University of Sri Jayewardenepura: Journals & Proceedings
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Assessing the Fishing Grounds and the Influence of Oceanographic Variables on Skipjack Tuna (Katsuwonus pelamis) Distribution and Abundance Along the Southern Coast of Sri Lanka
Get PDFSkipjack tuna (Katsuwonus pelamis) is one of the most economically and ecologically important species in Sri Lankan fisheries and world fisheries. Within the Indian Ocean, the southern coast of Sri Lanka has long been recognized as a prime fishing ground for Skipjack tuna. This region is affected by monsoonal cycles and produces rich upwellings that serve as productive fishing zones. Using 30-day processed and merged remotely sensed satellite data of the year 2019, this research focuses on the south coast of Sri Lanka (latitudes 0°N-6.5°N and longitudes 76°E–85.6°E), targeting offshore and high seas longline, gill net, and ring net Skipjack tuna fisheries catch data. Environmental data including sea surface temperature (SST), sea surface chlorophyll (SSC), sea surface height (SSH), eddy kinetic energy (EKE), sea surface salinity (SSS), and mixed layer depth (MLD) derived from the remote sensing satellites (RSS) were extracted from two Copernicus marine services products and spatially converted to a 1/3° spatial resolution. Then the catch data obtained from the Department of Fisheries and Aquatic Resources (DFAR), were merged with the satellite data. The effect of these oceanographic factors on Skipjack tuna abundance and distribution was studied using histogram analysis, generalized additive model (GAM), and empirical cumulative distribution function (ECDF). Skipjack tuna high catch rates were observed at 26.5°C-29.0°C of SST, 0.00 mg.m-3-0.50 mg.m-3 of SSC, 0.35 m–0.55 m of SSH, 0.00 m2.s-2-0.90 m2.s-2 of EKE, 31.5 PSU–35.25 of PSU SSS, and 10.00–27.50 m of MLD. The catch per unit effort (CPUE) shows variability in the main monsoon seasons of Sri Lanka, with peaks observed in March and October. The variability of the oceanographic conditions directly influences the distribution and abundance of Skipjack tuna. These results showed SST, EKE, and SSC are important environmental parameters affecting the abundance of Skipjack tuna resources in Sri Lankan southern coastal waters. The EKE showed a strong association with the Skipjack tuna catch rates when paired with the SST, suggesting that ocean eddies and sea surface temperature patterns play an important role in Skipjack tuna distribution and abundance along the Sri Lankan southern coastal region.
Keywords: Fishing grounds, Longline, Catch data, Relationship, Oceanographic condition
Screening and Quantification of Selected Penicillin Group Antibiotics (AMX, AMP, CLOX) and Resistant Bacteria in Solid Waste Dump Leachates
No full textThe escalating generation of solid waste due to rapid industrialization and urbanization necessitates effective waste management strategies to mitigate environmental pollution, notably through containing landfill leachate (LFL) contamination. This study reports the presence of penicillin group antibiotics Amoxicillin (AMX), Ampicillin (AMP), Cloxacillin (CLOX) and antibiotic-resistant bacteria in LFL, Leachate samples collected from Kegalle, Mathugama and Kegalle and subjected to identification, quantification of AMX, AMP and CLOX residues and screening of resistance bacteria against AMX, AMP and CLOX. Antibiotic residues were quantified using High-Performance Liquid Chromatography (HPLC). None of the samples detected AMX, AMP, and CLOX antibiotic residues. Antibiotic Resistance Bacteria (ARB) and Minimum Inhibitory Concentration (MIC) were determined against the antibiotics following the standard methods. Antibiotics using CLSI guidelines. In the collected leachate samples, resistance to AMX ranged from 2.2% to 13.7%, resistance to CLOX ranged from 3.3% to 5.1%, and resistance to AMP ranged from 1.6% to 10.3%. Over 50% of antibiotic-resistant bacteria (ARB) were found, with a minimum inhibitory concentration (MIC) greater than 360 μg/ml for both AMX and AMP. Multiple antibiotic resistance indices ranged from 0.1 to 0.6, underscoring the intricate interplay of environmental factors and selective pressures. These findings underscore the imperative for continuous monitoring and management strategies to curb the proliferation of antibiotic resistance in landfill leachates. By safeguarding environmental integrity and public health, such initiatives are essential for sustainable development and the preservation of ecosystems. Integrated approaches, informed by robust scientific investigations, are vital for addressing the multifaceted challenges of antibiotic contamination in landfill leachates.
Keywords: Leachate, Amoxicillin, Ampicillin, Cloxacillin, Antibiotic resistanc
Factors Affecting Growth, Survival and Leaf Functional Traits of Tree Saplings Planted Along a Successional Chrono-Sequence in Endane Biodiversity Corridor in Southwestern, Sri Lanka
Get PDFThe growth of a sapling is influenced by species, succession, and habitat characteristics such as shade and elevation. Forest restoration efforts often fail due to insufficient consideration of habitat characteristics and site-species suitability. In this study, we examined how habitat characteristics, successional age and elevation affect growth, survival, and functional traits of 13 threatened tree species planted in Endane Biodiversity Corridor in Southwestern Sri Lanka. The growth parameters and selected leaf functional traits in 13 threatened tree species interplanted within four successional ages (marginal tea, scrub, woodland 1, and woodland 2) with contrasting elevation and canopy closure were measured after one year of planting and analyzed using a linear mixed-effect model. We found that mean annual height growth in different habitats increased significantly with successional age, from the highest being in shaded woodland, the lowest growth (p<0.001) in open marginal tea habitats. Mean annual diameter growth also varied by successional age but did not follow the same trend as height growth due to differences in canopy closure. A strong positive correlation was observed between height and diameter growth one year after planting (r=0.71, p<0.001). Chlorophyll content increased with succession, the highest in a shaded woodland (p<0.001). In contrast, leaf dry matter content (LDMC) and leaf mass per area (LMA) decreased with successional age, with marginal tea showing the highest values (p<0.001). The LMA variability was explained by LDMC (r=0.41, p<0.001) and leaf thickness (LT) (r=0.42, p<0.001). These results provide valuable insights into long-term monitoring of restoration success in Endane Biodiversity Corridor in Southwestern Sri Lanka.
Keywords: Mean annual height growth, Species selection, Specific leaf area, Specific dry matter conten
A Comprehensive Environmental Life Cycle Assessment of Kelanitissa Combined Cycle Power Plant (KCCP): Gate-to-Gate Approach
No full textEven though the electric power industry has made significant strides in lowering pollution, fossil fuel-fired power plants continue to be a major source of pollution that impacts communities across the country in the air, water, and land. This study evaluates the Kelanitissa Combined Cycle Power Plant (KCCP) in Sri Lanka through an Environmental Life Cycle Assessment (LCA). The main goal of this study is to assess the environmental effects of its activities via a gate-to-gate approach and identification of environmental hotspots of electricity generation at KCCP through the LCA framework. This study covers the electricity generation process, starting from procurement of Naphtha and diesel and ends upon the production of electricity. The method of data collection included several approaches such as site observation, referring to daily and annual reports, emission reports, discussions with field level personnel and a literature survey on secondary data sources. Life Cycle Inventory stage involved conversion of input/output information and presenting them per 1 MWh of Electricity generated which is the functional unit. To assess the environmental impacts, the ReCiPe 2016 technique in SimaPro was used, concentrating on midpoint impacts and endpoint indicators. Finally, in the data interpretation step, the impacts were normalized, and a consistency check was performed to validate the findings. The results indicate that when 1 MWh is generated, it results in 523 kg CO2 eq Global warming potential, 6.28 kg NOx eq Ozone formation affecting human health and 0.547 kg NOx eq Ozone formation affecting terrestrial ecosystems, 0.38 kg PM2.5 eq Particulate Matter Formation and terrestrial acidification potential of 0.314 kg SO2 eq. After normalizing impacts in E-LCA, the highest impact was recorded under the category of ozone formation affecting human health, followed by global warming and ozone formation affecting terrestrial ecosystems. A comprehensive strategy is necessary to mitigate the public health damage, perhaps imposing a carbon tax on the KCCP. Such revenues can also be allocated to energy efficiency initiatives, renewable energy projects etc.
Keywords: Thermal power, Environmental Life cycle analysis, Human health, Greenhouse gas emissio
Slaughterhouse Wastewater Using Up Flow Anaerobic Sludge Blanket (UASB) Reactor: Evaluation of Net Energy
No full textThe Up flow Anaerobic Sludge Blanket (UASB) reactor is a potential solution for treating high-strength slaughterhouse wastewater, although it consumes more energy in the process. Present study investigated the energetic advantages of treating slaughterhouse wastewater using a UASB reactor. The major energy requirement for the operation of a UASB reactor includes the energy for heating the reactor and circulating the liquid inside the reactor. Methane production determines the energy benefits of a UASB reactor. In fact, net energy is the appropriate term to compare the performance of UASB rather than the rate of methane production. In this context, this study grasps a new look at evaluating the net energy from the UASB reactor. Based on the theoretical energy calculation, for an organic loading rate of 266.66 mg/l in terms of COD, the corresponding energy produced from methane is 1.03 kJ and the net energy is 2.14 kJ. Also, this approach was extended to evaluate the net energy of UASB systems that were previously reported in the literature. In most cases, heating energy seems to be the major energy demand compared to liquid pumping. Thus, the heating of wastewater and electricity to run the reactors can be managed using the energy produced from methane. In general, the study of alternatives for the energy use of sewage treatment byproducts must take into account the needs and the reality of the treatment plants. The mass and energy balances are essential for economic feasibility studies of energy use projects that can be considered technically viable for each sewage treatment plant.
Keywords: Organic loading rate, Methane, UASB reacto
Cultural Heritage and Sustainable Tourism: A Community Study in Ratnapura District, Sri Lanka
No full textThe Ratnapura District of Sri Lanka is celebrated for its rich cultural heritage, particularly in gem mining and traditional craftsmanship. With tourism rapidly expanding in this region, there is an urgent need to balance economic growth with the preservation of local cultural identities. Understanding this balance is critical for fostering sustainable community development and ensuring that tourism benefits the local populace without compromising their heritage. This study aims to explore the interplay between cultural heritage and sustainable tourism in Ratnapura. The primary objectives include assessing the impact of tourism on local traditions, evaluating the economic benefits derived from tourism activities, and identifying strategies to preserve cultural heritage while promoting responsible tourism practices. A mixed-methods approach was employed, combining qualitative and quantitative research techniques. Qualitative data were gathered through in-depth interviews with key stakeholders, including community leaders, artisans, and tourism operators. These interviews provided insights into local perceptions and experiences regarding cultural heritage and tourism. Additionally, quantitative surveys were distributed to visitors, allowing for the collection of data on tourist behaviour and attitudes toward cultural experiences. This comprehensive methodology facilitated a robust analysis of the relationship between tourism and cultural heritage preservation. The findings indicate that tourism significantly contributes to the local economy, with many residents benefiting from increased visitor spending. However, concerns were raised regarding the potential commercialization and dilution of cultural practices. Many locals expressed a desire for more meaningful tourist interactions that respect and honour their heritage. Successful initiatives, such as cultural festivals and artisan workshops, were identified as effective ways to engage both visitors and the community, promoting traditional crafts while enhancing the tourist experience. The study highlights the need for sustainable tourism practices that prioritize the preservation of cultural heritage. Collaborative efforts among government bodies, local businesses, and community members are essential for developing strategies that promote responsible tourism. By fostering community engagement and creating awareness of the importance of cultural heritage, Ratnapura can enhance its appeal to culturally conscious travellers. This approach not only supports economic development but also ensures that the unique cultural identity of Ratnapura is preserved for future generations. Ultimately, this study contributes to the broader discourse on sustainable tourism, emphasizing the vital role of cultural heritage in fostering community resilience and development.
Keywords: Cultural heritage, Economic, Tourism, Commercializatio
An Updated Checklist of Exotic Fish Species Recorded from Nine Urban Wetlands of Colombo District, Sri Lanka
Get PDFSri Lanka hosts a rich diversity of freshwater fish, with 139 species recorded, including 61 endemics. Colombo district, located in the southwestern ichthyological zone bears the highest number of endemic and threatened freshwater ichthyofauna. Furthermore, serving as the country’s economic hub, the Colombo district encompasses an interconnected network of wetlands of significant ecological value. Given the rapid urban development in the region, this study evaluates the composition of exotic fish species in nine urban wetlands in Colombo from June 2018 to October 2024. The surveyed wetlands included Diyasaru Park (DP), Beddagana Wetland Park (BWP), Thalangama Lake (TL), Diyatha Uyana (DU), Nawala Weli Park (NWP), Heen Canal (HC), Kimbulawala Jogging Pathway (KJP), Bellanwila-Aththidiya Wetland (BAW), and Kotte Rampart Wetland Park (KRW). Some fish were identified by direct visual observation in the field and others were collected through hand netting, and all species were identified to the species level. Across the study period, 14 exotic fish species were recorded: Betta splendens, Chitala ornata, Cyprinus carpio, Helostoma temminckii, Mayaheros urophthalmus, Oreochromis mossambicus, Oreochromis niloticus, Osphronemus gouramy, Pangasianodon hypophthalmus, Poecilia reticulata, Pterygoplichthys multiradiatus, Tilapia buttikoferi, Trichogaster trichopterus, and Trichopodus pectoralis. The highest proportion of exotic species was found in DP (57.1%), followed by BAW (50%), HC and DU (35.7%), BWP (28.6%), and KRW (21.4%). TL, KJP, and NWP had the lowest proportion (14.3%). Of the 14 recorded exotics, the majority were represented by the family Cichlidae (28.6%), followed by Belontidae and Osphronemidae (14.3%). Notably, KJP, BAW, HC, BWP, DP, and DU respectively recorded the introduction of 100%, 57.1%, 40%, 25%, 25%, and 20% of exotic species, primarily due to the ornamental aquarium trade, either deliberately or unintentionally. TL, KRW, and NWP showed no such introductions. Visual observations indicate that DU serves as a site where the general public releases ornamental fish into the natural environment. In addition, the study recorded 16 native fish species from seven families: Anabantidae, Applocheilidae, Bagridae, Channidae, Cyprinidae, Heteropneustidae, and Osphronemidae. Given the growing threats of pollution and urbanisation, these findings underscore the urgency of updated monitoring efforts, awareness, and regulations towards Colombo’s urban wetlands. Further research on the ichthyofaunal composition, breeding patterns, population density, and feeding behaviours in larger water bodies within these wetlands is crucial to assess their impact on native species.
Keywords: Ornamental fish, Colombo, Exotic, Introduced, Invasiv
Study the Change in Laterite Geochemistry with Atmospheric Conditions (Chemical Properties)
No full textLaterite is a porous, reddish-brown sedimentary rock formed in tropical climates by decomposition of parent rocks and leaching soluble elements. In this process, soluble elements like lime, magnesia, and potash are washed away by water during the wet season, while less soluble oxides of iron, aluminium, and manganese accumulate and cement within the residual soil. Known for its durability, laterite is widely used in construction, necessitating chemical studies under environmental conditions. This study investigates the geochemical behavior of dry and wet laterite under different atmospheric conditions. The methodology involved collecting hardened and fresh laterite samples and analyzing them through EDX analysis for Confirmation, measuring moisture content, Water absorbance, and iron leaching in weathering conditions using atomic absorption spectrometry and conductivity and pH variations to assess chemical changes of laterite in atmospheric settings. Laterite samples taken from the Gampaha district were analyzed throughout the study. In moisture content analysis with dry and wet samples, it was found to exhibit moisture content values of 20.68% and 8.88%, respectively. Conductance measurements revealed that wet laterite releases more ions into water compared to dry laterite, indicating that water interacting with laterite can increase the conductance over time. In acidic medium, higher conductance was observed for both laterite types than water with wet laterite giving higher conductance than dry samples. The study also confirmed that acidic water exacerbates Iron leaching from laterite, resulting in significantly higher Iron concentrations compared to neutral water. Consequently, both the laterite soil and groundwater in such acidic environments are likely to exhibit elevated concentrations of Iron. This emphasizes the enhanced impact of acid rain on soil chemistry. The pH variation of water with laterite indicated initial acidification, followed by stabilization, which is likely due to the dynamic exchange of hydrogen ions between negatively charged clay particles and the solution. This finding highlights the vulnerability of groundwater contaminations in regions with acidic precipitation. Additionally, water absorption tests demonstrated a rapid initial water uptake by dry laterite samples within the first two hours, moving to a moisture saturation with time. The study concludes that laterite undergoes substantial chemical transformations under atmospheric exposure, affecting both water chemistry and soil properties. These results provide valuable insights into laterite's interaction with environmental factors, contributing to its effective management in construction, and environmental engineering.
Keywords: Conductance, Iron leaching, Laterite, pH variation, Weatherin
PUBLIC DEBT DYNAMICS AND EXCHANGE RATE IN NIGERIA
Get PDFIn light of the persistent exchange rate depreciation and growing public debt in Nigeria over the last years, this study examined the dynamics between public debt and exchange rate in Nigeria. The study objective was to look at how external and domestic debts affect exchange rate in Nigeria. Using secondary data analysed through times series analysis with data for 43 years (1981-2023), the ARDL cointegration test was used because the data were composed of I(0) and I(1) variables. The result showed that there is no long-run relationship between public debts and exchange rate. However, there was evidence of a structural break, which then require running a pre and post-structural break analysis. External debt showed to reduce exchange rate pre-structural break, but it was insignificant. After structural break, external debt became positively significant on increasing the exchange rate. Domestic debt shows a positive relationship with exchange rate pre and post structural break. While it was insignificant pre 1999, it became significant after 1999. Debt servicing positively add to increasing exchange rate pre and post structural break but was only significant pre-structural break. Foreign reserve similar to debt servicing also have a positive relationship with exchange rate pre and post-structural break but only significant after the structural break. Using the granger causality test, there was no causation between public debts and exchange rate. Based on the research findings, the study recommends that external debts should be utilised for capital expenditures rather than recurrent expenditures to enhance future economic returns and the productive capacity of the economy. This recommendation is crucial due to the significant burden on Nigeria's reserves from the country's reliance on imports, which contributes to high exchange rates
Exploring Digital Diplomacy Practices amid Covid-19 Pandemic and its Challenges: Perspectives from Sri Lankan Diplomats
Get PDFThe sudden outbreak of Covid-19 pandemic forced states to shift their diplomacy practices into digital platforms to stay connected with the outside world while serving their citizens abroad. Consequently, Sri Lanka also enhanced the level of Digital Diplomacy practices to adapt to the ‘new-normality’ brought by Covid-19. This paper focused on examining the shifts in Digital Diplomacy as a response to the pandemic while exploring the challenges faced by diplomats in adapting to this new form of diplomacy. A snowball sample of eight diplomatic officers attached to the Ministry of Foreign Affairs of Sri Lanka were selected for the study. In-depth interviews were conducted for data collection and thematic analysis was used for data analysis. The study found digital diplomacy practices prior to Covid-19 under three main themes namely, traditional digital communication tools, limited digital public engagement and initial steps toward digital services. Digital Diplomacy practices after Covid-19 are presented under five themes as; expanded digital communication social media for public engagement, enhanced online services, adoption of virtual platforms and online portals and data management. This study further found that when practicing Digital Diplomacy, officers face challenges as, absence of legal or policy frameworks, inefficiencies in virtual meetings, officers’ reluctance, limitations in capacity, lack of citizens’ adaptability, data security issues, inadequate digital platforms and repository systems and, issues due to other state conditions. This study provides useful implications for policy makers on the effective use of Digital Diplomacy practices for national interest.
Keywords: Challenges, Covid-19, Digital Diplomacy, Ministry of Foreign Affairs (MFA), Sri Lank