Southwest Bangladesh Research Articles

Fishing Gears and Practices in the Bukbhora Oxbow Lake: Implications for Biodiversity Conservation in South-west Bangladesh

Bukbhora ox-bow Lake (baor) is one of the most renowned baors in the south west Bangladesh and supports diverse fisheries communities. The present study was conducted to identify the types of fishing gears and crafts including their mode of operation in fishing in the Bukbhora baor during the period from July 2023 to June 2024. A total of 18 fishing gears and crafts were recorded at different stations of the Bukbhora ox-bow Lake. Fishing gears were categorized as nets (8), traps (3), hooks and lines (3), wounding gears (2) and crafts (2). Among nets, highest mesh size recorded 5-8 cm in fash jal whereas the lowest was thela jal 0.25 cm. The highest fishing effort/day was found for Jhaki Jal (cast net) 13-15 and the lowest was recorded in case of current and punti Jal (01). Highest CPUE (kg/effort) was found in ber jal (15-18) and the lowest was found in Thela jal (1-1.5). Similarly seine net contributed to the highest catch (70.19%) and push net was the lowest (1.00 %). Maximum fishers had pieces of kochal (Seine net) and komar (drag net) 2-5 pieces and those were jointed together (each of 18 fishers groups separately work) during the harvesting period. Fishing (harvesting of carp species) started in November-December and completed on 30th June in each season. Based on the usage, the seine net was found as the most usable gear by the fishermen constituting 78.15% and fewer amount by traps. The highest price of fishing gear was observed in case of ber jal (about 1,00,000 BDT) and the lowest price was for punti jal (250-2500 BDT). Among 16 fishing gears 5 of these were found illegal in this study due to its mesh size and destructive behavior of fish biodiversity. Except some, majority fish species trapped in the recorded fishing traps were Small Indigenous Species, whereas fishing hooks and lines were used to catch carnivorous fish species mainly. Wounding fishing gears were used for wounding large size fishes during heavy flood or when water level becomes low. This study showed that 40.91% fishers had their own fishing craft (dingi nouka) where 59.09% had no craft. It is recommended to strong implementation of all conservation guidelines and acts to prevent illegal fishing, seizing of destructive fishing gears and also protecting potential breeding habitats.

Psychological health declined during the post-monsoon season in communities impacted by sea-level rise in Bangladesh

Sea level rise affects the long-term psychological health of coastal communities. However, research on long-term and seasonal impacts on vulnerable communities’ psychological health is limited. Here, we explore the effect of sea-level rise on the psychological health of the coastal population in Satkhira and Khulna districts of southwest Bangladesh across two seasons: before monsoon (March to April) and post-monsoon months (October to November) in 2021. We leveraged the longitudinal research that involved 1144 participants. We collected data on psychological health using established scales for distress, depression, anxiety, and stress and also measured environmental factors and resource losses. Results indicate that psychological health, particularly distress, depression, anxiety, and stress, increased during the post-monsoon months in communities more vulnerable to sea-level rise. Highly vulnerable communities showed increased psychological distress post-monsoon. Environmental stressors and resource loss escalated during the post-monsoon period, especially in moderate and highly vulnerable communities. Our findings emphasize the urgent need for targeted support and resilience-building interventions in affected communities to alleviate the psychological health impacts of sea-level rise.

Delineation of fresh groundwater potentiality zones in saline coastal aquifers, Southwest Bangladesh using remote sensing and GIS approaches.

Bay of Bengal in southern Bangladesh is a major source of water from coastal aquifers, but prone to contamination by seawater intrusion,making climate-vulnerable populations and economies unfit for potable, agricultural water, adopting crops, etc. The study area located in Khulna district lies in the southwestern coast of the country is among the most vulnerable due to its salinity issues. Therefore, this study identified fresh groundwater potential zones in the southwestern coastal zones of the country suited for community usage helping coastal peoples meet their demands. This study focused on twelve thematic layers employing remote sensing and GIS with analytical hierarchy process. Here, groundwater salinity is 84% brackish to saline over 70% of the region [electric conductivity: 295-16,295 micro-Siemens/cm]. However, groundwater chloride in 88% signifies a slightly to medium salty zone. The annual average rainfall reduced surface water infiltration in 75% of the area with little to very slightly soil salinity. The fresh groundwater resource zone has classified based on its potentiality as: very high (0.52%)-for drinking, agricultural irrigation, or industrial work; high (25%)-marginal salinity suitable for agricultural or industrial uses; low (11%)-low salinity, but usable for high salt tolerant crops in irrigation; and very low (64%)-very high groundwater salinity, and not suitable for human consumption and community uses. Finally, this study will help develop sustainable groundwater resources in the coastal region and a fresh groundwater supply plan in saline-prone areas.

Challenges in Agrobiodiversity Maintenance in Southwest Bangladesh: An Intersectional Analysis

Guided by the intersectional approach, the objective of the paper is to engage gender as an analytical variable across class and spatial inequalities to explore agrobiodiversity maintenance. The paper dwells on challenges faced, and factors influencing agrobiodiversity choices and its maintenance. Data was collected from a survey of 343 households, 14 focus group discussions conducted in seven villages, and in-depth interviews with 30 research participants in Southwest Bangladesh. The findings show that challenges in maintaining agrobiodiversity and its choices are gender, class, and spatially differentiated within the context of environmental change. The challenges faced by rural households in maintaining agrobiodiversity are not linear and straightforward and poor women are inclined to make choices to ensure food security and wellbeing of the family. Therefore, understanding how overlapping inequalities in rural farming areas experiencing environmental change is key to the design of agrobiodiversity-based solutions towards food security for the poor.

Organic Matter and Indigenous Vegetables in Sack under Waterlogged in Southwest Bangladesh

A study on the prospect and profitability of indigenous vegetables (Kalmi, Helencha and Malancha Shak) was conducted in Shyamnagar Upazila of Satkhira district in waterlogged conditions from September 2020 to May 2021. In the study, three indigenous vegetables (Ipomoea aquatica, Enhydra fluctuans and Jussiaea repens) were tested with four levels of growing media viz., T0, control (no organic matter); T1, 75% organic matter+ 25 % soil; T2, 50 % organic matter +50% soil; T3, 25% organic matter+ 75% soil. Results show a significant difference among the treatments and different indigenous marshy leafy vegetables. The maximum yield, gross and net income and BCR in all the vegetables were observed in T1. In the case of comparative analysis of different vegetables, the highest yield, gross and net income and BCR were also recorded from Helencha Shak and that was the lowest in Kalmi Shak.

Geochemistry of Arsenic and Salinity-Contaminated Groundwater and Mineralogy of Sediments in the Coastal Aquifers of Southwest Bangladesh

This study aimed to develop a geochemical database by thoroughly analyzing groundwater and sediments from coastal aquifers of southwest Bangladesh. Moreover, we investigated the source of sediment deposition and the mechanisms behind the presence of arsenic and salinity in groundwater. The seasonal distribution patterns of arsenic among the shallow and deep coastal aquifers were found to be 45.12 µg/l and 20.65 µg/l during dry and wet seasons, respectively. Moreover, the groundwater salinity distribution ranged from 3262.88 mg/l to 1930.88 mg/l during the dry and wet seasons. Cored sediment samples showed fine to medium sands of 92%, with silt and clay particles. The petrographic study of authigenic and heavy minerals revealed that the mineral grains were subangular to angular, indicating their textural immaturity of coastal sediments. The reactivity of goethite (FeOOH) and siderite (FeCO3) minerals suggests that the aquifers were subjected to slightly oxidized to moderately reducing conditions, with ORP values ranging from +50.40 mv to −149.5 mv. Such redox conditions could potentially result in the enrichment and mobility of arsenic in the groundwater. Although arsenic concentrations in deep aquifers are relatively low, higher salinity values are found in both shallow and intermediate coastal aquifers.

Local social-ecological context explains seasonal rural-rural migration of the poorest in south-west Bangladesh

Bangladesh is one of the countries most affected by climate change. Internal migration is often presented as a response to environmental degradation. Here, using a people-centred perspective, we explore the complexity of the links between climate-induced change, environmental degradation caused by waterlogging and seasonal rural migration. We used an inductive qualitative approach in social sciences, conducting fourteen semi-directed interviews and six focus group discussions in March-April 2022. We related those results to a rainfall analysis on CHIRPS data for 1981-2021and we represented interactions and feedback between changes and livelihoods in a model. A complex picture of the situation is emerging, showing the interweaving effects of non-climatic and climatic changes, their interplay at different scales, their cumulative effects, the interactions between livelihood types and feedback between social and natural systems. Most of the climate-induced changes gradually become noticeable over the past 25 years. Climate data confirm these changes in recent decades, with July being wetter and January being dryer. Villagers reported waterlogging as the most significant change in their community, pointing to its multiple causes, originating in non-local and local, non-climatic anthropic changes, exacerbated by shrimp farm enclosures and worsened by climate-induced changes such as heavier rains, wetter monsoons and cyclones. Tiger prawn farms, reported as a lucrative and local adaptation to waterlogging and salinisation for the ones who can afford it, worsen the situation for the less wealthy, causing waterlogging and salinisation of the adjacent agricultural lands and buildings, the disappearance of traditional fishing and a reduction of the local job market. In addition, erratic rain patterns, droughts and cyclones affect local production and labour markets. COVID-19 lockdowns, by impacting markets and mobilities, further aggravated the situation. Inequality has increased as the range of adaptations of the less wealthy appears limited in this context of multiple crises.

Examining the link between marginality and differential climate resilience among disaster-affected communities in southwestern Bangladesh

ABSTRACT This article uses a case study of one of Bangladesh’s most disaster-prone subdistricts to examine the role of marginality in determining differential climate resilience. It used a quantitative research design and a household questionnaire survey to acquire data. In order to determine the contributing factors and quantify the magnitude of the influence, ordinal logistic regression is utilized in conjunction with principal component analysis (PCA). The AHP-based indexing approach was used to quantify the degree of resilience and marginality. Results revealed a complex link between marginality and resilience in disaster-affected areas of Southwest Bangladesh. They exhibit four distinct connections, which is impressive because it demonstrates how resilient marginalized households can be and how the opposite is true. It also identifies a lack of access to the formal institutional network and support, restricted access to social support networks, exclusion from housing and public services, restricted freedom of choice networks, and lack of access to financial assets) that have a significant impact on differential resilience. Local governments or policymakers can implement several recommendations by emphasizing the factors that affect various levels of resilience, such as boosting institutional and monetary support, fortifying social networks, improving essential services, and creating livelihood opportunities.

Reducing social vulnerability to climate change: the role of microfinance organisations

ABSTRACT In theory, the work of microfinance organisations (MFOs) should help to reduce social vulnerability to climate change, and there is growing interest in using microfinance for this purpose. However, evidence of a relationship between MFOs and social vulnerability is limited and piecemeal, as is knowledge of which of their various services associate with the diverse dimensions of vulnerability. This paper investigates the role that MFOs play in reducing social vulnerability to climate change in Bangladesh, a country that has both a long history of microfinance services and many people who are acutely vulnerable to climate change. Quantitative and qualitative data were collected through interviews with 60 households across four villages in a disaster-prone coastal area in the south-west of Bangladesh. The results indicate that households who have engaged with at least one MFO have less social vulnerability than those who have not, and that the principal ways in which MFOs help reduce social vulnerability are through helping households to save regularly, providing vocational training, and facilitating participation in diverse social groups. Yet climate hazards can undermine these positive benefits, such as when cyclones damage infrastructure for which housholds still have outstanding loans. There are also households for whom accessing MFOs is difficult, such as those with very low levels of education or with chronic health issues. Such limitations need to be addressed if microfinance organisations are to provide more comprehensive and long-term reductions in social vulnerability to climate change.

Evaluation of Nutritional Composition of Small Ruminants’ Feed stuffs widely grown in Khulna Region of Bangladesh

Feed stuffs availability is one of the extreme obstacles to small ruminant production, particularly during the dry season. In Khulna region, there are several feed stuffs, fodders, grasses and weeds, but their potential has not yet been completely realized due to a lack of understanding of their nutritional value. Therefore, the research was carried out to determine the nutritional value of available feed stuffs for small ruminants in the Khulna region. Roughage and concentrate samples were collected from different areas of Khulna region. All of the samples were taken in triplicates and analyzed accordingly. The results revealed that among the grass species, the Gitlacontains the highestamount of DM content (39.74%)and lowest in Kalmilata (13.90%). The crude protein contents in grass species ranged from 6.5% to 25.65% being highest in Helencha and lowest in Para. Highest EE content was found in German lata (7.05%), followed by Kakpaya (6.72%). The CF content varied between 9.39% in Chanchito 40.05%in Para. Kakpayacontains the highest ash (17.45%), while Pakchong the lowest (8.68%).Mustard oil cake containsthe highestamount of DM (94.77%) among the concentrates, whereas red wheat contains the lowest (89.85%). Crude protein (CP) contents of concentrate feed stuffs ranged from 5.35% in gram bran to 50.75% in soybean meal. Rice polish (21.12%) showed the highest EE concentration and it was lowest in motor bran (2.50%). The maximum concentration of CF was found in Khesari bran (27.17%), while the lowest was in maize (1.82%). It could be concluded that evaluated concentrate feeds and grass species could serve as prospective livestock feeds in southwest Bangladesh. South Asian J. Agric., Vol. 9, No.1&2, 2022-‘23: 31-38

Evaluation of Aquifer Properties to Categorize Groundwater Potential in a Part of Southwest Bangladesh Using Catastrophe Theory

This paper evaluated aquifer properties in a part of Southwest Bangladesh to categorize groundwater potential using catastrophe theory (CT). Satellite image, lithologic, pumping test, rainfall and groundwater monitoring data were utilized for this purpose. Lithology-based stratigraphic cross- sections confirm six vertically distributed layers, classified into aquitard composed of surface clay with silt and very fine-grained sand with thickness varying from 1 to –24.4 m, whereas the aquifer comprising fine to coarse sand with 3–67 m thick. Pre- and post-monsoon average annual groundwater levels fluctuate from in 3.12 to 3.86 m and 6.97 to 8.36 m, respectively, while average annual recharge ranges from 0.4 to 0.59 m/yr. Groundwater potential index (GWPI) values, validated with specific capacity records, classified the study area into three zones with GWPI of 0.72–0.81 (moderately good), 0.81–0.87 (good), and 0.87–0.96 (very good), covering 25.44%, 47.60%, and 26.96% of the area, respectively. Sensitivity analysis identified rainfall as the most influential and land type as the least influential factor in defining groundwater potentiality. These results can serve as a foundation for the formulation of guidelines and recommendations for the governmental and affiliated agencies for future groundwater exploration, planning, and management.

Population structure of Indian river shad, Gudusia chapra (Hamilton, 1822) from the Rupsha River, south-west Bangladesh

The Indian river shad, Gudusia chapra, is a well-known species of potamodromous fish belonging to the Clupeidae family. The main focus of this study is to state the sex ratio, growth pattern, length-length relationship, form factor, Fulton’s condition factor and relative weight of G. chapra harvested from the Rupsha River (south-west Bangladesh). Altogether 300 specimens (male=166 and female=134) were harvested with the help of commercial fisher folks on seasonal basis (summer, rainy and winter) during 2022. Body weight and length of individual specimen were recorded with digital balance and measuring board. Total length varied between 12.7 to 16.5 cm for males and 13.0 to 17.3 cm for females. Further, body weight ranged between 15.82 to 42.48 g for male and 18.36 to 46.65 g for female. As a whole, both sexes revealed positive allometric growth pattern (b>3.00). Moreover, the length-length relationships were found highly correlated for both sexes. The estimated form factor was 0.0087 indicated fusiform body shape for G. chapra population. The mean Fulton’s condition factor was recorded close to 1 indicated a pleasant health condition for this species. Further, mean relative weight revealed a sound ecological atmosphere regarding prey-predator status. The research outcomes would be helpful to execute a sound management policy in the Rupsha River and connected ecosystem in the south-west Bangladesh.
 

Comprehensive pollution and ecological risk of heavy metals in an industrial region of south-west Bangladesh

Deterioration of water, soil and sediment due to industrial operation is well known. This study aimed to evaluate physicochemical properties of surface water and heavy metals in industrial effluent (n = 13), river water (n = 14), pond water (n = 5), soil (n = 11) and sediment (n = 19) collected from an industrial zone in south-west Bangladesh. Among the physicochemical parameters, pH and dissolved oxygen (DO) indicated relatively higher values in most of the samples than their respective lower guideline values of 6 and 4.5 mg L-1 and showed significant variation across environments. Based on the average concentration, none of the heavy metals in any environment surpassed the guideline values in the study area, except, Cr in both industrial effluent (0.034 ± 0.055 mg L-1) and river water (0.011 ± 0.005 mg L-1), Cd in both soil (1.11 ± 0.47 mg kg−1) and sediment (1.41 ± 1.04 mg kg−1). Possibly, continuous discharge of industrial effluents might increase the heavy metal concentrations in the effluent receiving environment. Concentration of others heavy metals were below the respective guideline values but varied significantly among the environments. Depth-wise variation was negligible which might be dependent on metal chemistry in soil and sediment. A very high pollution and ecological risk were observed for Cd, specifically in soil and sediment. Multivariate statistics showed strong correlation among heavy metals, which indicated considerable contribution from industrial effluent. Industrial operations control physicochemical properties of surface water, but temperature is dependent of meteorological conditions. This study concludes that the lower concentrations of heavy metals than guideline values in environmental samples still pose significant levels of pollution and ecological risks.

Exploring the Socio-economic Condition and Livelihood Vulnerability of Coastal People in Southwest Bangladesh

Exploring the Socio-economic Condition and Livelihood Vulnerability of Coastal People in Southwest Bangladesh

Site suitability assessment for solar power plants in Bangladesh: A GIS-based analytical hierarchy process (AHP) and multi-criteria decision analysis (MCDA) approach

Solar power plants are important alternatives to fossil fuel-based power plants because they reduce greenhouse gas emissions and mitigate the effects of climate change. The potential of harnessing solar energy is highly dependent on selecting the optimal locations for plant installation. This study primarily aims to select optimal sites for solar energy plant installation using the Analytic Hierarchy Process (AHP) of Multi-Criteria Decision Analysis (MCDA) in a Geographic Information System (GIS) environment. In the underlying processing phase, the AHP method was used to calculate the relative weights of the study area's physiographic, utility, and climate data. These weights were then used in the MCDA to identify the optimal locations for solar plants. The results of the MCDA were presented in the form of a solar plant suitability map, which showed that 44.59 % (66506.49 km2) of the study area in the south and southwest of Bangladesh is highly suitable for the development of utility-scale solar power plants. In contrast, there are substantial areas of about 31.18 % (46507.37 km2) of the country where the installation of any type of power plant is completely prohibited. This research can help authorities and stakeholders decide where to invest in solar energy.

SEX RATIO AND BIOMETRIC INDICES OF PAMA CROAKER, OTOLITHOIDES PAMA (HAMILTON, 1822) FROM THE BAY OF BENGAL, SOUTH-WEST BANGLADESH

The Pama croaker, Otolithoides pama is a prominent marine species under Sciaenidae family. This Sciaenid fish is a popular table food and a perceptible protein source for Bangladeshi rural people. Our research highlights a comprehensive description of the biometric indices of O. pama sampled from the Bay of Bengal, south-west Bangladesh, together with sex ratio, length-frequency distribution, growth pattern, form factor, Fulton’s condition and prey-predator status. Overall 252 specimens (male = 171 and female = 81) were sampled by gill net during 2022 on seasonal basis (summer, rainy and winter). Length and weight of the sampled fish were assessed with measuring board and digital balance. While the sex ratio (male: female = 1.00:0.47) deviated from the conventional ratio of 1:1, total length varied from 13.0 to 26.7 cm for pooled data. Both sexes revealed negative allometric growth (b < 3.00) pattern as a whole. Form factor (a3.0) was found 0.0074 which stated that the fish possessed a fusiform body shape. The mean Fulton’s condition factor denoted an indecorous state of health. Alternatively, prey-predator status was found quite suitable for O. pama population. The outcomes of our research would be highly effective for executing sound management policy in the marine water of Bangladesh.

Application of Sustainability Index of Tidal River Management (SITRM) in the Lower Ganges–Brahmaputra–Meghna Delta

The sustainability index (SI) is a relatively new concept for measuring the performance of water resource systems over long time periods. The purpose of its definition is to provide an indication of the integral behavior of the system with regard to possible undesired consequences if a misbalance in available and required waters occurs. Therefore, the tidal river management (TRM) approach has been implemented for the past three decades (from 1990 to 2020) within the polder system in Southwest Bangladesh to achieve water sustainability. TRM plan and watershed management plan (WMP) have commonalities as both are aimed at ensuring the sustainable use of watershed resources with the management of land, water, and the wider ecosystem of the watershed in an integrated way. The TRM plan focuses mostly on coastal regions, whereas the WMP focuses on both coastal and non-coastal regions. According to this, the aim of this study was to explore the application of the sustainability index of tidal river management (SITRM) in measuring the sustainability of tidal river management in the coastal area of the Lower Ganges–Brahmaputra–Meghna (GBM) delta. In order to quantify the sustainability of tidal river management, this research first provided the components and indicators of SITRM for the coastal region. The study follows a 5-point Likert scale for opinion survey of key informants and comprises households’ survey of farmers. In addition, it includes Landsat satellite images from Earth Explorer of the United States Geological Survey (USGS) and direct field observation to collect information regarding the indicators of SITRM. The study measures the index value of SITRM for identifying the water sustainability of Beel East Khukshia-TRM. The index value was 71.8 out of 100, showing good tidal river management for the Hari–Teka–Bhadra catchment. To achieve water sustainability and aid stakeholders and water managers in decision making, it may be possible to include the SITRM framework in tidal river management projects. In addition, the SITRM is more capable of facing drainage congestion, waterlogging, and climate change issues than watershed sustainability index (WSI), Canadian water sustainability index (CWSI), West Java water sustainability index (WJWSI), and water poverty index (WPI). Therefore, water professionals and policymakers can apply SITRM to assess the resilience of specific TRM schemes for greater sustainability in different coastal regions of the world.

HEAVY METAL CONTENT IN WATER AND SEDIMENT OF SHRIMP FARMS OF SATKHIRA, BANGLADESH

Toxic contaminants moving along with runoff usually contaminates shrimp farms in most areas of Satkhira district, southwest Bangladesh. An investigation was carried out to assess the Physico-chemical properties and heavy metal concentration of sediments and water in shrimp farms from Satkhira district, southwest Bangladesh during December 2020 to March 2021. Twelve water and sediment samples were collected from six Ghers of two Upazilla e.g., Debhata and Assasuni of Satkhira. Physico-chemical attributes such as temperature, DO, BOD5, pH, TDS, EC, turbidity, salinity, HCO3-/CO3-, SO4-, NO3-, PO4- were estimated. The concentration attributes such as TDS (2280-5250 mg/l), EC (4380-9670 µs/cm), Turbidity (50.8-348 NTU), HCO3-/CO3- (219.6-445.3 mg/l), NO3- (0.3635-1.94 mg/l) were observed to be higher than the allowable standards recommended by WHO and FAO. Five trace metals such as chromium (Cr), cadmium (Cd) copper (Cu), lead (Pb) and Zinc (Zn), were measured in sediments and water by Atomic Absorption Spectrometer. The range of metal concentrations in sediment were as follows: Cr (1.95–3.43 mg/l), Zn (205.76-265.71 mg/kg), Cu (0.60–1.1mg/kg), Cd (3.8-4.1 mg/kg), and Pb (0.92-1.11mg/kg wet weight. The range of metal concentration in water were as follows: Cr (0.1-0.8 mg/l), Zn (0.003-0.34 mg/l), Cu (0.10-0.13 mg/l), Cd (0.07-0.08 mg/l), and Pb (0.23-0.34 mg/l). Higher concentrations of metal were recorded in most of the sediment and samples of water of the studied Ghers except Cr and Cu, those were below standard as prescribed by WHO and FAO. The concentration of Cu ranges from 0.602 to 1.113 mg/kg and 0.10 to 0.13 mg/l and range of Cr concentration were 1.95 to 3.43 mg/kg and 0.156 to 0.807 mg/l in sediment and water respectively. However, Cd, Zn and Pb were higher than the allowable standard as recommended by WHO and FAO. The higher heavy metal concentrations in water and sediment of shrimp Ghers suggest that shrimp could be contaminated by these heavy metals as well.

The effect of the local environment on child nutritional outcomes: how does seasonality relate to wasting amongst children under 5 in south-west coastal Bangladesh?

The impact of short-term environmental changes on child nutritional status is not constant within populations. In many countries, the seasons are closely linked with many factors that are known to affect nutritional outcomes, such as food consumption, crop harvests, employment opportunities and illness. With extreme seasonal variation becoming more common, understanding how seasonality is related to child nutritional outcomes is vital. This study will explore spatial and temporal variation and determinants for acute malnutrition in a coastal river delta in south-west Bangladesh over the period of a year. Using a rural longitudinal survey, conducted in 2014–15 with 3 survey waves, wasting amongst children under 5 was studied. Spatial variation was analysed through ‘socio-ecological systems’, which capture interactions between ecosystems, livelihoods and populations. Wasting prevalence varied from 18.2% in the monsoon season to 8.7% post-major rice harvest (Aman). Seasons did not relate to wasting consistently over socio-ecological systems, with some systems showing greater variability over time, highlighting distinct seasonal dynamics in nutritional status. Wealthier socio-ecological systems had lower wasting generally, as expected, with greater livelihood diversification opportunities and strategies to smooth consumption. Nutrition interventions must consider seasonal peaks in acute malnutrition, as well as the environmental context when implementing programmes to maximise effectiveness. With increasing variability in seasonal changes, inequalities in the impact of season must be accounted for in health promotion activities. Furthermore, timing and season of survey implementation is an important factor to be accounted for in nutrition research, especially when comparing between two cross-sectional surveys.

BIOACCUMULATION OF HEAVY METAL IN FARMED TILAPIA AND SHRIMP IN SATKHIRA DISTRICT, SOUTHWEST BANGLADESH

Fish farmers in the Satkhira district, southwest Bangladesh, are progressively moving towards intensive aquaculture, and heavy metal contamination of the feed may frequently occur. This study explores the bioaccumulation of heavy metal in farmed tilapia (Oreochromis mossambicus) and shrimp species such as bagda (Penaeus monodon), golda (Macrobrachium rosenbergii), randomly collected from 3 gheer at Assasuni and Debhata Upazilla in Satkhira, Bangladesh from December 2020 to March 2021. The levels of elements including Fe, Mn, Zn, Cu, Cr, Cd, Pb, and As were evaluated using the flame-AAS and HG-AAS methods followed by Nitric Acid (HNO3)-Perchloric Acid (HClO4) digestion. The results revealed that the concentrations of Fe, Mn, Cr, and As were higher than the WHO and FAO recommended levels. Maximum concentrations (mg/kg) of Fe, Mn, Cr, and As were observed as 104.00 ± 8.30 in Tilapia (O. mossambicus) from gheer #3, 3.40 ± 1.71 in Tilapia (O. mossambicus) of gheer #3, 12.80 ± 1.45 in golda (M. rosenbergii) of gheer #1, and 1.96 ± 0.09 in Tilapia (O. mossambicus) from gheer #3, respectively. But on average, M. rosenbergii was discovered to contribute more to the maximum level of almost every metal compared to the other two species, whereas species from gheer #3 were found to be more contaminated. Overall, tilapia and shrimp from all three gheer were considered unsafe for consumption. More research is recommended for estimating the levels of heavy metal accumulation in fish and shrimp over a longer time period and across a wider geographic range.