment, it can be concluded that Ranisalute variety with the use of 30-days old seedling is better for low land area of southwestern coastal Bangladesh.

Development and analysis of a geospatial database for maritime spatial planning in Bangladesh

In this research we collect, prepare and analyze a geospatial database of maritime activities located in the northern Bay of Bengal with the final aim to simulate maritime spatial planning (MSP) - ready information source for future sectoral and multi-sector MSP in Bangladesh. The database is composed of 28 anthropogenic and environmental layers categorized into seven Blue Economy sectors. The database is analyzed with a set of geospatial models aimed at understanding the intensity distribution of human activities at sea and the potential marine use conflicts emerging from the aggregation of human activities. Ecological resources were characterized in terms of marine mammals, lobsters, commercially important and threatened fish species, and pelagic birds and mapped as biodiversity hotspots using geographic cluster analysis. Results show that the most intensely used sea areas are located along the northeastern coast of Bangladesh, as well as in the Swatch of No Ground (SoNG) area, with maximum Marine Use Intensity (MUI) scores ranging from 5 to 8. Offshore waters of Saint Martin's Island have higher MUI scores (≥ 5) as well. The pairwise spatial conflict analysis shows that nature protection sites particularly SoNG Marine Protected Area (MPA), Nijhum Dwip Marine Reserve (MR), and Saint Martin's Island MPA are exposed to the high Marine Use Conflicts (MUC) induced by fishing and shipping activities. Fishing operations generate the highest MUC value (MUC=30) in SoNG MPA, whereas shipping activities produce the highest MUC value (MUC=24) in Nijhum Dwip MR. Both of the MPAs exhibit 6 to 12 MUC scores induced by shipping. The proposed database together with the illustrated analytical techniques used in this study and key findings can provide the first understanding of the priorities for Ecosystem Based Management of Bangladesh's marine space and provide valuable insights on the urgency for MSP process in the country. The study concludes with an outlook on the utility of the database for future analysis.

Household’s Agricultural Vulnerability to Climate Induced Disasters: A Case on South-West Coastal Bangladesh

Climate change-related catastrophic events have a considerable influence on south-western coastal agriculture in Bangladesh. The objectives of this study are to measure the agricultural vulnerability of south-western coastal households in Bangladesh due to climate-induced disasters and to find the sub-indicators of adaptive capacity (AC) that influence the agricultural vulnerability. An agricultural vulnerability index (AVI) was developed by using the intergovernmental panel on climate change (IPCC) dimensions to measure the vulnerability. The sub-indicators of AC that affect agricultural vulnerability to climate-induced disasters were identified using an ordered logit model. This study employed a survey of 346 households from two villages (181 households from Sutarkhali and 165 households from Nalian) of the Sutarkhali Union of Dacope Upazila within a south-west coastal district (Khulna) of the country. The main respondents were the household heads. The findings demonstrated that Sutarkhali had a mean score of 0.703 (high) for exposure, 0.762 (high) for sensitivity, 0.397 (low) for AC, and 0.689 for AVI (high). Similarly, Nalian scored 0.658 (high) for exposure, 0.681 (high) for sensitivity, 0.410 (low) for AC, and 0.643 (high) for AVI. Non-farm employment, livestock ownership, irrigation pump access, improved crop diversification/saline tolerant high-yielding variety (HYV) crops access, and farm credit access were found to be statistically significant sub-indicators of AC that affect the agricultural vulnerability of both study sites. Finally, it is recommended that the relevant authorities and policy makers should implement the necessary agricultural adaptation initiatives in south-west coastal Bangladesh.

Vulnerability of Women and Climate Change in Coastal Bangladesh

This paper focuses on providing a comprehensive scenario of women’s vulnerabilities based on the effects of climate change in Bangladesh. To address the problem, this study focuses on the nature of suffering and how they have tried to mitigate it. This study followed the purposive sampling method of a total of sixty respondents from the Satkhira district. Primary data were collected through a structured questionnaire, survey, and observation method. Besides these, secondary sources of national and international levels have been used in this study. This study found that sanitation problems of women and young girls as well as the lack of pure drinking water are common during the disaster time in the study area. In the context of a patriarchal society like Bangladesh, women are compelled to be submissive and obey the decision of male members due to prevalent social and cultural norms and conditions. As a result, most of the time, even when problem arise, women do not take any decision about whether they would stay at their home or seek shelter. The study uses an exploratory approach, and it will provide an insight into different sorts of sufferings as well as the detrimental effects of such natural disasters. It will also provide a better understanding and intensity of the problem. Although innumerable studies of climate change and its effects have been published, underlying scenarios are not properly focused on. Therefore, it would obviously help for further study as well as policymaking.

Mangrove forest conservation vs shrimp production: Uncovering a sustainable co-management model and policy solution for mangrove greenbelt development in coastal Bangladesh.

Mangrove forests are remarkably diverse and productive ecosystems, with distinctive biophysical environments in intertidal coastal regions of the tropics and subtropics. In these regions, shrimp cultivation is identified as a profitable business and one of the main reasons for clearing of mangroves to construct shrimp farms. Against this backdrop and based on the first author's previous PhD research and other relevant scholarly works, in this commentary we discuss the aspects and contexts of the mangrove-based integrated shrimp farming system. Then, we recommend a model of co-management and a set of policy option towards sustainable silvo-aquaculture to protect/restore the mangrove forests and sustain shrimp production in coastal areas of Bangladesh. Mangroves and shrimp culture are not necessarily incompatible. Many mangrove species have been identified as beneficial for shrimp culture for a number of possible reasons. Most importantly, the nutrients in the leaf litter of several mangrove species have been found to enhance natural food production for shrimp. Besides the nutrient input, the leaf litter also provides surface area for biofilm development, on which different life stages of shrimp can graze. In addition, the combination of mangrove leaf litter and feed has been shown to enhance shrimp production synergistically. Additional economic benefits from mangrove-shrimp co-management include the production of timber (e.g. buildings, boats and fuel woods) and non-timber products (e.g. fruits, honey, fibers, firewood, resins and bark). Thus, mangrove-based aquaculture or silvo-aquaculture system can be considered as a nature-based solution to sustainably revitalize the economy in coastal areas where shrimp has been the economic mainstay. Though there are positive effects, we point out some potential negative impacts of mangrove-based shrimp culture, like the anti-nutrients content in the leaf litter, which might impact shrimp production. In addition, the long term use of mangrove leaf litter might degrade the water quality. Therefore, the co-management policy recommends a controlled practice of mangroves in shrimp culture to balance conservation of mangrove-based ecology and profitable shrimp production. The approach promotes nature-based solutions and fosters sustainable pathways for food production, considering socio-economic and environmental dynamics.

Effect of Coriolis Force on the Numerical Estimation of Water Level Elevation Due to a Catastrophic Cyclone along the Coast of Bangladesh

A two-dimensional vertically integrated shallow water equation in the Cartesian coordinate model is used to estimate the water level considering the impact of Coriolis force. The shallow water model equation was discretized by a finite difference method (FDM). Consider the forwarding of time and central space as a moderator of this discretization. The model approximates coastal boundaries, small islands, small rivers and complex tributaries by an accurate stair step representation. The model equations are solved by a static semi-implicit finite difference technique where a structured Arakawa C-grid system is used as the condition. A one-way nested scheme technique is used to incorporate complex land-sea interfaces such as small offshore islands and water depths with sufficient accuracy as well as decreasing the computational cost. A stable tidal condition was created by applying M2 tidal forcing with the largest tide along the southern open boundary of the Bay of Bengal. The model uses the Coriolis force as an external force that can affect water buoyancy. The main task is to analyse the effect of Coriolis force on water buoyancy. The described model was applied to simulate sea-surface elevation associated with the severe cyclone in April 1991 that strike on the east coast of Bangladesh. We have found a significant impact of Coriolis force on surge height. However, the model gives an accurate numerical estimate of surge height.

Performance study of imageries from MODIS, Landsat 8 and Sentinel-2 on measuring shoreline change at a regional scale

In monitoring shoreline change, remote sensing data plays a pivotal role. Although different freely accessible satellite data are used in studies of shoreline change at various scales, it is imperative to identify their effectiveness at a regional scale. This study aims to determine how effectively MODIS, Landsat 8, and Sentinel-2 satellite images measure regional shoreline change. Digital Shoreline Analysis System (DSAS), an ArcGIS extension, was utilized to analyze the changes in the shoreline of Ganges deltaic coast in Bangladesh. The Shoreline Change Envelope (SCE) technique was applied to compare the shorelines extracted from MODIS, Landsat 8, and Sentinel-2 for the year 2016 with high-resolution Google Earth image. Next, using the End Point Rate (EPR) method, shoreline change rates between 2016 and 2019 were calculated separately from each satellite data. The study points out which satellite data was more accurate in delineating shoreline. Due to a higher spatial resolution, Sentinel-2 data were more effective than Landsat and MODIS data at a regional scale. In addition, MODIS, Landsat 8, and Sentinel-2 data indicate that the Ganges deltaic coast experiences landward movements of 54.65 m/yr, 12.56 m/yr, and 1.79 m/yr, respectively. Hence, it can be concluded that if the spectral resolution is coarse, shoreline change is overestimated. Therefore, in order to analyze or predict shoreline change (even at a regional scale), priority should be given to using images with fine spatial resolution. The spectral analysis of MODIS, Landsat and Sentinel showed a similar pattern of separability among the land cover classes observed along the Ganges deltaic coast. The separability is higher in NIR (Near Infrared) and SWIR (Short Wave Infrared) bands. This study will direct researchers in the selection of remote sensing data sources for shoreline change detection within a regional scale.

Assessment of household-level adaptation strategies to water stress in southwestern coastal Bangladesh: a counter-factual analysis

AbstractDespite the growing emphasis and global initiatives to ensure safe drinking water and sanitation for all (Sustainable Development Goal 6), households in coastal areas are at risk of growing water stress across the globe. However, little is known about households' adaptation strategies to water stress in coastal areas. This study explores the determinants and impacts of adaptation strategies to household-level water stress (both drinking and non-drinking), considering the behaviors of adopters and non-adopters in the southwestern coastal area of Bangladesh. We applied an endogenous switching regression model by analyzing questionnaire survey datasets (n=502) to estimate the effect of adopting adaptation strategies on household-level water stress in four saline-prone coastal sub-districts of Bangladesh. Results reveal six commonly-practiced adaptation strategies: reducing vegetable production, reducing livestock production, paying more to access water, increasing time for water collection, preserving water, and using reservoirs to collect water. Determinants such as migration, support from government and non-government agencies, age, gender, literacy, occupation, income, access to tube wells, and distance from drinking water sources play a significant role in adopting adaptation strategies. Results from the endogenous switching regression model denote that adopting all six adaptation strategies appears to significantly reduce household-level water stress. Through counter-factual analysis, results demonstrate that, on average, households that did not adopt adaptation strategies would have encountered less water stress if they had. Therefore, determinants that stimulate adaptation strategies will indirectly reduce household water stress.

Hydrochemical characterization and groundwater potential of the deep aquifer system in southwest coastal region of Bangladesh

Maintaining the water quality of a coastal aquifer is very important for its sustainable development and management. The shallow aquifers in the southwest coast of Bangladesh are highly saline. This research was conducted to explore the hydrochemistry and potential of the deep aquifer using pumping test, hydrochemistry, multivariate statistics, and groundwater quality index. The groundwater is mostly of NaHCO3 type (85%), but small amount of NaCl (15%) type waters are also present. Principal component analysis indicates four factors (73.43% of the total variance) controlling the composition of groundwater: paleo-seawater, cation exchange, mineral dissolution, and oxidizing conditions. Zonation of hydrogeochemical processes within the deep aquifer are well established by hierarchical cluster analysis. Seven clusters have been distinguished from this analysis: cluster 1 (paleo-saltwater), clusters 2 and 4 (freshwater influence), clusters 3 and 7 (freshwater invasion and mineral dissolution), cluster 5 (no specific geographical location) and cluster 6 (mixed water). The groundwater quality index shows that 88% sampled water is of excellent to good and only 3% is unsuitable for drinking purposes. However, 53% of water has Na+ concentration above drinking standard. This parameter has very little contribution in groundwater quality index calculation, which we consider a shortage. Pumping tests revealed that transmissivity of deep aquifer has a median value of 888 m2/day and a hydraulic conductivity of around 15 m/d, indicating a good hydrodynamic potential. The overall water quality is good, except in the southwest corner of the study area. It is, therefore, recommended to exploit groundwater from the deep aquifer.

Impact of cropping system diversification on productivity and resource use efficiencies of smallholder farmers in south-central Bangladesh: a multi-criteria analysis

Diversification of smallholder rice-based cropping systems has the potential to increase cropping system intensity and boost food security. However, impacts on resource use efficiencies (e.g., nutrients, energy, and labor) remain poorly understood, highlighting the need to quantify synergies and trade-offs among different sustainability indicators under on-farm conditions. In southern coastal Bangladesh, aman season rice is characterized by low inputs and low productivity. We evaluated the farm-level impacts of cropping system intensification (adding irrigated boro season rice) and diversification (adding chili, groundnut, mungbean, or lathyrus) on seven performance indicators (rice equivalent yield, energy efficiency, partial nitrogen productivity, partial potassium productivity, partial greenhouse gas footprint, benefit-cost ratio, and hired labor energy productivity) based on a comprehensive survey of 501 households. Indicators were combined into a multi-criteria performance index, and their scope for improvement was calculated by comparing an individual farmer’s performance to top-performing farmers (highest 20%). Results indicate that the baseline system (single-crop aman season rice) was the least productive, while double cropped systems increased rice equivalent yield 72–217%. Despite gains in productivity, higher cropping intensity reduced resource use efficiencies due to higher inputs of fertilizer and energy, which also increased production costs, particularly for boro season rice. However, trade-offs were smaller for diversified systems including legumes, largely owing to lower N fertilizer inputs. Aman season rice had the highest multi-criteria performance index, followed by systems with mungbean and lathyrus, indicating the latter are promising options to boost food production and profitability without compromising sustainability. Large gaps between individual and top-performing farmers existed for each indicator, suggesting significant scope for improvement. By targeting indicators contributing most to the multi-criteria performance index (partial nitrogen productivity, energy efficiency, hired labor energy productivity), results suggest further sustainability gains can be achieved through future field research studies focused on optimizing management within diversified systems.

Exploring the parameters of central redox hub for screening salinity tolerant rice landraces of coastal Bangladesh

Regulation of oxidative stress towards origin of favorable internal redox cue plays a decisive role in salinity stress acclimation and least studied in rice and hence is the subject of present investigation. Redox landscaping of seedlings of ten experimental land races of rice of coastal Bangladesh grown under post imbibitional salinity stress (PISS) has been done through characterization of ROS-antioxidant interaction dynamics at metabolic interface, transcriptional reprogramming of redox-regulatory genes along with the assessment of biomarkers of oxidative threat for standardizing redox strategies and quality parameters for screening. The results exhibited a strong correlation between salinity induced redox status (pro-oxidant/antioxidant ratio, efficacy of H2O2 turnover through integrated RboH-Ascorbate–Glutathione/Catalase pathway and estimation of sensitive redox biomarkers of oxidative deterioration) and germination phenotypes of all landraces of rice. Transcript abundance of the marker genes of the enzymes associated with central antioxidant hub for H2O2 processing (CatA, OsAPx2, SodCc2, GRase and RboH) of all experimental landraces of the rice advocate the central role of H2O2 turnover dynamics in regulating redox status and salinity tolerance. Landraces suffering greater loss of abilities of decisive regulation of H2O2 turnover dynamics exhibited threat on the oxidative windows of the germinating seeds under salinity.

Monitoring Changes in Land Use Land Cover and Ecosystem Service Values of Dynamic Saltwater and Freshwater Systems in Coastal Bangladesh by Geospatial Techniques

Assessing and modeling the changes in land use and land cover (LULC) patterns and associated ecosystem service values (ESV) has become an important global agenda for formulating sustainable land management policies. Taking the coastal region of Bangladesh (CRB) as a case study, we utilized remote sensing and GIS techniques to analyze Landsat data of 1999 and 2019 to estimate the effect of LULC changes on the ESVs. The LULC classification, ESV quantification, and spatial variations were performed by semi-automated classification, per-unit value transfer, and spatial autocorrelation techniques, respectively. First, between 1999 and 2019, LULC altered dramatically (agricultural land and coastal wetlands decreased, while all other LULC types increased). Second, the total ESV decreased by 1.87%, which was mostly attributed to a 70% growth in both rural settlement and aquaculture/saltpan, and a 30% decline in both agricultural land and wetlands. Third, significant spatial correlation and moderately high spatial clustering were observed, which consisted mostly of mangrove forests, waterbodies, and wetland zones. Both high-high and low-low values increased, but spatial outliers remained unchanged. Conserving agricultural land should be prioritized in future land use plans of CRB to meet the ever-increasing food demands, control natural land conversion, and make land use sustainable.

Adapted Conservation Agriculture Practices Can Increase Energy Productivity and Lower Yield-Scaled Greenhouse Gas Emissions in Coastal Bangladesh

While numerous studies have documented the benefits of conservation agriculture (CA) in South Asia, most focus on favorable environments where farmers have reliable access to energy supporting irrigation and inputs. The performance of CA in South Asia’s under-developed coastal environments is comparatively understudied. In these environments, farmers are increasingly interested in growing a second crop to meet food security and income generation objectives in rotation following the predominant monsoon season rice crop, though labor, energy costs, and investment constraints limit their ability to do so. We hypothesized that rotating rice (Oryza sativa) with maize (Zea mays) using conservation agriculture, or CA (i.e., strip-tilled maize followed by unpuddled transplanted rice), or seasonally alternating tillage (SAT, i.e., strip-tilled maize followed by fully-tilled, puddled rice with residues retained across rotations) would reduce costs and energy use, increase energy-use efficiency, and reduce yield-scaled CO2-eq emissions (YSE) and total global warming potential (GWP), compared to farmers’ own practices (FP) and conventional full-tillage (CT) under the same rotation in Bangladesh’s coastal region. Starting with winter maize followed by summer rice, we evaluated four tillage and crop establishment treatments in farmer-managed experiments in partially irrigated and rainfed environments over three years in 35 farmer’s fields across Bangladesh’s coastal districts. Treatments included FP, CT, complete CA, and SAT under a rice-maize rotation. Across years, the full suite of CA practices and SAT were significantly more energy-efficient and energy-productive than FP or CT. The order of YSE in rice was CA< CT or FP < SAT while in maize, it was CA or SAT < FP < CT. Across environments, CA and SAT resulted in 15-18% higher yield at the cropping systems level (maize and rice yields combined) and 26-40% less manual labor than CT or FP. CA and SAT also reduced by 1-12% and 33-35% total production costs respective to CT and FP. This was associated with 13-17% greater grain energy output in CA and SAT, and 2-18% lower YSE, compared to CT or FP. While our data suggest that both CA and SAT can result in a range of positive agronomic, economic, and environmental outcomes compared to FP or CT, post-trial surveys and discussions with farmers revealed a strong practical aversion to use of the full suite of CA practices and preference for adapted practices due to logistical constraints in negotiating the hire of laborers for unpuddled manual transplanting.

Determinants of households' livelihood vulnerability due to climate induced disaster in southwest coastal region of Bangladesh

Climate-related disasters have a severe impact on the livelihoods of people in south-western coastal Bangladesh, and the adaptive capacity is linked to this. However, this subject has not received any thorough attention. This study therefore identified the adaptive capacity indicators that affect the livelihood vulnerability to climate-induced disasters in the three unions (Dakshin Dedkashi, Bagali, and Koyra) of Koyra Upazila (sub-district) in the Khulna district (a climate-vulnerable southwest coastal region) of Bangladesh. We surveyed 300 households from the three unions using an interview schedule. The data were analyzed by using an ordered logistic regression. Gender and education of household heads, presence of dependents, family members working in different communities, crop growing, agricultural activities as the primary source of income, access to support from relatives or friends, access to local government services, and membership in community-based social organizations were identified as the significant indicators of adaptive capacity that determine vulnerability in this study. A partnership between government agencies and the community might lead to new perspectives on climate risk mitigation measures; the cost-effective adoption of innovative adaptation solutions; and social inclusion and empowerment in terms of livelihood opportunities.

Climate Change Impact and Frequency of Cyclone Surge in Bangladesh Coast: Proper Plan to Address Sustainably

Climate Change Impact and Frequency of Cyclone Surge in Bangladesh Coast: Proper Plan to Address Sustainably

The effect of drinking water sources due to Cyclone Aila at Shyamnagar, Sathkhira district, Bangladesh

Bangladesh is the most vulnerable country to disaster and its impact. Coastal Bangladesh along with the Bay of Bengal is the most important and suffered group of cyclone impacts. Cyclone Aila hit the southwestern coast of Bangladesh on 25 May 2009. About two million people were affected and washed away a huge number of households, lives, livestock, crops, and all other resources of the affected area. Water resources in the coastal area are always a term of crisis and even the aila mostly damaged all the resources including surface or groundwater sources. This study focuses on the recovery status of the affected area with considering the drinking water sources. About 36 water samples had been collected for the experiment including rainwater harvesting (6), pond sand filters (6), protected pond (6), and hand tube well (6) from specific six unions of Shyamnagar Upazilla under Sathkhira District in between the time of August to October 2016. A questionnaire field survey was conducted in the most affected coastal area in Bangladesh where about 103 households (309 respondents) participated in their willingness and the study considering their frequency of loss. The results showed a huge dimension of the water crisis and its mitigation. Protected pond and tube well water exceeded the DoE standard for almost all chemical parameters except potassium (3.28 mg/L and 3.75 mg/L), sulfate (377.19 mg/L and 225.66 mg/L), chloride (365.05 mg/L and 349.10 mg/L) and arsenic (1.76±0.25 mg/L and 3.78±1.43). Pond sand filter (PSF) and rainwater harvesting (RWH) had shown the lowest amount of all chemical concentrations compared with another two sources. The respondents face the problem of the distance from the household and the yearly availability of drinking water. They demand monitoring and source management system improvement along with community-based resource management. From the aila event, a huge recovery application is implemented here but these are not sufficient. Respondents gave some opinions to solve this crisis. Considering all aspects, they need a low-cost and more efficient drinking water source to survive their situation.

Mangrove apple (Sonneratia caseolaris): A promising fruit in Patuakhali coast of Bangladesh

Mangrove apple (Sonneratia caseolaris) is a widespread underutilized fruit species of coastal region of Bangladesh. The present study was undertaken to find out the flowering, fruiting, nutritional quality and extent of variability among different mangrove apple germplasm. Twelve germplasm were selected from three locations - six (SC 02, SC 03, SC 04, SC 05, SC O6 and SC 07) from Dumki sadar, two (SC 01 and SC 08) from PSTU germplasm centre and four (SC 09, SC 10, SC 11 and SC 12) from Patabuniya, Dumki, Patuakhali. Flowering season started from May and continued up to November. Percentage of fruit setting ranged from 96.03 to 89.96% in SC 01 and SC 12, respectively. Required time for fruit maturation ranged from 106 days (SC 06) to 55 days (SC 05). Single fruit weight varied from 122.3 g (SC 01) to 54.33 g (SC 04). The length and diameter of fruit ranged from 2.9 cm (SC 05) to 2.20 cm (SC 07) and 5.20 cm (SC 05) to 3.60 cm (SC 04), respectively. The maximum edible portion (66.15%) was recorded in SC 01, and it was the lowest (51.45%) in SC 07. Chemical analysis was done with the pulp of selected germplasm where the germplasm SC 01 exhibited the best performance in all parameters of chemical analysis. This analysis was performed at four different ripening stages. The highest TSS (8.72%) was recorded in stage I. The highest pH level (3.51) was observed in stage III and the lowest pH level (2.83) was found in stage I. The highest ascorbic acid content (37.50 mg/100g) was noted in stage IV. Flower of mangrove apple produces a kind of honey. Fresh fruits and seeds have high nutritional and medicinal value. Wood of this plants provides great livelihood support to the local residents for fetching good price in the markets. Proper utilization of S. caseolaris may contributes the nutritional security of the women and children of this area by fulfilling the demand for micronutrients, especially vitamin C. Bangladesh J. Agri. 2019-2021, 44-46: 9-17

Appraisal of different attributes of fish community in Andharmanik River of coastal Bangladesh and socio-economic conditions of fishermen

The purpose of this study was to determine the fish species composition and appraise the status of fish diversity through sampling in six sample locations and to observe the socio economic conditions of the fishermen surrounding the river during the study period. There were 81 fish species found, classified into 13 orders, 40 families, and 69 genera. The most dominant order was Perciformes (55.42 %), followed by Clupeiformes (20.44 %), Cypriniformes (8.96 %), Siluriformes (8.13 %), and others (7.05%). To illustrate the species diversity, fish species richness and evenness in sampling areas, indices of fish community viz. Shannon-Wiener's Index (H), Simpson's Dominance Index (D), Simpson's Diversity Index (1-D), Margalef's Index (d) and Gibson's Evenness (€) were used and 3.29–3.48, 0.05–0.069, 0.93–0.95, 6.88–8.43 and 0.39–0.49 respectively were the overall values of the indices. S1 station is significantly differ in species richness from the rest of the five stations (P < 0.05). The analysis of similarity (ANOSIM) displayed significant (P-value < 0.05) variations in fish community among stations and months. In compliance with similarity percentage (SIMPER) analysis, 35.8% similarities were observed among the fish species from different stations, while 59.36% similarities were detected among the fish species from different months. One species is critically endangered (CR), three species are nearly threatened, eight species are endangered (EN), and eight species are vulnerable among the 81 fish species recorded at various sampling locations. The socioeconomic conditions of fishermen were determined on the basis of a personal interview and focus group discussion. Unfair fishing practices as well as environmental instabilities such as reduced water volume, increased sedimentation, water abstraction, and pollution have ravaged fish habitat and diminished fish diversity over time. As a result, fish preservation in the Andharmanik River has become imperative, and an integrated management plan should be designed and executed as soon as possible.

Livelihood assets, mutual support and disaster resilience in coastal Bangladesh

Livelihoods, and the household assets that support them, are crucial for households' own disaster resilience, and for their capacity to provide support to other households during an emergency and recovery phases. Using a combination of a quantitative survey, and interviews and focus group discussions for qualitative depth, this study looks closely at the human capital, natural assets, physical assets, and financial capital that households in two Bangladeshi coastal villages rely on for disaster resilience. During the emergency response period, health and physical strength (human capital), and food stocks (physical capital) are the assets that households most rely on. Other kinds of assets (natural, and financial) play larger roles during early and long-term recovery phases. On average, each household has one healthy member of working age who is not employed, so expanding livelihood opportunities, both locally (e.g. in fish processing) and in skilled employment elsewhere (e.g. through technical education) is fundamental. Coastal households in Bangladesh are generally very poor. Only 4% of households were housed in concrete homes that are relatively cyclone resilient. Their main livelihood assets - boats, nets and agricultural land - are also all very vulnerable to cyclonic impacts. Strengthening disaster resilience via improving the asset base of coastal households is a ‘general resilience’ agenda. This broader development agenda is the foundation for improving disaster resilience.