University of Sri Jayewardenepura: Journals & Proceedings
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Trophic Ecology of Ichthyofauna Associated with the SS Orestes Shipwreck: Insights into Artificial Reef Ecosystems in Sri Lanka
No full textThe SS Orestes shipwreck, located at a depth of 24 meters and 4 km off the coast of Unawatuna-Sri Lanka, has evolved into a thriving marine ecosystem over time. It serves as a vital artificial reef, providing a unique habitat for diverse marine life. The present study aimed to identify the feeding habits of ichthyofauna inhibiting the shipwreck to understand their ecological roles and interactions within this artificial ecosystem. Data was recorded through direct underwater observations and video recordings over a period of three months, from January to March 2024. An extensive review of existing literature on the dietary habits of the observed species was carried out. Video surveys documented a total of 31 fish species belonging to 18 different families. The ichthyofauna exhibited diverse feeding strategies, categorized into four trophic guilds based on their feeding habits namely, carnivores, herbivores, omnivores, and planktivorous with significant representation across all four guilds. Carnivorous species (38.71%) such as Cheilodipterus artus, Gnathanodon speciosus, and Lutjanus fulviflamma were prevalent, highlighting the role of the shipwreck as a hunting ground for predatory fish. Herbivorous species (16.13%), including Acanthurus lineatus and Thalassoma lunare, were also well-represented, indicating the presence of plant material and algae for grazing. Omnivorous species (22.58%) like Pterocaesio chrysozona, Heniochus diphreutes and planktivorous species (22.58%) like Neopomacentrus filamentosus, Chromis xanthochira and Pempheris analis further contributed to the ecosystem's complexity. Therefore, notable trophic interactions included grazing by herbivores on algal growth, predation by carnivores on smaller reef-dwelling organisms, and scavenging activity among detritivores, observed. The findings highlight the shipwreck’s role in supporting complex food webs and sustaining ichthyofaunal diversity. Although this study relied on literature to infer feeding behaviors, future research incorporating gut content analysis would provide more precise insights into species-specific trophic interactions. This would further enhance the understanding of the ecological importance of artificial reefs in supporting marine biodiversity and their role in ecosystem conservation in Sri Lanka.
Keywords: Artificial reefs, SS Orestes shipwreck, Ichthyofauna, Feeding habit
Navigating Peril: Climate Change Impacts and Adaptive Strategies for Coastal Security in Colombo District
No full textAbstract
As a small island nation, Sri Lanka is highly vulnerable to the adverse effects of climate change including sea level rise, coastal erosion, landslides, flooding, heavy rainfall, and rising temperatures. These changes, as a non-traditional security threat, pose significant challenges to the country’s national security, causing coastal infrastructure damage, human displacement, disruption to fisheries and livelihoods, and conflict over resources. Hence it is crucial to identify the specific impacts of climate change on the country, particularly in vulnerable regions like coastal zones, to develop effective adaptation and mitigation strategies. The objective of the study was to identify the risks faced by the vulnerable coastal zones in Colombo District due to climate change and to suggest appropriate measures to adapt these challenges. The study employed a qualitative method, utilizing both primary and secondary data. To gather primary data, semi structured interviews were conducted with key stakeholders, including representatives from the Coastal Conservation and Coastal Resource Management Department, Marine Environment Protection Authority, Sri Lanka Coast Guard, Disaster Management Center and National Aquatic Resources Research and Development Agency. Secondary data were gathered from existing journal articles, case reports and government publications. Thematic Analysis was used to interpret the data, focusing on patterns related to climate impacts on the coastal zone. Key findings highlight that rising sea level, coastal erosion and storm surges are the most pressing climate-related issues affecting the Colombo District’s coastal zone. While sea level rise impacts essential facilities and the natural ecosystem, coastal erosion exacerbates loss of land and biodiversity. Additionally, storm surges pose a significant threat to human safety and livelihoods. Most significantly, the study outlined the national security risks posed by climate change, such as the destruction of critical infrastructure, displacement of coastal communities and increased competition over resources. These factors could lead to social unrest and strain national defense capabilities. In conclusion, the study emphasizes the urgent need for coordinated efforts at the local, national and international levels to address climate-induced disasters affecting Colombo District coastal zones. Recommendations include expanding research and development, increasing funding for coastal management and integrating modern technology and community participation in adaptive strategies. Implementing such measures is critical for safeguarding both the region and the country’s national security from climate change impacts.
Keywords: Climate change, Coastal zone, Colombo district, National securit
Application of Remote Sensing Technology to Study Human Encroachment Patterns in Marginal Villages of Wilpattu National Park
No full textUnderstanding the impact of human encroachment at national parks is essential to implementing optimum management strategies for protecting wildlife and forest resources. This research used multispectral imagery (Landsat 5 and Landsat 8) to scientifically evaluate human encroachment in Wilpattu National Park's selected influenced GNDs using methods from remote sensing. The primary goal of this study is to utilise multispectral images for a quantitative evaluation of human encroachment in selected GNDs in Wilpattu National Park through a remote sensing approach, focusing on assessing spatial and temporal patterns using high-resolution satellite imagery and analysing vegetation cover using the NDVI index. The present research was focused on selected eight marginal villages (Hunuwilagama, Mahawilachchiya, Rajanganaya Track 18, Matha Kiramam, Palaikuli, Pahala Puliyankulama, Parana Eluwankulama and Andiyapuliyankulam) in Wilpattu National Park along the buffer areas. Land use maps and the Normalised Difference Vegetation Index (NDVI) were used to measure the changes in land use cover in these areas between 2009 and 2022. Image processing and supervised classification methodology were employed, and the study area was categorised into four different classes: dense vegetation, sparse vegetation, barren lands, and water bodies. Using ArcGIS Pro software, NDVI maps were created, and quantitative data was categorised throughout three separate periods (2009, 2015, and 2022). Using the change detection wizard tool, the overall change between 2009 and 2022 was evaluated according to land use category. Finally, NDVI-derived maps were crossed with developed land use maps in 2009 and 2022 to access the actual forest cover area. The results indicate that during the last 13 years. Over a decade, significant changes have occurred in forest areas, agricultural fields (paddy, coconut, chena), and residential gardens. According to the study's findings, all the GNDs experienced actual forest cover loss between 2009-2022 and Pahala Eluwankulama GND exhibited the most significant reduction in forest cover, resulting in a 12.54% loss. According to the results of the classification of the buffer zone, paddy cultivation, and human settlement areas experienced the highest expansion throughout the 13 years from 2009 to 2022. This study emphasizes the effectiveness of incorporating remote sensing data into land use change detection, especially in faraway locations like national parks and forests where access and data collection are difficult.
Keywords: Wilpattu National Park, Land use change detection, NDVI, Remote sensin
Assessment of Anthropogenic Influence on Blue Carbon Stocks of Tidal Salt Marshes in Northwest Coast, Sri Lanka
No full textBlue carbon ecosystems are now in the global spotlight, due to their significant ability to sequester carbon, positioning them as key players in climate change mitigation. Among these ecosystems, salt marshes have received the least attention compared to other blue carbon ecosystems such as mangroves and seagrasses. Despite their immense value, these ecosystems face significant threats due to anthropogenic activities around the world. Salt marshes along the Northwest coast of Sri Lanka, particularly near the Puttalam lagoon, have suffered rapid degradation due to anthropogenic activities such as shrimp farming, salterns, and encroachments. Therefore, this study aims to assess the influence of human disturbances on blue carbon stocks by comparing an undisturbed natural salt marsh site and a disturbed site subjected to anthropogenic impacts. Vegetation carbon stock was assessed by developing species-specific allometric equations, providing an accurate estimate of the carbon stored in above-ground biomass. Soil carbon stocks were assessed through the loss on ignition method, using soil samples collected from a 1-meter depth. The estimated total carbon stock in the natural site was significantly higher (162.87±38.58 Mg C ha⁻¹) than that of the disturbed site (118.01±23.47 Mg C ha⁻¹), indicating that human activities have a detrimental effect on the carbon sequestration potential of these ecosystems. Moreover, soil chemical properties (pH, electrical conductivity, total dissolved solids, salinity) were analyzed along the depth profile in both sites. It revealed further differences between the two sites. The natural salt marsh exhibited an alkaline pH throughout the soil profile, supporting optimal conditions for long-term carbon storage. In contrast, the disturbed site showed acidified conditions in the upper 30 cm of soil, accompanied by a significant reduction in electrical conductivity, total dissolved solids, and salinity parameters that are essential for maintaining the unique characteristics of salt marsh environments. There was no significant difference in chemical parameters in the deeper layers (below 30 cm) in both sites. The degradation in the surface layers suggests that human activities have accelerated the disruption of ecosystem functions critical to carbon storage. These findings highlight the urgent need to address the impacts of anthropogenic pressures on salt marshes, particularly in the context of climate change. Our research emphasizes the necessity for further investigation into salt marsh blue carbon dynamics, as well as the implementation of conservation and management strategies to ensure the long-term sustainability of these crucial ecosystems.
Keywords: Blue carbon, Carbon sinks, Salt marsh, Soil organic carbon, Anthropogenic influenc
Evaluation of Coir Pith Aging in Enhancing Expansion Ratios for Sustainable Land Use in Agriculture
No full textCoir pith, a byproduct of coconut processing, has gained prominence in sustainable agriculture due to its favorable water retention and aeration properties, making it an effective growing medium. One commonly held belief is that aging coir pith enhances its physical characteristics, particularly its expansion ratio (ER), which is crucial for plant growth. However, this practice of aging increases the demand for storage facilities, labor, and production costs, raising concerns about both economic viability and environmental sustainability. This study evaluates the impact of short-term aging on the expansion ratio of coir pith to determine whether non-aged or minimally aged coir can be used as an alternative, reducing costs while maintaining its effectiveness. The objective of this study is to determine the variation in expansion properties of coir grow bags with respect to the aging duration of coir pith. The research investigates three treatments of coir pith: non-aged (T1), two-month aged (T2), and four-month aged (T3). The expansion ratio was calculated as ER=(V1-V0)/V0, where V0 is the initial volume and V1 is the final volume after expansion. Data were subjected to statistical analysis (ANOVA) to determine whether significant differences existed between treatments. The results indicate that there were no statistically significant differences between the expansion ratios of non-aged and aged coir pith. These findings suggest that aging coir pith for two to four months does not lead to substantial improvements in its expansion ratio. Consequently, non-aged or minimally aged coir pith can be utilized in agriculture without compromising its performance as a growing medium. This has important implications for sustainable land use in agriculture, as reducing the need for aging lowers the costs associated with storage, labor, and production. Moreover, adopting non-aged coir pith contributes to more resource-efficient and environmentally sustainable agricultural practices. In conclusion, the study shows that aging coir pith for short periods does not significantly enhance its performance. The use of non-aged coir pith can therefore promote more sustainable agricultural systems by reducing operational costs while maintaining the effectiveness of the growing medium. Further research on long-term aging is recommended to explore any potential benefits that may arise from extended aging periods.
Keywords: Coir pith aging, Expansion ratio, Sustainable agriculture, Growing medium, Resource efficienc
Factors that Effect on Employees’ Adoption of Mobile Banking Services: Special reference to Mahara Divisional Secretary Office & Mahara Samson Rubber Industries Pvt (Ltd)
Get PDFMobile banking is one of the thriving industries in modern world. It is one of the convenient ways to formulate banking activities within short time. In Sri Lanka; there is a new trend for adoption of mobile banking as volume of transactions has been increased each and every year. However, its volume of transactions is relatively lower than the volume of transactions of online banking. In Sri Lankan context; there is a gap in literature because there were few studies which have considered the factors that effect on adoption of mobile banking under occupational context. This study investigates the factors that effect on employees’ adoption of mobile banking services and the relationship between the factors. Descriptive Analysis examines the demographic profile and Correlation Analysis, Multiple Regression Analysis examine how Perceived Ease of Use, Perceived Usefulness, Perceived Risk and Perceived Trust effect on the dependent variable of Employees’ adoption of mobile banking services. The Correlation Analysis concludes that all the independent variables have strong positive relationship with the dependent variable and Multiple Regression Analysis revealed that except Perceived Risk; all other independent variables have significant and positive relationship between the dependent variable. The R square value of the model was 0.584. It indicates that the dependent variable is described by 58% through PEOU, PR, and PT. The findings of this study conclude that banks and software engineers can develop banking apps and attract employees towards mobile banking services by considering Perceived Trust, Perceived Ease of Use and Perceived Usefulness.
DOI: http://doi.org/10.31357/fhss/vjhss.v09irchss2023.a0
Impact of Selected Macroeconomic Variables on the Unemployment Rate in Sri Lanka (2005-2020)
Get PDFUnemployment is one of the socio-economic problems that exist globally. As a developing country, unemployment has been a long-term problem in Sri Lanka. It can be identified as one of the main macroeconomic variables affecting the sustainable economic growth in Sri Lanka. The youth unemployment rate, especially the, female unemployment rate, has increased significantly. Afterward, this has created negative consequences for the country’s economy and citizens. This study examines how macroeconomic factors, such as Gross Domestic Product (GDP), inflation, export, and exchange rate, impact the unemployment rate in Sri Lanka from 2005 to 2020. Quarterly data relevant to these variables from 2005 to 2020 were used for the analysis. The Vector Error Correction Model (VECM) was employed to determine the effect of these variables on the unemployment rate. It was revealed that Sri Lanka’s GDP, exports, and inflation significantly affect the unemployment rate, while the exchange rate did not significantly impact during the reference period. It can be suggested that the government and policymakers should implement policies to maintain a low unemployment rate in Sri Lanka by increasing GDP and exports while keeping the inflation rate at a substantial low level
Analytical Representation Technique of Modelling Present Value Function and the Application to Life Table Functions under the Framework of Chebyshev Polynomial
Get PDFIn life insurance analysis, weighing insured’s benefits and contributions which occur over time requires discounting those amounts to present value equivalents. Therefore, the choice of discount rate can be consequential for the valuation of insurance policies. Out of the functions making up the life insurance products, there seems to be no closed form numerical estimates for the interest rate intensity and present value functions. This identified problem may either be in favour of the insured or ortherwise. However, the practice favours the life insurer most in actuarial valuation under the deterministic parsimonious setting. Empirical evidence suggests that new theoretical model advances given the future uncertainty likely suggesting lower long-term rates. This evidence generally supports lowering discount rates under a feasible best guess based on the available financial information. This necessitates deriving a discount rate which can adjust for the fact that benefits are more valuable at present than in the future if policyholders prefer to buy cover now rather than wait or if insurers could be earning a positive return on invested incomes. In this study, the objectives is to develop model for the present value function under the Chebyshev polynomial series framework within the interval of orthogonality and then define some life table structures on the model. From our analytical constructions, as the argument of the polynomial series tends to, we obtain the present value function, which attempts to balance the interests of the policyholders and the life insurers
Optimizing Seed Germination and Establishment of Sonneratia caseolaris for Propagation and Reforestation
Get PDFThe mangrove apple (Sonneratia caseolaris), locally known as Kirala in Sri Lanka, is a salt-tolerant species with significant ecological and commercial importance. However, limited seedling availability hinders its propagation and reforestation. This study investigated seed viability, germination enhancement techniques, and optimal growth conditions to address these challenges. Viable seeds were treated to overcome the hard seed coat barrier, achieving a germination rate of 44% compared to 23% in untreated seeds. Soil media trials demonstrated the highest germination rate (38%) in sand/charcoal/coconut coir mix, outperforming sand (16%), compost (14%), and natural soil (20%). Field stability was assessed using quadrats in flood-prone and non-flooded areas. Seedlings in non-flooded quadrats exhibited higher survival rates (79% after one month), whereas those in flooded quadrats suffered significant mortality due to prolonged inundation. These results emphasize the efficacy of seed coat treatment and optimized soil media in enhancing germination, as well as the importance of site selection for successful reforestation. The study provides a foundation for advancing propagation techniques and sustainable population establishment of S. caseolaris.
Keywords: Germination enhancement, Soil media, Flooding tolerance, Sonneratia caseolaris, Mangrove reforestatio
Avian Nesting Patterns and Preferences in Urban Road Median Trees: A Case Study from Galle Road, Sri Lanka
No full textUrbanization affects the nesting patterns of birds and causes limited selection of nesting trees. Road medians serve as potential nesting sites, to help this issue. The objective of this study is to determine how different trees in the road median islands are utilized by different bird species. The study was conducted from August 2024 to December 2024, involving surveys on the 5 km median island of the Galle Road from Borupana Junction to Kurusa Junction, covering 107 trees. Avifaunal observations were conducted while traveling along the road median between 0700h and 1000h. Birds were observed directly and with the aid of a 10 × 50 binocular. Active nests were located by searching the vegetation and following parent birds carrying nesting materials. Tree species were identified, and tree height, canopy diameter, diameter at breast height and number of branches were recorded. Nest type, concealment, canopy cover, distance from the nest tree to the adjacent tree and distance to the nearest road were measured. Disturbances for the nests were seen and recorded. There were 361 birds observed, representing 21 species from 18 families. The highest number of individuals (251) were recorded from house crow (Corvus splendens). Spot-billed pelicans belonging to the near threatened category (NT) was recorded. A total of 281 nests were recorded during the study period (271 open cup nests and 10 cavity nests) in 46 trees belonging to eight species in four families. Maximum numbers of nests (265) were recorded from house crow and 28% of these nests were in active stage. Highest number of nests were constructed in trees belonging to Family Moraceae: Ficus benghalensis and Ficus religiosa (85 for each species). Nests were constructed utilizing trees belonging to the Fabaceae, Sapotaceae, and Bignoniaceae families. Most of the nests were observed in larger trees characterized by broad canopies and high number of branches. The heights of the nesting trees and nests varied from 18.8 to 3.0m and 18.0 to 2.0m, respectively. The nests were exposed to open spaces characterized by minimal concealment (12%) and limited canopy cover (21%). The trees were found at a distance of 5±1.2 m close to adjacent trees and 2±4.2 m from the nearest road. There were no apex predators, therefore house crows preyed on the majority of the other bird species' nests. The present study reveals that the nests were utilized by Corvus splendens due to their adaptive success in urban environments. To enhance the bird diversity in this habitat, urban development should emphasize the significance of densely foliated trees in attracting and preserving nest sites of native bird populations.
Keywords: Avian nesting, Urban ecology, Road median trees, Nesting preferences, Galle road – Sri Lank