Zoology
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Item Long-term exposure to environmentally relevant Bisphenol-A levels affects growth, swimming, condition factor, sex ratio and histology of juvenile zebrafish(Scientific Reports, 2024) Pathirajage, K. S.; Rajapaksa, G.Bisphenol A (BPA) is an environmental estrogen which perturbs hormone signaling pathways adversely affecting aquatic organisms. To evaluate the impact of developmental exposure to long term yet environmentally relevant low doses of BPA, wild-type juvenile zebrafish of 35 days post fertilization were treated with BPA (1 and 10 μg/L), treatment control (0.5% v/v methanol) and control for 60 days. Both BPA treatments led to significantly increased morality overtime. Length increment and specific growth rates became significantly high in BPA exposed zebrafish overtime. Obesogenic property of BPA was not evident with longexposure to low BPA doses. A significantly high and BPA dosedependent female-biased sex ratios were observed following the juvenile exposure. Significantly low swimming speed was recorded in the fish of both BPA-treated tanks than that of control. Condition factor was significantly low in BPA exposed fish indicating the poor-wellness. There were numerous histopathological alterations of gonads, liver and kidney indicating impacts of juvenile exposure in zebrafish. Altered growth, swimming, mortality, feminization and histopathological changes in zebrafish induced by BPA indicate the risks associated with developmental exposures. The findings call for more comprehensive studies to comprehend the ecological risks imposed by low concentrations of environmental estrogens in urban aquatic ecosystems.Item Bioaccumulation and health risks of chromium and cadmium in Basella alba with emphasis on Urea, muriate of potash and triple super phosphate mixtures(National Science Foundation of Sri Lanka, 2024) Amarasena, M. D. M. C. K.; Wijeyaratne, W. M. D. N.Basella alba is a commonly consumed green leafy vegetable in South Asian countries and it is considered as an economical source of essential vitamins and dietary fibers. Urea, muriate of potash (MOP) and triple super phosphate (TSP) mixture is the most commonly used inexpensive fertilizer mixture in the commercial cultivation of B. alba. This study was conducted to assess the effect of using a mixture of Urea-MOP-TSP on the bioaccumulation potential of cadmium (Cd) and chromium (Cr) by the leaves of B. alba. Pots treated with the Urea-MOP-TSP mixture and compost were maintained in a greenhouse with controlled light and temperature settings. The concentrations of Cd and Cr in the root zone soil, roots and leaves of B. alba were analyzed using an Atomic Absorption Spectrophotometer after acid digestion. The health risk of consuming B. alba was evaluated using the daily intake of metals, health risk index and cancer risk index. The results showed that Cd and Cr can bioaccumulate in the leaves of B. alba. The bioaccumulation potential of Cr was higher than that of Cd. Although the daily intake of Cd and Cr from B. alba were below the maximum values stipulated by the WHO, the cancer risk index indicated potential cancer risks based on Cd intake due to consumption of B. alba cultivated using the Urea-MOP-TSP mixture. Furthermore, the health risks associated with the hyper-accumulation of Cd and Cr in the edible parts of B. alba cultivated using compost were significantly less compared to that of the plants treated with the Urea-MOP-TSP mixture. Therefore, if B. alba is cultivated using chemical fertilizer, it is recommended to regularly monitor the concentrations of Cd and Cr in the cultivation soil, chemical fertilizer and in the edible parts of B. alba to prevent the excessive buildup of Cd and Cr along the food chain. In addition, it is recommended to identify the potential microbial assemblages that can be inoculated to the cultivation soil to reduce the bioavailability of Cd and Cr.Item Spatial variation in avian bill size is associated with temperature extremes in a major radiation of Australian passerines(2024) Subasinghe, Kalya; Symonds, Matthew R. E.; Prober, Suzanne M.; Bonnet, Timothée; Williams, Kristen J.; Ware, Chris; Gardner, Janet L.Morphology is integral to body temperature regulation. Recent advances in understanding of thermal physiology suggest a role of the avian bill in thermoregulation. To explore the adaptive significance of bill size for thermoregulation we characterized relationships between bill size and climate extremes. Most previous studies focused on climate means, ignoring frequencies of extremes, and do not reflect thermoregulatory costs experienced over shorter time scales. Using 79 species (9847 museum specimens), we explore how bill size variation is associated with temperature extremes in a large and diverse radiation of Australasian birds, Meliphagides, testing a series of predictions. Overall, across the continent, bill size variation was associated with both climate extremes and means and was most strongly associated with winter temperatures; associations at the level of climate zones differed from continent-wide associations and were complex, yet consistent with physiology and a thermoregulatory role for avian bills. Responses to high summer temperatures were nonlinear suggesting they may be difficult to detect in large-scale continental analyses using previous methodologies. We provide strong evidence that climate extremes have contributed to the evolution of bill morphology in relation to thermoregulation and show the importance of including extremes to understand fine-scale trait variation across space.Item Multimetric socio-ecological assessment of water hyacinth (Eichhornia crassipes (Mart) solms) invasion of an urban Ramsar wetland lake(Wiley, 2024) Wijeyaratne, W. M. Dimuthu Nilmini; Liyanage, Uditha PrabhathWater hyacinth (Eichhornia crassipes (Mart) solms), a widely distributed invasive aquatic plant in Sri Lanka, has invaded the Diyawannawa wetland lake located in Colombo city, which is the first Ramsar wetland city in South Asia. The present study was conducted to assess the water quality parameters that influence the distribution of water hyacinth and to identify the environmental, economic, and social consequences of its invasion of the Diyawannawa wetland. Five sampling sites were selected from the Diyawannawa lake, and the water pH, temperature, conductivity, total dissolved solids (TDS), salinity, dissolved oxygen concentration (DO), nitrate concentration, and total phosphorus concentration were measured at monthly intervals in the rainy and dry seasons of 2020. The abundance of water hyacinth was recorded at each site at each sampling event. Interviews and focus group discussions (FGDs) were conducted with the representatives of the community associated with the wetland to assess the ecological, economic and social effects of water hyacinth invasion. Principal component analysis of the water quality parameters revealed that phosphorus and nitrate concentrations in water significantly influenced the abundance of water hyacinth. Further, the water quality index (WQI) indicated poor water quality in the sites invaded by water hyacinth. The interviews and FGDs revealed that water hyacinth invasion has adversely affected the lake's fisheries and navigation pathways and increased the frequency of flooding, resulting in an increased mosquito population. The results of the present study highlighted the importance of implementing water quality management programmes in the Diyawannawa wetland to control the invasion of water hyacinth. Further, we recommend increasing community participation in water hyacinth control programmes and providing opportunities for the community to engage in self-employment activities associated with the uses of water hyacinth.Item A systematic literature review on integrating disaster risk reduction (DRR) in sustainable tourism (SusT): Conceptual framework for enhancing resilience and minimizing environmental impacts(Elsevier, 2024) Jayasinghe, G.Y.; Perera, T.A.N.T.; Perera, H.A.T.N.; Karunarathne, H.D.; Manawadu, L.; Weerasinghe, V.P.A.; Sewwandi, B.G.N.; Haroon, M.H.; Malalgoda, Chamindi; Amaratunga, Dilanthi; Haigh, RichardThis literature review meticulously explores the integration of Disaster Risk Reduction (DRR) techniques into sustainable tourism (SusT), placing a focal point on enhancing resilience and mitigating environmental impacts. By examining several disciplines, including tourism management, disaster management, environmental science, green innovation, and sustainable development, this study recognizes major themes, research gaps, and best practices in this emerging subject. It underlines the importance of SusT and the need for effective DRR programs to alleviate the negative effects of catastrophes on tourism destinations and ensure their long-term sustainability and resilience. Science Direct, Springer, SAGE Publications, and Wiley's online library were the selected databases and the inclusion criteria were based on studies that looked at how DRR measures were implemented in SusT practices and how effective they were in increasing resilience and lowering environmental effects. The selected literature reveals many concepts and ways for integrating DRR in tourism, such as pre-disaster planning, risk assessment, capacity building, and stakeholder involvement. The assessment identifies the vital part played by government agencies, local entities, and tourist service providers in organizing and coordinating these programs. It points out potential obstacles to DRR integration within the tourism sector. The review emphasizes the importance of monitoring and measuring the outcomes of DRR programs in tourism, and it suggests the use of metrics and indicators to assess how well resilience-building and environmental impact reduction strategies are implemented. These insights may be utilized by policymakers, academics, and practitioners to design methods that enhnace the resilience of tourism destinations while minimizing environmental consequences.conditions in Sri Lankan marine waters, thus qualifying mangrove ecosystems in microtidal coasts as effective carbon sinks.Item A systematic literature review on integrating disaster risk reduction (DRR) in sustainable tourism (SusT): Conceptual framework for enhancing resilience and minimizing environmental impacts(International Journal of Disaster Risk Reduction, 2024-08) Jayasinghe, G. Y.; Perera, T. A. N. T.; Perera, H. A. T. N.; Karunarathne, H.D.; Manawadu, L.; Weerasinghe, V. P. A.; Sewwandi, B.G.N.; Haroon, M. H.; Malalgoda, C.; Amaratunga, D.; Haigh, R.This literature review meticulously explores the integration of Disaster Risk Reduction (DRR) techniques into sustainable tourism (SusT), placing a focal point on enhancing resilience and mitigating environmental impacts. By examining several disciplines, including tourism management, disaster management, environmental science, green innovation, and sustainable development, this study recognizes major themes, research gaps, and best practices in this emerging subject. It underlines the importance of SusT and the need for effective DRR programs to alleviate the negative effects of catastrophes on tourism destinations and ensure their long-term sustainability and resilience. Science Direct, Springer, SAGE Publications, and Wiley's online library were the selected databases and the inclusion criteria were based on studies that looked at how DRR measures were implemented in SusT practices and how effective they were in increasing resilience and lowering environmental effects. The selected literature reveals many concepts and ways for integrating DRR in tourism, such as pre-disaster planning, risk assessment, capacity building, and stakeholder involvement. The assessment identifies the vital part played by government agencies, local entities, and tourist service providers in organizing and coordinating these programs. It points out potential obstacles to DRR integration within the tourism sector. The review emphasizes the importance of monitoring and measuring the outcomes of DRR programs in tourism, and it suggests the use of metrics and indicators to assess how well resilience-building and environmental impact reduction strategies are implemented. These insights may be utilized by policymakers, academics, and practitioners to design methods that enhnace the resilience of tourism destinations while minimizing environmental consequences.Item Impacts of a partially connected wastewater treatment plant on the water quality of stormwater drains used as an irrigation source(2024) Samaraweera, S. A. P. T.; Najim, M. M. M.; Alotaibi, Bader Alhafi; Traore, AbouUrban stormwater drains in Kurunegala City collect runoff and untreated wastewater, leading to public health problems. The Greater Kurunegala Sewage Treatment Plant (GKSTP) was commissioned in 2018 and currently operates at 73% of its capacity to combat public health issues. This study assessed the water quality of canals, comparing it with standards and pre- GKSTP conditions. Water samples were collected from seven sites during dry and wet seasons, and physicochemical parameters were measured. The data underwent spatial and temporal analysis using the general linear model (GLM). Additionally, cluster analysis and distance-based redundancy analysis were employed. The water quality index (WQI) was employed to evaluate the effectiveness of the treatment plant. The study revealed significant spatial and temporal variations in physicochemical parameters along the canals (p < 0.05, GLM), with higher pollution levels during wet months. The WQI improved from 35 (2005) to 49 at present, indicating enhanced water quality (p < 0.05, ANOVA), although it remains unsatisfactory. This study provides novel insights into the limitations of conventional wastewater treatment practices, demonstrating that merely treating wastewater and discharging it back into canals is insufficient. Research underscores the importance of rethinking treated wastewater reuse in achieving multiple sustainable development goals (SDGs). This approach offers a pragmatic path forward for enhancing water security and environmental] sustainability globally.Item The Financial Market of Indices of Socioeconomic Well-Being(2024) Mahanama, Thilini V.; Shirvani, Abootaleb; Rachev, Svetlozar; Fabozzi, Frank J.This study discusses how financial economic theory and its quantitative tools can be applied to create socioeconomic indices and develop a financial market for the so-called “socioeconomic well-being indices”. In this study, we quantify socioeconomic well-being by assigning a dollar value to the well-being factors of selected countries; this is analogous to how the Dow 30 encapsulates the financial health of the US market. While environmental, social, and governance (ESG) financial markets address socioeconomic issues, our focus is broader, encompassing national citizens’ wellbeing. The dollar-denominated socioeconomic indices for each country can be viewed as financial assets that can serve as risky assets for constructing a global index, which, in turn, serves as a “market of well-being socioeconomic index”. This novel global index of well-being, paralleling the Dow Jones Industrial Average (DJIA), provides a comprehensive representation of the world’s socioeconomic status. Through advanced financial econometrics and dynamic asset pricing methodologies, we evaluate the potential for significant downturns in both the socioeconomic well-being indices of individual countries and the aggregate global index. This innovative approach allows us to engineer financial instruments akin to portfolio insurance, such as index puts, designed to hedge against these downturn risks. Our findings propose a financial market model for well-being indices, encouraging the financial industry to adopt and trade these indices as mechanisms to manage and hedge against downturn risks in well-being.Item Cyanotoxins availability and detection methods in wastewater treatment plants: A review(Elsevier Ltd., 2024) Manjitha, K.G.L.; Sewwandi, B.G.N.; Takahashi, Toshinori; Fujino, TakeshiResearch interest in ecological significance, toxicity, and potential applications of cyanobacterial metabolites has grown as a result of the current extensive cyanobacterial blooms in water bodies. Under favourable conditions, specific cyanobacterial species release cyanotoxins, hepatotoxins, dermatoxins, neurotoxins, and cytotoxins, creating a heightened threat to aquatic ecosystems and human health. Wastewater treatment plants (WWTPs) offer one of the best culture media for cyanobacterial development and synthesis of cyanotoxins by providing optimum environmental conditions, including temperature, light intensity, lengthy water residence time, and nutrient-rich habitat. To discover the intricate relationships between cyanobacterial populations and other living organisms, it is important to comprehend the cyanobacterial communities in the ecology of WWTPs. Monitoring strategies of these cyanotoxins typically involved combined assessments of biological, biochemical, and physicochemical methodologies. Microscopic observations and physicochemical factors analysis cannot be carried out for toxicity potential analysis of blooms. Due to their high sensitivity, molecular-based approaches allow for the early detection of toxic cyanobacteria, while biological analysis is carried out by using water bloom material and cell extracts to screen cyanotoxins build up in organisms. As each approach has benefits and drawbacks, the development of an integrated multi-method laboratory system is essential to obtain trustworthy results and accurate detection of cyanotoxin levels in WWTPs allowing us to take necessary proactive and preventative approaches for effective wastewater treatment.Item Cytogenotoxicity of raw and treated dairy manure slurry by two-stage chemical and electrocoagulation: An application of the Allium cepa bioassay(Elsevier Ltd., 2024) Meetiyagoda, Thenuwara Arachchige Omila Kasun; Samarakoon, Thilomi; Takahashi, Toshinori; Fujino, TakeshiLivestock farming is an essential agricultural practice. However, the improper management of livestock wastes and discharge of untreated or partially treated livestock manure slurry poses significant environmental problems. In this study, we aimed to compare the cytogenotoxic potential of untreated and treated dairy manure slurry treated with a two-stage chemical and electrocoagulation (EC) using the Allium cepa bioassay. The A. cepa bioassay is a well-established standard tool for assessing the cytogenotoxic effects of environmental contaminants, especially those that are occurred as complex contaminant mixtures. The dairy manure slurry was subjected to chemical treatment utilizing polyaluminum chloride (PAC) and cationic polyacrylamide (CPAM) at optimized conditions, followed by EC utilizing either aluminum (Al) or steel anodes. The treated and untreated samples were then evaluated for their potential cytogenotoxicty using the A. cepa bioassay, by measuring the nuclear abnormalities (NAs) and chromosomal aberrations (CAs), along with the mitotic indices (MIs). Our findings revealed a significant reduction in cytogenotoxic indicators in the treated liquid fraction compared to the untreated dairy manure slurry. Specifically, the frequency of total NAs showed a significant reduction from 154 ‰ to 37 ‰ when the dairy manure slurry was treated with chemical coagulation followed by EC utilizing an Al anode. Moreover, the MI exhibited a significant improvement from 7 ‰ to 123 ‰, suggesting the mitigation of toxic effects. These results collectively demonstrate the effectiveness of the two-stage chemical and EC treatment under optimal conditions in treating diary manure slurry while reducing its cytogenotoxicity for living systems. The A. cepa bioassay proved to be a sensitive and reliable method for assessing the toxicity of the treated samples. The efficient solid–liquid separation and the reduction of toxicity in the liquid fraction for biological systems achieved through this treatment process highlight its potential for sustainable management of livestock waste and the preservation of water quality. Nevertheless, further studies are required to assess the toxicity of solid fraction.