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Item Pervasive Microplastic Ingestion by Commercial Fish Species from a Natural Lagoon Environment(Water, 2024) Athukorala, A.; Amarathunga, A. A. D.; De Silva, D. S. M.; Bakir, A.; McGoran, A. R.; Sivyer, D. B.; Dias, B. C. G.; Kanishka, W. S.; Reeve, C.Microplastics have emerged as a significant global environmental concern in the recent decade. The aim of this study was to elucidate microplastic contamination of commercial fish species in a natural lagoon environment. Microplastic contamination was examined in the gastrointestinal tracts and gills of 157 commercial fish from 18 species with varying feeding habits in a vital and sensitive lagoon ecosystem, which connects to the Indian ocean. Microplastics were extracted using digestion, followed by stereomicroscopic inspection using Nile Red stain, and identified via μ-FTIR analysis. Over half of studied fishes ingested microplastics (54.14%). Filaments (50%) and blue items (43%) were the most commonly ingested. Of all the fish species, Eubleekeria splendens had the highest average concentration of microplastics in GIT (1.41 ± 2.52 items/g w.w. tissues), although no statistically significant difference in amount of ingested microplastics (items/g w.w. tissues) was observed among species. The highest concentrations of inhaled microplastics were recorded in Sillago vincenti (1.38 ± 1.30 items/g w.w. tissues). The majority of the extracted microplastics (33%) belonged in the size class 500–1500 μm with rayon, polyethylene terephthalate, and polypropylene as the primary polymers. This study found no correlation between microplastic ingestion and fish species and feeding habits, but a positive correlation with fish size was observed. These findings reveal widespread microplastic contamination in edible fish, posing potential risks to commercially important species due to increasing pollution in lagoon ecosystems.Item Validation of logbook catch records in offshore fishing vessels of Sri Lanka using VMS data.(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Gunawardane, N.D.P.; De Croos, M. D. S. T.; Amarasinghe, U.S.Accurate information on fishing position is a timely need in the offshore fisheries, especially for preventing illegal, unregulated and unreported (IUU) fishing. Vessel monitoring system (VMS) is recognized as one of the effective mechanisms for validating the fishing positions of fishing vessels provided by logbook system. In the present study, an attempt is made for developing an approach to identify and validate the fishing locations of offshore vessels in Sri Lanka using VMS data. VMS data based on the speed, distance and angle filters were adopted to identify the fishing locations. Here, the best angle of the zig-zag shapes recorded in the cruise tracks of VMS was determined as < 15o using the flooding data of VMS. Similarly, speed level of <3 knots was identified as the possible speed of fishing. Distance gaps of fishing locations were recorded and converted to distance buffers. Data from 1291 multiday vessels, operated from 21 fisheries harbors of Sri Lanka from May 2017 to April 2018 were analyzed in the present study. Predicted fishing locations based on VMS data were compared with fishing data of log sheets reported by skippers were compared using paired t-test. Results of the analysis showed that fishing occasions predicted using the speed and course angle of VMS alerts had a good agreement (p<0.05) with the fishing locations reported by fishers. However, potential cruise occasions showed significant deviation from log-book records. Although the time differences of the locations of the two monitoring systems were > 4 hrs, most of the matched locations were recorded within 24 hrs. This may be due to the practice of skippers, who only record their fishing locations only once a day, which was found to be insufficient for reliable reporting. While the current manual logbook system is recognized as appropriate to comply with the enforcement and management needs, there is a need to adopt more appropriate method of reporting catch data by fishermen. Present analysis indicated that the use of VMS data provided an alternative approach for reporting fishing locations of offshore vessels with sufficient accuracy. Need for further improvement of the data recording system representing fishing duration, and species composition is discussed for preventing IUU fishing by offshore fishing vessels.Item Identification of suitable areas to cultivate Aloe vera in Kegalle District, Sri Lanka using GIS(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Dissanayake, C. T. M.; Weerasinghe, V. P. A.Aloe vera (Aloe barbadensis Miller) is used in ayurvedic medicine, pharmaceuticals, cosmetic products and also as a food product such as drinks or mixer with yoghurt. It is getting popular with the improvements in technology of harvesting and processing the product. In Sri Lanka, it is popular as a home garden crop, but not as a crop growing in large-scale. Most Sri Lankans are less aware of getting an income from Aloe vera. Therefore, the aim of this study is to make Aloe vera cultivation popular by identifying suitable areas to cultivate Aloe vera in Kegalle district, which was the study area of this research. Data analysis was done by using ArcGIS software tools to select the suitable areas. The criteria to grow Aloe vera successfully were selected using relevant literature. They were namely land uses such as coconut or bare lands, annual rainfall range as 1800 mm-2300 mm and annual temperature range as 25 °C - 26 °C. Those criteria were considered as most favorable factors to grow Aloe vera successfully with demanding leaf thicknesses. Land use data was collected from the Survey Department, Colombo and rainfall and temperature data were collected from the Meteorology Department, Colombo. Rainfall and temperature layers were developed by using Kriging interpolation technique in spatial geostatistics in ArcGIS software. Then land use layer, rainfall layer and temperature layer were overlaid using spatial analysis tools to identify the most suitable area, moderately suitable areas and not suitable areas. Kelegama and Rambukkana DSD areas are the most suitable areas to grow Aloe vera in Kegalle district. The final map generated from this study will be useful for extension/field officers of the Department of Agriculture, to enhance the awareness of people in Kegalle district about suitable places to grow Aloe vera in order to get an extra income as well as to get the maximum utility of the land.Item Implications of Fall Armyworm epidemic in Sri Lanka: A case study in Rathnapura district(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Perera, R. N. N.; Magamage, M. P. S.; Siriwardhana, C.The first emergence of the Fall Armyworm (FAW; Spodoptera frugiperda) was reported in Sri Lanka during August 2018 and caused a substantial yield loss in maize cultivation especially in Uva, Eastern, North Central, North Western, Northern and Sabaragamuwa provinces. During the 2018/19 Maha season, over 50 percent of the entire maize cultivation has been infested by the pest. The objective of the study was to understand the magnitude of FAW infestation, social response and its implications in Rathnapura district in Sri Lanka. This was considered as mandatory in terms of easiness in accessibility to close supervision by the university as well as with the objective of preventing infestations reaching economically catastrophic levels. Simultaneously to the field inspection programme, a survey was conducted in January-March 2019 in 13 maize growing agriculture instructor (AI) areas in the Rathnapura district to evaluate the severity of FAW infestation with the collaboration of the Provincial Department of Agriculture, Sabaragamuwa Province. University academia, students, and field officers from Department of Agriculture were participated to the survey and all 13 divisions were covered for collecting pest incidence information. GIS data were recorded in each point of infestation together with related other information such as land extent, host plant characteristics and the type of cropping system which plays important role in forecasting the pest occurrence in the subsequent cropping season. Based on the field survey, there were no evidences reported that pest occurrence in other crops apart from maize. Moreover, even in mixed cropping systems with little number of maize plants, heavy infestation was recorded only in maize. Data analysis was done based on the primary land infestation records obtained from each AI range by using MS office Excel 2010. Amount of land extent use for maize cultivation in Rathnapura district was estimated as 292.65 ha, while 32.95ha were infected with the pest (11.3%). Kaltota, Embilipitiya, Ambawila and Thimbolketiya were the AI areas with highest infestation recorded in the Ratnapura District reporting 5%, 4.8%, 4.5% and 3.85 % infestations respectively. Throughout the study period, attention was made by the research team for minimizing livelihood damage by conducting interactive awareness programs, which were directed to proper identification and control further spread of the pest. Even though maize was cultivated comparatively lower land extent in Rathnapura, effective and organized disaster management response in Rathnapura was able to minimize the pest impact to 11.3% from total losses. Mobilization of the whole agriculture community has wider implications in effective controlling of FAW while preserve the farmer trust on agriculture policy in Sri Lanka.Item New Records of Ants (Hymenoptera: Formicidae) from Sri Lanka, Including Four Tramp Species(Sociobiology, 2018) Dias, R.K.S.; Udayakantha, W.S.; Wachkoo, A.A.; Akbar, S.S.Five ant species are reported for the first time from Sri Lanka: Ooceraea alii (Bharti & Akbar, 2013); O. biroi (Forel, 1907); Prionopelta kraepelini Forel, 1905; Strumigenys emmae (Emery, 1890) and S. membranifera Emery, 1869. Among the newly reported species, four species (O. biroi, S. membranifera, S. emmae and P. kraepelini) are known for their invasive and tramping nature, spreading via human commerce and have attained broad cosmopolitan distribution. Impact of these ants on regional fauna is not known and needs immediate attention. A brief diagnosis, distribution, and illustrations are provided for each species.Item Critical better management practices and critical bio-security measures for prevention of entry and spread of white spot virus and pathogenic Vibrio in grow-out farms of cultured Penaeus monodon in Sri Lanka(Sri Lanka Journal of Aquatic Sciences, 2018) Kumara, K.R.P.S.; Hettiarachchi, M.Since the first record of white spot disease (WSD) in 1996, PCR tested, white spot virus (WSV) free post larvae of Penaeus monodon (Fabricius 1798) are stocked in grow-out farms as the major bio-security measure. However, significantly high mortality in young shrimp and total rejection of harvest have been recorded in North Western Province, Sri Lanka due to WSD and/or vibriosis. Present study was planned to identify critical better management practices (CBMPs) and critical bio-security measures (CBSMs) that should be strictly adopted to prevent the entry and spread of WSV and pathogenic Vibrio in grow-out farms of P. monodon. A questionnaire survey, carried out at randomly selected 100 grow-out farms located in the North Western Province, revealed that there was a relationship between the occurrence of WSD and /or vibriosis and levels of practicing better management practices (BMPs) and/or bio-security measures (BSMs). Proper pre-stocking pond preparation, adoption of zero water exchange, monitoring and controlling water quality parameters including pathogenic Vibrio in culture water and use of a suitable bioaugmenter and a probiotic were identified as the CBMPs while proper disinfection of culture water, stocking of WSV and MBV free post larvae and prevention of WSV contamination through other routes over the rearing period were the identified CBSMs. Entry and spread of WSV and pathogenic Vibrio in P. monodon grow-out farms in the North Western Province, Sri Lanka could be prevented by strict adoption of CBMPs and CBSMs identified during the present study.Item Determination of selenium content in selected edible green leaves(Ceylon Journal of Science, 2019) De Silva, D.S.M.; Dayarathna, A.G.S.The selenium (Se) contents in seven conventional Edible Green Leaves (EGL) that consumed by Sri Lankans were determined using Hydride Generation Atomic Absorption Spectrometric method (HGAAS). The EGLs that were grown in five districts under different climatic conditions in Sri Lanka were collected from Gampaha, Kandy, Kurunegala, Anuradhapura and Puttalam areas. The EGL that were subjected to current study are Centella asiatica (Sin. Gotukola), Alternanthra sessilis (Sin. Mukunuwenna), Basella alba (Sin. Nivithi/ Spinach), Boerhavia diffusa (Sin. Sarana), Ipomoea aquatica (Sin. Kankun), Amaranthus spinosus (Sin. Thampala) and Hygrophila schulli (Sin. Neeramulliya). Soil samples corresponding to each EGL sample were also collected from Gampaha, Kandy and Anuradhapura districts in order identify a relationship between the Se content in plants and soils. Prior to the analysis EGL samples and corresponding soil samples were subjected to acid digestion with nitric acid. Se contents in the EGL were in the range of 31.2 – 103.2 μg kg-1on dry weight basis. According to the results, Centella asiatica and Hygrophila schulli varieties showed relatively higher Se content, while Hygrophila schulli shown the highest value and the lowest was reported in Boerhavia diffusa. The Se content in corresponding soil samples were ranged from 96.4 to 133.9 μg kg-1on dry weight basis. The Se content in soil was higher than that in plants, but there was no significant correlation between the Se content in soil and EGLs.Item Identification of Macrophyte Indicator Species to Evaluate the Water Quality in Wetland(Proceedings of the 22nd International Forestry and Environment Symposium 2017, 2017) Bellanthudawa, B.K.A.; Wijeyaratne, W.M.D.N.Present study conducted to assess the SP?ti?! yeri?tion of mecrophvte distribution 2nd water quality parameters of a rehabilitated and non-rehabilitated areas of the Diyawannawa wetland with the aim of identifying suitable macrophyte indicator species for water quality monitonng. Sites A, B and C were located in non-rehabilitated area and the sites D, E and F were located in rehabilitated areas in Diyawannawa wetland. The sampling was conducted from April to October 2016. At each site, water pH, temperature, conductivity, sa!inity, total dissolved solids (TDS), dissolved oxygen concentration (DO), biological oxygen demand (BOD5), chemical oxygen demand (COD), depth, visibility, total nitrate (TN), chlorophyli a (Chl a) and total phosphorus (TP) concentration were measured and the percentage cover of macrophytes were recorded. The correlation of percentage cover of macrophyte species to the water quality parameters were assessed using Pemson's correlation analysis. Principal component Analysis (PCA) based on the percentage cover of macrophyte species was performed to identify the characteristic species at each site. M[NITAB 14 software was used for statistical analysis ofdata. The percentage cover of Hydril/a verticil/ata, Pistia straiiotes and Cypreus iria did not show significant spatial variations among rehabilitated and non-rehabilitated areas. Significantly high percentage cover of Nymphaea ampla (64%) and Annona glabra (l I %) were recorded in site A in non-rehabilitated area. Eichhornia crassipes (22%) showed significantly high percentage cover in site B in non- rehabilitated area and site E in rehabilitated area. Cryptocoryne wendtii recorded significantly high percentage cover In sites A (10%) and E (7%), The highest mean percentage cover of Salvinia ;nolesta (30%) were recorded in site E. The spatial variation of physico chemical parameters Indicated significantly high DO in sites E (10.61 mg/l) and F (10.28 mg/l). Significantly high Chl a concentrations were recorded from sites B, E and F. In addition, site F recorded significantly high BOD5 (6.56 mg/l), TN (0.04 mg/l) and COD (454.8 mg/l). There was no significant spatial variation of TP among sampling sites. S. molesta and E. crassipes showed positive correlations with Chl a and TP and N. rubra showed a positive correlation with TN. H. verticillata and P. stratiotes did not show significant correlations with water quality parameters. According to PCA, considering PC scores I to 3, site A in the non-rehabilitated area was characterized by N. ampla and C. wendtii, site B by E. crassipes and P. stratiotes and site C by A. glabra. In rehabilitated area, site D was characterized by C. iria and Ceratophyllum demersum, site E by S. molesta and site F by N, rubra. The PCA based on water quality parameters grouped the sites E and F together and were characterized by high TN and Chl a concentrations. The results of the present study indicated that there is significant spatial variation of percentage macrophyte cover in relation to water quality parameters. Further, this study identified S. molesia and Eichhornia crassipes and N. rubr.a as suitable indicator of Chl a and TP and TN in wetland health monitoring studies.Item Abundance-Biomass Comparison approach to assess the environmental stressors in Diyawannawa wetland in monsoonal and non-monsoonal seasons(Sri Lanka J. Aquat. Sci, 2018) Wijeyaratne, W.M.D.N.; Bellanthudawa, B.K.A.Abundance-Biomass Comparison (ABC) approach is a graphical approach that compares the abundance and biomass of organisms in order to predict the environmental stress level of an ecosystem. The present study was conducted in selected sites located at non-rehabilitated and rehabilitated areas of the Diyawannawa wetland in Sri Lanka in the monsoonal and non-monsoonal seasons. The ABC was performed on the macrobenthic mollusk species collected from the study sites. Eight species of macrobenthic mollusks, namely, Bithynia tentaculata, Melanoides turbeculata, Melanoides turriculus, Thiara scabra, Lamellidens marginalis, Pila globosa, Gyraulus saigonensis and Lymnaea stagnalis were recorded during the study period. Based on Principal Component Analysis, B. tentaculata, and, P. globosa were identified as characteristic gastropod species that could be used to classify study sites in the rehabilitated and non-rehabilitated areas of this tropical wetland system. In the monsoonal season, overlapping cumulative percentage dominance of abundance and cumulative percentage dominance of biomass curves in sites A, B, and F indicated partially disturbed environmental conditions. The site C of the non-rehabilitated area, showed a typical undisturbed condition and the sites D and E of the rehabilitated area the cumulative percentage dominance of biomass curve was located above the abundance curve, indicating disturbed environmental conditions in these sites during monsoonal season. During the non-monsoonal season in all the sites except site F of the rehabilitated area, the cumulative percentage dominance of abundance curve was located above the biomass curve, indicating undisturbed environmental conditions in these sites. In the site F, the cumulative percentage dominance of abundance and the cumulative percentage dominance of biomass curves were crossing each other, indicating partially disturbed environmental conditions at this site. The values of the W statistic, which ranged from 0.004 to 0.374 in the non-monsoonal season and ranged from 0.1 to 0.2 in the monsoonal season, and pollution and water quality categorization by modified biotic index (MBI) were in agreement with the results of the ABC approach.Item Assessing factors driving price premium between voting and non-voting stock at CSE(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Rasanjani, P. M. D.; Peter, P. L. S.In a dynamic capital market, the speed of information flow is crucial in maintaining an efficient market. Asymmetric information in the capital market creates either the buyer or seller a better (arbitrage) opportunity to make a profit. The party having more information on the past, present or future performance of the shares may know whether the share is underpriced or overpriced relative to its aggregate performance. Therefore, the speed of symmetric information flow of the share prices is a very important feature in the capital market domain. Publicly traded companies sometimes issue different classes of shares. The main benefit of dual class voting structures for shareholders and a company’s management is to focus on long-term goals and a company’s strategic direction while maintaining the freedom, rather than contending with the threat of a hostile takeover. The key difference between voting shares and non-voting shares in dual class structure is the voting right. When perusing historical data for past few years in companies that trade both voting and non-voting shares in the Colombo Stock Exchange (CSE), it was observed that the voting premium varies from company to company and within the company itself over the time. These reasons lead to an initial empirical examination of the factors affecting the voting premium of voting over nonvoting stocks. The purpose of the research was to explore the factors affecting the voting premium in the CSE and quantify the price gap between voting shares and non-voting shares. After conducting a systematic review of literature, factors affecting voting premium that is described using different models, frames and processes were identified. Consequently, the study identified the set of factors; namely, differences in liquidity (free float), restriction on transferability, share ownership structure and corporate control, percentage of private benefits of control, investor’s purpose, management status, sector specific factors, macroeconomic factors, firm specific factors and effect of time as possible reasons for the existence of the premium. Expert opinion has been sought to aid verification. It is envisaged to analyze historical data in the CSE including share prices, published financial statements and ratios while integrating previous literature, to verify and introduce a comprehensive model or framework-based solution approach for quantifying price gap between voting shares and non-voting shares in CSE. As an extension, this research expects to introduce an exact mathematical formula for quantifying the voting premium.