International Research Conference of UWU-2019

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Browsing International Research Conference of UWU-2019 by Author "Abeygunawardana, A.P."

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    Assessment of Suspended Plastic Levels in Surface Water of Southern Coastal Belt in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2019-02) Athapaththu, A.M.A.I.K.; Athawuda, A.M.G.A.D.; Dias, P.C.B.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.
    Plastic pollution is a growing concern all over the world including Sri Lanka due to serious negative consequences. Thus, current study focused on investigation of occurrence, quantification and spatial distribution of visually observed plastics and microplastics (MPs) in surface coastal water from 12 locations (Hikkaduwa, Gallefort, Dodanduwa, Unawatuna, Weligama, Mirissa, Dickwella, Tangalle, Polhena, Rekawa, Godawaya, Hambantota) as covering 3 districts of southern coastal zone in Sri Lanka during July-December 2018. Surface water samples were collected by towing neuston, manta net (380 µm) along surface layer parallel to the shoreline using repeated measures approach. The samples were passed through 4000 µm, 500 µm and 250 µm mesh sieves and residual MPs were subjected to Wet Peroxide Oxidation protocol. Visually observed plastics and recovered MPs were observed through Trinocular Microscope, enumerated for density and confirmed by hot needle test. MPs were further sorted according to the color and shape. As results revealed, all the coastal water in sampling sites were contaminated with plastic accumulation. Overall average density of macroplastics and mesoplastics were recorded as 3.32 and 3.37 items/m³. Sampling location had no significant effect (p>0.05) on total MPs density (average total MPs density: 18.06±11.45 items/m³). Plastic accumulation sources of the affected sites were identified as harbor operational activities, residential actions and recreational events. MP debris with 0.512.00 mm consists of >65% of total number of MPs, whereas maximum size of microscopic plastic in coastal water was 11.04 mm. Fibers were the most common MPs followed by films. Blue colored and Transparent MPs were the majority of plastic items in coastal water due to prevalence of above plastic categories used in the packaging, bottles and fishing gears. In summary, southern coastal water in Sri Lanka is polluted by plastic debris and pollution control programmes are recommended by this study.
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    Development of Fish Balls Using Catla Fish (Catla catla): Exploration the Potential of Better Utilization of Freshwater Food Fish in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2019) Leshika, D. L.; Athawuda, A.M.G.A. D.; Abeygunawardana, A.P.; Thushari, G.G.N.; Jayamanne, S.C.
    Catla fish is the one of mostly cultivated, freshwater food fish in aquaculture sector. Present study was aimed to enhance Carp fish production by developing a value added fish ball products from Catla using appropriate processing technologies. Catla fish were collected from Ulhitiya reservoir. Three different treatments of fish meat:ice water ratios (w/v) as: 50%:37% (treatment1), 70%:17% (treatment2) and 85%:2% (treatment3) were used for fish ball processing after the preliminary trials. Organoleptic evaluation was conducted to determine color, texture, aroma, mouth feel, taste and overall acceptance of products using 30 untrained panelists. pH, color, and TBARS values of all final products at -20°C freezing condition were measured weekly. The proximate compositions of fish ball products were analyzed following standard protocols. Based on the results, highest scores for aroma, taste and overall acceptance were recorded for treatment 2 (fish meat: ice water-70%:17%). Ash content of treatment 1, 2 and 3 were 4.06±0.4%, 4.27±0.92% and 4.00±0.82% respectively with no significant difference (P>0.05). However, moisture and lipid contents had significant difference (P<0.05) among the treatments, while the highest lipid content was recorded in treatment1 (6.96±0.60%) and the lowest moisture content was recorded in treatment2 (70.15±2.43%). Protein content of Catla fish ball products varied from 14.00 to 15.00%. TBARS and pH of all treatments were at the range of 6.41-6.51 and 0.36-0.90 mg MDA/kg respectively which were within acceptable levels for consumption during storage. L*, a* and b*values of final products gradually decreased during storage period, but without significant (P>0.05) variation during storage period. In conclusion, Catla is a suitable alternative source for production of high quality, consumer preferred fish balls.
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    Screening the Effects of Microplastics on Selected Invertebrates along Southern Coastal Belt in Sri Lanka: A Preliminary Approach to Coastal Pollution Control
    (Uva Wellassa University of Sri Lanka, 2019-02) Wijethunga, H.N.S.; Athawuda, A.M.G.A.D; Dias, P.C.B; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.
    Primary and secondary microplastics entering into coastal and marine environment are potentially harmful to the health of aquatic organisms. Current study intended to assess plastic pollution effects on sessile invertebrates along the Southern coastal belt of Sri Lanka during July-December 2018. Twelve sampling sites (Hambantota, Godawaya, Rekawa, Tangalle, Dickwella, Polhena, Mirissa, Weligama, Unawatuna, Gallefort, Dodanduwa and Hikkaduwa) with different anthropogenic activities were selected as representing 03 districts (Hambantota, Matara, Galle) of Southern province. Biodiversity survey was conducted to identify prevalence of natural inhabitants in selected regional coasts and 03 dominant coastal mollusks: Saccostrea cucullata (Rock Oyster), Littorina sp. (Periwinkle) and Patella sp. (Limpets) were selected for screening microplastics accumulation level. Alkaline digestion protocol was identified as the most suitable procedure for microplastics extraction considering plastics recovery rate and digestion efficiency of flesh. Randomly collected, pooled biological samples (N=20-2) were subjected to KOH digestion and resultant microplastics were verified using hot needle test. As results revealed, all 03 invertebrates were contaminated with microplastics accumulation at average rates of 7.2-2.8counts/g in all sampling sites. Majority of contaminated microplastics were filamentous types (>90%) followed by rod shapes (1%). Microplastic accumulation rate varied significantly according to the type of species (p<0.05) due to differences of their feeding mechanism. Further, filter feeding organisms (Rock Oysters) were highly susceptible in accumulation of microplastics (7.24.1counts/g) in their bodies, while plastic accumulation rate was highest in oysters from Hambantota. Microplastic accumulation rate of mollusks was not significantly different according to the sampling site due to closer proximity (p>0.05). Tourism, unsustainable coastal fishery and harbor operational activities were identified as key factors affecting on higher plastic pollution level on Southern coast. Current study reflects negative aspect of plastic pollution on intertidal organisms.
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    Some Aspects of the Reproductive Biology of Dasyatis zugei (Paleedged stingray) in the Gulf of Mannar, Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2019-02) Gayathry, L.D.; Abeygunawardana, A.P.; Jayawardana, J.M.D.R.; Jayamanne, S.C.
    Dasyatis zugei is one of the major non-target species caught in the bottom-set crab nets used for catching blue swimming crab (Portunus pelagicus) in Gulf of Mannar. This study aims to determine the length–weight relationship, size at first maturity and fecundity of D. zugei. In total of 1,404 individuals were collected from crab nets in two landing sites; Vankalai and Thalvupadu in Gulf of Mannar during the period of September - November, 2018. Disc Width-WD of all the individuals were measured to the nearest mm, body weight was weighed to the nearest gram and sex was determined. The state of maturity of gonads of females was identified through dissection and macroscopic examination of ovaries. Mean ova diameter significantly varied among females according to the different maturity stages (P<0.05). Sex ratio in the catch was 1:1.35 (M: F). Disc width of males ranged from 85-260 mm with a mean of 175.43±22.42 and females ranged from 110-220 mm with a mean of 167.27±17.55. The Disc width-weight relationship was analyzed by Simple Linear Regression using log transformed data and it showed Log W = -0.5923 + 2.364 log WD for male and Log W = -3.497 + 2.599 log WD for female. The results show negative allometric growth (b<3) for D. zugei. There was no significant statistical difference (P>0.05) in the male and female regression co-efficient. The size at first maturity was 166.5 mm for female D. zugei. Embryos were found only in females ≥ 160 mm of WD. The maximum fecundity was three embryos per female which is varied with the size of the female. This study reports the first findings on length- weight relationship and size at maturity of D. zugei in Sri Lankan waters.