Aquatic Resources Technology Degree Programme ( AQT)

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    EVALUATION OF THE IMPACT OF THE FUEL SUBSIDY ON SOCIOECONOMIC DEVELOPMENT OF THE NEGOMBO FISHING COMMUNITY
    (Uva Wellassa University of Sri Lanka, 2013) WIJESINGHE, W.M.S.
    The marine fishery sector in Sri Lanka is one of the most significant livelihoods and significant industry which contribute 2.3% of GDP to national economy, generates export earnings with the engagement of mechanized and non-mechanized boats. With the fuel price hike in 2012, the government has decided to grant a fuel subsidy to the owners of mechanized fishing crafts. Assessing of the socioeconomic impact of the fuel subsidy scheme to the fishery community was suggested by DFAR after a year of its introduction. The research was conducted at Negombo town fishing area and using its typical fishing community in order to understand the living situation of boat owners, skippers, crew members and the family members of the fishermen. They were interviewed regarding their knowledge & attitudes towards the fuel subsidy. The secondary data of the fish production from 2012 to July 2013 was gathered to compare the production differences before and after the introduction of the fuel subsidy. In general, the fishery community of Negombo has agreed with the fuel subsidy grant and it minimizes the expense for fuel, increase number of fishing days and increases family savings. But the most of community members said that the fuel grant has not directly affected to increase the fish harvest, daily income, improve, children's education and boat condition even though the number of fishing days increased. According to the ideas of the same fishermen the fuel subsidy was indirectly supported to the social improvement of the community such as children's education, savings, etc. The large scale boat owners were getting more subsidy grant and it was helped to maintain their boats properly other than using recurrent expenditures of their family. Due to subsidy, the fishery community has dbled to maintain the fish production after the hike fuel price even though the fish production has no significant improvement. A year after the introduction of the fuel subsidy grant has showed a positive impact to the fishery community even though it was not significantly affected to the economic and social development of the community so far. However it is proposed to revised the scheme in order to implement the same with more descriptive manner and the benefit should be given to the small scale fishermen and to the fisheries sector as whole rather than targeting individual boat owners. Key words: Fuel subsidy, Negombo, economy, social development, fish production
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    A STUDY ON THE OPTIMUM CONCENTRATION OF COPPER SULFATE AND BIOMASS OF VALISNERIA PLANT IN CONTROLLING GREEN ALGAE UNDER AQUARIUM CONDITION
    (Uva Wellassa University of Sri Lanka, 2013) PRIYADARSHANA, R.W.H.H.
    Ornamental fish industry plays a considerable role in the economy of Sri Lanka since the globalization ornamental fish industry. Maintenance of aquariums with ornamental fish has become a hobby of people and aquarium owners but the controlling excessive algal bloom has become a hindrance. Excessive algal growth is a nuisance for aquarists, due to decreasing dissolved oxygen level, absorbing the nutrients. It is also hazardous to fish and plants. Present study attempts to develop a method to control excessive green algal blooms in aquariums combining the effects of Copper Sulfate and aquatic plant Valisnaeria. Complete randomized design was used under laboratory condition. Thirty six tanks were used for the experiment and seventy two Betta Splendens fishes were used. five treatments (concentrations) for Copper Sulfate, Valisneria spiralis plants and controls for both treatments were used in triplicate. This survey was done using ANOVA and Minitab 14 software. Results indicate that both the Copper Sulfate and the Valisneria plants are effective in controlling algae under aquarium condition. Tukey's pairwise comparison has shown that all the treatments with Copper sulfate were significantly different from the control (P<0.05). The highest algal decline level was shown in 0.5 ppm significant level. And also it can be concluded that biomass of 7.12 g /in 6 1 of water is adequate for controlling algae in a volume of 230 1 water containing 0.12,Ing/1 Chlorophyll a. Key words, Aquariums, Chlorophyll, Copper Sulfate, Green algae, Valisncria biomass
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    STUDYING THE FISHERY AND BIOLOGY OF SCADS, (DECAPTERUS SPP.) IN THE EEZ OF SRI LANKA
    (Uva Wellassa University of Sri Lanka, 2013) KULIYAPITIYA, P.M.
    The Scads or Decapterus spp. are commonly known as "Linna" in Sri Lanka. This study aimed to fill information gaps in Decapterus fishery, reproductive biology and feeding ecology in Sri Lanka. Preliminary survey was conducted from Matara to Hambanthota all fish landing sites. Field sampling and laboratory analysis examined the biological characteristics of Decapterus spp. caught by two different landing sites including size, growth rate, age, and sex ratio, maturity, spawning condition, and feeding ecology. A total of 70 specimens were examined during the study period. 98% of the samples were D. macarellus. Therefore, major predominant Decapterus species was Decapterus macarellus and other than that Decapterus russelli, was recorded in small quantities. In southern coastal areas and Beruwala this fishery is dominant over other areas. Both day boat and multiday boats contribute to Decapterus fishery. But day boats contribution is negligible when compare with multiday boats contribution. Major fishing gear is ringnet in multiday boats while gillnet is in day boats. . Even though there is no season for this fishery July to December is the peak season of this fishery. Mean total length of male D. macarellus was 27.91 ± 2.71 cm and female was 28.73 + 1.58 cm. Length weight relationship of female was W =0.0098TL3 and male W = 0.0262TL2.71. From the sex ratios it can be seen that in D. macarellus males dominated over females. More than 50% of D. macarellus females were matured in the length group 29-30 cm and males were matured in the length group 28-29 cm TL. Out of 45 males 15% were immature and other 85% were matured and also out of 25 females 4% were immature and 96% were mature. . The fecundity of D. macarellus was found which vary fiom 85955 to 168148 ova. The average fecundity was 118933 + 28046 ova. . In the present study also the fecundity of D. macarellus increase with increase in length of the fish. The dominant food item was zooplanktons and few phytoplankton were identified .Shrimp larvals were abundant food item many of gut content other than Copepods, Rotifers and diatoms were identified. Key words: Decapterus spp., Fishery, Reproductive biology, Feeding ecology
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    Study of Effectiveness of Aquamimicry on the Seed Production of Black Tiger Prawn (Penaeus monodon)
    (Uva Wellassa University of Sri Lanka, 2013) AHMED, M.R.R.
    Currently, Aquamimicry concept was introduced and practiced in shrimp farms in aiming of providing natural estuarine condition for the culture species. The success of this method includes reducing feed conversion ratio, minimizing water exchange and improving post larvae quality. In light of this, an attempt was undertaken to investigate the effect of Aquamimicry on the seed production of black tiger prawn (Penaeus monodon), compared with a control tank (without natural estuarine condition). The result showed that several issues significantly improved with the administering Aquamimicry system in the experimental tanks compared with the tanks without Aquamimicry system. Data were analyzed using MANOVA (P < 0.05) in SPSS software to determine significant differences of growth parameters. The size variation was observed lower in the control tanks than in the experimental tanks. Moreover, the muscle gut ratio of PLis was about 80±1.677% in the Aquamimicry tanks and 78.5±2.905% in the control tanks during the two cycles of production. The fouling organisms were more in the control tanks compared to the experimental tanks. The average lengths of PLio and PLis were maximum when reared in the experimental tanks compared to the control tanks. Which shows significant difference and the \Tattles are 10.56+0.043mm in experimental tanks and 10.38+0.043mm in the control tanks. Several test were perform to test the Post larvae quality but those test did not show any significant difference. During stress test the experimental tanks showing more survival than the control tanks. And also the test for the necrosis and abnormalities and swollen. hind gut also shows a decreased percentages than a control tanks with a difference of 1.5%, and 0.17% respectively. The final survival rate of PLis from the control and experimental tanks was 44.9±0.825% and 50.22±0.477% respectively. The present investigation indicated that Aquamimicry concept played an important role in the health, growth and survival of Penaeus monodon larvae.
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    Detecting Mislabelling of Packaged Frozen Seafood Products in Sri Lanka: a Dna Barcoding Approach
    (Uva Wellassa University of Sri Lanka, 2013) PERERA, A.G.D.M.
    The seafood trade has conquered a vast market in global, as well as the local context. Substitution of high value seafood 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. Mitochondrial cytochrome oxidase subunit I gene (COI) was amplified in those samples with appropriate primers. Then five successful PCR products of tuna (T1 & T2), sailfish (SF1 & SF2) and crab (Cl) were selected for sequencing to obtain DNA barcodes. The prepared DNA sequences were compared with the Barcode of Life Database (BOLD) system for species identification. Closely related sequences for each sample were downloaded from NCBI Genbank and phylogenetic trees were constructed using Maximum Parsimony, Maximum Likelihood and Neighbour 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 resulted from all three methods and three major clades were revealed in the phylogenetic tree as tuna, sailfish and crab groups. All five selected samples matched with more than 95% identification percentage showing that correct labelling had been done by the packaging companies. This study concluded that DNA barcoding is a feasible, efficient and reproducible method for detection of mislabelling of packaged frozen seafood products.
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    Development of Optimum Conditions for Inducing Release of Swarmers in Ulva Lactuca
    (Uva Wellassa University of Sri Lanka, 2013) DISSANAYAKE, D.T.A.S.
    The green algae, Ulva lactuca plays a vital role in the economy. Due to periodic reproduction of Ulva spp, the continuous supply of swarmers (reproductive bodies) is low and also as a result of excessive pollution, natural sporulation of seaweed is becoming less feasible. Hence, the productivity is reduced. Transformation of vegetative cells directly into swarmers by stimulating them through environmental shock treatments has been practiced in many countries as a remedy to this problem. In this study, attempts are made to determine best temperature-time combination, best dehydration, salinity condition for inducing release of swat-liters in Ulva lactuca. To induce release of swarmers, Ulva (15 g for one treatment) was shocked at 2°C, 4°C and 6°C temperatures for different shock time periods of 5, 10 and 15 minutes. The control treatment was done without providing temperature shock and all treatments were triplicated. Subsequently those were chopped and placed in petri dishes with filtered autoclaved seawater (30 ml) for a week of incubation period at 25°C. All treatments in experiments were done simultaneously. The reproductive output of Ulva lactuca was determined by quantifying the number of discharged swarmers per millilitre using a hemocytometer. Collected data were subjected to univariate analysis (P<0.05) to determine significant differences of parameters. It was identified that 2°C and 10 minutes was the best temperature which gave maximum (1,293.333 x103±52.061x103 Individual/ ml) density of swarmers. In the second experiment, effect of dehydration was determined by exposing thalli (15 g for one treatment) to different dehydrations (0, 15, 30, 45, 60 and 90 minutes) at constant 2°C and 10 minutes temperature shock and data were analysed using one-way ANOVA (P<0.05). From different dehydration periods, 30 minutes was noted as the optimum dehydration time which resulted maximum density of swarmers (5,503.3 x103±768.396x 103 Individuals / ml). In the third experiment, after thalli (15 g for one treatment) was exposed to constant 30 minutes dehydration, 2°C for 10 minutes temperature shock, thallus was chopped and cultured in artificial seawater with different salinity series (10 ppt, 20 ppt, 30 ppt, 40 ppt, 50 and 0 ppt) including three replicates. Collected data were analysed using one-way ANOVA (P<0.05). As best salinity, 30 ppt artificial seawater medium was identified which gave highest density of swarmers (5,586.667x103± 373.511x103 Individuals / ml) in all three experiments. The results (P < 0.05 level) indicated, temperature, dehydration and salinity affects the release of swarmers in Ulva lactuca. Highest swarmer density was resulted when thallus was dehydrated for 30 minutes followed by temperature shock at 2°C for 10 minutes and incubated in 30 ppt filtered autoclaved artificial seawater. This can be used as baseline method for mass production of swarmers in tropical Ulva lactuaca.
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    Study on Accumulation Levels of Pb, Hg and Cd in two Selected Reservoirs in Badulla District, Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2013) MADHUSHIKA, N.M.S.H.S.
    Contamination of aquatic ecosystems with heavy metals is an emerging problem in Sri Lanka. Ulhitiya and Mapakada are two reservoirs situated in Badulla District, Sri Lanka. They are important for inland fishery, flow balancing and irrigation. The aim of this study was to determine the levels of Pb, Hg and Cd in sediment, surface water, fish skin, fish gill and fish muscle samples of Ulhitiya and Mapakada reservoirs. Sampling sites were selected for each reservoir based on simple random sampling method to represent entire reservoir. Collected fish, sediment and surface water samples were subjected to microwave accelerated acid digestion before the analysis. Pb, Hg and Cd concentrations of digested fish, sediment and surface water samples were determined using atomic absorption spectroscopy (AAS). The data obtained were analyzed using multivariate analysis. Results revealed that Hg was not detected in all the surface water and sediment samples of both reservoirs. Pb was not detected in all fish samples of both reservoirs. Moreover, all three heavy metals were not detected in all the water samples in both reservoirs. The mean concentrations of heavy metals namely Pb and Cd in sediments of Ulhitiya reservoir were recorded as 6.357+0.871, 0.081+0.024 mg kg-1 and Pb and Cd concentrations in sediments of Mapakada reservoir were recorded as 8.809+1.041, 0.104+0.029 mg kg'. The mean concentrations of Hg and Cd in fish samples of Ulhitiya reservoir were recorded as 0.008+0.031, 0.002+0.005 mg kg' besides Hg and Cd concentrations in fish samples of Mapakada reservoir were recorded as 0.000+0.000, 0.106+0.026 mg kg-1 respectively. Significant differences accepted at <0.05. As per the results of the study, no significant differences were observed in Pb and Cd concentrations of sediments between two reservoirs. In addition, no significant differences were observed in Hg and Cd concentrations of fish samples between two reservoirs. Thus, it can be concluded that Pb, Hg and Cd concentrations in water of these two reservoirs do not exceed the maximum allowable limits stipulated by WHO and EU for drinking purposes. Nevertheless, sediments are considerably comprised of Pb and Cd in both reservoirs. Therefore, it is important to mitigate the emission of untreated water and sewage into the reservoirs. Keywords: Reservoirs, Fish, Water, Sediment, Pb, Hg, Cd, Uva province
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    Preliminary Study of the Elasmobranch Fishery in Valaichchenai, Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2013) DHARMAKEERTHI, T.N.
    Sharks and rays are included within the sub class Elasmobranchii. Indiscriminate fishing techniques have resulted in the progressive depletion of their populations globally. In Sri Lanka these fisheries are driven by demand for shark fins, mobulid gill plates, their fresh meat and dried fish. This study collected information on shark and ray landings to provide information to recommend sustainable management practices. A questionnaire survey was conducted with 140 fishers and biological data collected from 123 shark specimens and 129 ray specimens in Valaichchenai(7 055.58', 81 ° 31.80'), in the Eastern Province of Sri Lanka. Results showed a female biased sex ratio for sharks with 11.76% of them observed to be pregnant. Of the male sharks, 16% were determined to be immature. For the rays, 40% were immature, comprising of 67% of females of which 3.44% were pregnant. The growth coefficients and condition factors for the most abundant species were Carcharhinus brevipinna(1.25; 1.09) and Neotrygon kuhlii (1.86; 1.98). All species showed a negative allometric growth, and most of the species have shown condition factors above one. The questionnaire revealed that fishers were aged between 18 to 68 years (mean = 37.553 ± 11.23 SD) and 64% of fishers stated they go as far North as Jaffna, and offshoreranging from 10 to 700 km for fishing. There was no significant difference between attitudes on the awareness of rules and regulations with fishers of varying age groups. However, propensity of crossing waters of Sri Lankan boundaries showed a significant difference (p < 0.05). The results showed that some endangered species such as Sphyrna lewini and also vulnerable species such as, Mobula tarapacana were being caught and that immature males and pregnant females were being landed. These results indicate the need for proper implementation of management plans to ensure sustainable utilization of these resources. Thus, conducting awareness programs, declaring restricted areas or closed seasons, imposing catch or export quotas, and introducing optimum length at first capture are important for sustainable resource use. Keywords: Elasmobranch, Growth factor, Condition factor, Maturity, Gill plates
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    ANTIMICROBIAL ACTIVITY OF SELECTED MARINE PLANTS IN SOUTH WEST COAST OF SRILANKA
    (Uva Wellassa University of Sri Lanka, 2013) ARULANANTHAN, A.
    Natural products from marine plants are known to have a variety of biological properties including antimicrobial activity. Even though these activities are well known, only a limited number of studies have assessed the antimicrobial properties of extracts from marine vegetation in Sri Lanka. To address this issue, the antimicrobial activity of extracts from selected algae and a seagrass species were tested. Samples were collected from the Barberyn reef off Beruwela coast and beach rocky platforms in Hikkaduwa. Using different solvents (chloroform, methanol, and water) natural products were extracted from four macroalgae species; Ulva pertusa, Gracilaria salicornia, Gracilaria hikkaduwensis and Padina minor, and a seagrass species Cymodocea serrulata. The antimicrobial activity of each extract was assayed by using agar well diffusion and agar disc diffusion method against two pathogenic bacteria Staphylococcus aureus (ATCC 29213) and Escherichia coli (DS 5a) and one yeast species Candida albicans (Bench culure) Testing was carried out for varying quantities of extracts (1 mg, 2 mg and 5 mg for disc diffusion; 5 mg, 10 mg and 20 mg for well diffusion). The antimicrobial activity of extracts was comparable with Kanamycin and fluconazole which were used as positive controls for antibacterial and antifungal activity respectively. Methanol and chloroform extracts of C.serrulata and G. hikkaduwensis showed antibacterial activity against S.aureus. Chloroform extract of Upertusa showed antimicrobial activity against S.aureus and C. albicans. Additionally, chloroform extract of C.serrulata gave positive results against C. albicans. The maximum antibacterial activity was observed in the methanol extract of C.serrulata of 11 mm and minimum activity was 0.33 mm observed in chloroform extract of G. hikkaduwensis against S. aureus. Water extracts did not show antimicrobial activity. The results from this study confirm antimicrobial activity in C.serrulata, Upertusa and G.hikkaduwensis found in Sri Lanka. Further research is needed to identify the individual compounds responsible for antimicrobial activity, which may in turn lead to developing therapeutic drugs from locally available marine vegetation. Key words: antimicrobial activity, seaweed, bioactive, solvent extracts
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    Analysis of Functional Properties of Fish Protein Hydrolysates from Scomber Japonicus Canned Fish Processing Fin Wastage
    (Uva Wellassa University of Sri Lanka, 2013) EDIRIWEERA, T.K.
    Pacific chub mackerel (Scomber japonicas) is a salience fish species which highly utilized in canned fish processing. In production, around 30% of raw fishes are discarded as wastes which leads to economic losses and environmental pollution. Hence, production of Fish Protein Hydrolysates (FPH) utilizing fish wastes, which contains bioactive compounds may be an ideal remedy. In this study Scomber japonicus canned fish processing fin wastage was collected and blended. Aqueous extracts of Fish Protein Concentrates (FPC) were produced with 04 different ratios as sample: distilled water, 1:1, 1:2, 1:3 and 1:4. Crude extraction was observed using 10% SDS-PAGE. Extracted FPCs were hydrolyzed using Papain, Pepsin, Trypsin and Protease enzymes (1:100) under 37°C with their optimum pH conditions for 0, 3, 6, 9, 12 and 24 hours followed by heat inactivation at 100°C for 15 minutes. Hydrolyzed samples were lyophilized and observed for antioxidant activities by TBARS and DPPH scavenging assay, metal chelation activity by Fe (II) chelating activity and antibacterial activities by agar well diffusion method. According to the observations there was no significant difference between the 04 ratios in yield (p>0.05). So 1:1 ratio was selected with periods as Papain-24 h, Pepsin-3 h, Trypsin-3 h, Protease-0 h for further experiments. According to the results obtained from TBARS assay, none of the FPHs showed antioxidant properties (p<0.05), insttad all demonstrated high oxidative activity. However DPPH scavenging assay showed significant difference among the treatments (p<0.05). Results obtained by Fe (II) chelation activity analysis revealed that the produced FPHs show Fe(II) releasing activity instead of chelation (1.84, 13.99, 16.48, 1.84%,), while FPHs produced according to standard protocol showed a slight chelating activity (0.73%). Further, the results of antibacterial activity against E.coli and Salmonella spp. was highly positive in all four types of hydrolysates and the best activity against both strains was demonstrated by Trypsin hydrolysate. This concludes the FPHs produced using aqueous extracts of Scomber japonicus contain strong antibacterial activity, though they do not contain strong antioxidant activity and they have iron releasing properties. Keywords: Fish Protein Hydrolysates (FPH), Enzymes Treatment, Antioxidant, Metal Chelating, Antibacterial
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    A STUDY ON EXTRACTING GELATIN FROM BIG EYE TUNA (Thunnus obesus) SKIN: AN ALTERNATIVE TO MAMMALIAN GELATIN
    (Uva Wellassa University of Sri Lanka, 2013) AZHAR, A.M.
    Gelatin represents a major source of protein biopolymer with many applications in food, pharmaceutical, photographic and cosmetic industries. Fish skins are major by-products of the fishery and aquaculture industries with high collagen content that can be used to produce fish gelatin. The Objective of this study was adding value to the fish processing skin waste in fish processing industry and to develop the best processing method for extracting gelatin. Gelatin was extracted from big eye tuna (Thunnus obesus) skin by alkaline pretreatment followed by acid extraction method. Different acid (sulfuric acid) and alkaline (sodium hydroxide) concentrations (0.1 %, 0.2 %, and 0.3 %) and soaking time (48 h and 72 h) were used for gelatin extraction. Big eye tuna skin gelatin was subjected for different characters such as yield, gel strength, melting point, color, odor, pH and proximate composition for evaluating best method. Based on highest yield, gel strength and melting point, sample treated with 0.1 % of NaOH and HC1 for 48 h was selected as best sample. The most appropriate sample was compared with commercially available gelatin product. The gel strength of selected big eye tuna skin gelatin (260 Bloom) was higher than bovine gelatin (200 Bloom), while melting point was lower (24.2°C). 19.67 % yield was obtained. Proximate composition of big eye tuna skin gelatin sample was 15.2 % moisture, 82.17 % crude protein and 0.97 % crude lipid respectively. Gelatin sample of Big eye tuna fish skin treated using concentration of 0.1 % NaOH and H2SO4, with a soaking time of 48hrs at 60 °C hot water extraction for 5 hours is concerned as most suitable method for gelatin production. Key words: Fish gelatin, Big eye tuna, Fish skin, Characteristics
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    STUDY ON THE IMPACT OF DEVELOPMENT OF COLOMBO-KATUNAYAKE EXPRESS WAY ON THE BENTHIC HABITATS IN THE NEGOMBO LAGOON
    (Uva Wellassa University of Sri Lanka, 2013) RANASINGHE, V.S.K.
    Colombo- Katunayake express way is running through part of the Negombo lagoon called Madabokka. Therefore water circulation of that part is not functioning well. It affects to the biological habitat such as benthic fauna and flora of the lagoon. The aim of this research was to study the present benthic diversity and the sea grass biomass distribution of this part of the lagoon. Sampling was conducted in 16 sites of sie selected trasects in the affected area. Water samples and benthic samples were collected in each study site. Benthic samples were analysed to identify and quantify benthic fauna, pH, salinity, P034- and NO3- were measured. These results were compared with data obtain prior to the construction of Colombo¬Katunayake Express way using mini tab 14 software. According to the results there was a significant difference between prior and after data obtained. Four transect out the 6 showed the significant difference. Other two locations also affected by the express way, did not show the difference because one is situated near to the some kind of inlet and the other location is open to the water current which coming from the Katunaya area. It is concluded that the benthic habitats of the lagoon area called Madabokka heavily affected with the CKE.
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    APPLICATION OF GIS TO IDENTIFY POTENTIAL AREAS FOR AQUACULTURE IN BADULLA DISTRICT , UVA PROVINCE
    (Uva Wellassa University of Sri Lanka, 2013) SANDAMALI, M.A.N.
    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 of Geographic Information System (GIS) in identification of potential areas for aquaculture in Badulla district, because GIS can use as powerful analytic and decision-making tool for the selection of potential and suitable site for aquaculture. The study was carried out in Badulla district, Sri Lanka located at longitude 80°.45 to 81°.15. Latitude 6°.34 to 7°.18. It covers an area of about 2,827 km2 . Secondary sources data have been collected and used to generate maps to identify the fresh water bodies in Badulla district as seasonal tanks, perennial 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). 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 integrated using map algebra 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. The study thus demonstrates that GIS is very useful tool for delineating aquaculture potential areas in Badulla district. Key words: Aquaculture, Geographic Information System, Analytic. Hierarchy Process, potential area
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    Preliminary Study on Factors Influencing the Mangrove Distribution Around Selected Coastal Lagoons in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2013) GAMAGE, S.G.
    Mangroves are unique and valuable ecosystems, but vulnerable to various natural and anthropogenic threats. Knowledge of the present status of these ecosystems and their distribution is a prerequisite in achieving conservation and management goals. The present study was conducted to find out whether there is a dissimilarity of mangrove distribution between different coastal sectors in Sri Lanka and the most influencing factor(s) for mangrove distribution. In this study, eight coastal lagoons representing eight coastal segments in the island were mapped using freely available Landsat satellite images for the year 2017. A supervised image classification technique in ERDAS IMAGINE 2011 was used to identify mangroves and other land use patterns in the area. From each classified map, the present mangrove extent was derived in ArcMap 10.1. Present mangrove extent of each coastal sector showed dissimilar distribution patterns. Then mangrove distribution influencing factors such as rainfall, maximum wind speed, humidity, temperature, fetch length and freshwater inflow were collected for each lagoon for the past two years. Pearson correlation of factors and the current mangrove extent showed that none of the considered individual factors are statistically significant to influence the distribution pattern and the occurrence (P>0.05). As these casidered factors influence on flora distribution as collective rather than individually, regression analysis was conducted. Results revealed that none of the factors haS collective influence over the mangrove distribution (P>0.05). Hence, the present study arrives at the conclusion that the mangrove distribution in eight coastal sectors in Sri Lanka is different. Even though, rainfall, relative humidity, temperature,' fresh water inflow or wind speed of the environment has no effect on the distribution dynamics of selected coastal lagoon's mangrove extent. If the sample sizes and the number of considered factors increased more significant results could have been obtained. Keywords: Mangroves, Lagoons, GIS, Remote sensing
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    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.
    Calcium supplement is a preparation intended to supply calcium that are missing or not consumed in sufficient quantity in a person's diet and it used to boost the Calcium content of the diet. Calcium supplement for human consumption was prepared by using Yellow fin Tuna (Thunnus albacares) fish bones by several processing steps including, pretreatment by using NaOH, followed by neutralization step and drying. Pretreatment step was carried out by boiling with different Sodium Hydroxide (NaOH) concentrations and time combinations. Experimental Design 01 was conducted to determine most suitable range of NaOH Concentration (6%, 8%, 10%) time (70 minutes, 90 minutes, 110 minutes) combination. Experimental Design 02 was carried out to determine best NaOH Concentration (9%, 10%, 11%) time (80 minutes, 90 minutes, 100 minutes) combinations and evaluated the softness and color of the treated fish bones by considering dissolution of fish bones in NaOH solution. After selecting the best sample, treated bones were washed with running tap water for 07 times and drained to remove excess moisture under room temperature (30 °C). Drying step was carried out with Experimental Design 03 (Si - 80 °C,70 minutes, S2 - 80 °C,80 minutes, S3 - 80 °C,90 minutes, S4 - 90 °C,70 minutes, S5 - 90 °C,80 minutes, S6 -90 °C,90 minutes, S7 - 100° C,70 minutes, S8 - 100 °C,80 minutes, S9 - 100 °C,90 minutes) and evaluated the Moisture content, Drying Kinetic Rate Constant and Calcium content for each sample. The selected best sample (S7) was further tested for proximate composition and counted the Total Plate Count (TPC). The most appropriate processing method was evaluated by considering Moisture content, Calcium content and Drying. Kinetic Rate Constant of the samples in Experimental Design 03 and it was boiling the fish bones in 10% NaOH at 90 °C for 80 minutes, neutralization by 07 times and drying the neutralized pretreated fish bones, at 100 °C for 70 minutes. The Proximate composition of the final product (S7) was Crude fat 13.433%, Crude protein 7.303%, Crude ash 75.33% and 5.2% Moisture and Lead content 0.01 mg/Kg. The calcium composition of the selected final product was 30.6% and it met the standard requirements for supplementary foods and this research will be indicate significant role in value addition sector of aquatic byproducts in Sri Lanka. Key words: Calcium supplement, Drying Kinetic Rate Constant (k), Moisture Content, Softness of fish bones, Value addition.
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    PERFECTING EXPLANTS STERILIZATION PROCEDURE AND MULTIPLE SHOOT INDUCTION MEDIUM FOR IN VITRO PROPAGATION OF LAGENANDRA SPECIES
    (Uva Wellassa University of Sri Lanka, 2013) PREMATHILAKE, P. G.A.D.
    Lagenandra species are important aquatic plants in the aquaculture industry of Sri Lanka. In the absence of a regular supply due to lack of effective propagation methods, Lagenandra species are indiscriminately harvested from the wild to supply to the export market. The threat on the species is further compounded by the loss of their rainforest habitats. Out of six Lagenandra species that occur in Sri Lanka, five are classified as "Highly threatened" species in the red list of international union for the conservation of nature. In order to overcome the problem of species loss and inadequate supply to the local and foreign markets, an in vitro micro- propagation method was developed for Lagenandra lancifolia and Lagenandra ovata. The present investigations were carried out to standardize surface sterilization of explants, evaluate different concentration of growth regulators and evaluate effect of basal media and liquid agitated culture for shoot initiation and multiplication. The study on surface sterilization of Lagenandra ovata revealed that explants treated with combination of 0.2 % mercuric chloride and 25% sodium hypochlorite, showed the highest aseptic culture establishment. Early response for sprouting and bett9r culture establishment of rhizome segments were observed on Murashige and Skoog (MS medium) medium with 5 mgl-1 BAP with presence or absence of IAA. The maximum shoot length was observed full MS media contain 5 mgl-1 BAP with 0.1 mgr 1 IAA. Though there was no leaf formation in semisolid media, 3-4 leaves per plant was observed in liquid media. Maximum number of leave were produced in liquid MS media contain 3 mgl-1 BAP with 0.1 mgl-1 IAA and 5 mgl-1 BAP . But the shoot length of liquid agitated culture was less than semi solid culture. The study on surface sterilization of Lagenandra lancifolia revealed thato, explants treated with combination of 0.2 % mercuric chloride and 20% sodium hypochlorite, showed the highest aseptic culture establishment. Shoots sprouted only on full MS liquid media contain 5 mgl-1 BAP within a period of six weeks. Key words — Explant sterilization, Growth regulator, in vitro propagation, Lagenedra species
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    Impact of Thermocline Variability on Yellowfin Tuna Catch Rates of Sri Lankan Long-Liners
    (Uva Wellassa University of Sri Lanka, 2013) Sinhakula, S.M.B.
    Tuna fishery is an important source of income to Sri Lanka, having a greater potential for development. Yellowfin tuna is a major species, exported to Japan and EU countries. Harvest of yellowfin tuna is associated with the thermocline layer and its seasonal changes, causing vertical migration is considered as an important parameter to ensure fishing efficiency. The objective of the present study was to investigate the influence of vertical structure. of temperature to catch rates of longline fishery. Temperature-depth 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 800-1000. 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 close to buoy-line is —70 m and —100 m 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 effoA was ranged between 15-70 (kg/1000 hooks) and thermocline depths varied between 100-125 m with corresponding temperatures varied between 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. Keywords: Yellowfin tuna, Thermocline, Longline, Temperature—Depth recorders
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    A STUDY ON THE EFFECT OF DIFFERENT LEVELS OF HEAT ON THE QUALITY OF DARK AND LIGHT MUSCLES OF YELLOW FIN TUNA (Thunnusalbacares)
    (Uva Wellassa University of Sri Lanka, 2013) JAYASINGHE, L.L.S.L.
    Yellow fin Tuna (Thunnus albacares) belongs to the family Scombridae is a highly demanded fish in all over the world. It is composed of both dark and light muscles that are different in physical and chemical quality. Dark muscle portion is removed at the fish processing operations as a by-product. It is important to add value to these by¬products to make optimum use of the harvested fishes. These muscles may show different quality changes with exposure to heat. Therefore it is very important to know the quality changes of YFT muscles when undergo thermal preservation techniques prior to make further decisions on value addition. Scope of this study was to evaluate the effect of different levels of heat treatments on the physical, chemical and organoleptic properties of YFT Dark and Light muscles. Fresh dark and light muscles were significantly different (p<0.05) in protein content, pH, water holding capacity and lightness (L*). Water holding capacity, lightness (L*), moisture and protein contents of both muscles are affected by different levels of heat (p<0.05). pH, water soluble protein and fat contents are affected by heat depending on the muscle type. Frying caused a greater water loss compared to other heat treatments (approximately 30% in dark muscle and 25% in light muscle). Frying treatment is recommended for dark and light muscles according to organoleptic properties. It can be concluded that light muscle is more susceptible to heat than dark muscle. Further improvements have to be made to dark muscle to develop a value added product. Key words Dark muscle, Heat treatments, Light muscle, Yellow fin Tuna (Thunnus alba' cares)
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    PRODUCTION OF SIMULATED CAVIAR USING READILY AVAILABLE FISH SPECIES
    (Uva Wellassa University of Sri Lanka, 2013) ABEYRATHNA, I.G.S.N.K.
    Simulated caviar or imitation caviar is defined as salted roe that comes from a fish other than the sturgeon. Fish roe is removed as a by-product and doesn't have a high demand at present. Therefore it is important to add value to fish roe which is low demand. As a commercially significant freshwater fish species in inland fishery sector, Mrigal (Cirrhinus mrigala) was selected as resource fish species for experiment 01 and marine fish species, Yellow fin tuna (Thunnus albacares) was selected for experiment 02. Roe samples of both species were subjected to "Dry salting" method and three different salt (g): fish roe (g) ratios as 0.05:1(S1), 0.25:1(S2) and 0.45: 1(S3) were used to determine the best ratio. Yellow fin tuna roe was subjected to three maturity stages while three different salt ratios were used for each maturity stage and finally selected three samples with different salt (g): fish roe (g) ratios as 0.05:1(S1), 0.05:1(X1) and 0.25 :1(Y2) after microbial analysis and pH test, sensory and proximate analysis. For experiment 01: Highest protein content is recorded for S2 treatment, while maximum lipid percentage is recorded for Si treatment. Moisture content of three samples were statistically different when compare to each other. pH changed significantly with storage time.TPC was not changed significantly only in S3 with the time. Highest sum of rank for four sensory parameters were recorded for S2 treatment. Therefore S2 treatment (0.25 salt: 1 fish roe) can be considered as the best treatment for preparation of simulated caviar using Mirigal roe. Foe experiment 02: Chemical composition significantly different according to maturity stages at 0.05 levels. Highest protein content, lowest TPC and best consumer preference for all sensory parameters are recorded for X1 treatment. Production cost of X1 is low due to less salt requirement. Therefore X1' (0.05 salt: 01 fish roe by weight) with eggs of half maturity stage can be considered as the best method for preparation of simulated caviar from Yellow fin tuna roe.
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    A REVIEW OF EXPORT TRADE OF INDIGENOUS FRESHWATER FISH SPECIES IN SRI LANKA. AND THEIR CONSERVATION ISSUES
    (Uva Wellassa University of Sri Lanka, 2013) FERNANDO, M.S.R.
    Ornamental fish are exported to 71 countries around the world. Many species of fresh water fish in Sri Lanka are collected from wild habitat for ornamental fish export trade which causes a series conservation issue on the particular endemic freshwater fishes. Present study was intended to analyze and evaluate the trade of freshwater fish in Sri Lanka with a particular focus on endemic species. Data on the freshwater fish species subjected to ornamental export trade and their quantities were extracted from 3037 Customs Goods Declaration Forms submitted by the ornamental fish exporters to the Air Cargo Terminal in Katunayake under the Department of Sri Lanka Customs during the period of 1st September 2012 to 31st August 2013. During the one year period total of 29 fish species under 15 families were collected from freshwater habitats for the export from Sri Lanka. Among the total, 18 species were indigenous, 10 species Endemic, 3 salt dispersants and one were exotic and the most common species exported was the Garra ceylonensis, and Anguilla bicolor was the species exported in least quantities. When considering the foreign exchange G. ceylonensis has earned highest amount while Devario pathirana were has brought least earnings. Total income generated from the ornamental fish trade during one year period was SL Rs.1, 069,066,413 and contribution of endemic freshwater fish was 0.001% with compare to total earnings of ornamental fish trade. Among more than 200 exporters who registered in Sri Lanka Customs for the export of ornamental fish, only 15 exporters were exported endemic freshwater fishes. According to present study there are no any exporters who practicing captive breeding and do 100% wild collection of endemic fishes. Therefore endemic freshwater fish trade is in the declining trend and due to the lack of involvement of government authorities in the development of sector almost due revenue which can generate from the trade is lost. For sustainable management of this resource need the collaboration of each and every shareholders who are involving in the ornamental fish industry. Key words — Conservation, Endemic, Export, Freshwater fish, Revenue