Research Symposium-2015

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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.
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.
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.
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.
Consumption pattern of fish among households in Batticaloa District
(Uva Wellassa University of Sri Lanka, 2015) Komahan, S.; Sivarajah, P.
Fisheries sector in Sri Lanka provides livelihood for more than 2.5 million coastal communities as well as providing more than 50% of animal protein requirement of people in the country (NARA, 2012). The fact that fish is relatively cheap compared with meat, beef, mutton, poultry, and pork, which also contains protein of high biological value tends to make it preferred to other sources o f animal protein (Adeniyi et al., 2010). In Batticaloa District presence of a long seacoast and the mile long lagoon provides a good fishing environment. It leads to high availability and production of both inland and marine fish (Dist. Planning Secretariat, 2013). About 85% of people in Batticaloa District consume fish as their major protein food (Devadawson and Jayasinghe, 2014). Therefore, this study was designed to determine the quantity of fish consumed, expenditure on fish and preferences for various fish varieties by households in Batticaloa District. Methodology Data related to frequency of fish purchases, price of different fish varieties, preference of fish varieties and other fish purchasing details were collected from 120 respondents at 3 rural and 3 urban markets in 6 DS Divisions in the Batticaloa District. Purposive sampling technique was used to select the respondents and a pre tested and well-structured questionnaire was used to collect data. The data was analyzed using SPSS Ver.22.0 software. Result and Discussion The data revealed that the majority of the respondents (66%) were consuming both marine and inland fish varieties, while 24% of the respondents consume marine fish only and 10% consume inland fish only. It was also evident from the data that about 34% of the respondents had some specific reasons for the avoidance of certain fish types in their meal. Avoidance of marine fish varieties in fish purchase occurs only due to the high market price compared to inland fish. In case of inland fish avoiders, 82% of them avoid due to the unfavorable odor emanating during the cooking process, 62% of them avoid due to polluted and unsatisfactory sanitary conditions prevalent in fishing areas and rest (13%) avoids inland fish due to unpalatable taste. In purchasing fish about 26% of the consumers considered only the desirable characters of fish, around 68% considered both price of fish and fish characters equally and only 6% considered the price of fish in purchasing decisions. Freshness of fish is the important fish character considered in fish purchasing. Around 97% of consumers were very specific about the freshness of fish they purchase. About 60% consumers were concerned about taste of the fish they purchase and 43% of consumers concerned about the allergic condition of fish to their family members and a quarter of the respondents (28%) pay attention to the appearance of the fish which include firmness of flesh, bone content and thickness of skin.
Development of a suitable culture media for mass culture of Moina macrocopa
(Uva Wellassa University of Sri Lanka, 2015) De Silva, G. N. M.; Jayamanne, S. C.; Chandrarathna, W. P. R.
Two experiments were conducted to develop a suitable method for culturing Moina macrocopa in National Aquaculture Development Authority (NAQDA) at Rambadagalla. Experiment 1 was conducted to find out possible culture media and to determine its concentration for mass culture. Experiment 2 was conducted to find out the best culture medium and its concentration for mass culture of Moina macrocopa. All bottles and tanks used in experiments were cleaned, drained and sun dried for two days and then filled with water, left for two days before using. Moina macrocopa for all experiments were taken from stock culture developed in NAQDA Centre at Rambadagalla. Pure culture of Chlorella vulgaris (1×10 cells per 1 ml) was acquired from NAQDA Centre at Rambadagalla. Filtered tap water was used in both experiments. In experiment 1, five culture media; mineralized cow dung, steamed cow dung, 15 min. boiled chicken manure, 30 min. boiled chicken manure, and 1 hr. boiled chicken manure were prepared with four different concentrations such as 5 . Different concentrations with various media tested with and without adding Chlorella into the medium. As control, a medium only with Chlorella and water was maintained. Three replicates from each treatment were maintained during experiment. Five individuals of Moina macrocopa were inoculated into each bottle. After that, top of the bottles were covered with a mosquito net to prevent entrance of undesired insects. They were allowed to stay 10 days and after that data were collected. Three samples from every tank were collected using 3 ml of fine dropping pipette. Samples were taken from the surface to bottom at three random points. Collected data (number of Moina macrocopa ) were analyzed using Minitab 16 software with ANOVA, general linear model. According to the results of experiment 1, the positive culture media and their concentrations were used in experiment 2. Selected treatments were prepared as same as in experiment 1. 150 individuals of Moina macrocopa were introduced into each tank. After ten days, 25 ml samples were taken as earlier and preserved using two drops of 1.007 g cm Lugol’s solution. Values of all tanks were recorded. Data were analyzed as in experiment 1. Results and Discussion According to the preliminary experiment, there was a significant relationship between number of Moina macrocopa and culture medium (p<0.05). There was a significant relationship between medium and concentration to the number of Moina macrocopa (p<0.05). There were no results of of mineralized cow dung media. There were no results of Moina macrocopa in 15 g l and 20 g l of steamed cow dung media. Those media may be not favorable for growth of Moina. There were no results found in 15 min. boiled chicken manure and 30 min. boiled chicken manure media. The major reason for boiling chicken manure is to prevent the Salmonella effect. Low time duration for boiling might be not enough for destroy the undesirable pathogens. There may be not a favorable environment for growth of Moina macrocopa in both of those media.
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.
Development of garment leather from Yellowfin tuna (Thunnus albacares) skin
(Uva Wellassa University of Sri Lanka, 2015) Eakanayake, E.M.B.S.; Jayamanne, S.C.; Wickramasinghe, W.
Leather is defined as hide or skin with its original fibrous structure more or less intact, tanned to prevent putrefaction (Covington, 2009). Due to tanning, skins that have been processed to prevent putrefaction retain its characteristics such as flexibility and toughness. Hides and skins from cattle, buffalo, sheep, pig, goat, horse, crocodile, snake and fish are used for leather production. When considering the fish leather, fish skins are used for production of leather after tanning and re-tanning processes. Texture of fish leather depends on pocket size of the scales. Presently, carp, pacific salmon, bass, sturgeon, shark, tuna, catfish, salmon, tilapia and several other fish species are taken for leather production. Garment leather is tanned with chrome and treated with softeners. The quality of the garment leather should be thin enough to use on garments and it should feels softer and smoother than any other types of leather. These types of leathers are made from the top-grain of a hide. Good stitch tensile strength and light weight are some other characters of garment leathers. Cow hide and skins from deer, pig and lamb are commonly used for garment leather manufacturing. But there is a potential to develop garment leather from fish skin similar to other garment leathers. The present study was carried out to add value to waste generated during the Yellowfin tuna (Thunnus albacares) fish processing and promote a fish leather production in Sri Lanka through developing garment type leather using discarded skins. At present, hides and skins from cattle, buffalo, sheep and goat are used for leather production. In addition, fish species including carp, pacific salmon, shark, tuna, catfish and tilapia are taken for leather production in the world. The objectives of this study were to find out the best fat liquor percentage to obtain maximum softness of chrome-tanned Yellowfin tuna fish leather and to find out the best tanning method for garment leather production from Yellowfin tuna skin. Methodology The current study was carried out at the tannery of Ceylon Leather Product PLC (CLP), Mattakkuliya. Tuna skins were collected from the processing factory of Jay Sea Food (Pvt) Ltd in Ja-Ela. Two experiments were carried out to find out best fat liquor concentration and best tanning method. In experiment 1, yellowfin tuna skins were treated with 33% basic chromium sulphate and five different concentrations (12%, 14%, 16%, 18% and 20%) of fat liquors (on weight of pelt). In experiment 2, yellowfin tuna skins were treated with four different tanning methods (Full chrome tanning, full vegetable tanning and two types of semi chrome tanning methods - vegetable tanned skins directly tanned with chrome and vegetable tanned skins tanned with chrome after stripping with NaHCO3). Before initiating the experiments pre-trial was conducted to find out the optimum conditions for liming. Six pieces of raw skins were immersed in solutions of 0.25%, 0.5% and 1% Na2S, 6% Ca(OH)2 and 200% water (on weight of skins). One day after, skins were taken out and scales and flesh were removed. Then, skins were kept for another 5 days in a new 6% Ca(OH)2 solution. Weight and the physical conditions (scale pockets, colour and plumpness) of the skin were observed daily. After identifying the optimum conditions for liming 40 skins were subjected to 8 production process steps (liming, de-liming, pickling, tanning, basifying, fat-liquoring, fixing, drying and dying). Experiment 1 was done in fat-liquoring step and experiment 2 was done in tanning step. Then, the dried leathers were dyed and waxed. Finally softness, feel, tensile strength, tear strength and stitch tear strength were measured in developed leathers. Physical evaluation was done to check softness and feel by ten expertise. Tensile strength, tear strength and stitch tear strength were done using universal testing machine. This experiment was designed according to Complete Randomized Design (CRD). The collected data were analyzed using Friedman test and one-way ANOVA in MINITAB 16 and SPSS 22 statistical analyzing software to find out the significant difference between treatments. Mean separation was done using pairwise comparison.
Development of micropropagation protocols for two aponogeton species of Sri Lanka (Aponogeton crispus and Aponogeton natans)
(Uva Wellassa University of Sri Lanka, 2015) Amarawansha, T.W.G.J.C .; Bambaranda, B.V.A.S. M.; Jayamanne, S.C.; Herath, H.M.I
Sri Lanka being a tropical country contributes for a highly diversified flora and fauna. These climatic conditions have become a critical factor for the occurrence of highly diversified aquatic flora as well. Aponogeton is genus of aquatic plants which belongs to the family Aponogetonaceae. Methodology The study was carried out at tissue culture laboratory of Royal Botanic Gardens, Peradeniya. Mother plants were collected from different areas of Sri Lanka. Experiments were done to determine hormonal effect on shoot initiation and multiplication using rhizomes of Aponogeton crispus and A. jacobsenii; leaf and leaf stalks of A. natans and A. jacobsenii and seeds of A. crispus and A. natans. For the Sterilization of A. crispus and A. jacobsenii rhizomes were kept under running tap water for 3 hours and dipped in a fungicide for 30 minutes. Then disinfected using 20 % NaOCl (Clorox) with 2 drops of Tween twenty for 10 minutes and washed with 0.1 % HgCl2 for 7 minutes. Finally rhizomes were washed 5 times thoroughly with distilled water per 5 minutes. For seeds sterilization seeds were kept under running tap water for 10 minutes, disinfected using 5 % Clorox with 2 drops of Tween twenty for 15 minutes and washed 3 times with distilled water. Three sterilization procedures were carried out for leaves and leaf stalks. Firstly leaves kept under running tap water for 1 ½ hours and dipped in fungicide (topsin) for half an hour.
Development of Tomato (Solanum lycopersicum) Incorporated Fish Nuggets
(Uva Wellassa University of Sri Lanka, 2015) Perera, R.W.M.E.D.; Abeyrathne, E.D.N.S.; Lalantha, N.
Modern consumers prefer processed foods and the changes in consumer life styles have resulted in increasing demands for ready-to-eat and ready-to-cook seafood products (Venugopal, 2005). But due to high post-harvest losses and busy life style fish consumption has reduced gradually in Sri Lanka. Therefore value added fish products have become familiar among most consumers (Sri Lanka Fisheries Year Book, 2009). Fish nuggets are formed meat product in ready-to-cook form and it is a good substitute for above situations. Most of the people nowadays concern more about their health and prefer to have healt hier diets. Tomato is considered as one of the healthiest vegetable and fruit in the world (American Cancer Society, 2014). Tomato contains carbohydrates and several vitamins such as Vitamin A, Thiamine, Niacin, Vitamin B6, Vitamin C and Vitamin E. In addition, tomatoes possess one of the most powerful antioxidants, lycopene (Choski and Joshi 2007; Kavanaugh et al., 2007). It has shown a wide variety of positive health benefits, including a reduced risk of cancer (American Cancer Society, 2014). Therefore tomato incorporated fish nuggets contain more health benefits and deliciousness due to incorporation of tomato. On the other hand, the production of value added fish products using locally available resources is important for the wide range of consumers and manufactures and it is also important to fulfill the market gap by production of healthier fish based formed meat product in ready-to-cook or ready-to-eat forms. The objective of this research is to develop a tomato (Solanum lycopersicum) incorporated fish nugget with higher levels of antioxidants. Methodology Initially, the basic composition of fish nuggets was determined. The ingredients for fish nuggets were identified and new recipes were formulated based on different fish percentages (30%, 35%, 40% and 45%). After production fish nuggets, a sensory evaluation was carried out using 10 trained panelists to find the best combination. For selection of the best heat treatment for tomatoes, keeping qualities (pH, titratable acidity, moisture content and salt content) and sensory qualities of different heat treated tomato pastes were evaluated. Boiling (10 min, 100 C), microwave-cooking (50 s, 800 W) and steaming (10 min) were selected as the best heat treatments (Kamiloglu et al., 2013). After selecting the best heat treatment for tomatoes, the best level of tomato paste to be incorporated in to the selected fish nugget recipe was determined by a sensory evaluation. Tomato paste was incorporated at 5%, 8%, 12% and 15% (w/w) (Deda et al., 2007). Tomato incorporated fish nugget and fish nugget without tomato incorporation (control) were further analyzed for its physicochemical properties and microbiological quality. Proximate composition, pH value and water holding capacity of the final product were determined. Microbiological analysis was done for Escherichia coli, Staphylococcus aureus, Total Plate Count (TPC) and Yeast and Moulds. Sensory data were analyzed according to the Friedman test using MINITAB 15 software package. Data obtained from melting tests were analyzed by analysis of variance using MINITAB 15 software package. Results and Discussion 45% fish incorporated fish nugget sample was selected as the best sample. According to the sensory evaluation, there was significant difference (p˂0.05) among treatments. Then 45% fish incorporated fish nugget sample was used as the control. According to another sensory evaluation and keeping quality evaluation, boiling (10 min, 100 C) was selected as the best heat treatment for tomato paste. The results of the above mentioned sensory evaluation showed that there was significant difference between different heat treatments of tomato paste related to the quality parameters such as appearance/ color, aroma flavor/ taste and mouth feel (p<0.05). According to the results (Figure 01), there was significant difference between fish nugget samples with different tomato incorporation levels related to the organoleptic properties such as appearance, color, taste, texture and overall acceptability (p<0.05). Finally 12% tomato incorporated fish nugget sample was selected as the best.
Effect of growth regulators on in-vitro multiplication of Lagenandra ovata and Lagenandra lancifolia
(Uva Wellassa University of Sri Lanka, 2015) Senavirathne, W. M. A.; Bambaranda, B. V. A. S. M.; Jayamanne, S.C.; Krishnarajah, S. A.
Sri Lanka is a country which consists with number of endemic aquatic plants. These endemic aquatic plants are having high demand in aquatic plant industry (Galapitagedra, n.d.). Due to the lack of effective propagation methods plant collectors collect plant from wild to fulfill the market demand. It leads to the depletion of natural plant stock and bio diversity. Lagenandra species only can observe in Sri Lanka, Southern India and Bangladesh (Dassanayake et. al., 2001). In Sri Lanka there are seven species and six species are considered as endemic. Red List of International Union for the Conservation of Nature in 2013, categorized five of those endemic species under the highly threatened category. Main purpose of this study is to develop a proper method for micro propagation of Lagenandra ovata and Lagenandra lancifolia to overcome inadequate supply and depletion of natural plant stock. Present study was carried out to evaluate effect of different hormone concentrations in basal media for shoot initiation and multiplication of rhizome explants,to identify the best explant of L. lancifolia for micro propagation and to identify the best medium for L. ovata seed culture.
Evaluation of the attitude and awareness of the international resolution on responsible fishing: a case study on the multiday fishermen of Matara
(Uva Wellassa University of Sri Lanka, 2015) Dilini, K.L.N.; Wickramaratne, I.U.; Liyanage, N.P.P.; Gunawardane, N.D.P.
E longitudes. This island has approximately 1700 km long coastline and sovereign power for the 21,500 km territorial sea and an Exclusive Economic zone (EEZ) of 517,000 km (MFAR, 2013). Therefore fisheries industry significantly contributes to the food security and the foreign exchange earnings of Sri Lanka. This IUU fishing is a serious threat to the sustainability of fisheries in both national jurisdictions and high seas. Therefore regional resolutions are implemented by the Indian Ocean Tuna Commission (IOTC) to reduce these IUU fishing activities. Although there are laws and regulations, many problems in the fisheries sector are caused due to lack of awareness of fishermen regarding these implemented national and international laws. Therefore identification of awareness of fishermen on these laws and regulations are very important before the implementation of awareness programs. This study was done with the objectives of investigating international resolutions which highly impact to Sri Lankan fisheries sector, investigate responses of fishermen on international resolutions, identify and suggest procedures which can improve the awareness and behaviors of fishermen on international resolutions. Keywords: Illegal Unreported Unregulated (IUU) fishing, Indian Ocean Tuna Commission (IOTC), International Resolutions Methodology Matara fisheries district was selected as the research area. The sample for the case study was selected from multiday boat owners, crew members, skippers and other service providers of Matara fisheries district through the Stratified random sampling. The sample size was determined using “Moving average method”. Data was collected from both primary and secondary sources. Primary data was collected from selected sample, through the questionnaire and interviews. The questionnaire was prepared using international resolutions which developed by the IOTC. Both open ended questions and closed ended questions were included in the questionnaire. Secondary data was collected from sources of Department of Fisheries and Aquatic Resources and IOTC web site. Collected data was analyzed using “Likert method” (Likert, 1932) and one way ANOVA (Analysis of Variance) at 95% significant interval. “Minitab 16” software was used for analyzing all the collected data. Results and Discussion The sample size was selected as 105. According to the finalized results of the study, total mean of awareness and attitude regarding these international resolutions is 3.38 ± 1.58. It means that the level of awareness and attitude of fishermen of Matara fisheries district on these international resolutions are medium. The statements used for the questionnaire have derived from the IOTC resolutions (IOTC, 2013). The current awareness of stakeholders on these international resolutions is helped to keep the Sri Lankan fishermen under the international resolutions. It helps to enhance the acceptance for Sri Lankan fish and fish products in the international market. Not only that but also the awareness on some resolutions are directly influenced on the management of fishery resources. The community has a high level of knowledge (3.67 ≤ Mean Likert scale ≥ 5.00) on the statements of importance of registration of fishing vessel, importance of having a flag in the fishing vessel, importance to mark vessels according to the regulations (Resolution 01/02 relating to control of fishing activities), importance of establishing a vessel monitoring program (Resolution 06/03), idea about prohibition of bottom trawling and crossing sea boundaries without proper permission, requirement of permission from the department for landing harvest at another country or for exchanging harvest with the foreign vessels at sea (Resolution 12/05 on establishing a program for transshipment by large scale fishing vessels), prohibition of catching endangered shark species and sea turtles (Resolution 12/09 on the conservation of Thresher sharks and Resolution 12/04 on the conservation of marine turtles) and preference of carrying equipment in the vessel which was used for catching sea birds and sea turtles. The registration of fishing vessel and vessel marking according to the regulations are already in place in the national regulations (1980). Therefore all of them have to comply with the registration of fishing vessel and marking them according to the regulations for having other subsidies and insurance. The awareness was medium (2.34 ≤ Mean Likert scale ≥ 3.66) on the statements of importance of maintaining a log book on board (Resolution 01/02), the requirement of providing information about harvest to the Department of Fisheries, willingness to support the government officers, agree to carry a department officer as an observer when they request, importance to inform navigation path for the department or harbor (Resolution 05/03 and Resolution 10/11). According to the attitude of some stakeholders, it is difficult to carry a department officer as an observer due to the limitation of space in the vessel and several other difficulties. The idea of some skippers was important to maintain a log book to have an idea in future regarding places and time of high densities of fish. It was considered as an additional trouble for their hard occupation by others. According to the responses of stakeholders, there are some people who unable to keep records on this log book due to inability of writing. The overall awareness was very low (1.00 ≤ Mean Likert scale ≥ 2.33) on the statements of international trade barriers which are occurred to Sri Lankan fisheries sector due to the ignorance of international resolutions, prohibition of large scale driftnets on the high seas in the IOTC area (Resolution 12/12), closed area (Resolution 12/13). With the high sea fishing operation license, printed material including the statements regarding the Resolution 12/12 has received by the boat owners. Therefore regarding the prohibition of large scale driftnets on the high seas, there was awareness among some people specially with the boat owners and skippers. But even the response of these people was not agreed with the idea. According to them, 2.5 km length gill nets are not enough to recover their fuel cost. The awareness of fishermen was very low regarding the closed area (Co- North, 40 - 60 East in the Indian Ocean during February month) for fishing (Resolution 12/13 for the conservation and management of Tropical Tunas stocks in the IOTC area of competence). Therefore the overall response for a closed area was seriously disagreed. But some of the stakeholders believe it is necessary to have a closed area for the sustainability of fishery resources.
A Geographic Information System (GIS) approach in identification of the potential reservoirs for Giant Freshwater prawn (Macrobrachium rosenbergii) culture: A case study in Moneragala district, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2015) Nisansala, R.A.C.; Rathnayake, R.M.C.W.M.
Culture Based Fishery (CBF) is a better approach to overcome poverty and malnutrition in Moneragala District since the district is enriched with large number of village reservoirs and minor perennial reservoirs. Introducing a valuable, high demanding and protein rich species such as Giant Fresh Water Prawn (Macrobrachium rosenbergii) through CBF is the best way to get the maximum utilization of these natural resources. Current practice of stock enhancement of Macrobrachium rosenbergii in reservoirs has resulted a heavy loss of stock and low returns. Therefore it needs a careful selection of potential reservoirs prior to stocking of post larvae. As a tool in decision making, Geographic Information System (GIS) is still a new concept for CBF in Sri Lanka for aquaculture planning. The main intent of this study was to highlight the role of GIS in identifying potential reservoirs for stock enhancement of Macrobrachium rosenbergii under inland CBF in Moneragala District, Sri Lanka by developing a map. Methodology Nineteen minor perennial reservoirs distributed over nine divisional secretariat divisions in Moneragala District were visited during the dry season as the sample. Climate (Rainfall, Temperature), Bio-physical (Elevation) and Water quality (pH, Temperature, Hardness, Alkalinity, Dissolved Oxygen, transparency) and Socio-economic factors (proximity to roads and village, land use, poverty and population) were identified as influential factors for Macrobrachium rosenbergii culture based fishery. Data were collected from field surveys and responsible government institutes. Water quality parameters were tested on site and the university laboratory. In order to generate thematic layers for above each factors Interpolation techniques were applied for climate, elevation and water quality data; Population and poverty were considered in respective to DS divisions; multiple ring buffers were created for the proximity factors. Each factor was classified according to four suitability scales; very suitable, suitable, moderately suitable and unsuitable. Land use types in the district land use map were classified according to their suitability. Factors were ranked according to their relative influence on Macrobrachium rosenbergii fishery and weights were assigned according to their relative influence using the method of “Rank Sum”. Finally, all thematic layers were integrated in ArcGIS 10.1 (Esri, 2012) environment to generate the potential map. Results According to the resulted map (Figure 1) unsuitable areas occupy about half of the extent of the district. If potential reservoirs for Macrobrachium rosenbergii culture were indicated in respective to DS divisions, Badalkumbura, Moneragala, Wellawaya, Medagama and Sevanagala divisions were resulted as highest potential areas. Thanamalwila, Bibile, Madulla, Buttalaand Siyambalanduwa divisions were resulted as Suitable areas and Latter part of Madulla was indicated as Moderately suitable area.The district can gain more benefits by stocking M. rosenbergii in reservoirs that fall in most suitable areas.Since the water quality parameters were given the highest weight final result has high influence by water quality factor. Results are basically applicable to the dry season which is the period that water quality data were collected. According to the field observations dry season is not favorable for CBF. Application of CBF at present is not in a satisfactory level with compared to the existing number of reservoirs.Potential areas resulting from multi-criteria evaluation (MCE) are mostly associated around the reservoirs where the optimum water quality for M. rosenbergii culture exists. Results could be advanced by tallying the obtained results with catch data of Giant Prawn as some reservoirs are already practicing prawn culture, but lacking of accurate catch data was a limitation for the research.
Induced breeding of Silver Dollar (Metynnis hypsauchen) using ovaprim
(Uva Wellassa University of Sri Lanka, 2015) Kodisinghe, K.A.J.L.; Jayamanne, S.C.; Abeysinghe, A.H.M.S.S.K.
Production of ornamental fish is a rapidly growing sector of the aquaculture industry (Tlusty, 2001). Among the ornamental fish production in Sri Lanka, exotic ornamental fishes have a significant demand in the market.Silver Dollar (Metynnishypsauchen) which was originated from South America is such kind of exotic ornamental fish in Sri Lanka that a higher demand has been achieved. Silver Dollar is not breeding very often in Sri Lankasince it takes a longer spawning period. To avoid that problem, the fish can be bred artificially. Among all the artificial breeding methods, induced breeding by hormone administration is the most reliable method (Yanong, et al., 2013). In this study attempts were made to develop induced breeding of Silver Dollar (Metynnis hypsauchen) in Sri Lankan environmentusing inducing hormone “Ovaprim”. Materials and method Sexually matured and healthy Silver Dollar brooders were selected based on the external features. Eighteen pairs in same age were randomly collected and conditioned. Then Ovaprim as a single dose and 0.6 mlkg of body weight was administered to the brooders. Natural spawningwas also allowed without inducing by Ovaprim as a control. After the hormonal injection, the best range of Ovaprim dose to have least response time and better breeding performance of Silver Dollar was determined based on response time (hours). Relative fecundity, post mortality rate of brooders and water quality parameters in experimental tanks were also monitored.Data analysis was done by one way ANOVA and Tukey test. Results and Discussion The effects of different doses on the breeding performance of Silver Dollar are shown in Table 1.Salmon gonadotropin releasing hormone analogue sGnRHa (Ovaprim) successfully induced spawning in Silver Dollar (Metynnis hypsauchen). Five different Ovaprim doses supported the spawning activity and the breeding performance was favored by lower and middle inclusion level of Ovaprim dose in the experiment. Ovaprim is a well-known commercial spawning aid which is mostly used in induced breeding of fish (Anonymous, 2012). It has been used in successful manner for several fish families (Hill et al., 2005). In the present study,all the brooders spawned, except the brooders which were injected with 0.6 ml
Isolation and incorporation of Nitrogenous compounds from Yellow Fin Tuna (Thunnus albacares) to produce a fish flavored vegetable burger
(Uva Wellassa University of Sri Lanka, 2015) Jeewantha, P.D.A.; Abeyrathne, E.D.N.S.
Fish processing industry is increasing continuously in the world Thunnus albacares is a one of the major fish used bymany processing companies. Value added products are produced using tuna which include tuna steaks, tuna loin, tuna fillets, tuna blocks and canned tuna. At processing, trimmings are resulted as waste and discharged without any utilization. Hence, maximum utilization of fish waste is important. There are many nitrogenous compounds present in fish flesh. Nitrogenous compounds play an important role in flavor and taste of fish. Fish flavor components are non-protein-nitrogen trimethilamines, trimethilamonia bases (trimethylamine oxide and betaines), and guanidine derivatives such as creatine and argenine (Teerasuntonwat and Raksakulthai, 1995).Soya bean and chick pea can be used to produce vegetable burger sinceboth contain high amounts of protein. Soya bean contains 38% to 42% protein (Balasubramaniyan and Palaniappan, 2004). Chickpea has significant amounts of all essential amino acids and is rich in nutritionally important unsaturated fatty acids such as linoleic and oleic acid (Jukanti, 2012).The objectives of this study was to find out the ways to maximize the utilization of fish waste generated in fish processing industry and to use them to extract flavor compounds in order to incorporate it in to a vegetable burger. Methodology Vegetable burger was prepared using soya and chick pea as the main ingredients. Dried soya bean was steamed at 80°C for 20 minutes and ground using a grinder (IS 4250,Jaipan family mate, India). Weighed ingredients were mixed and the pulp was made. Prepared mixture was then cooked in a steamer (WP5525, WIPRO, China) at 80°C for 20 minutes. Ingredients level of the burger was determined by preliminary sensory evaluations keeping soy and chick pea flour levels constant. For determination of best combination of soya and chick pea flour, 5 recipes of vegetable burger were prepared by decreasing the soya level from 100% to 0% and increasing the chick pea level from 0% to 100% while keeping the other ingredients constant. Thirty untrained panelists were used to select the best formula for the burger. Fish flavor was extracted according to the method of Teerasuntonwat and Raksakulthai (1995) with some modifications. Yellow fin tuna trimmings were cut in to small pieces and ground using the grinder (Jaipan family mate) with 1% (w/v) NaCl (Fluka, England). Blended samples were transferred in to a 1000 mL beaker (PYREX, England) and heated at 60°Cfor 15 minutes using a stirrer (SR No:67702, VELP® SCINTIFICA, Europe). Heated samples were filtered using Whatman No: 4 filter papers. Filtration was dialysised to remove salt. Extracted fish flavor was kept under freezing condition and used instead of water (28%) in vegetable burger preparation. For determination of best concentration to extract volatile compounds series different concentrations (w/v) of NaCl (0.1%, 1%, 5% and 10%) were prepared. Vegetable burger was prepared using the recipe developed and separated dialysis solutions. Best NaCl concentration was determined by a sensory evaluation test using 30 untrained panelists. Sensory evaluation data were statistically analyzed using non parametric Friedman test in Minitab 16. Lipid oxidation, pH value and proximate composition were determined in triplicate during 30 days of storage at 4°C.Microbiology tests were done for Escherichia coli, Salmonella, Staphylococcus and total plate counts. Crude protein, crude fat, moisture and ash contents of fish flavored vegetable burger were analyzed using AOAC standard methods (2002) with some modifications. The cost of product was calculated for the best treatment selected from the final trial.
Preliminary study on mangrove diversity in Irakkandy lagoon, Trincomalee
(Uva Wellassa University of Sri Lanka, 2015) Krishnanantham, K.; Jayamanne, S.C.; Seneviratne, Y. B. M. C. J.
The term ‘mangrove’ describes both the ecosystem and the plant families that have developed specialized adaptations to live in the tidal environment (Tomlinson, 1986). Preliminary study on diversity of the mangrove stands at Irakkandy lagoon (Trincomalee) was investigated to document the status of the mangrove forest and the mangrove distribution in relation to the soil salinity variation. Due to the past two decades war dilemma and present developmental activities increase the pressure on mangrove ecosystem at an alarming rate Eastern region of Sri Lanka. In addition, Tsunami has collectively contributed to the destruction of mangroves at large in the Eastern province. In this backdrop, this research aims to analyse the diversity of mangrove in the Irakkandy lagoon which further attempts to provide some suggestions to protect mangrove and its ecosystem. Methodology Fifteen transect lines were laid perpendicular to the shore in different sites of the lagoon and sampling was conducted from May 2014 to July 2014 at selected locations. The precise locations were determined by portable GPS unit (ETREX 10) and hydro physico-chemical parameters of each site were recorded over high tide and low tide. Whilemeasuring the mangrove diversity, Temperature and pH were checked using Multiple Test Kit (Thermo scientific) and turbidity was measured using Turbidity meter (Hach model (2100q)) in Nephelometric Turbidity Units (NTU). Salinity was measured using a Refrectrometer (Erma Hand Refractometer, Salinity: 0-100) in units parts per thousand (ppt). Data on floristic composition was identified using standard identification keys. Moreover height of the species was measured by Suunto Clinometer. Three soil samples were collected along the transect line of each site from the edge of the lagoon to end of the mangrove existence. Soil salinity was calculated according to Gibbs, 2000. Shannon-Wiener diversity index and Pielou’s eveness index incorporated in the Primer software version 6.1.2 and Minitab ver.16 used for data analysis and statistical analysis. Results and Discussion Five different true mangrove species and nine mangrove associate plants were identified from the study site. Avicennia marina was the dominant species with Height (H) of 1.392.54m followed by Lumnitzera racemosa (3.131.92m), Excoecaria agallocha (3.282.662 m), Rhizophora apiculata (3.28 4.79m) and Heritiera littoralis was found as rare species with Height of (5.27 2.21m) respectively.
A preliminary study on the effectiveness of organic fertilizers for the survival rate of Catla catla
(Uva Wellassa University of Sri Lanka, 2015) Prabhani, K.G.M.; Liyanage, N.P.P.; Somarathna, K.M.D.M.
Fish can be considered as one of the main sources of animal protein (26.2%) in human diet (Khan et al., 2004). Fish also become a popular source of food in Asia and developing countries. Both aquaculture and fisheries activities conducting in marine and inland waters, cater the protein requirement of people in Sri Lanka. Indian and Chinese Carp species are commonly used today in inland aquaculture. Catla catla (Catla) is a zooplankton feeding Indian major carp species which was introduced to reservoirs in Sri Lanka to uplift the inland fishery production. This species has become a very popular fish species among the fish farmers due to higher growth rate, ability to co-exist with other major carps and consumer preference. Aquaculture Development Center (AQDC), Udawalawa belongs to National Aquaculture Development Authority (NAQDA) is producing fish seeds of carp species including Catla, for the development of inland aquaculture and fisheries. The problem identified in fish seed production in the AQDCs was the low survival rate of Catla at rearing of post larvae (PL) to fry stage. Moreover, it was observed that survival rate in mud ponds is lower than the survival rates in cement tanks. In the AQDC Udawalawa, cow dung is commonly used for fertilization of rearing tanks and ponds. This study was carried out to find out what the best effective organic fertilizer for the higher survival rate and growth of Catla catla. Cow dung, Leucaena leucocephala (Ipilipil) and Oriza sativa (rice) straw were selected as organic fertilizers as they are of low cost and readily available in the area of the study. Materials and Methods The experiment was conducted in nursery ponds (mud ponds) and nursery cement tanks in AQDC, Udawalawa. A mud pond and a cement tank which were already fertilized during five days (as normal practice in the AQDC) using cow dung (250g/m ) were selected and plankton densities (individuals per liter) were recorded by assuming ponds were reached optimum plankton density. Mean value of those densities was calculated and used as baseline value. Dried cow dung (250g/m ) was selected as control for the study as it was the normal practice in the AQDC. Rice straw (30g/m ) and dried Ipilipil (30g/m ) were the selected treatments for the study. These are the commonly used fertilizer concentrations in the field. Initially, the time taken to reach the plankton density to the baseline value was recorded for Rice straw and Ipilipil fertilizer types. The surrounding of three mud ponds was cleaned and four hapa net cages were fixed to the bottom of the three mud ponds to prepare four replicates. All the four replicates were fixed in same way to maintain the same volume of water. Firstly the ponds were filled up to 50 cm with water. Complete Randomized Design (CRD) was conducted as the experimental design. Four days old PL in a single cohort, who spent seven days in hatchery were stocked in the morning in cement tanks and hapa net cages in mud ponds. The recommended stocking density in tanks and ponds was 250-300 PLs per square meter (FAO, 2014). Three hundred PL were stocked in cement tanks per square meter and 250 PL per square meter were stocked in hapa net cages in mud ponds. Altogether 54 000 PL were stocked in nine cement tanks including 6 000 PL in each tank (20 m ) and 6 000 PL were stocked in 12 hapa net cages fixed in three mud ponds including 500 PL in each cage (2 m ). Harvesting of fry (2.5 cm) was done after three weeks rearing time period. Total length (TL) and weight were measured weekly using randomly taken samples (10% of population) of PLs from each tank and happa, until harvesting. Analytical balance (±0.001 g) was used in measuring the weights of PL. Venire caliper (±0.01 cm) was used for measuring the total length of PL. Average weight and average TL was calculated using the data obtained. Temperature and pH were measured daily using electronic pH meter and thermometer. Dissolved oxygen (DO) level was observed using Winkler method to keep the treatment units at the optimum DO level during the study period. Secchi disk values were taken weekly by using secchi disk. Percentage survival rate, percentage weight gain (PWG) and percentage length gain (PLG) were calculated (Okunsebor and Ayuma, 2011). Obtained data were analyzed using analysis of variance (ANOVA) using the General Linear Model (GLM) procedure of MINITAB 16 and Excel 2010 office package. Results The highest value of survival rate could be observed in the treatment of rice straw as 80.02 % (< P = 0.05) in cement tanks. The highest value of survival rate in mud ponds could be observed in the treatment of rice straw as 36.45 % (< P = 0.05). The highest percentage length gain (PLG) (309.29±2.50 cm) and the highest percentage weight (PWG) gain (4667±252 g) were observed in the treatment of rice straw in cement tanks (P <0.05). Further the highest PWG (14950±173) and the highest PLG (305.73±2.60) were observed in the mud ponds fertilized by rice straw (P < 0.05). In considering the values of plankton count, the highest mean value of phytoplankton number in cement tanks could be observed in the ponds fertilized by cow dung (control). The lowest mean value was observed in the ponds fertilized by rice straw. In mud ponds also the same results were obtained at the date of stocking PL for rearing up to fry. The highest zooplankton count in cement tanks could be observed in the ponds fertilized by rice straw while the lowest value was observed in the ponds fertilized by rice straw. In mud ponds also the highest zooplankton count was observed in the treatment of rice straw at the date of stocking PL. As Catla catla was a zooplankton feeder the highest survival rate, the mean values of highest PWG and highest PLG were observed in the treatment unit of rice straw that included highest zooplankton amount in the water. The highest zooplankton amount in the water could provide more live feed and it might be the reason for the highest survival and growth of fry at harvesting. The highest secchi disk value was observed in the treatment of rice straw throughout the study period in both cement tanks and mud ponds. Discussion European Inland Fisheries Advisory Commission indicates that turbidity can have a harmful impact on freshwater fish by reducing food supplies and affecting gill function, killing them or reducing their growth rate, preventing successful development of fish egg and larvae and affecting the efficiency of methods for catching fish (MPCA, 2008). Very high phytoplankton blooms create high turbidity and it causes negative effects on survival of larvae. In this study also shows that both cement tanks and mud ponds fertilized by rice straw shows lower phytoplankton and higher zooplankton community. Fluten et al. 2002 found that feeding and growth rates reduced due to more turbid water. The lower turbidity could be observed in the treatment of rice straw than two other treatments. Catla PL can easily find out their live feed in low turbid water. It was commonly found copepods, daphnia and rotifers as zooplankton in water sampled in the mud ponds and cement tanks fertilized by rice straw.
A review of export trade of indigenous aquatic plants species in Sri Lanka and their conservation issues
(Uva Wellassa University of Sri Lanka, 2015) Bandaranayake, R.D.C.; Bambaranda, B.V.A.M.S.; Jayamanne, S.C.; Niyarepola, R. D. A. M. G.
Aquatic plants are adapted to aquatic environments and are required special adaptations for living submerged in water or at the water’s surface. In addition to various ecological and industrial values, most of aquatic plants are having ornamental value. Due to the ornamental value of the aquatic plants, they have a huge demand and are exported from Sri Lanka. Along with ornamental fish industry, aquatic plants are introduced and exported as a simultaneous industry. Present study was intended to analyze and evaluate the trade of ornamental aquatic plants in Sri Lanka with a particular focus on indigenous species. The objectives of the study are determine the exported species and their quantities, the actual foreign exchange earnings, identify the conservation issues related to indigenous species, identify the trends to occur irregularities in exportation procedure and propose suitable. Materials and Methods Exported aquatic plants species data and their quantities were extracted from the Customs Goods Declaration Forms (CusDec) submitted by the ornamental aquatic plants exporters to the Air Cargo Terminal in Katunayake under the Department of Sri Lanka Customs. The Customs Goods February 2014 were analyzed. A questionnaire was also used to gather information regarding the conservation issues through ornamental aquatic plants exporters, Custom officers at frontier and local villagers. Results and Discussion February in 2014, a total of 218 species of aquatic plants has been exported to 43 countries from Sri Lanka. Among the total, 176 species were indigenous, 1 species was endemic. When considering the total quantities of exported indigenous aquatic plants during the one year period, the most common species exported was the Dracaena sanderiana white (168185 individuals) and Lobelia cardinalis “small leaf”(4 individuals) was the species exported in least quantities. During the one year study period, 1504531 individuals of aquatic plants and 2047620 all types of live plants have been exported from Sri Lanka. When considering the proportions of species exported during one year period, the endemics consist of 0.04% (685individuals) and other indigenous species consisted of 80.91%(1217353individuals) among all other aquatic plants. The proportion of indigenous aquatic plants species consisted of 59.45% and endemics consisted of 0.03% among exported all types of live plants from Sri Lanka. And the proportion of exported aquatic plants to all live plants is 73.47% from Sri Lanka during my study period.
Seashell processing: An emerging industry in Kinniya divisional secretariat division of Trincomalee district
(Uva Wellassa University of Sri Lanka, 2015) Sajitha, A. H.; Geretharan, T.
The seashell processing industry functions by grinding the seashells for production of lime for building construction purposes and for making poultry feed (Fisheries Year Book, 2007).The low income people in the Kinniya Divisional Secretariat (DS) division collect seashells to earn money for their daily living. The people who are engaged in this industry earn sufficient income (Sunday Observer, 2012). Seashell deposits are available in Kakkamunai village of Kinniya DS division, which is located closer to the mouth of Thampalagamam Bay, which is enriched with bivalves. Shell mining has taken place for last three decades in a sustainable manner. There is a high demand for shells from the poultry feed industry, thus generating a good income from this activity (Minerals Year Book, 2007). In this context a survey was carried out to study this emerging industry in Kinniya DS division of Trincomalee district. Methodology This study was carried out during the months of April and May, 2014 in ten villages in Kinniya DS division. Using random sampling procedure, a total of 90 seashell processors were selected, which includes collectors, grinders, transporters, loaders and mill owners and a structured interview schedule was used to collect the information through personal interview at their home and seashell processing mills. Collected data were analyzed using the SPSS package. Result and Discussion Personal and socio-economic characteristics of seashell processors in Kinniya DS division of Trincomalee district revealed that all the seashell processors (100%) were males. Young age and middle age categories were same (40%). 80% were under primary level of education. Majority (68.9%) of the respondents depended mainly on seashell industry. More than half (54.5%) of seashell processors belonged to medium income group of Rs.20, 000 to Rs. 40,000 per month. Majority of respondents (87.8%) were part time workers. Majority (85.6%) of respondents had 5 to 10 years experience in seashell processing. Only 11.1% respondents had organizational membership; because the mill owners only had the membership with social organizations. The seashell processors have not participated in any extension activity related to seashell processing. All the respondents (100%) indicated that seashell collection was the most difficult work in seashell processing. Among the people who involved in seashell collection, most of them obtained medium income of Rs.1000 - Rs.1500 per day. Most of people who involved in seashell grinding obtained high income (Rs. 420 per bag) from seashell grinding per day. Majority (91.1%) of the respondents involved in seashell industry were rural people. All the respondents (100%) were in the view that the overall business condition of the industry is good. All (100%) of respondents reported that the ground seashell bags were marketed directly to the consumers. The demand for ground seashells is high in Kurunagale district. Kandy, Matala, Puttalam, Kalutara, Colombo, Avissawella and Galle are the other places getting ground seashells from Kinniya mills.
Study of water quality changes and growth of cultured edible oysters (Crassostrea madrasensis), culture sites at Gagewadiya and Kandakuliya in Puttlam district
(Uva Wellassa University of Sri Lanka, 2015) Wijayananda, H.I.; Rajapaksha, R.M.G.N.; Liyanage, N.P.P.; Kithsiri, H.M.P.; Corea, S.; Rupika, G.R.H.; Fernando, U.; Dejager, T.
Global bivalve production from aquaculture has consistently increased over the years. Sri Lanka is a country which has vast natural resources and suitable environmental conditions for aquaculture. Therefore it has a great potential for develop and contribute to national fish and shellfish production. Although the bivalve industry is highly developed industry in East Asian region finfish and shellfish, specially mollusk and sea cucumbers cultures are at very initial stage in Sri Lanka (Samarasundera, 2010).Sustainable utilization of unexploited high demand finfish and shellfish species are a good alternative to develop the industry. Oysters are nutritious, still unexploited fishery resources in Sri Lanka. Which has good export demand worldwide. Although Sri Lanka have required resources naturally to uplift the industry in large scale, lack of information, limited supply of seeds and lack of trained personals are act as major constraints (FAO, 2006). The success of bivalve culture greatly depends on suitable environmental factors that ensure both optimal growth and quality as well as ensure food safety (FAO, 2006). Kandakuliya and Gagewadiya areas are blessed with natural oyster resources but which are not used commercial scale at present. Therefore the two locations have significant possibility to conduct oyster culture in large scale which providing self-employment opportunities for fisher communities. The study of water quality changes and growth of edible oysters (Crassostrea madrasensis) culture, sites at Gagewadiya and Kandakuliya in Puttlam district was carried out to investigate the possibility of establish these culture in commercial scale. Methodology The research project was conducted in two experimental sites (Gagewadiya and Kandakuliya), locates in Puttlam district, Sri Lanka. Field data were collected during October 2013 to July 2014from pre- establish two experimental culture sites. There were four sampling points in each site separately K1, K2,K3, K4in Kandakuliya and G1, G2, G3, G4in Gagewadiya. Water quality data, growth data and phytoplankton data were collected each site separately. Water quality and phytoplankton data were collected twice a month, and growth data were collected once a month during the studied period. Temperature, pH, salinity, transparency were recorded as onsite measurements. Further analysis were conducted for nitrite, nitrate, phosphate and ammonia using DR-4000U spectrophotometer according to standard procedures of Parsons et al., 1984. Unionized ammonia levels were calculated using total ammonia levels. Phytoplankton samples were collected using phytoplankton net (50 µm mesh size).The samples were examined under light microscope and identified to genus level using identification keys (Newell and Newell, 1963; Rebert, 2003; Swadling, 2008; Verlencar and Somshekar, 2004).Length (distance between the end of umbo and the ventral shell margin) and width (length at the widest axis of the body) were taken as growth parameters. Twenty five C. madrasensis organisms were used to take measurements from each site separately, for the growth study. Both primary and secondary data were used to analysis. Secondary data were taken from IDRC oyster research and culture programme. Minitab 16 statistical package was used to data analysis. All data were analyzed statistically using one way ANOVA (Turkey test) for all selected locations. Person product movement correlation coefficient analysis was done between water quality parameters and growth of oysters to find whether there were significant relationship between those variables.

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Browsing Research Symposium-2015 by Subject "Aquaculture and Fisheries"

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