Browsing by Author "Liyanage, N.P.P."

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    Analyze the Histamine level in various positions of the Histamine developed Tuna fish
    (Uva Wellassa University of Sri Lanka, 2015) Kalubowila, K.S.H.; Liyanage, N.P.P.; Perera, A.
    Sea food processing industry is a high income generating field in Sri Lanka and it brings high foreign exchange to the country. Big eye tuna (Thunnus obesus) and yellow fin tuna (Thunnus albacares) are the major tuna types which are exported by Sri Lanka to the international market. (FAO, 2014).However the presence of Histamine is the problematic factor inTuna fish processing industry which leads the industry to many health issues and income losses. Histamine is a chemical compound created from histidine and enteric bacteria are capable of transforming histidine to histamine by the enzyme decarboxylase. Once histamine is formed, it cannot be not destroyed by freezing, cooking, smoking, curing or canning. Histamine level of more 2012).Histamine level varies position of the tuna fish body. Hence this research was carried out to identify and analyze the Histamine level in various positions of the Histamine developed tuna fish. Methodology Survey was done to select the positions of taking samples from tuna fish. 15 fresh fish processing companies were selected and questionnaire was given. Three positions were selected based on the questionnaire filled by the fish processing companies. Three positions of the tuna fish were selected, beneath the pectoral fin of the fish, near the belly area and the tail end respectively and thirty tuna fish were subjected to Histamine test individually. ELISA method and histaminevertox test kit were used to analyze the histamine levels in the tuna fish.Sample preparation, sample extraction, sample dilution and Histamine testing are the major steps done in ELISA method. Collected data were analyzed by using Minitab 17 software.Highest mean values and variance values were taken from those positions. Non parametric Mann-Whitney test was done to find out the significant different among positions. Results and Discussion Highest mean values and variance values were taken from those positions. High Histamine was recorded in the belly area due to the most of the bacteria which responsible for converting Histidine to Histamine, lived in the gut of tuna fish. Through poor post-harvest techniques, low hygiene practices, bad catching method, bad killing methods and bad handling methods could expose the gut material to the fish muscles and so enteric bacteria easily release the Histidine decarboxylase enzyme to Histidine free specific amino acid and then forming Histamine (Koohdaret al., 2010).This reaction cannot be stopped and can only be controlled. Usually low histamine levels could be observed from gilled and gutted fish because gilled and gutted fish had low probability to contaminate by histamine forming enteric bacteria (Ebrahimet al., 2012).Very low Histamine level was recorded in the tail area because effect of enteric bacteria which lived in the tail was very low because of that ability to bacterial contamination also very low and histamine also very low.
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    Anesthetic Efficacy of Clove oil, Benzocaine and MS-222 under Simulated Long Transportation Conditions of Koi (Cyprinus carpio L.)
    (Uva Wellassa University of Sri Lanka, 2020) Silva, S.S.U.; Liyanage, N.P.P.; Mudalige, A.R.; Fernando, E.S.R.
    Koi (Cyprinus carpio) is one of the most popular temperate ornamental fish species. Growth of the Koi trade in Sri Lanka is hindered by poor packing strategies and mortalities during transport. Therefore, the study aimed at evaluating the anesthetic efficacy of Clove oil, Benzocaine, and MS-222 in simulated long transportation conditions on Koi. 75 d old Koi with standard length (6.025 ± 0.04 cm) and weight (6.153 ± 0.23 g) were selected for the experiments. These individuals were subjected to four different dosages of anesthetics, based on the results obtained at the range-finding test. Each sample consists of 10 individuals and dosages were triplicated. Samples were exposed to simulated transportation conditions for 10, 20, 30, 40 h, and effective dose for each anesthetic was determined by assessing the Sedation Induction Time (SIT), Recovery Achievement Time (RAT), Mortality Rate and Post-exposure Survival Rate of Koi. Changes in water quality parameters including pH, ammoniacal nitrogen, and dissolved oxygen in transport water were recorded. Results obtained were analyzed using one-way ANOVA followed by Tukey's’ method and General MANOVA using Minitab 17.0 version (p< 0.05). Among four different test concentrations used for clove oil, 145 µLL-l was recorded as the best concentration while 140 µLL-l and 70 mgL -1were obtained for Benzocaine and MS-222 respectively, based on the results obtained from statistical analysis of SIT and RAT (p<0.05). Further, there were 0% mortalities for the 40 h test period and 7 d after recovery for all the three anesthetics at effective concentrations (p<0.05). In conclusion, the present study indicates that all three anesthetics perform well in the above concentrations. However, clove oil can be used as a good substitute for synthetic anesthetics because of its efficacy at a lower dosage with higher safety at a low cost. Keywords: Sedation, Ornamental carp, Ornamental fish trade, Mortality rate, Packing density
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    Application of GIS to Identify Potential Areas for Aquaculture in Badulla District in Uva Province
    (Uva Wellassa University of Sri Lanka, 2013) Sandamali, M.A.N.; Rathnayake, R.M.C.W.M.; Liyanage, N.P.P.; Jayamanne, S.C.
    Aquaculture is farming aquatic organisms including fish, mollusks, crustaceans and aquatic plants (FAO, 1990). The main intent of the present study is to highlight the role Geographic Information System (GIS) in identifying potential areas for aquaculture in Badulla district. The study was carried out in Badulla district in Sri Lanka by the geographical coordinates of longitude 80 .45 to 81 .15. Latitude 6 .34 to 7 .18. Data have been collected from secondary sources and used to generate maps to identify fresh water bodies in Badulla district. Map of seasonal tanks, reservoirs and tanks, stream network and rivers of Badulla district were developed. Water availability (proximity to rivers), soil texture, soil pH, rainfall, temperature and topography (slope, elevation) and land use factors were considered to identify potential areas for aquaculture (pond culture). Protected areas are considered as constraints. Water availability, soil texture, soil pH, slope, elevation, rainfall, temperature, land use/ land cover thematic layers were created using ArcGIS 10.1 software. All these thematic layers have been assigned the weights according to their relative influence on pond construction using Analytic Hierarchy Process (AHP) and GIS approach. Finally, all thematic layers have been integrated in a ArcGIS 10.1 environment to generate an aquaculture potential map. Thus, four aquaculture potential areas have been Identified, viz. “Most suitable”, “Suitable”, “Fairly suitable”, “Unsuitable”. The north part of the Badulla district is identified as most suitable and the southern part of the Badulla district is identified fairly and unsuitable for aquaculture in Badulla district. Methodology Data collection: Secondary data were collected from secondary sources. GIS analysis: reservoirs and tanks, Rivers, Stream network of Badulla district were digitized using Arc View 3.1 software. GPS coordinates of seasonal tanks were stored & developed a map using ArcGIS 10.1 software to identify fresh water resources in Badulla district and all data were stored in ArcGIS 10.1 environment and factor thematic layers were generated to identify potential areas for aquaculture. Analytic Hierarchy Process (AHP) - AHP is a multi-objective, multi criteria decision making approach that employs a pair wise comparison procedure to arrive at a scale of preference among a set of alternatives (Dai et al., 2001). Thematic layers were evaluated using scores and each weighted according to their relative importance on the aquaculture using Analytic Hierarchy Process (AHP) and GIS approach. Map Generation -Each thematic layer was evaluated using the scores that were obtained according to the weighted linear combination in ArcGIS 10.1 environment. Vector format was converted to raster format. To reject the constraints the final result was multiplied by absolute constraints. The protected areas were allocated a zero score. Finally, the potential areas for aquaculture map was created and categorized into four levels: Most suitable, Suitable, Fairly suitable, Unsuitable based on the total scores obtained from the weighted linear combination.
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    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 ecosystems
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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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    Balancing the benefits of protein content and the risks of trace metal toxicity exposure from Skipjack tuna (Katsuwonus pelamis) consumption in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2015) Mahaliyana, A.S.; Liyanage, N.P.P.; Jayamanne, S.C.
    Fish is considered as an excellent source of protein that can provide immense health benefits to human being. Protein is the major nutrient in fish consumption and it is highly digestible and consist all the essential amino acids. However, recent claims that marine fish are contaminated with trace metals exceeding the recommended maximum allowable limits have raised concerns among consumers regarding fish consumption. This may lead to rejection of marine fish both by local and export markets (Liyanage, 2009) as fish contaminated with toxic trace metal can lead to acute and chronic effects in human being. In the present study, protein content and major toxic trace metal concentrations in skipjack tuna (Katsuwonus pelamis) which is a major commercial marine fish species were studied with the aim of assessing benefits and risks in consumption of skipjack tuna in Sri Lanka. Materials and Methods Samples of skipjack tuna fish (n = 44) were collected to represent all fish landing site areas around Sri Lanka during April-July, 2014. Concentrations of toxic trace metals Hg, Cd, Pb and As were analysed individually for all the samples while the protein content analysis was carried out for composite samples that were prepared based on gender and standard length of each fish. Crude protein content was analysed according to 928.08, AOAC 2000 standard method. Crude protein content was determined using UDK 132 (VELP Scientifica, Usmate, Italy) semi-automated Kjeltec system. All composite samples were analysed in triplicates. Hg, Cd, Pb and As trace metal concentrations were analysed by Atomic Absorption Spectrophotometer (AAS; Varian240 FS, Varian Inc., Australia) following the standard method in AOAC 1998. All analyses were strictly adhered with quality control procedures. Protein content of skipjack tuna was assessed in terms of benefits with reference to its Recommended Dietary Allowance (RDA) value whereas the toxicity of each trace metal was assessed based on the stipulated Provisional Tolerable Weekly Intake (PTWI) with the Probable Weekly Intake (PWI) values. Average consumption of skipjack tuna flesh in Sri Lanka was considered as 2.8 g/person/day (MFARD, 2013) and the average body weight of a Sri Lankan adult person was assumed as 55 kg. In addition, resulted mean toxic trace metal concentrations were compared with the established maximum allowable limits for toxic trace metals in Sri Lanka and European Union standards for skipjack tuna. Results and Discussion In order to determine the recovery percentage in crude protein analysis, spiked samples with (NH4)2SO4 were used and the recovery values were maintained within the acceptable range of 90- 110%. The method of trace metal analysis was evaluated for its suitability in terms of their respective Limit Of Detection (LOD) and recovery levels using spiked samples and certified quality control materials. Calculated recovery values for all the trace metals were within the expected recovery range of 80%-120%. The mean standard length of the analysed skipjack tuna fish was 47.4±3.9 cm and the range was 36- 56 cm whereas the mean total weight was 2.2±0.5 kg and it had a variation of 1.1 - 4.2 kg. Among the analysed specimens 24 were males and 20 were females.
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    Bio assay on effectiveness of the chemical hydrolyzation for denaturing agrochemical contaminated wastewater
    (Uva Wellassa University of Sri Lanka, 2015) Wickrama, G.M.G.M.M.; Rajapakshae, R.M.G .N.; Liyanage, N.P.P.
    Pesticides provide the primary means for controlling organisms that compete with man for food and fiber, livestock and crops. Global insecticide use in 2007 has been estimated 404 000 metric tons of active ingredient (Grube et al. 2011). The agricultural sector is the primary user of pesticides, consuming over four million tons of pesticides annually (Chen et al. 2009 and Chevillard et al. 2012). Most agrochemicals imperviousness to microbial degradation and has tendency to bio-accumulate in the soil fauna and flora. Water contamination has turned into a significant danger to the presence of living life forms in aquatic environment and aquatic organisms are highly susceptible for the agrochemical lethality. Many studies have shown the toxicity effect of agrochemical, but few studies have done to investigate the effectiveness of those treatment methods. Since the usage of agrochemical cannot be banded, best thing is finding a suitable method to detoxify them and understand the effectiveness of the particular method. Hydrolysis is a chemical reaction in which natural constituents respond with water and break into more diminutive (and less toxic) compounds. Fundamentally, hydrolysis is a destructive technology in which the original molecule forms two or more new molecules (EPA, 1993). Hydrolysis could be a viable treatment technology for agrochemical wastewater. In this study the effectiveness of the alkaline hydrolysis was estimated by using field data which were taken from the effluent treated plant (ETF) of agrochemical formulation and repacking industry, and also a bio assay was used to analyze the effect to the aquatic species from the treatment method.
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    Breeding performance of Pterophyllum scalare (Angelfish) fed with enriched Daphnia magna
    (Uva Wellassa University of Sri Lanka, 2018) Mohamed Rashath, M.R.; Coswatte, A.C.W.W.M.C.L.K.; Withanage, P.M.; Liyanage, N.P.P.
    Ornamental fish industry is a popular and profitable trade in the world. The production cost of ornamental fish varies with the cost of fish feed. The objective of the study was to investigate the breeding performance of Pterophyllum scalare fed with enriched Daphnia magna. The live feed of Daphnia magna was enriched with culture media, contained 58% crude protein and artificial feed with 40% crude protein were used to feed Pterophyllum scalare brooders (body weight l0g - 27g) as treatment I and II respectively. Square cement tanks with a size of 0.45 x 0.45 m2 were used for each treatment with 4 replicates for 80 days experimental period. Average Temperature, pH, Dissolved Oxygen, and Alkalinity in the two treatments were maintained at 28 °C, 7.4, 6.9 ppm and 560 mg 1-1 respectively. Although the brooders spawned in both treatments, the relative fecundity was not significantly different (P>0.05). Other breeding performances such as fertilization rate, spawn recovery and spawning period have shown significant differences (P<0.05) between Treatment-1 and Treatment-11. Comparatively highest fertilization rate (93.19%) and survival rate (70.87%) were observed in the Treatment-1, whereas lowest (fertilization rate: 67.31%) (survival rate: 50.55%) in Treatment-11. Most of the eggs in the Treatment-11 remained immature. Highest breeding performance was resulted with enriched Daphnia magna when compared to artificial feed in Pterophyllum scalare. The results revealed that the nutritional quality of the live feed considerably influenced on the breeding performance of Pterophyllum scalare.
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    Comparative Analysis of Morphological Characters of Blue Swimming Crab, Portuntis pelagicus (Linnaeus, 1758) Populations of Western and North-Western Regions in Sri Lank
    (Uva Wellassa University of Sri Lanka, 2018) Disnika, A.V.H.R.; Senevirathna, J.D.M.; Liyanage, N.P.P.; Jayamanne, S.C.
    The blue swimming crab, Portunus pelagicus, is abundant in indo-west pacific regions and extremely contributes for commercial fishery industry. In Sri Lanka, this species is typically found in Western, Northern, North-Western and NorthEastern Coasts. Morphological studies of P. pelagicus are important to identify population clusters and distribution patterns. Hence, this study was conducted to identify morphological variations of blue swimming crabs collected from Puttalum and Kalpitiya areas of the North-Western coastal region and the Negombo area of the Western coastal region. A Total of 240 individuals, 80 from each site were analyzed using twelve morphometric parameters. Standardized morphometric measurements were subjected to Discriminant Function Analysis (DFA) to observe intra-specific variations. According to the results, two discriminant functions were derived with 63.8% and 36.2% of variance for function I and 2 respectively, while function 1 was predicted as the strongest component (P < 0.05). The length to width ratio of the major cheliped merus (MEL/MEW=0.71) and ratio between carapace width (including 9th anterior-lateral tooth) to carapace length (CW2/CL-0.59) were identified as highly contributing parameters for function 1 and 2 respectively. The overlapped group plots suggested that there was no intra-specific morphological variability among three populations. Based on the results, it can be suggested that all three P. pelagicus groups are morphologically similar and consider as one population. The length-weight relationships of crabs in all three sites recorded negative allometric growth (b<3). However, results need to be confirmed using molecular data. Results of the current study provide basic information which could be utilized when constructing management plans on fisheries and conservation for this economically important carb species.
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    A Comparative Study on Ancient and Contemporary Fisheries Management Systems in Inland Reservoirs of Anuradhapura District in Sri Lanka: A Review
    (Uva Wellassa University of Sri Lanka, 2019-02) Lakpawan, W.M.P.; Liyanage, N.P.P.; Tennakoon, T.M.P.S.I.; Herath, H.M.T.N.B.; Kulathilaka, C.J.P.
    Archaeological evidences prove that fishery activities were initiated during pre-historic era. According to historical evidences, inland fishery was one of the important economic activities in ancient Sri Lanka and it was regularized after introduction of freshwater fish species during British period. This study was focused on investigation of ancient and contemporary fisheries management systems under four criteria such as, decision making, fishing gears, fish varieties, fish selling and revenue process in Anuradhapura District. 220 fishermen were selected using stratified sampling and data were collected using selfadministrated questionnaire, interviews with key persons and group discussions with fishermen. Secondary information was collected from National Aquaculture Development Authority (NAQDA), Department of Fisheries and Aquatic Resources and library survey. Results of the present study revealed that current fishery practices were managed through community based organizations, NAQDA officers and strong legal framework. As recorded in literature, ancient inland fishery activities were managed by Welwidane with the support of set of norms. In ancient time karaka, Kemana, Iratiya, Athnagu were used as fishing gears to catch native fishes such as Heteropneustes sp, Anabas sp, Channa sp, Wallago sp. At present, pole & line and gill nets were used as legally accepted gears to catch exotic food fishes such as Indian/ Chinese carps and Tilapia. Mainly barter system was applied during the ancient period and Machchabaga & Diyabeduma taxes were applied for harvest & usage of tank. Currently, organized fish selling system is practicing at landing sites and in well managed fishery systems, toll collection was observed. However, no direct taxes were applied in contemporary systems. Both pros and cons were identified in two systems. Abiding nature of villagers, dissemination of harvest and community services practiced can be taken as positive examples from ancient system
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    A comparative study on the effectiveness of gillnet and longline fishing methods used by multi-day fishermen in Matara fisheries district
    (Uva Wellassa University of Sri Lanka, 2015) Jathunga, M.I.; Wickramaratne, I.U.; Liyanage, N.P.P.; Gunawardane, N.D.P.
    The fisheries sector of Sri Lanka is a primary source of animal protein production. According to the high rate of population growth in Sri Lanka, fish food demand is increasing. To fulfill this increasing demand, there should be an effective fishing method for high rate of exploitation and exploited resources should be high quality and high value for the better utilization. In the late 1980s, Sri Lankan state introduced multiday offshore fishing vessels for the development of Sri Lankan offshore fisheries (Kariyawasam, 2010). The gillnet fishery and the longline fishery is the common fishing methods used in the deep sea fishing in Sri Lanka. According to the DFAR statistics in 2013, Matara fisheries district is one of the districts which provide high fish production to the nation. The gillnet fishery is most commonly used fishing method in multiday boats fishermen in Matara fisheries district and they do not engage in longline fishery very much. The identification of the suitable fishing methods is important to increase production level, quality of the production and income of the multiday fishermen. Therefore the present study is focused on comparison of the effectiveness of gillnet fishing and longline fishing methods as a deep sea fishing method used by multiday fishermen in Matara district. Materials and Methodology The data were collected from multiday fishing boats in “Dondra” fisheries harbor from 1 of May to 14 of June 2014. The sample size was determined by “Moving average method” and the total landings and fishing methods of 66 multiday boats were collected accordingly. Catch and effort data, income of the fishermen and quality of the landing were collected using prepared data sheets. The catch and effort data collection sheet was consisted of data regarding the duration of the fishing, the fishing techniques (gear) used in the trip, total catch per day, the species composition of the catch in number and/ or weight, gear information (length of net, mesh size, number of hooks per long line, soaking time,) vessel information (storage facilities, hauling technique, length of boats). The income data collection sheet was consisted of species composition, total weight of each fish species and price of the fish in particular day. Organoleptic survey has been done in order to determine the quality of the fish yield of each boat. According to the organoleptic evaluation, nature of the fish skin, nature of the gill, eye appearance and consistency of flesh were evaluated. The quality of the fish has been evaluated by scoring them according to the level of quality. Then mean of the score of the quality parameter was calculated to determine quality of the harvest in each multi-day boat. The collected data have been analyzed by using “Microsoft excel-2010” and compared with “One-way ANOVA table” by using “Minitab 16” software. Results and Discussion According to the study, there were 3 types of main fishing methods which were used by multi-day fishermen in Matara fisheries district. They are, gillnet, longline and combination of gillnet and longline fishing methods. There were 39.4% multiday fishing boats which used only gill net, 22.7% multiday fishing boats which used only long line and 37.8% fishing boats which used a combination of gillnet and long line. Mainly tuna and tuna like species were targeted in the study. The total catches of the different fishing gears were taken as weight of harvest per boat day. According to the results, the mean catch per boat day of the gill net, long line and combination of the longline and gill net were 133.7 kg, 94.2 kg, and 165.1 kg respectively. Therefore the multiday boats which used combination of gillnet and longline fishing method gained significantly higher yield than that of gillnet and longline fishing methods. The lower mean catch per boat day was gained by the longline fishing method. When considering main fish species which were caught by each fishing gear, the mean catches per boat day of Skipjack tuna (Katsuwonus pelamis) were 62.11 kg, and 64.76 kg respectively for gill net, and combination of the gill net and longline. In Matara fisheries district there were no multiday fishermen who used longline fishing method to catch skipjack tuna. The mean catches per boat day for yellow fin tuna (Thunnus albacares) were 7.05 kg, 79.39 kg and 70.56 kg respectively for gillnet, longline and combination of gillnet and long line. Similarly the mean catches per boat day of frigate tuna (Auxis thazard) were 12.29 kg, and 70.56 kg in gillnet, and combination of gillnet and longline respectively. There was no frigate tuna catch in long line fishery. According to this result, mainly long line fishing gear was used to harvest yellow fin tuna. The skipjack tuna and frigate tuna were harvested by using gillnet fishing method. When considering income of the multiday fishermen, the mean of the total income of multi-day fishermen who harvested fish using gill net, longline and combination of gillnet and longline is Rs 300,577.00, Rs 1,251,567.00 and Rs 1,068,474.00, respectively. The highest income was gained by the multi-day fishermen who used longline fishing method and the lowest income was gained by fishermen who used gillnet fishing method, among the three fishing methods. According to the organoleptic survey data, the quality of the fish in gill net, long line and combination of gill net and long line fishing methods were 1.99  0.41,2.32  0.31 and 2.04  0.39,respectively. The quality of the fish was high in fish which were harvested by longline and quality was low in fish which were harvested by gillnet. In the ANOVA test, there was not significant different between gear categories and the total catch per boat day (P>0.05). But, there was a significant different between gear categories and catch per boat day of tuna and tuna like species (P<0.05). Similarly, there were significant differences between gear categories and income of the fishermen and also gear categories and quality of fish (P<0.05). According to these result, it shows gear categories are not significantly affect on the total catches per boat day but it significantly affect for the catches of tuna and tuna like species, income of the fishermen and quality of fish. According to the above results, the gillnet fishing method has recorded, high catch, low income and low quality fish and long line fishing method has recorded low catch, high income and high quality fish while combination of gillnet and long line fishing method has recorded high catch, medium income and medium quality fish. But the ANOVA result showed total catch per boat day was not significantly affected by fishing gear categories. Therefore, though they have similar amount of fish harvest, multi-day boat fishermen who used longline fishing method has had high income and high quality fish than other two types of fishing methods. The analysis of catch composition of tuna and tuna like species showed that long line fishing method is much more species selective fishing gear than other two types of fishing methods. It is used to catch only target fish species which having high commercial value. And also, the amount of fish discarded by the longline is less than that of gillnet due to harvest of high quality fish in longline fishing method. The reason is that the fish remain alive for much longer period when hooked than when gilled (Santoset al., 2002). Because of that reason, the quality of the fish that harvested by longline is higher than gillnet fishing method. Because of their high quality, the value of the fish increases and fishermen obtained higher income with the longline fishing method.
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    Comparative Study on Total Chlorophyll, Carotenoid, Fucoxanthin in Seaweeds Ulva reticulata, Sargassum ilicifolium and Gracilaria multipartita and Colour Enhancing Commercial Ornamental Fish Feeds
    (Uva Wellassa University of Sri Lanka, 2019-02) Samarakoon, S.M.N.U.; De Silva, M.P.K.S.K.; Senaarachchi, W.A.R.K.; Liyanage, N.P.P.
    Seaweeds are photosynthetic marine macro algae, contain various natural colour pigments. Considering high bioavailability and low cost of processing, this study aimed on evaluating the potential of using seaweeds as a feed additive for colour enhancement of ornamental fish compared to commercial colour enhancing ornamental fish feeds by assessing three types of pigments. Three algae species (green algae-Ulva reticulata, brown algae-Sargassum ilicifolium and red algae-Gracilaria multipartita) were collected from Dickwella area. Pigments were extracted into 10 ml of 99% acetone from sun-dried algae and from 3 types of commercial feeds having green, brown and red colours. Total chlorophyll, carotenoid and fucoxanthin content of seaweeds and commercial feeds were quantified using UV spectrophotometer. Non-normally distributed data were analyzed by Kruskal Wallis test in Minitab version 17 at 0.05 significant level. Highest total chlorophyll content was observed in U. reticulata (70.50±0.39 µg g-1) & S. ilicifolium (59.53±4.34 µg g-1) and it was significantly different from their respective colour feeds (green 4.57±1.63 µg g-1 and brown 7.69±5.56 µg g-1). Similarly, U. reticulata and S. ilicifolium had significantly different carotenoid content (1.44±0.16, 2.11±0.07 µg g-1) compared to their respective colour feeds (green 0.22±0.09 µg g-1 & brown 0.21±0.07 µg g-1). Chlorophyll & carotenoid content had no significant difference between G. multipartita and its respective red colour feed. Fucoxanthin content was also higher in seaweeds (U. reticulata 2.12±0.89 µg g-1, S. ilicifolium 4.69±3.05 µg g-1 and G. multipartita 1.52±0.82 µg g-1) than three commercial feeds (green 1.82±1.81 µg g-1, brown 0.53±0.33 µg g-1 & red 0.49±0.06 µg g-1) with no significant difference. Results indicate that sun-dried seaweeds contained comparatively high level of pigments studied; the selected sea weeds may be taken as an effective feed additive for the colour enhancement of ornamental fish.
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    Comparison of Blue Swimming Crab, Portunus pelagicus (Linnaeus, 1758) populations from Batticaloa and Trincomalee areas in Sri Lanka using Morphometric Parameters
    (Uva Wellassa University of Sri Lanka, 2018) Soyza, W.A.D.; Senevirathna, J.D.M.; Liyanage, N.P.P.; Jayamanne, S.C.
    Western, Northern and Eastern areas of Sri Lanka are famous for blue swimming crab fishery. However, very limited studies have been carried out to identify their population structure. This study investigated the utility of morphological characters to differentiate Portunus pelagicus populations of two different areas in eastern province of Sri Lanka. Samples were collected from Batticaloa (n=46) and Trincomalee (n=46) waters throughout its known geographic range. Twelve morphometric characteristics were measured up to nearest 0.01 mm. Discriminant Function Analysis (DFA) was performed to analyze significant intra-specific variations of two populations using standardized morphometric characteristics. The derived single discriminant function was totally accounted for 100% variance (Wilks' Lambda=0.74, P<0.05). The carapace width to carapace length ratio (CW2/CL) was recorded the highest canonical discriminant function coefficient (0.89), thus CW2/CL was selected as the most suitable parameter for the predicted model. The two centroids derived by DFA were 0.59 and (-0.59) respectively for the Trincomalee and Batticaloa, and predict the separation of two groups. According to the plotted graph, minimal overlapping between two groups was observed with possible variation between two populations. Two different allometric coefficients (b) were recorded as 2.92 (closer to isometric growth) and 2.76 (negative allometric growth) for Trincomalee and Batticaloa populations respectively. Hence, the results suggest that there is a possibility of having two P. pelagicus stocks in the 2 sites of the eastern part of the island. Changes of prevailing environmental conditions and habitat are the factors that lead to morphological differences of two P. pelagicus populations. Finding of this study is important for implementations of site-specific sustainable fishery management programs. Further, population genetic studies are recommended to confirm the results of the present study.
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    Detecting Mislabelling of Packaged Frozen Seafood Products in Sri Lanka: A DNA Barcoding Approach
    (Uva Wellassa University of Sri Lanka, 2018) Perera, A.G.D.M.; Amarakoon, A.A.D.G.U.; Herath, D.R.; Senevirathna, J.D.M.; Liyanage, N.P.P.
    Seafood trade has conquered a vast market in global, as well as the local context. Substitution of high value species with those of low cost has become an emerging problem for the expanding market, since some of the products are visually unrecognizable and morphologically indistinguishable. The objective of this study was to assess the suitability of DNA barcoding as a method for species identification of packaged seafood to detect any mislabelling. Eight packaged frozen seafood product samples including finfish, crab, shrimp and cuttlefish were obtained from randomly selected supermarkets and subjected to DNA extraction by standard phenol chloroform DNA extraction protocol. Mitochondrial cytochrome oxidase subunit I gene (COI) was amplified in those samples with appropriate primers. Then successful five PCR products of tuna (T1 & T2), sailfish (SF1 & SF2) and crab (Cl) were selected for sequencing to build DNA barcodes. The prepared DNA sequences were compared with the Barcode of Life Database (BOLD) system for species identification. Close related sequences of each sample were downloaded from NCBI Genbank and phylogenetic trees were constructed using Maximum Parsimony, Maximum Likelihood and Neighbor Joining methods. Samples were identified as follows, T1 - Thunnus albacares (100%) and T2 Thunnus alalunga (99.85%), SF1 and SF2 - Istiophorus platypterus (100%) and Cl - Portunus pelagicus (97.71%). Identical tree topologies were resulted from three methods and three major clades were revealed in the phylogenetic tree as tuna, sailfish and crab groups. All selected five samples were matched (100%) showing that correct labelling had been done. This study concluded that DNA barcoding is a feasible, efficient and reproducible method for detection of mislabelling of packaged frozen seafood. However, the packaged frozen seafood trade has not reached high extent in Sri Lanka yet, hence substitution of seafood products does not occur frequently.
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    Determination of the Appropriate ayza sativa (Rice) Straw Fertilizer Loading Level to Enhance Survival Rate of Catla calla (Catla) Post Larvae
    (Uva Wellassa University of Sri Lanka, 2018) Maddumaarachchi, M.A.D.U.; Somarathna, K.M.D.M.; Liyanage, N.P.P.
    Introduction of the Indian major carp species like Catla calla (Catla), Labeo rohita (Rohu) and Cirrhinus mrigala (Mirigal) has been resulted in a significant development in inland fisheries in Sri Lanka. Among these introduced fish species, Catla contributes to freshwater fish production in Sri Lanka significantly. One of the identified problems in Aquaculture Development Center, Udawalawa was lower survival rate of Catla post larvae at nursery stage. Hence this study was conducted to determine appropriate rice straw loading level to enhance survival rate of Catla post larvae reared in nursery tanks of 20 m2. The experiment was conducted using a Completely Randomized Design (CRD). A preliminary fertilizing procedure was done to determine a defenitive range (75-90 g m2 of dried rice straw) to conduct the experiment and the tanks were fertilized at above rates. Body weights and total lengths of post larvae were recorded at stocking and water quality parameters were recorded twice a day in each treatment. Number of survived post larvae in each treatment were recorded with the body weights and total lengths at the end of the rearing period. Recorded data were analyzed using one way ANOVA and Tukey test was used to compare mean values at 5% significance level. Total plankton count, survival rate, length gain and weight gain of post larvae were significantly different (p<0.05) among treatments. 80 g m-2 loading level of rice straw was the best treatment showing highest survival rate (66.6210.69), greatest length gain (159.0816.99 cm), maximum weight gain (2,5761176g) and highest mean value of total plankton count (54,9101646). Adequate amounts of planktons and proper water quality parameters act as major reasons for higher survival rate of Catla post larvae. Therefore, the loading rate of 80 g In-2 was found to be best among treatments for fertilizing Catla nursery tanks with rice straw to enhance survival rate.
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    Determination of the Effect of Coconut Shell Extracted Carbon Monoxide on the Quality of Frozen Yellow Fin Tuna (Thunnus albacares) Products
    (Uva Wellassa University of Sri Lanka, 2013) Jayasinghe, J.M.P.; Wijesundara, W.M.N.M.; Liyanage, N.P.P.; Wijesena, G.K.C.P.K.
    Seafood provides the world's prime source of high-quality protein to the consumers and processed frozen and fresh fish products account for major portion of the diets. Prolonged shelf life and fine quality give the advantages to the frozen fish products in the market and bright red color is used as an indicator of high quality in yellow fin tuna (Thunnus albacares). Carbon monoxide (CO) either alone or as part of a filtered process, is being applied to seafood to maintain the desirable color attributes. CO complexes with the heme-iron of myoglobin, forms a stable red pigment, carboxymyoglobin. The heme-proteins are strong catalysts of lipid oxidation in muscles and reduced heme-protein may suppress the lipid oxidation and other off odour and flavour production (Faustman et al., 1989). CO or filtered smoke is capable of retarding the microbial growth of the muscle (Kristinsson et al., 2008). In Sri Lankan context, coconut shells can be used for processing of filtered smoke with CO. The present study evaluates the effect of coconut shell extracted filtered smoke, a low cost source of CO on the chemical, physical, microbiological and sensory quality attributes of yellow fin tuna (Thunnus albacares). Methodology The study was carried out in a specially designed experimental laboratory of the Global Sea Foods (Pvt) Ltd. Imported grade “A” frozen yellow fin tuna (Thunnus albacares) from 57 Food and Agriculture Organization of the United Nations (FAO) area caught by long lines was used for the study. Average thickness and weight of the processed steaks for the experiment were respectively 22±1.2 mm and 170±6 g. CO was extracted from coconut shells following the Kowalski and William (1999) (United States Patent 5972401) process of making super purified smoke using organic material. CO free, 15%, 30%, 45%, 60% and 75% CO concentrations were used as treatments and CO injected steaks were stored under 4 ˚C for 48 hours and subsequently individually vacuum packed. Complete randomized design (CRD) was adopted for the experiment. Random number table (SLS, 428) was adopted to select the steaks for treatment in five replicates. Treated steaks were stored under -18 ˚C for 2 days and frozen steaks were subjected to analysis for chemical, physical, microbiological and sensory attributes. 15 trained panelists were used for sensory analysis and standards and criteria that were developed by the National Oceanic and Atmospheric Administration and U.S. Department of Commerce (USDC/NOAA) seafood analysts were adopted. All results were reported as means and the significance of the differences were determined by one-way analysis of variance (ANOVA) followed by tukey’s tests for the comparison of data with 5% level of significance. Minitab 16 statistical software and Microsoft Excel 2010 (Microsoft Corp) were used for the statistical analysis. Results and Discussion Chemical, physical, microbiological and sensory quality attributes were analyzed to determine the effect of coconut shell extracted CO on the quality of frozen Yellow fin tuna products. Result showed that there was no significant difference among the histamine level of different CO concentration treated frozen steaks (p>0.05) indicating that decomposition of histidine in to histamine was not affected by the treatment of coconut shell extracted CO smoke.
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    Development of Fishmeal using Knifefish Chitala ornata
    (Uva Wellassa University of Sri Lanka, 2015) Wanniarachchi, S.P.; Liyanage, N.P.P.; Epasinghe, E.D.M.
    Knifefish (Chitala ornata) is a freshwater fish introduced to Sri Lanka as an aquarium ornamental fish in 1980’s (Gunawardena, 2007). They were introduced to wild habitat s by accidental release and now found in the rivers and lakes in Colombo and Kalutara districts (Sriyananda, 2004). The predatory nature of the knifefish and its ability to spread fast has posed a threat to native aquatic animals in Sri Lanka, especially to endemic species. At present, knifefish is listed as one of the invasive alien species in Sri Lanka (Gunawardena, 2007). Due to their large size and predatory nature, they have lost demand as aquarium fish and they have no demand as food fish. Hence, in order to eliminate these fish from wild habitats a new use should be introduced which would encourage the fishermen to catch them. In this research the possibility of using knifefish to produce fishmeal which could be used as a protein source in fish feed was evaluated. Knifefish for the experiment was collected from Kalutara area. Large bones and skin were removed and flesh was sun dried for 4-5 days. Dried flesh was ground and sieved to produce fishmeal powder. Two experimental diets were prepared as treatment 1 (containing Peliyagoda fishmeal) and treatment 2 (containing knifefish fishmeal) using the trial and error method. Other ingredients used were wheat flour, soyabean meal, rice bran and fish oil. Both diets were formulated to contain 30-35%. Proximate analysis was done for the ingredients and the two diets. Feeding trial was conducted for 20 days using guppies (2.34 ±0.24 cm), male and female separately. Three replicates were used for each treatment. Length and weight of the fish were measured weekly. At the end of the experiment Feed Conversion Ratio (FCR), Specific Growth Rate (SGR), weight gain and protein efficiency ratio (PER) were determined. Production cost of 1 Kg of each diet was calculated and compared. Statistical analysis was done using two-way ANOVA using minitab16 software. Results and Discussion Proximate compositions of the two diets are shown in Table 01. As shown by table 2 there was no significant difference between mean values of the two treatments with respect to FCR, SGR, weight gain or the PER. There was also no effect of the interaction between the sexes and the treatments on the above parameters (P>0.05) according to the results of the two-way ANOVA. Therefore, it is possible to use knifefish fishmeal as a substitute for Peliyagoda fishmeal in fish diets.
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    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 product
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    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.
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    Effect of Aquaponic System in Increased Stocking Densities of Guppy Fish (Poecilia reticulata) at Grow-out Phase One
    (Uva Wellassa University of Sri Lanka, 2021) Aththanayake, A.M.M.B.; Liyanage, N.P.P.; Bambaranda, B.V.A.S.M.; Silva, S.S.U.
    Guppy (Poecilia reticulata) is one of the widely marketed ornamental fish. Fry rearing density recommended by NAQDA, Sri Lanka for grow-out phase one was 20 fish ft-2. However, grow-out farmers are using different stocking densities. Production efficiency of existing facilities can be enhanced by increasing the recommended stocking densities. Therefore, identifying possibility of enhancing stocking density is vital for increasing production. Current study was focused to improve the efficiency of grow-out rearing of Guppy by incorporating aquaponic system using water spinach (Ipomea aquatica). Guppy juveniles with mean body size of 2.63±0.06 cm were stocked in similar glass tanks at three different stocking densities as 20 fish ft-2 (T1), 25 fish ft-2 (T2), and 30 fish ft-2 (T3), with three replicates. NAQDA recommended stocking density was used in T1 and increased densities were used in T2 and T3. Fish were fed three times a day with commercial larval rearing feed at 10% of their mean body weight. A mixture of sterilized brick-lets and coconut coir were used as media for the grow bed with 10.6 cm thickness. Six plants of same size and age were introduced to each aquaponic system. Temperature, pH, dissolved oxygen level, nitrate, nitrite, and phosphate concentrations were tested. Growth performance was determined using Mean Length Gain (MLG), Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), and condition factor (K). Collected data were subjected to one-way ANOVA and Tukey’s pairwise comparison at a significance level of p < 0.05, using Minitab 17 software. T3 showed significantly lowest MLG and SGR, whilst T1 showed the highest. However, T1 and T2 did not show significant difference. Significantly highest FCR was observed in T3. Condition factor did not show significant difference and no mortality was observed. Nitrate, nitrite concentrations were significantly high in T3 whilst other parameters did not vary significantly among treatments. According to the results obtained, the medium stocking density of 25 fish ft-2 can be suggested as the optimum stocking density for guppy grow-out phase one for aquaponic coupled rearing facilities as it allows medium level stocking density while obtaining satisfactory growth and maintaining favorable water quality. Keywords: Aquaculture; Aquaponics; Fish growth performance; Ornamental fish