Browsing by Author "Athawuda, A.M.G.A.D."

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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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    Quantitative Assessment of Microplastics in Surface Water of West Coast — off Colombo, Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2018) Athawuda, A.M.G.A.D.; Jayasiri, H.B.; Jayamanne, S.C.; Weerakoon, W.R.W.M.A.P.; Guruge, K.P.G K.P.; Thushari, G.G.N.
    Contamination of water with plastic litter including microplastics is a serious environmental issue. This study addressed morphological identification and quantification of microplastics (1-5 mm) with spatial variability in surface waters of 7 sites; Uswetakeiyawa, Kerawalapitiya, Dikowita, Portcity, Kollupitiya, Bambalapitiya and Wellawatta along west coast - off Colombo during AugustNovember 2017. Marine floating litter was collected, by towing a manta net, mesh size of 300 𝜇m and microplastics were recovered from samples using visual observation. Microplastics were confirmed by hot needle test and categorized into 4 classes based on color: black, white, colored and transparent. Sorted plastics were quantified as number and weight. Total microplastic density does not significantly change with geographical location, as distribution of microplastics has been affected by oceanic waves and winds (p > 0.05). Rough sea state causes mixing of surface microplastics, and altering distribution pattern over the sites during sampling period. Overall mean density of micro plastics was 0.33 ± 0.13 mg m-3 and 0.39 ± 0.05 No M-3 by weight and number of items respectively. Density of white colored microplastics significantly varied spatially, due to site-specific anthropogenic activities (p < 0.05). Highest number of white microplastics accumulated in water samples of Uswetakeiyawa (0.35 ± 0.06 No m-3), by land based sources of tourism and recreational activities. According to results, all study sites are affected by plastic pollution and cause significant health risk on coastal biota. Microplastic contamination level in surface waters acts as a key indicator on high pollution level in west coast. Site specific management measures are suggested to mitigate microplastic pollution. Frequent estimations of microplastic density in surface water are recommended throughout year in west coast of Sri Lanka. This study provides baseline information on microplastics level in surface water of west coast.