Browsing by Author "Thushari, G.G.N."
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Item Assessment of Macroalgae Diversity along the Economically Important Southern Coastal Zone of Sri Lanka during North East (NE) Monsoon Period(Uva Wellassa University of Sri Lanka, 2020) Wijethunga, H.N.S.; Silva, A.P.R.; Shanuke, D.S.; Abeygunawardana, A.P.; Senevirthna, J.D.M.; Bambaranda, B.V.A.S.M.; Thushari, G.G.N.; Liyanage, N.P.P.Southern coastal zone acts as a highly productive ecosystem with rich macroalgae diversity. However, limited scientific studies have been conducted on macroalgae diversity in the southern coastal belt of Sri Lanka. The current study is focused on the assessment of the intertidal, macroalgae diversity along this coastal belt. This study was conducted using systematic sampling technique along the intertidal zone at 12 selected regional coasts (Hambantota, Godawaya, Rekawa, Tangalle, Dickwella, Polhena, Mirissa, Weligama, Unawatuna, Galle Fort, Dodanduwa and Hikkaduwa) representing three districts (Hambantota, Matara, Galle) of the southern province during NE monsoon period (December 2019 to February 2020). NE monsoon period was selected to minimize the climatic effects during sampling in different seasons. Macroalgae species were taxonomically identified using the recommended pictorial guides and literature records. Oneway Analysis of Variance (ANOVA) was employed to identify the variations of macroalgae diversity with sampling location (p<0.05). According to the results, a total of 26 macroalgae species (10 belong to Chlorophyta: >38% richness, 10 in Rhodophyta: >38% richness, and 6 from Phaeophyta: >23 % richness) were identified in this coastal belt. Ecologically dominant species belong to division Chlorophyta out of all the sampling sites. Shannon-Wiener biodiversity index (H') of the macroalgae in respective ecosystems significantly changed with sampling locations (p<0.05). The spatial variation pattern of biodiversity is correlated with unsustainable anthropogenic activities and natural factors. Shannon-Wiener biodiversity index (H') ranged at 0.67-2.59 in the study sites. The highest composition of macroalgal species (20) was recorded from the Godawaya site due to the minimum anthropogenic effect. Mirissa (02) and Dodanduwa (01) regions had the lowest macroalgae species richness and commercial activities were relatively higher along these coastal zones compared to all other sites. Accordingly, macroalgae act as the biological indicators reflecting the health status of respective ecosystems. So, the findings of this study would be important to identify the quality of the coastal zones and apply appropriate coastal conservation and management measures in the future. Also, the commonly recorded macroalgae species which belong to Chlorophyta and Rhodophyta can be sustainably utilized in processing value-added foods and other products. In conclusion, this study reveals the current status of macroalgae diversity on the southern coast during the NE monsoon period and detailed investigation of species composition is strongly recommended throughout the year. Keywords: Biodiversity assessment, North east monsoon, Macroalgae, Intertidal zone, Coastal ecosystemsItem 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.Item Characterization of Hydroxyapatite Synthesized from Commonly Available Saccostrea cucullata (Rock Oyster) Shells in Sri Lanka: Identification of a Commercial Application of Bivalve Shells(Uva Wellassa University of Sri Lanka, 2020) Peiris, M.S.D.; Thushari, G.G.N.; Pitawala, H.M.J.C.Biological shells with simple components result in outstanding properties compared to the man-made materials. Bivalve shells can be reused as a low-cost raw material for different industrial applications. This study was focused on the characterization of Saccostrea cucullata (Rock Oyster) shells collected from the Southern coastal zone in Sri Lanka and identification the potential of synthesizing commercial products from oyster shells. Collected oyster shells from Dickwella coastal belt were subjected to prepare shell powder after sieving the crushed shells using a metal sieve with 600 micron of mesh size. Shell powder samples were sintered at 1000◦C for two hours in the muffle furnace for removal of moisture, gases, and other remnants. Raw oyster shells and prepared shell powder samples were characterized using Fourier Transform Infrared Radiation (FT-IR), X-ray Diffraction (XRD) and X-Ray Fluorescence (XRF) Spectroscopy. After analysis of shell structure, functional groups, and composition, two wet precipitation techniques were employed to synthesize Hydroxyapatite (HA): (Ca10(PO4)6(OH)2). The first method includes converting shell CaCO3 into CaO as starting material, reacting with Nitric acid, Phosphate provider & NH4OH at pH 10 and sintering. The second method consists of converting calcined shell CaCO3 into Ca(OH)2, reacting with Phosphoric acid & NH4OH at pH 10, and sintering. Based on characterization results, the oyster shell is mainly composed of CaCO3 (98%), and extracted CaCO3 powder is compatible with properties of commercial CaCO3 product. Based on XRF, the oyster shell also consists of trace elements such as Zr, MgO, SO3, SiO2, and Sr. CaO level of shell powder was 97.9 % after thermal decomposition of CaCO3 during firing. HA produced from the second method recorded characteristic peak with high intensity at 2 theta value of 31.79◦ by signifying the crystalline phase only for HA compound in XRD analysis. XRD and XRF results revealed that HA powder which was produced from the second method using Ca(OH)2 as starting material & sintering at a temperature of 900oC recorded similar composition (CaO>77%, P2O5>20%) to the commercially available HA. In conclusion, rock oyster shells act as environmentally friendly, value-added by-products to manufacture HA for medical applications with the technical possibility to replace commercial HA. Keywords: Bivalve shells, Shell characterization, Fourier transform infrared radiation, Xray diffraction, X-Ray fluorescence, Industrial applications, HydroxyapatiteItem Comparative Analysis of Physicochemical and Sensory Attributes of Mature and Immature Tumid Venus Clam (Gafrarium tumidum) in Different Locations of Jaffna Lagoon, Sri Lanka(Uva Wellassa University of Sri Lanka, 2018) Jeyaamuthan, S.; Kumar, S.A.; Jayawardana, J.M.D.R.; Thushari, G.G.N.; Jayasena, D.K.D.D.Tumid Venus clam (Gafrarium tumiduni) is one of the dominant and readily available coastal bivalves consumed by local residents in Jaffna district of Sri Lanka. Scientific data on physicochemical and sensory attributes of this species is however scarce. Therefore, the objective of this study was to determine physicochemical and sensory attributes of Tumid Venus clam in four different sites of Jaffna lagoon at two different maturity stages. Randomly collected 200 clams from each different sites of Jaffna lagoon: Karainagar (9.7481°N, 79.8829°E), Mandaitivu (9.6165°N, 79.9920°E), Kayts (9.6526°N, 79.9081°E) and Navanthurai (9.6687°N, 80.0007°E) were graded into two maturity stages as mature (100 clams >35 mm in each location) and immature (100 clams <35 mm in each location) based on the shell length. The composite flesh samples were then subjected to analysis of physicochemical and organoleptic attributes using standard analytical protocols. Results revealed that there was a significant difference in color a* (redness), b* (yellowness), L* (lightness), pH value, water holding capacity, moisture and ash contents with the location as food availability is changed with inhabiting region (p<0.05). However, maturity stage had significant effects only on color a*, b* and L* values and water holding capacity (p<0.05). Based on the sensory evaluation, the appearance and taste of cooked clams were significantly varied with the location and maturity stage due to qualitative & quantitative changes of food items under different environmental conditions and variable nutritional requirements with maturity level (p<0.05). The highest consumer acceptance was recorded for immature bivalve samples from Navanthurai. In conclusion, current study showed the suitability of low cost bivalve resources as a substitute for conventional, expensive seafood sources. Furthermore, location and maturity stage had a significant effect on physiochemical and sensory attributes of Tumid Venus clam.Item Current Status of Coastal Debris Accumulation along Beach Ecosystems in Southern Province of Sri Lanka(Uva Wellassa University of Sri Lanka, 2020) Athapaththu, A.M.A.I.K.; Egodauyana, K.P.U.T.; Jayarathna, W.N.D.S.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.Coastal debris accumulation in coastal and marine ecosystems is considered one of the serious, the emerging environmental problem in several countries including Sri Lanka. This study aims to identify the current status of debris accumulation in the coastal zone of Southern province in Sri Lanka. The 180 stakeholders were interviewed to collect data using a pre-tested questionnaire survey through 15 open-ended and rank order closedended questions (maximum 1-10 of scale) as a convenience sampling method. Based on the estimated median rank data, the majority of waste types were plastic (991.5), followed by glass (819.5) and papers (768.5) in the Southern coastal zone. Soft drink/water bottles (1264) were recorded as the major disposal items followed by food wrappings (1225) and Styrofoam food containers (1146) considering rank scores. Burning or collecting wastes (32.09%), handing over the garbage to the municipal council (25.5%), usage of public garbage bins (25.11%) are common waste disposal methods along the southern coast. The highest percentage of waste separation practices were recorded from Hikkaduwa (81.81%), Galle fort (60%), and Polhena (61.11%) regions. Hambantota and Tangalle beaches have regular waste collection services (100%) to a satisfactory level. Rekawa and Godawaya regional coasts had not recorded any frequent waste collection mechanism. Tourism and recreational activities (86.36-52.94%) and fisheries and harbor operations (93.33-60%) are major waste accumulation sources in study sites. Coastal debris is also accumulated by residential and household activities and unsustainable constructions to a lesser extent. Thus, unsustainable anthropogenic activities are major sources of coastal debris accumulation. The majority of fishermen and coastal residents did not adequately aware of the ecological and commercial impacts of coastal debris. This study suggests implementing integrated coastal management programs focusing on plastic debris accumulating sources. In conclusion, this study provides a basic platform on the issue of coastal debris deposition on the southern coast of Sri Lanka. Keywords: Plastic pollution, Coastal debris accumulation, Coastal environment, Pollution sources, Anthropogenic activitiesItem Development of Calcium Supplement from the Bones of Yellow Fin Tuna (Thunnus albacares)(Uva Wellassa University of Sri Lanka, 2013) Gunawardane, K.A.D.D.S.; Thushari, G.G.N.; Jayamanne, S.C.; Malavige, M.The mineral calcium is mainly important in building of bones and teeth and regulating certain metabolic processes in human body. According to the sources of Health ministry, daily dietary requirement of calcium for adults in Sri Lanka is 750-800 mg. Insufficient intakes of dietary calcium produce hypocalcaemia and osteoporosis (Piratheeban, 2013). Therefore, it is important to use food supplement to enhance the calcium content in various kinds of foods. Fish bones are well known to contain a high amount of calcium and fishbone ash normally contains 34 -36% calcium, particularly calcium phosphate (Hamada et.al., 1995). Yellow fin Tuna (Thunnus albacares) is one of the commercially valued fish species in fish processing industries in Sri Lanka and its’ bones are discarded as waste by processing industries causing environmental pollution. The present study therefore, focuses on developing a method for producing a calcium supplement suitable for human consumption using the bones of Yellow fin Tuna (Thunnus albacares) and reduces accumulation of fish bone as waste causing environmental pollution. Development of a calcium supplement using fish bone will be a new implication in value addition sector of aquatic products in Sri Lanka. Methodology Bones of Yellow Fin Tuna were collected from Global Sea Foods (Pvt) Ltd., Badalgama. Collected samples were manually rinsed to remove adhered muscle residue after transporting to Animal Science laboratory of Uva Wellassa University. The processing steps include pretreatment using NaOH, neutralization, drying, grinding and sifting. Two experimental trials with different treatments were conducted including three replications for each treatment. Trial I was carried out to find out the best NaOH concentration and boiling time combination based on the softness of fish bones (T1- 9%, 80 minutes, T2- 9%, 90 minutes, T3-9%, 100 minutes, T4- 10%, 80 minutes,T5-10%, 90 minutes,T6-10%, 100minutes,T7-11%, 80 minutes,T8-11%, 90 minutes,T9- 11%, 100 minutes).The best treatment was selected by assessing the easiness of grinding 10 g of pretreated fish bones by mortar and pestle for 1 -2 minutes. After neutralization (rinsing by water 7 times), selected best pretreated sample was subjected to Trial II. Trial II was conducted to find out the best time and temperature combination (S1- 80 ºC, 70 minutes; S2-80 ºC, 80 minutes; S3-80 ºC, 90 minutes; S4-90 ºC, 70 minutes; S5- 90 ºC, 80 minutes;, S6- 90 ºC, 90 minutes; S7-100 ºC,70 minutes; S8-100 ºC, 80 minutes and S9- 100 ºC, 90 minutes) for powder form final products. All final products were packed using polyethylene cover and stored at room temperature. Then all final products were analyzed for different parameters. Moisture contents and Drying ) (MR- Moisture ratio, Mt- Moisture content at a specific time, Mo- Initial moisture content, Me- Equilibrium moisture content, k- Drying kinetic rate constants, t-Time) (Techochatchawal et al., 2009) were evaluated for all final samples of Trial II. Calcium content (AOAC Standard Method 927.02) was determined for final treatments of Trial II and most suitable treatment was selected using above parameters. Proximate composition of selected final product was determined for Pb content (AAS, Method 7082), crude fat, ash and crude protein level (AOAC, 1995). Microbiological analysis was conducted using Total Plate Count (TPC) for selected treatment at 37 C. Finally, best treatment was compared with Standards for Supplementary food (Notification of the Ministry of Public Health o.293 B.E. 2548, 2005). Results were analyzed using Kruskal-Wallis test and Analysis of Variance (ANOVA) incorporated in MINITAB 14 soft ware.Item 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.Item Development of Seaweed Based Ready-to-Serve (RTS) Beverage using Elkhorn Sea Moss: Kappaphycus alvarezii - A Novel Approach in Value Addition to Seaweed Resources in Sri Lanka(Uva Wellassa University of Sri Lanka, 2020) Karunarathne, K.M.C.S.; Kulasinghe, W.M.A.A.; Thushari, G.G.N.; Abeygunawardana, A.P.; Silva, A.P.R.; Jayarathne, D.S.W.N.; Liyanage, N.P.P.In Sri Lanka, the development of seaweed-based food products such as nutritious drinks still gained less attention. This study was focused on the identification of product processing potential with appropriate production technology for the RTS beverage using common red algae: Kappaphycus alvarezii having high culture potential in Sri Lanka. Preliminary trials were conducted to identify the composition of raw materials and ingredients for the development of RTS products. Then, final experiments were followed using 3 levels of Kappaphycus extracts (15, 20, and 25%) blended with 5% fresh lime juice. Final products were subjected to pasteurization at 90 ºC for 5 min and stored at room temperature. The selected final product was analyzed for organoleptic parameters, proximate composition, and keeping quality characters. Results indicated the production potential of value-added RTS beverage using red algae. Final treatment with 20% of K. alverazii recorded as the best product with the highest consumer preference. Based on the results, this RTS beverage contained a significant amount of minerals (2.05±0.01%) and high antioxidant potential (~70%) with 0.001% of carbohydrate level closer to zero (atkins drink) compared to the market available products. pH level (4.37±0.06 - 3.90±0.05), antioxidant property (70.98±1.7 - 53.3±2.0%), acidity (0.30 - 0.36%) and Total Plate Count (2.60 - 3.60 log CFU ml-1 ) of final product had a significant effect with storage time period (P <0.05). Total Soluble Solid level of the product (1.2 ºBrix) was constant during the storage period due to extremely low sugar content. According to physicochemical parameters and microbiological tests, this product was safer for consumption within 4 weeks of the period. Moreover, the production cost is relatively lower compared to the market available, common beverage products. In conclusion, this seaweed-based product can be introduced as a healthy, low-cost, atkins drink as an alternative to conventional beverages. Keywords: Nutritious beverage, Red algae, Atkins drink, Physico-chemical properties, Seaweed based productItem Development of Value Added Products from Tilapia: A Preliminary and Innovative Approach to Improve Tilapia Fishery Sector in Sri Lanka(Uva Wellassa University of Sri Lanka, 2019) Weerasinghe, K.B.S.; Ediriweera, T.K.; Abeygunawardane, A.P.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.Tilapia is one of the popular freshwater food fish in aquaculture industry over the world including Sri Lanka. The present study focused on development of low cost, value added, nutritional fish products using Nile Tilapia: Oreochromis niloticus. Raw tilapia fish were purchased from Sorabora reservoir, Badulla. Fish wafer was processed using three different ratios of tapioca and corn flour (Treatment 1-1:1; Treatment 2-2:1; Treatment 35:1). Minced fish was used to prepare the fish noodles using four treatments with different flour and oil combinations (Treatment1: wheat flour 43%+coconut oil 1.5%; Treatment2: wheat flour 43%+ vegetable oil 1.5%; Treatment3: red rice flour 43%+ coconut oil 1.5%; Treatment4: red rice flour 43%+vegetable oil 1.5%). Final products in polythene packaging were analyzed for organoleptic parameters, proximate composition, keeping quality tests and color during 28 days of storage period at room temperature. Fish wafer with 1:1 of tapioca: corn flour and fish noodles with 43% of wheat flour+1.5% of vegetable oil were recorded the highest overall acceptability from consumers (P<0.05).Average protein levels of fish wafer and noodles were 10% and 18%, respectively. Tapioca: corn flour ratio had a significant effect on lipid content of wafer products (P<0.05), while lipid levels of all noodles products were not significantly different between the treatments (p>0.05). There was no significant difference in color a* (redness), b* (yellowness), L* (lightness) values, pH, TBARS, moisture and ash contents among treatments of wafer (pH:7.48-6.60, TBARS:0.1-1.3 mg MDA kg-1, moisture:12.52-14.38%, ash:3.20-5.26%) and noodle products (pH:7.43-6.46, TBARS: 0.2-1.5 mg MDA kg-1, moisture:10.16-11.83%, ash:1.63-2.15%) implying suitability for consumption during storage period (p>0.05). The present study showed the possibility of processing value added fish wafer and noodles using low cost Tilapia as an alternative for conventional and expensive seafood sources.Item Effect of Frying in Different Cooking Oils on the Fatty Acid Profile and Sensory Characteristics of Tilapia (Oreochromis niloticus) Fillets(Uva Wellassa University of Sri Lanka, 2016) Fernando, N.F.K.R.; Thushari, G.G.N.; Jayasena, D.K.D.D.Fish is one of the most abundant sources of essential fatty acids. Among many fish species, Nile tilapia (Oreochromis niloticus) is a popular culture species in aquaculture industry and they heavily contribute to the worldwide fish consumption. Fish is mainly consumed in fried forms in many countries and the alterations in the fatty acid composition during frying process may have significant effects to human health. This study was performed to determine the effects of frying with three different cooking oils (soybean, sunflower and coconut oil) on the fatty acid profiles and sensory characteristics of tilapia fillets. Fish were purchased from local fish shop in Badulla and transported to the university laboratory under chilled condition. Tilapia fillets were deep fried in the three different cooking oils separately and the fatty acid composition of each group was evaluated using gas chromatography. The fat content of the fillets increased after frying in all evaluated samples (P<0.05). Mean saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, Total (E) -3 and E-6 contents of raw fillets were 43.2610.55, 29.9011.26, 26.3111.65, 15.4311.17 and 10.8810.53%, respectively. Frying led to exchange of fatty acids between the tilapia fillets and cooking oils. As a result of interactions, PUFA, E-6 and PUFA/SFA ratio of samples fried in soybean and sunflower oil significantly increased while the amounts of SFA decreased (P<0.05). Frying had a negative effect on the E-3, EPA and DHA amounts in all fried samples. E-6/-3 ratio was optimum in soybean oil fried samples while sunflower and coconut oil fried samples values were not in the recommended level to health. Frying with coconut oil showed high SFA, MUFA and low PUFA levels among all samples. in concern to sensory results, both sunflower and soybean oil-fried samples obtained positive results. By considering all the facts, soybean oil can be considered as the best cooking oil to fry tilapia fillets. Keywords: Tilapia, Deep frying, Soybean oil, Coconut oil, Fatty acidsItem Impact of Thermocline Variability on Yellowfin Tuna Catch Rates of Sri Lankan Long-Liners(Uva Wellassa University of Sri Lanka, 2018) Sinhakula, S.M.B.; Rajapaksha, J.; Thushari, G.G.N.; Guruge, K.P.G.K.P.Tuna fishery is an important source of income to Sri Lanka, having a greater potential for development. Yellowfin tuna: Thunnus albacares is a major species, exported to Japan and EU countries. Vertical migration of fish with changes in temperature is considered as an important parameter to ensure fishing efficiency, thus harvest of yellowfin tuna is associated with the thermocline layer and its seasonal changes. The objective of the present study was to investigate the influence of vertical structure of temperature on catch rates of longline fishery. Temperaturedepth recording sensors were used to understand the depth penetration level of hooks and associated temperatures, during the period from July 2012 to February 2014. Based on sensor data and catch records, fishing depth was determined by means of sag caused by slack of the main line in between two buoys. Thermocline variability was analyzed using oceanographic datasets obtained from Copernicus Marine Environmental Monitoring Service. Temperature vertical profiles were extracted from those datasets at each fishing positions and a 5-parameter sigmoid model was used to determine the thermocline properties. Most commonly, 6-9 hooks per basket have been used in longlines, while total number of hooks was 8001000. Buoy-lines and branch-lines were ranged between 20-30 m and 45-50 m, respectively. Based on the hooks per basket, the depth penetration level closer to buoy-line is -70 m and -100 In at the center of a basket. Sagging variability of hooks in a basket have shown a linear relationship (r2=0.9992) with the distance between branch lines starting from buoy-line to the middle of a basket. Catch per unit effort was ranged between 15-70 kg / 1000 hooks. Thermocline depths altered between 100125 m with variations of corresponding temperatures at 21-23 °C. The developed model is capable of predicting hooking depths, thus the longline configuration can be adjusted with thermocline information for successful fishing operations.Item Integrated Wastewater Treatment Using Water Hyacinth (Eichhornia crassipes) and Blue Swimming Crab (Portunus pelagicus) Shell Waste(Uva Wellassa University of Sri Lanka, 2018) Samarasinghe, U.S.; Thushari, G.G.N.; Abegunawardana, A.P.; Liyanage, N.P.P.; Pitawala, H.M.J.C.Natural compounds and biotic structures are used as low cost, eco-friendly methods to treat industrial wastewater by phytoremediation and adsorption/biosorption. Objective of this study was to assess applicability of readily available blue swimming crab (P. pelagicus) shell waste and water hyacinth (E. crassipes) for removing of heavy metals, organic and inorganic pollutants from wastewater. Integrated waste water systems (IWWS) with 10 different treatments of crab shell powder + water hyacinth (Shell powder as dry weight + water hyacinth as wet weight basis: 2 g & 100 g/ 2 g & 200 g/4 g & 100 g/4 g & 200 g/6 g & 100 g/6 g & 200 g/8 g & 100 g/8 g & 200 g/10 g & 100 g/10 g & 200 g) were subjected to analyse efficiency of each treatment. Efficacy of improved rate of Dissolved oxygen, removal capacity of COD, pH, TS, TDS and P03-4 was tested in each treatment for 6-day retention period. Removal capacity of Cr, Cd and Cu levels was assessed in each treatment for 4-day contact period. According to results, both blue swimming crab shell powder levels and water hyacinth weight significantly affect on water quality improvement (p < 0.05). pH in all treated systems improved at 7.0, indicating optimum levels. The 4 g of crab shell powder with 200 g of water hyacinth recorded highest DO (4.1 ± 0.16), while removal rate of COD (95% ), TS (72%), TDS (61%) and PO3-4 (65 - 55% for 1 - 3ppm of PO3-4 levels) were most effective at same treatment. Integrated system with 4 g crab shell +200 g water hyacinth had 92 - 78%, 86 - 77% and 96 - 86% of maximum removal efficiency for Cr, Cu and Cd respectively indicating suitability of crab shell and water hyacinth for IWWS. Metal adsorption capacity depends on adsorbent dosage, pH level, metal ion charge, initial heavy metal concentration, and ionic radius of metal. This study implies novel approach in wastewater treatment as a cost effective, environmentally acceptable method, while controlling freshwater invasive alien species load and value addition to crab shell residues.Item Occurrence of Microplastics in Gut and Muscles of Commerson's Anchovy in Madu-Ganga Estuary of Southern Province, Sri Lanka(Uva Wellassa University of Sri Lanka, 2020) Praboda, M.W.K.; Egodauyana, K.P.U.T.; Wijethunga, H.N.S.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.Plastic pollution causes serious ecological risks on biodiversity with toxicological effects on the biota. The objective of this study was to assess microplastic accumulation in seasonally common fishery resource: Stolephorus commersonnii (Commerson's Anchovy) harvested from Madu-ganga estuarine ecosystem. Fifteen matured fish samples (n=15) were randomly collected from local fishermen from November 2019 to January 2020. Microplastic particles were extracted from the digestive tract and muscles of anchovies using the recommended protocol of 10% KOH digestion. Hot needle test and Fourier Transform Infrared Radiation (FTIR) analysis were used for the confirmation of microscopically observed microplastics in anchovy samples. Microscopically observed microplastics were counted and categorized according to the size, color, and shape of plastics. Results revealed the microplastic accumulation in both the digestive tract and muscles of anchovies. Microplastics accumulate into the muscles via translocation and different respiratory modes. The average microplastic accumulation rate of anchovy gut and muscles were recorded as 301.70±3.58 items/g and 29.33±1.19 items/g respectively. White/transparent microplastic particles were the most abundant type in both guts (145.50±2.18 items/g) and muscles (13.55±1.23 items/g) of fish. However, blue (71.33+0.83 items/g: gut, 9.85+1.13 items/g: muscle), black (37.85+1.07 items/g: gut, 2.49+0.44 items/g: muscle), red (28.31+0.60 items/g: gut, 2.31+0.3 items/g: muscle) and pink (15.31+0.34 items/g: gut 0.96+0.24 items/g: muscle) microplastic debris were also recorded from gut and muscle samples. The majority of accumulated plastics in both gut and muscles were at the size range of 0.50 -1.00 mm. Fiber shape microplastics were observed in all the samples. FTIR results revealed that polypropylene as the only polymer type of microplastics in fish muscles and gut. This polymer is a key component of fishing ropes, netting materials, bottle caps, and packaging materials that enter through tourism/recreational activities and fishery operations into the estuarine ecosystem. Therefore, the current study recommends sustainable, integrated fishery management and eco-tourism programs focusing on plastic pollution control and prevention activities in Madu-ganga estuarine ecosystem. In conclusion, this study highlights the occurrence of microplastic contamination in the estuarine biota and the urgent need for plastic wastes management programs. Keywords: Coastal fishery resources, Estuarine ecosystem, Integrated fishery management, Microplastic accumulation rate, Plastic pollution control programmesItem Phytoplankton Diversity in Six Major Reservoirs of Badulla District, Uva Province, Sri Lanka(Uva Wellassa University of Sri Lanka, 2020) Eheliyagoda, P.G.R.; Kumarage, N.T.; Abeygunawardana, A.P.; Thushari, G.G.N.; Liyanage, N.P.P.; Chandrasena, G.; Silva, A.P.R; Wijethunga, H.N.S.Phytoplanktons are major primary producers and act as a bioindicator in inland waters. The present study investigated the phytoplankton species composition of six reservoirs (Ulhitiya, Rathkinda, Mapakada, Nagadeepa, Dambarawa, and Sorabora) with highest inland fish production in Badulla district. Samples were collected using a plankton net (60 μm mesh size) from five sampling points of each reservoir during November 2019- January 2020. The taxonomical status of collected samples was identified using previous literature records, standard pictorial guides (The Genera of the Freshwater Algae of Sri Lanka). Biodiversity indices were calculated to identify the variations of phytoplankton diversity among sampling points and reservoirs. Total of 41 phytoplankton species belonging nine major taxonomic classes; Bacillariophyceae (10), Chlorophyceae (10), Cyanophyceae (08), Zygnemaphyceae (06), Eugenophyceae (02), Fragilariophyceae (02), Chryotophyceae (01), Xanthophyceae (01), Dinophyceae (01) were recorded. Diatoms (Bascillariophyceae) recorded the highest relative abundance (61.57%) from selected reservoirs. Sampling points of each reservoir had no significant effect (p>0.05) on the phytoplankton diversity while it showed a significant effect (p>0.05) on phytoplankton diversity among reservoirs. The highest Shannon-Wiener index (1.61±0.06), Simpson’s Index (0.71±0.01), evenness (0.52±0.024) and richness (21±1.62) were reported from Dambarawa, while lowest Shannon-wiener index (1.25±0.19), Simpson’s index (0.59±0.08), evenness (0.42±0.19) and richness (19±0.89) resulted for Ulhitiya Reservoir. The current study reveals that Aulacoseira sp, Microcystis sp, Pediastrum sp, Staurastrum sp, Arthrospira sp shows the highest abundance in all six reservoirs. Dominant species play a vital role as primary producers, bioindicators (Aulacoseira sp, Microcystis sp), and feed (Staurastrum sp, Arthrospira sp) for fish. Due to the high abundance of Microsystis sp. (51.58%) in the Ulhitiya reservoir, the potential to generate toxic algal blooms was identified by the current study. In conclusion, this study identified the dynamic phytoplankton community and dominant species which act as the major autotrophs in studied reservoirs. Further, data collected could be used as the baseline information for the aquatic ecological studies and inland fishery enhancement programs Keywords: Shannon-Wiener index, Simpson’s index, Biodiversity, Inland fishery, Primary producers/autotrophsItem Preliminary Study of Salinity Change on Vibrio Count and Gut – Muscle Ratio of Penaeus monodon Post Larvae(Uva Wellassa University of Sri Lanka, 2013) Kumara, B.W.V.P.S.; Thushari, G.G.N.; Jayamanne, S.C.; Pradeeban, S.Marine shrimp farming is one of the most important aquaculture practices in the world. It showed a booming expansion since start and soon became a multimillion dollar industry (Islam et.al., 2004). However, there are many issues and challenges of the sector especially related to the culture techniques, environmental quality, biodiversity and natural brood-stocks. Natural brood stock is not enough to fulfill requirements of shrimp seed for culture practices. As a solution, farmers and other relevant stakeholders have established hatcheries which can provide shrimp seeds for stocking of shrimp farms throughout the year. Gut – Muscle Ratio (GMR) is a standard main parameter that can be used as an index to measure the quality of the post larvae in shrimp industry. GMR is defined as the microscopic examination of the relative thickness of abdominal segment of the tail of post larvae stages (Madhukiran et al., 2009). Microbiological count (availability of Vibrio bacteria) is a critical factor affecting growth and survival rate of shrimp post larvae from hatching to grow- out stage. As chemical water quality parameter, salinity has a potential on changing microbial count and Gut - Muscle Ratio. Therefore, present study was conducted to find out the effect of salinity on those two factors for the quality of selected post larval stages of the Peneaus monodon. Methodology Study was carried out in King Aqua Hatchery (Pvt) Ltd, Udappuwa, Chilaw. Nine hundred and sixty post larvae (PL) were selected for the study. Four hundred and eighty post larvae were used as experimental sample and remaining 480 PL were maintained as replacement stock. PL was obtained from same brood stock. Bulk stored tank was monitored from hatching stage to the nursery stage with same condition. Randomly selected PL were transferred into 06 glass tanks (S1, S2, S3, S4, S5, S6) from nursery tank representing 20 PL in each treatment . Four replicates were used for each treatment. Temperature (30 ˚C), pH (8.2) and Dissolved Oxygen (7 mg/l) were maintained at constant levels. Salinity levels were changed in each glass tank by adding fresh water and concentrated brine solution based on final salinity level (S1 – 27 ppt, S2 – 28 ppt, S3 – 29 ppt, S4 – 30 ppt, S5 – 31 ppt, S6 – 32 ppt). S3 (29 ppt) was used as control. Gut-Muscle Ratio of the post larvae was determined under microscope (x10). Ten post larvae ventral muscle was recorded. Water samples were collected twice per day (8.00 a.m. and 8.00 p.m.) for bacterial detection. Water samples were diluted with sterilized distilled water up to 10x1 and cultured using TCBS agar medium. After 24 hours of incubation, plates were observed by using colony counter. Recorded data was analyzed by using MINITAB 15 statistical software (Two-Way ANOVA, α – 0.05). Results and Discussion Results of mean Gut-Muscle Ratio and Vibrio count with salinity are given in Table 1. At the salinity level of 27 ppt, mean Gut Muscle Ratio shows the minimum value for all stages, while highest GMR for PL 9 and PL 10 was recorded at 30 ppt (Table 01). With increasing salinity, mean Gut Muscle Ratio for PL9 and PL 10 stages are gradually increasing up to a specific salinity level (30 ppt). At highest level of salinities (>30 ppt) there was a slight decline of Gut Muscle Ratio for these stages, but it is closer to the maximum mean value of GMR recorded for 30 ppt level of salinity. GMR for PL 11, PL 12 and PL 13 stages had not changed at grea ter level of salinities (30, 31 and 32 ppt). Commonly highest mean value of GMR was recorded at 30 ppt. There was no significant difference for Gut Muscle ratio and PL11, PL12 and PL13 stages of Peneaus monodon post larvae with salinity levels of 30, 31 and 32 ppt (p > 0.05). Muscle gut ratio is one of the major criteria for selecting the good post larvae (Bauman et al., 1990). Usually high muscle to gut ratios is preferable (FAO, 2013). According to manual of Asean Good Shrimp Farm Management Practice (n.d.), Muscle Gut Ratio of 4:1 (or >4:1) is recommended as accepted ratio for high quality PL stages. However, in practice, it was found that this measurement can always be difficult due to the unacceptable management practices. Therefore, salinity level that always records gut muscle ratio closer to recommend value (4:1) is concerned as the best salinity for shrimp hatchery practices.Item Production of Imitation Caviar Using Yellow Fin Tuna Fish Species: Thunnus albacares – A Novel product using Fish Roe in Sri Lanka(Uva Wellassa University of Sri Lanka, 2013) Abeyrathna, I.G.S.N.K.; Liyanage, N.P.P.; Thushari, G.G.N.; Jayamanne, C.Caviar is defined as salted fish roe that basically prepared with eggs or roe of sturgeon fish. Imitation caviar is defined as roe that comes from a fish other than the sturgeon, and it can be classified as a caviar substitute. This product is not so popular among Sri Lankans, because of lack of knowledge regarding processing of caviar and its cost. In Sri Lanka, fish roe is discarded from processing plants and sold in the local market. Therefore it is important to add value to fish roe and make them a high demanded product. Since discarded fish roe is used for this product, there will be no threat of over exploitation by production of imitation caviar. Local people can acquire nutritional benefits from the imitation caviar due to high nutritional quality. Yellow fin tuna: (Thunnus albacares) was selected as the resource fish species for the present study. T. albacares is a species in family Scombridae found in pelagic water of tropical and subtropical oceans waters. In Sri Lanka, it is considered as a commercially important food fish that represent considerable portion of tuna fishery. Therefore, main objective of present study is to develop proper methodology and select suitable maturity stage of fish roe for production of imitation caviar. Methodology Roe samples of T. albacares were collected from Ceylon Fresh sea food (Pvt) Ltd. and Jay sea food (Pvt) Ltd. in Ja-Ela, Sri Lanka. Then collected samples were transported to the Animal Science laboratory of Uva Wellassa University using cooler boxes with ice. First, ovary sacks with fish roe were separated according to maturity stage as immature roe, half mature roe and mature roe using external features of ovary sac. Then fish roe were separated from the ovary sac using manual screening method. Blood and other connective tissue on the roe were removed by rinsing with 5 % brine solution and fish roe were sieved using the sieve set. Prepared roe samples were subjected to “dry salting method” separately. Surface moisture of the roe samples were removed using clean cloth and arranged in plastic boxes with one layer of powder form Iodized salt and one layer of roe alternatively. Three different salt (g): fish roe (g) ratios as 0.05:1, 0.25:1 and 0.45:1 were used to determine the best ratio/s of each maturity stage after preliminary experimental trials (S:immature roe : S1 -0.05:1, S2-0.25:1 S3-0.45:1/ X:half mature roe: X1-0.05:1, X2- 0.25:1, X3-0.45:1, Y: mature roe: Y1- 0.05:1, Y2- 0.25:1, Y3- 0.45:1). Three replicates were used for each treatment. Salted roe samples were kept for two and half hours. During this period they were pressed gently by fingers for five minutes for effective absorption of salt. Afterwards they were dipped in tap water bath to remove excess salt and then covered with a wet cloth for 4-4.5 hours. Then the caviar were placed in a dry cool place (approximately 20 C) to be dried (Celic et al., 2012). Final products were filled into glass jars manually and pasteurized using hot water bath at 68 C for 45 minutes. Final products were analyzed for different parameters. Protein and fat contents were determined using Kjeldahl method (6.25×N) and Soxhlet method respectively (AOAC, 1990). Moisture content was determined by drying the sample at 105 C to a constant weight (AOAC, 1990). The pH values of the samples were determined with a pH meter and microbial Count (TPC) of the final products was determined. pH and TPC values were recorded once in 07 days for 02 months of storage period (0, 07, 14, 21, 28 days). All final products were evaluated using 30 untrained panelists in terms of color, texture, aroma, salty taste, mouth feel and overall acceptability on a 5 point hedonic scale to identify the organoleptic properties. Differences between mean values of proximate composition, pH values and microbiological factors were analyzed using ANOVA. Friedman non parametric test was used to analyze the results of sensory evaluation. MINITAB statistical package (16 Version) was used for analysis of results at 0.05 probability level. Results and Discussion Based on the results obtained from protein level, lipid content, sensory evaluation and microbial count studies, three samples (Salt: Fish roe by weight) 0.05:1 g, 0.25:1 g and 0.45:1 g of each maturity stage were separately compared to select best sample. Treatment that shows highest protein level, lowest lipid content, greatest consumer preference and lowest microbiological content was selected as the best sample for each maturity stage. S1 (0.05:1; salt: fish roe) was selected for immature stage, whilst X1 (0.05:1; salt: fish roe) and Y2 (0.25:1; salt: fish roe) were selected for half mature stage and mature stage respectively. The ratio of 0.45: 1 (salt: fish roe) was recorded having lowest nutritional quality, unsatisfactory consumer preference and greater microbial count for each maturity stages compared to other two treatments.Item 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.Item Screening of Plastic Pollution Effects in Madu-ganga Estuarine Ecosystem in Southern Province, Sri Lanka: An Approach toward the Coastal Zone Management(Uva Wellassa University of Sri Lanka, 2020) Praboda, M.W.K.; Wijethunga, H.N.S.; Silva, A.P.R.; Gayathry, D. L.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.Plastic pollutants act as the emerging contaminant with possible threats to aquatic ecosystems. The present study attempts to assess microplastic (MP) content in surface water and sediments of Madu-Ganga estuary which is one of the ecologically and commercially important Ramsar wetlands in Sri Lanka. Manta net (380 μm) was employed to collect surface water samples by towing net horizontally along water surface for 10 m with 1.8 ms-1 of average flow rate, while Ekman grab was used for sampling sediments from 4 study sites during October 2019 to January 2020. Wet Peroxide Oxidation (WPO) protocol was applied after subjecting both water and sediment samples to the wet sieving process. Fourier Transform Infrared Radiation (FTIR) analysis was used to confirm polymer types of extracted MPs in samples. MPs in digested samples were enumerated and categorized microscopically according to their size, shape, and color. One Way Analysis of Variance (ANOVA) was applied to identify the differences of MPs density with sampling location (p<0.05). According to the results, both surface water and sediment layers had contaminated by MPs accumulation. Sampling location had not significant (p>0.05) effect on the MP content of surface water and sediment samples. Average MPs accumulation rate of surface water and sediment samples were recorded as 40.06±1.84 items/m3 and 5.88±1.33 items/100g respectively. Whitetransparent, blue, black, and red were major color categories observed in MPs, while white-transparent color was dominant MP type of water and sediment samples. Most of the accumulated MPs were at the 0.50-1.00 mm of long-range. Fiber, sheet, and fragment shape MPs were commonly found in water and sediment samples. According to FTIR analysis, polypropylene (Characteristic absorption bands: 2950 cm−1 , 2915 cm− 1 , 2838 cm− 1 , 1455 cm− 1 , 1377 cm− 1 ) was abundant polymer type in surface water, while sediment contains polypropylene and polyvinyl chloride (Characteristic absorption bands: 1427 cm−1 , 1331 cm−1 , 1255 cm−1 ,1099 cm−1 , 966 cm−1 ). As per the preliminary survey, two major anthropogenic activities: commercial fishery and tourism were identified as the main point and non-point pollution sources in this ecosystem. In conclusion, this study emphasizes the growing risk of plastic pollution and the urgent need for a sustainable management plan to reduce plastic pollution in the Madu-Ganga estuary ecosystem. Keywords: Plastic contamination, Microplastics, Coastal ecosystem, Surface water, Benthic sediments, Anthropogenic factorsItem 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.Item A Study on Extracting Gelatin from Bigeye Tuna (Thunnus Obesus) Skin: An Alternative to Mammalian Gelatin(Uva Wellassa University of Sri Lanka, 2013) Azhar, A.M.; Thushari, G.G.N.; Jayamanne, S.C.; Asoka, M.D.C.Gelatin is not a naturally occurring protein, obtained by partially hydrolysis of native collagen (Karim, and Bhat, 2009). It is a colorless or slightly yellow, nearly tasteless and odorless compound with translucent property. Gelatin is widely used in food, pharmaceutical, photographic and cosmetic industries (Karim and Bhat, 2009). Currently, gelatin is produced using beef bone, hide, and pig skin and pig bone. However, Bovine spongiform encephalopathy (BSE) disease as well as religious concerns is negatively affecting the gelatin market. There is also a high competition for this kind of mammalian sources among producers. Therefore, it is important to introduce alternative sources rich in collagen for production of gelatin. Fish skin, which is enriched with collagen, has a potential to be used for extraction of gelatin (Badii and Howell, 2006). Furthermore, fish skin is concerned as a major byproduct of the fish-processing industry, causing waste accumulation and pollution. Utilization of this collagenous fish waste minimizes environmental pollution, while it adds value to fish based by-product sector. For the present study, Bigeye tuna (Thunnus obesus) skin was used, since Bigeye tuna is one of the most commercially important tuna fishery resource in Sri Lanka. The study aims to extract fish methodology characterization of physical, chemical and functional properties of extracted gelatin. The cleaned fish skin samples were chopped in to small pieces and washed with running tap water for about 10 minutes. Six treatments with three different NaOH and H 2SO4 concentrations at two different time combinations were selected for final experiment after conducting preliminary experimental trials. First 30 g each of six samples were soaked in different concentrations of Sodium Hydroxide (w/v) for two different time combinations (S1- 0.1 % for 24 hrs, S2- 0.2 % for 24 hrs, S3 -0.3 % for 24 hrs,S4- 0.1 % for 36 hrs, S5-0.2 % for 36 hrs, S6- 0.3 % for 36 hrs) separately. Then each pretreated skin samples were rinsed with running tap water and allowed to drain using muslin cloth. Each partially treated sample was again treated with different diluted H2SO4 concentrations (w/v) for two different time combinations (S1-0.1 % for 24hrs, S2-0.2 % for 24 hrs, S3-0.3 % for 24 hrs, S4-0.1 % for 36 hrs, S5-0.2 % for 36 hrs, S6-0.3 % for 36 hrs) separately. Each treated skin samples were again rinsed with tap water and allowed to drain using muslin cloth separately. Treated samples with different acid, alkaline time combinations were performed using distilled water (1:2 w/v) in a water bath at 60 C for 05 hours for gelatin extraction separately. Finally, differently treated gelatin solutions were filtered through 2 layers of muslin cloth to remove residual skin parts and final products were oven dried at 90 C for 06 hrs. Then the final products were analyzed for different parameters. Yield was expressed as a percentage (%) of the wet weight of the fish skin used. Gel strength was determined by using a Texture Analyzer (53205 Digital fruit firmness tester). The melting point was determined by preparing 6.67 % (w/v) gelatin solutions and maturating in a refrigeration temperature at 07 C for 16-18 hrs. Then melting points of final products were recorded by increasing the temperature in a water bath until the gelatin samples are dissolved (Karim and Bhat, 2009).