Kaptai Lake Research Articles

Assessing Responsible Tourist Behavior at Kaptai Lake, Rangamati, Bangladesh

Assessing Responsible Tourist Behavior at Kaptai Lake, Rangamati, Bangladesh

An overview on hydro-biology and management of Kaptai Lake Fisheries, Bangladesh

Kaptai Lake is the largest artificial Lake in Bangladesh. This Lake provides most of the fish stock for the people of the Hill tract. Over the years, due to various anthropogenic and environmental reasons population of Indian Major Carp (IMCs) has declined, and some native species are on the way to extinction in this Lake. Considerable research has been conducted on different aspects of lake fishery with hydrology, culture technology, fish diversity, management, threats, and mitigations, but no such consolidated report on the overall overview is not available on this Lake. This review paper has been prepared to combine all the available information along the information gap, further study of which will be helpful to enhance the Indian major carp catch and sustainable management of fish stock.

Techno-economic assessment of power generation potential from floating solar photovoltaic systems in Bangladesh

Floating Solar Photovoltaic (FPV) plants, also known as floatovoltaic plants are showing great potential in the renewable energy sector all around the world. They can contribute to the national grid and provide support to the existing hydropower plants. Moreover, they positively impact the environment by reducing evaporation and improving aquatic lives simultaneously. Despite a decade of research, there has been no study on the technical potential of FPV plants on a riverine country like Bangladesh. In Bangladesh, there are several water infrastructures to accommodate FPV plants. In addition, a considerable amount of solar irradiation is available throughout the year because of the country's geographical location, making FPVs a significantly viable option for generating electricity. To this end, this study provides the first technical potential and economic feasibility assessment of some of the important water bodies of Bangladesh. The technical potential study is performed with the help of solar PVGIS and focuses on the contribution these plants can make to the national grid. The economic viability assessment simulations are done in System Advisory Model (SAM). Moreover, a thorough comparison between FPVs and inland solar plants is also conducted. The results show that after the installation, even with a conservative approach, FPV plants will be able to meet 1.1% of the demand of the capital Dhaka, the city with one of the highest population densities. In addition, FPV installation at Kaptai lake, which already has an existing hydropower plant, can meet up to 7% of the demand of the port city Chattogram. Moreover, economic parameters NPV, IRR and LCOE all indicate the projects are profitable and can be deployed in large-scale. This study will open doors to further research into the FPV potential of Bangladesh and help implement FPVs to meet the renewable energy goals of the country.

Risk assessment and source apportionment for metals in sediments of Kaptai Lake in Bangladesh using individual and synergistic indices and a receptor model

Metal enrichment in lake sediments originating from multiple sources can threaten both the aquatic ecosystem and human health. Therefore, assessment of the eco-environmental risks and potential sources of metals in the sediments is essential for effective lake management. Here, we analyzed the sediment metal contents of Kaptai Lake, the largest lake in Bangladesh for the first time with this study. The results indicated that only Cr and Ni contents among the metals studied exceeded the probable effect concentrations (PEC) at 25.42 % and 55.93 % of the sampling stations, respectively. All metals at most sampling stations showed low contamination and low ecological risk based on the individual indices (geoaccumulation index, contamination factor, ecological risk factor, enrichment factor and modified hazard quotient). There was no significant risk from the combined metals in the sediments of the lake according to the synergistic indices (toxic risk index, Nemerow risk index, ecological risk index, Nemerow pollution index and pollution load index). Organic matter and silt were significant sediment parameters that favored the accumulation of Cr, Fe, Cu, Pb and Mn. In the absolute principle component scores-multiple linear regression model (APCS-MLR), five potential sources of metals were identified in the sediments: Zn, Mn, Co and Cd mainly from natural sources and to a lesser extent from agricultural and aquacultural activities, Ni, Cr and Fe from parent materials, Pb and Cu mainly from natural sources and to a lesser extent from vehicle emissions, Hg and U from lithogenic sources, and As from natural sources. This study will improve our knowledge of the sedimentary metal contents of Kaptai Lake and provide helpful information for developing effective lake management and pollution control strategies.

Potential Assessment of 80 kW Floating Solar Photovoltaic System (FSPV) at Kaptai lake, Bangladesh

Based on the massive amount of electricity generated, the world's lifestyle and economy have greatly expanded. However, due to the scarcity of fossil fuels, the provision of power is under pressure in this country. Renewable energy provides an exception at this point, and solar energy—among all the renewable energy sources—plays a prominent role because it is environmentally friendly and indestructible. The cost and accessibility of land, however, poses a significant obstacle to the construction of land-based, large-scale solar power plants in Bangladesh. In a riverine nation like Bangladesh, a floating solar photovoltaic system offers a solution with a lot more possibilities. This research will outline the potential for floating solar photovoltaic systems in Bangladesh's Kaptai lake area and discuss feasible investigations with location prospect, FSPV costs, project revenue, environmental aspects and further research opportunities. The potential investigation for the establishment of FSPV based on financial parameters will be validated in this paper using RET-screen energy management software.

Socio-economic condition of the indigenous fishermen in and around an artificial lake for Bangladesh

The present study assessed the socio-economic circumstances of the fishermen of Kaptai lake, situated beside the Rangamati Sadar in the Rangamati district. The present study found that 4 categories of cast fishermen are engaged in fishing or fisheries-related activities. Moderate literacy rates were found among the tribal fishermen as only 15% of people were entirely illiterate, and 6% were above higher secondary education. The tribal fishermen in the surveyed area were mainly poor; their annual income ranged closely between Tk. 24000 and Tk 38400. Around 49% of houses were made of bamboo fences, whereas 27% were found to be made of mud, and only 6% of brick was built. 51.5% of the fishers' families had no adequate sanitation system, whereas earthen and sanitation latrines were found at 40% and 8%, respectively. About 45.5% of the tribal fishermen had little access to pure drinking water. The tribal fishing community suffers from various problems such as extortion, lack of fishing gear, inadequate credit facilities, ineffective marketing system, etc. Finally, it may be concluded that the socio-economic condition of the tribal fishermen is not indifferent to other traditional fishermen of Bangladesh.

Seasonal Variation of Water Qualities in River, Lake and Waterfall in Rangamati and Khagrachhari Hill Tracts, Bangladesh

This study was conducted to investigate the seasonal variation of water qualities for drinking and conservation of aquatic organisms from river, lake and waterfalls in Chattogram Hill Tracts of Bangladesh during pre-monsoon, monsoon and post-monsoon seasons from the period of March 2021 to February 2022. Water samples were collected from four sampling locations and analysed in the research laboratory of the Department of Environmental Science and Resource Management, Mawlana Bhashani Science and Technology University. Results were recorded on the parameters like temperature, EC, TDS, DO, BOD, pH, total alkalinity and total hardness in Kaptai Lake, Chengi River, and Shuvolong and Risang Waterfalls. The study revealed that the temperature, EC, TDS, BOD and pH were higher in pre-monsoon than monsoon followed by post-monsoon seasons. On the other hand, total alkalinity and total hardness were higher in post-monsoon than monsoon followed by pre-monsoon seasons. In the waterfalls, DO was higher in monsoon season when compared to pre-monsoon and post-monsoon seasons. The study provides baseline data on physiochemical water qualities in lake, river and waterfalls at the Chattogram Hill Tracts, which contributes to the long-term conservation of those aquatic ecosystems for human consumption and fisheries management.

A case study of illegal fishing causes during seasonal fishery closure in Kaptai Lake, Bangladesh

AbstractGrowing evidence shows that conservation strategies such as fishing bans may adversely affect the livelihoods of low‐income communities, which often encourages community members to fish illegally. In this study, we determined the underlying factors that influenced fishermen to engage in illegal fishing during the closed season in the largest lake of Bangladesh, Kaptai Lake. Out of 231 fishermen interviewed, 46.8% were engaged in illegal fishing during the closed season. Engagement in illegal fishing was positively related to receipt of a financial loan and negatively related to receipt of a government subsidy and secondary occupation of the fishermen. Financial gain by selling the fish was the prime motive for illegal fishing. Surprisingly, fishermen received a 36% lower price for illegally harvested fish during the closed season (mean price ± SD, BDT 95.8 ± 64.9), when compared to that during the open fishing season (BDT 151.5 ± 64.9). Mid‐level actors secured 99%–154% more profit during the closed season. This study shows that multiple factors are important for the engagement of fishermen in illegal fishing, and therefore, an integrated conservation policy considering all causative factors should be employed to achieve more effective conservation in the region's inland waters.

Genetic diversity of Ganges River sprat, Corica soborna, from Kaptai Lake and Kirtankhola River in Bangladesh

Genetic diversity of Ganges River sprat, Corica soborna, from Kaptai Lake and Kirtankhola River in Bangladesh

Analyses of Protection and Conservation According to the Fish Act 1950 in Bangladesh’s Kaptai Lake Fisheries Management

Kaptai Lake (KL), the largest inland watershed in Bangladesh (ca. 700 km2) and one of Southeast Asia’s largest artificial reservoirs, features an abundant variety of indigenous fishery species. Moreover, it provides a plethora of ecological benefits to society. Nevertheless, the KL is suffering from multidimensional natural and anthropogenic stressors that threaten these wetlands’ sustainability. Though the legal framework assures sustainable conservation of fisheries resources, the implementation scenarios of fisheries laws, regulations, and policies in the KL wetland are insufficient. This study aimed at assessing the fisher’s perception of the regulation implementation efficiency of the Protection and Conservation Fish Act of 1950, while analyzing the effectiveness of the legal framework in the context of biodiversity conservation and the management sustainability of KL. By integrating qualitative and quantitative data collected through participatory Rural Appraisal (PRA) tools viz. 225 interviews with fishers, four focus group discussions, and 12 key informant interviews, the investigation was performed in four selected areas in KL. The findings show that fishers routinely disregard laws and restrictions of the Protection and Conservation of Fish Act 1950 due to various socioeconomic and political forces. Although the annual fish harvest rate from KL appears to be increasing, the lake is losing its charismatic biological diversity primarily due to inappropriate and ineffective enforcement of fishing regulations. Many fishers believe that they still follow the act’s significant laws and regulations while being involved in several destructive and prohibited fishing practices. There is a link between community awareness, the scope of the act’s provisions, the effectiveness of its enforcement, and the strength of its execution. One of the leading causes of biodiversity loss in the KL is inadequate and ineffective fishing regulations. Improvement in the enforcement of the fishing act may be the prominent option to ensure better biodiversity conservation and sustainable management of this wetland. This result calls for functional and policy attention to revising the regulations to account for socioeconomic and political elements contributing to environmental degradation. This study also highlights the urgent need for transdisciplinary collaboration initiatives and synchronous cooperation among the agencies in order to effectively implement the fishing laws and contribute to better conservation and sustainability of the Kaptai lake fisheries resources.

Physico-Chemical Parameters, Length-Length and Length-Weight Relationships and Condition Factor of the Vulnerable Gudusia chapra in the Kaptai Lake, Rangamati, Bangladesh

Physico-Chemical Parameters, Length-Length and Length-Weight Relationships and Condition Factor of the Vulnerable Gudusia chapra in the Kaptai Lake, Rangamati, Bangladesh

Assessment of Temporal Variation of Water Quality Parameters and the Trophic State Index in a Subtropical Water Reservoir of Bangladesh

This study was conducted to determine the suitability of water quality for fisheries management in Kaptai Lake from February 2019 to January 2020. Results showed that the temperature, transparency, TDS, pH, DO, EC, alkalinity and hardness were 20.9 to 31.8°C, 17 to 303 cm, 40 to 105 mg/L, 6.82 to 7.96, 6.1 to 7.65 mg/L, 75.33 to 172.33 µS/cm, 37 to 83 mg/L and 35 to 190 mg/L, respectively. However, nutrients as NH3, NO3-, NO2-, PO43- and SO42- were 0.01 to 0.05, 0.03 to 2.21, 36 to 96, 0.01 to 0.04 and 0.3 to 1.9 mg/L, respectively. Chlorophyll a and trophic state index (TSI) were 0.70 to 2.12 µg/L and 27.43 to 37.79, respectively. Study revealed that SO42-, DO and TDS were higher than the standard of ECR. On the other hand, NH3, NO3-, NO2-, PO43-, temperature, transparency, pH, EC, total hardness, total alkalinity, Chlorophyll a and TSI were within the standard levels. Concentrations of NO3-, NO2-, PO43-, Chlorophyll a and TSI (CHL) showed no significant variation with seasons. Conversely, TDS, transparency, EC, alkalinity, hardness, and SO42- were lower in monsoon compared to pre-monsoon and post-monsoon seasons. Besides, temperature, NH3, DO and TSI (SD) were higher in monsoon season. Results concluded that the Kaptai Lake is in mesotrophic condition with TSI (CHL) less than 40, and prominently there was a positive relationship between Chlorophyll a and Trophic State Index (TSI). In this regard, major nutrients and Chlorophyll a concentration in the Kaptai Lake may have an impact on the aquatic environment.

Assessing the exploitation status of main catfish Eutropiichthys vacha based on length based stock assessment models in the Kaptai Lake from Bangladesh

The current study focuses on the detailed data on stock assessments including population structure, growth parameters, mortality, recruitment pattern, exploitation rate (E), maximum sustainable yield (MSY) and relative yield per-recruit of Eutropiichthys vacha (Hamilton, 1822) based on 2512 specimens through regular monthly sampling using gill net, cast net, and square lift net in the Kaptai Lake, located in the hilly region of Bangladesh during January to December 2017. Total length (TL) and body weight (BW) were measured using digital slide calipers and electronic balance with 0.01 cm and 0.01g accuracy for each individual. The asymptotic length (L∞) was 44.40 cm and growth coefficient (K) was 0.70 year−1. The growth performance index (Ø′) was 3.14. The age at zero length (t0) was 0.027 year and life-span (tmax) was 2.73 year. We estimated total mortality (Z), natural mortality (M) and fishing mortality (F) as 4.23, 1.27 and 2.96 year−1, respectively. The recruitment pattern was throughout the year with two pick-events during May and September. Length at first capture (Lc) was 20.65 cm TL. The E was 0.70 where the Emax (exploitation rate producing maximum yield) was 0.45 which indicates 25% over fishing. The MSY was estimated as 34257 metric ton. In conclusion, the results of this study would be very operative to execute specific management for E. vacha in Kaptai Lake, Hilly region of Bangladesh.

Production Trends, and Challenges for Biodiversity Conservation and Sustainable Fisheries Management of Kaptai Lake, the Largest Reservoir in Bangladesh

Kaptai Lake (KL), the largest artificial lake in Bangladesh, supports an important inland open water fishery. Nevertheless, detailed studies on its fish diversity and environmental threats are still limited. Hence, a study was conducted to evaluate the current fish management scenarios, fish production, relative abundance to improve the production and biodiversity of KL. Data were collected from stakeholders through personal observation, focus group discussions, and cross-check interviews from September 2018 to July 2019. The fish production of KL increased from 1,200 metric tons (MT) in 1965–1966 to 10,577 MT in 2018–2019. The output of the lake was dominated by small fish remarkably, Gudusia chapra (Hamilton, 1822), Gonialosa manmina (Hamilton, 1822), and Corica soborna Hamilton, 1822, accounting for 64 % of the total production in 2018–2019. A total of seventy-six fish species were observed under ten orders, including seven exotic fish species. According to the IUCN Bangladesh, 14 % of total species were identified as vulnerable, 11 % as endangered, 3 % as critically endangered, 11 % as near threatened and 51 % as least concern. The study also identified that climate change and various human-driven causes threaten the fish production and biodiversity of this lake. These findings suggest that community-based fisheries management, protection of natural breeding grounds of carps, control of pollution, amendment of existing fishing laws, and collaborative research would be a necessary approach for mitigating the negative environmental impact of this lake. The overall practical knowledge of this investigation could assist in policymaking and further research.

Sediment organic matter and physicochemical properties of a multipurpose artificial lake to assess catchment land use: a case study of Kaptai lake, Bangladesh

The Kaptai lake, situated in the north-east region of Bangladesh, is the largest reservoir in south-east Asia, built by impounding an artificial earth-dam on the Karnaphuli river in 1961 for hydropower generation. It now serves in various ways, including fisheries, inland navigation, tourism, seaport operation, and municipal water supply. This study has been carried out to know the physicochemical characteristics of sediment, focusing on the organic matter of sediment of Kaptai lake. With the assumption of sediment characteristics being a predictor of catchment land-use, the spatial change of sediment properties across the reservoir also discussed. By doing hydrometrical analysis of sediment physical properties, we found that sediment sand, silt and clay contents are 35%-67.5%, 11.75-39.5%, 5.75-45.75% respectively. The bulk density, organic matter (OM), organic carbon (OC), inorganic matter (IOM), pH ranged for 1.72 - 2.48g/cm3, 4.25 - 8.18%, 2.23 - 4.30%, 91. 82-95.76%, and 6.25 - 6.62 respectively. Sediment texture (e.g. sand, clay, and silt) showed significant variations at different sites (p<0.05). Catchment areas with higher urban land-use showed a higher concentration of clay, moisture, OM, and OC contents to the lake's sediment compared to areas with a little settlement. Contrary to these, areas with limited settlement and land use activities have a higher concentration of sand, silt, IOM, pH, bulk density, particle density and porosity. A strong positive correlation (p<0.05) was found between OM to moisture (0.907), OC to moisture (0.907), porosity to particle density (0.799), which indicate their origin of the source is identical. This study suggests that lake sediment can indicate land-use change in the catchment area. The difference in sediment properties reveals that sediment transport from upstream to the main reservoir is not significant, which may reduce the usable lifespan of this reservoir and the navigability of the rivers. Sediment characteristics signify that major sediment trapping/deposition occurred in the main reservoir part as well as in the Chengi tributary.

Cost-Benefit Analysis of Kaptai Dam in Rangamati District,Chittagong, Bangladesh

This study aims to assess the net benefit of the kaptai dam on the Karnafuli river in Kaptai, Chittagong, Bangladesh. Kaptai Dam, the only hydroelectricity power source in Bangladesh, provides only 5% electricity demand of Bangladesh. The Dam is located on the Karnafuli River at Kaptai in Rangamati District, 65 km upstream from Chittagong. It is an earth-fill or embankment dam with a reservoir with a water storage capacity of 11,000 skm. Though the Dam's primary purpose is to generate electricity, it became a reservoir of water used for fishing and tourism. To find the net benefit value and estimate the environmental costs and benefits, we considered the environmental net benefit from 1962 to 1997. We identify the costs of Kaptai Dam, including its establishment cost, operational costs, the costs of lives that have been lost due to conflicts, and environmental costs, including loss of biodiversity, loss of land uses, and loss of human displacements. Also, we assess the benefits of electricity production, earnings from fisheries production, and gain from tourism to Kaptai Lake. The findings show that the Dam contributes tremendous value to Bangladesh. As a source of hydroelectricity, the Kaptai Dam is a source of clean energy, and its value might have been worthy of this Dam produced a significant portion of the electricity. However, providing less than 5% of the national demand for electricity followed by various external and sensitive costs, the Dam hardly contributes to the Bangladesh economy. This study thus recommends that Bangladesh should look for other sources of clean energy that have no chances of eco-political conflicts.

Fish Disease Detection System: A Case Study of Freshwater Fishes of Bangladesh

The proposed system is designed for automatic detection and classification of fish diseases in freshwater es-pecially Rangamati Kaptai Lake and Sunamganj Hoar area of Bangladesh. Our experimental result is indicating that the proposed approach is significantly an accurate and automatic detection and recognition of fish diseases. This study presents fish disease detection based on the K-means and C-means fuzzy logic clustering method to segment the filtering image. Gabor’s Filters and Gray Level Co-occurrence Matrix (GLCM) are used to extracts the features from the segmented regions. Finally Multi-Support Vector Machine (M-SVMs) is used for classification of the test image. The proposed system demonstrated a comparison between K-means clustering and C-means fuzzy logic. The proposed methodology gave 96.48% accuracy using K-means and 97.90% using C-means fuzzy logic which is the highest accuracy rate to compare other existing methods. The proposed system has been experimented in the MATLAB environment on infected fish images of Rangamati Kaptai Lake and Sumangan Hoar area. It is a challenging task of fisheries farming in Hoar areas and Lake areas to detect fish diseases initially. The proposed methodology can detect and classify different fish diseases in early stages and also contributes to improved results for fish disease detection.

Biometric indices of five miniature fish from the catchment area of Kaptai Lake, Bangladesh

The present study reports on biometric indices comprising length-weight relationships (LWRs) of five miniature freshwater fish species from the Kaptai Lake, the largest lake in the People's Republic of Bangladesh. The study area included 3 stations in the 11,122 km2 catchment area of the lake and each station was sampled from November 2017 to April 2018 using push net (mesh size 2 mm) for capturing the species. The values of growth coefficient b of the LWRs (W = aTLb) of the species Oryzias dancena, Oryzias melastigma, Gobiopterus chuno, Brachygobius nunus and Badis chittagongis were 2.9575, 3.1467, 3.0535, 3.058 and 2.9396 with above 0.95 coefficient of correlation (r2). These results represent the first study of LWRs for these fish species which may help in management and conservation of the species in the whole country, including its geographical distribution.

Length‐weight relationships of seven cyprinid fish species from the Kaptai Lake, Bangladesh

Length-weight relationships (LWRs) were estimated for seven small indigenous cyprinid fish species including Securicula gora, Osteobrama cotio, Esomus lineatus, Pethia gelius, Megarasbora elonga, Gonialosa manmina and Glossogobius aureus occurring in the Kaptai Lake, Bangladesh. Fish were collected monthly basis between March and October, 2018 from fishermen catches landed in the fish landing center, Rangamati. Fishermen operated lift net (mesh size < 0.5 cm), punti net (mesh size < 0.5 cm) and cast net (mesh size < 0.5 cm) for capturing these species. The value of exponent b ranged between 2.769 and 3.212 and regression parameter r2 was between 0.926 and 0.992. New maximum total lengths were recorded for E. lineatus and G. manmina in this study.

Physico-chemical Characterization of Kaptai Lake and Foy’s Lake Water Quality Parameters in Chittagong, Bangladesh

In order to protect the quality of the environment and human health, freshwater assets are tremendously important in various ways. To ensure the freshwater resources in the Chittagong region of Bangladesh, we have studied the water quality parameters of Kaptai and Foy’s Lake. This research has done based on the essential surface water standard parameters such as pH, temperature, DO, BOD, COD, TDS, TSS, TS, EC, hardness, turbidity, salinity, total alkalinity, total acidity, SO42-, PO43-, NO3--N, NO2-, CO2, and most of the heavy and toxic metals (As, Cd, Cr, Cu, Co, Fe, Pb, Mn, Ni, and Zn) of two lakes namely Foy’s (Chittagong) and Kaptai (Rangamati) Lakes in Chittagong , Bangladesh. The statistical approaches to sampling were utilized for collecting samples. The samples were assembled from ten different locations of each lake. Samples were conserved using a satisfactory preservation procedure. Water samples from the surface-water assets were collected from various locations, and tide conditions and at various seasons for continual monitoring during the hydrological years 2014-2015. The results showed that Kaptai Lake and Foy’s Lake all physicochemical parameters are within the permissible limit of WHO guidelines. The results also supplied data to view, and quantify the enemy of the impact of climate alter on freshwater resources of this region. The outcomes further showed data for water quality of surface-water resources of greater Chittagong zone to match national and international quality for drinking, agricultural, manufacture and livestock requirements. A strategic water quality management plan has been proposed.