Research Symposium-2016

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The Aspects on Reproductive Biology of Blue Swimming Crab Portunus pelagicus, (Linnaeus, 1758) in Mannar Area
(Uva Wellassa University of Sri Lanka, 2016) Abeygunawardana, A.P.; Jayamanne, S.C.
Blue swimming crab fishery is a newly emerging export oriented fishery in North and North-Eastern provinces of Sri Lanka. Since the exploitation is heavy in these areas establishment of management strategies are important for sustainability of the fisheries. Hence the aspects on reproductive biology such as maturity stages, pre-spawning and post spawning fecundity, size at first maturity and gonadosomatic index of the Blue swimming crab (Portunus pealagicus) in Mannar area were studied during the period, May to July, 2015. The fecundity was estimated using Gravimetric method. Six ovarian development stages, immature, developing, early Mature, late mature, ripe and spent were identified in non ovigerous crabs and five ovarian development stages, light yellow ovaries, pale yellow ovaries, pale orange ovaries, black colour ovaries and grey colour ovaries were identified in ovigerous female crabs. The size at first maturity was determined as 57.5 mm carapace length and carapace width 113.50 mm. The pre spawning fecundity estimates ranged from 105874 to 516000 in the crabs of 133 mm to 158 mm carapace width. The post spawning fecundity estimates ranged from 537600 to 1739000 in the crabs of 121 mm to161 mm carapace width. The pre spawning fecundity and the post spawning fecundity showed positive correlations with the carapace width, carapace length and the body weight (P<0.01). The Gonadosomatic Index of the female crabs varied from 0.94+0.0208 in immature crabs to 30.6 +0.8048 in matured crabs. More than 80 % of the catches contained immature crabs while percentage of ovigerous females was 8%. High exploitation of immature crabs and ovigerous crabs may have serious impacts on the sustainability of the Blue swimming crab fishery in future. Keywords: Carapace length, Pre spawning fecundity, Post spawning fecundity, Reproductive biology.
Determination of a Suitable Hardening Medium for Micropropagated Anubias nana
(Uva Wellassa University of Sri Lanka, 2016) Kumari, A.M.S.M.; Jayamanne, S.C.; Chandrarathna, W.P.R.
Most of aquatic plant varieties are used in aquariums as ornamental plants due to their aesthetic and ecological value. The genus Anubias of the family Araceae is considered as one of the highly demanded plant types among other aquatic plant species. Among Anubias varieties, A. barteri var. nana is considered as a most cultivated and commercially important species. Micropropagation is currently applied to this plant as a tool for large scale multiplication of plants since the planting material has a very low multiplication rate. However, the high rate of mortality experienced by micro propagated plants during or following laboratory to outdoor transfer is still existing as a major limitation in large scale applications. Therefore, it is a requirement to develop an effective acclimatization procedure for a successful establishment and survival of plantlets. The present experiment was carried out in order to determine a suitable hardening medium for micropropagated Anubias nana using complete randomized design. The study was conducted at the Ornamental Fish Breeding and Training Centre, Rambadagalle. Four weeks old uniform sample of in vitro rooted Anubias nana plantlets were hardened by using five different potting media. Coir dust, coconut husks, clay brick shards, boggy soil and sand were used as different hardening media/treatments. Each treatment was replicated ten times. Every plantlet was provided with a constant amount (N: P: K-4:2: 1) of a commercial fertilizer in once a week. The performances of plantlets were measured by using survival rate and growth in each treatment. The measured growth parameters were number of roots and leaves, length of roots and leaves, fresh weight and dry weight of plantlets after 6 weeks of hardening period. Data were analyzed by using one way ANOVA and Tukey's test. The maximum survival percentage (100%) was obtained in coir dust, clay brick shards and sand. Out of five treatments of media, a significant difference (p<0.05) of root growth was shown by plantlets in coconut coir dust and sand. A significant difference (p<0.05) of leaf growth and weight was reported in plantlets in clay brick shards media. Keywords: Anubias nana, Micropropagation, Hardening
Development of A Fish Burger Incorporating Sea Lettuce (Ulva lactuca) and Catla (Calla calla)
(Uva Wellassa University of Sri Lanka, 2016) Kumarathunge, R. N. C.; Abeyrathne, E.D.N.S.
Catla fish has limited scope for consumption due to presence of intermuscular bones. This investigation was carried out to develop high protein and fiber containing ready to eat catla fish burger, incorporating seaweed (Ulva lactuca). Control fish burger was prepared without adding seaweed. Recipe development was carried out with different levels of spices. Suitable amount of spices were determined by preliminary trials. Four different levels (0.5%, 1%, 1.5% and 2%) of Ulva lactuca powder were tested. On the basis of sensory evaluation results; 0.5% (w/w) incorporated seaweed sample was found suitable due to significance difference (p<0.05) in taste, color, flavor, appearance and overall acceptability. Cooked burgers were packed in polyethylene bags in safety manner for further use. Proximate analysis revealed that seaweed incorporated fish burger contains higher amount of protein and fiber compared to regular fish burgers. Color of the burgers treated with seaweed (Ulva lactuca) showed significant difference for a* value compared with control. Shelf life studies were carried out by using microbiology and pH tests. The present study of seaweed incorporated fish burger showed slightly increased in pH from 5.47-6.47 up to 14th day where no significant increase observed (p>0.05). When pH of the control burger ranging from 6.16-6.6 stored at freeze temperature (-18°C). E.coli and Salmonella they did not present in the both seaweed incorporated and control burgers which were negative in samples because of the hygienic preparation, handling ofproduct and it is not subjected to cross contamination. Proximate composition of seaweed incorporated catla fish burger recorded as 62.83%, 16.25%, 2%, 12.43%, and 7.21% respectively for crude moisture, protein, fiber, fat and ash. It can be concluded that 0.5% (wlw) Ulva lactuca incorporated fish burger increase not only the protein and fiber content but also it fulfil the nutritional requirement of consumer. Keywords: Fish burger, Catlacatla, Seaweed powder; Ulva lactuca
Development of a Fish Paste Incorporated with Mature Flower Buds of Rhizophora apiculate as a Nutritional Supplement
(Uva Wellassa University of Sri Lanka, 2016) Tharaka, T.H.S.; Abeyrathne, E.D.N.S.
Indian carps (Catla catla) are considered as an excellent source of high proteins, vitamins and minerals and they are low in saturated fats. However, carps have limited consumer acceptability due to presence of intramuscular bones. Recent studies showed that mangroves provide priceless therapeutic agents in both modern and traditional medicines systems. Present study was conducted to develop a value added fish paste incorporating mature flower buds of Rhizophora apiculata which can be used as a nutritional and medicinal supplement. Fish paste was prepared mixing with boiled and minced fish with adequate amounts of other ingredients. Finally, it was pasteurized at 85°C for 15 minutes. Preliminary investigations were conducted to determine the suitable levels of all ingredients with 30 untrained panellists. According to the results, 89% (w/w) of catla, 6% (w/w) of mature flower buds of Rhizophora apiculata, 1% (w/w) chili, 1% (w/w) salt, 1.5% (w/w) white pepper and 1.5% (w/w) lime juice were determined as the best (P<0.05). Proximate analysis showed that final product contained 72.5010.03%, 20.8211.49%, 2.8110.02%, 2.1010.11% and 1.9410.01% of moisture, protein, fat, fiber and ash, respectively. Shelf life studies of bread spread were carried out using microbiological and pH tests. In addition pH of the fish paste did not change significantly during the storage period of 30 days under refrigerated condition (p>0.05). According to the microbiological observations, total coliform and Salmonella were absent while total plate counts were within the acceptable level for 28 days. Therefore the developed fish paste can be considered as a safe food for the consumers up to 28 days which can provide high nutritional and medicinal benefits. Keywords: Catla catla, Bread spread, Rhizophora apiculata, Sensory evaluations, Shelf life studies
Development of a Simple and Economical Method for Chitin Extraction from Prawn (Penaeus monodon) Shell Waste
(Uva Wellassa University of Sri Lanka, 2016) Wehella, M.N.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N. S.
Chitin is the second most important biopolymer on earth and found mainly in invertebrates and several other organisms. It exhibits a wide range of applications in biotechnology, medicine, agriculture, food processing, environmental protection and textile industry. Disposal of shell waste is a major problem in relevant processing plants. Objective of this research was to develop a simple, economical, high yielding, non-toxic and cost effective method for chitin extraction from prawn (Penaeus monodon) shell waste. Samples were collected from a local prawn processing plant and crude chitin was obtained through deproteinization, decolourization and demineralization using NaOH, butanol and citric acid respectively. Crude chitin was then converted in to chitosan by deacetylation. Purity analysis, yield analysis, physiochemical and functional properties analysis such as moisture content, Water Binding Capacity (WBC), Fat Binding Capacity (FBC) and Ce chelating activity were measured. Control was prepared using 5% (w/v) NaOH, 100% (vlv) Acetone and 1% (vlv) HC1 solution. FBC and WBC of the present study showed significantly higher values (539.20 ± 0.40', 560.00 ± 0.23') than those of control (304.66 ± 0.23', 285.06± 0.40"), respectively (p<0.05). However, results of the yield analysis did not show a significant difference between the developed method (32.40 ± 0.01) and the control (24.80 ± 0.08). A low purity value (10%) for crude chitin was showed by the developed method compared to prepared control (25%). However, OP chelating activity was significantly higher in the developed method (51%) compared to prepared control (-16%). Observations obtained in the 3 step extraction process suggested that butanol and citric acid were the most suitable chemicals compared to acetone and HC1. WBC, FBC and chelating activity of chitosan extracted by the present method can be involved in many applications. In contrast to previous studies, the present research showed that the suggested method is a simple way to extract chitin. Keywords: Chitin, Prawn shell, Demineralization, Decolourization, CeChelating activity
DNA Fingerprinting of Thunnus obesus and Thunnus albacores Fish Species for Proper Identification in Large Scale Fish Processing Industry
(Uva Wellassa University of Sri Lanka, 2016) Perera, D.R.C.; Gunathilaka, P.A.D.H.N.; Rodrigo, W.W.P.; Athapaththu, A.M.M.H.; Bulumulla, P.B.A.I.K.
Detection of species substitution has become an important topic within the food industry and there is a growing need for rapid, reliable, and reproducible tests to verify species in commercial fish and seafood products. The effects of species substitution are far-reaching and include economic fraud, health hazards, and illegal trade of protected species. In Sri Lanka tuna fish industry is a rapid developing field. However, the species identification prior to the processing is achieved through morphological characteristics, which is not a reliable method. Therefore, the aim of this study was to develop a diagnostic method by combining Polymerase Chain Reaction with Restriction digestion to differentiate Thunnus obesus (bigeye tuna) and Thunnus albacores (yellowfin tuna) species in order to facilitate the fish processing industries and fish exporters by developing the test for species confirmation. Deoxy ribonucleic acid (DNA) extracted from muscle tissues of T obesus and T albacores were analyzed. DNA was amplified using primers flanking a region of cytochrome b gene of 558 by and digested using two restriction endonucleases, EcoNI and Scat A product having band sizes of 187 by and 371 by was observed from T albacores after digesting with EcoNI. The digestive product by Scal resulted 215 by and 343 by band sizes for both T albacores and T obesus. The polymorphism of DNA profiles obtained by restriction digestion was used to differentiate the T albacores and T obesus species. Therefore, the current study carries a reliable approach to identify and distinguish T obesus and T albacores from the other tuna species. Keywords: Tuna species, DNA extraction, Polymerase chain reaction, Restriction Enzyme digestion
Effect of Diets Incorporated with Dried and Autolyzed Shrimp Waste on Growth Performance of Goldfish (Carassius auratus)
(Uva Wellassa University of Sri Lanka, 2016) Rathnayake, R.M.C.P.; Liyanage, N.P.P.; Athula, J.A.; Guruge, K.P.G.K.P.; Senaarachchi, W.A.R.K.
The shrimp processing industry turns out tons of head, tail and shell waste every year and this is a rich source of protein that could be used to prepare aquaculture feeds. The efficiency of different methods for extracting protein from shrimp waste were observed. This study has been designed to assess the possibility of partial replacement of fish meal with shrimp waste in diets formulated for goldfish. Known amount of shrimp waste samples were subjected to autolysis and subsequently subjected to oven drying and make fine powder. Crude protein, crude lipid, ash and moisture were estimated for both autolysed and powdered dried shrimp waste (purchased from Agri-Star Compost private limited). Two different diets were prepared by incorporating autolysed shrimp waste powder and dried shrimp waste powder as supplementary source of protein. Commercial feed that contains 42% protein was used as the control diet. Uniform sized glass tanks were stocked with twenty individuals with an initial mean weight of 0.13 f 0.00 g per tank. Fishes were hand-fed daily three times per day for 30 days with three diets. Wet weight of the fish were measured weekly. Feed Conversion Ratio (FCR), Specific Growth Rate (SGR), Protein Efficiency Ratio (PER) and Condition Factor (K) were calculated for each diet. The highest protein level (65.55%± 0.60) and lowest ash level was observed (11.35% ± 0.03) in autolysed shrimp waste. Significantly higher SGR, PER and survival rate (91.25% + 3.15) were observed in individuals fed with diet incorporated with autolysed shrimp waste while significantly low FCR was observed in the same (P<0.05). Condition Factor was not significantly changed among the test diets (P>0.05). The findings of this study indicate that autolysis is the best method to extract protein form shrimp waste. During the process of autolysing meat part was detached from the shell and extracted to the aqueous medium. This process will facilitate to collect comparatively pure source of protein with compared to the dried shrimp meal. Therefore, autolyzed shrimp waste powder that contains significantly higher protein percentage can effectively enhance the growth parameters while use as protein supplement in the diet of goldfish. Keywords: FCR, SGR, Fish feed, Fish nutrition, Ornamental fish.
Effect of Frying in Different Cooking Oils on the Fatty Acid Profile and Sensory Characteristics of Tilapia (Oreochromis niloticus) Fillets
(Uva Wellassa University of Sri Lanka, 2016) Fernando, N.F.K.R.; Thushari, G.G.N.; Jayasena, D.K.D.D.
Fish is one of the most abundant sources of essential fatty acids. Among many fish species, Nile tilapia (Oreochromis niloticus) is a popular culture species in aquaculture industry and they heavily contribute to the worldwide fish consumption. Fish is mainly consumed in fried forms in many countries and the alterations in the fatty acid composition during frying process may have significant effects to human health. This study was performed to determine the effects of frying with three different cooking oils (soybean, sunflower and coconut oil) on the fatty acid profiles and sensory characteristics of tilapia fillets. Fish were purchased from local fish shop in Badulla and transported to the university laboratory under chilled condition. Tilapia fillets were deep fried in the three different cooking oils separately and the fatty acid composition of each group was evaluated using gas chromatography. The fat content of the fillets increased after frying in all evaluated samples (P<0.05). Mean saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, Total (E) -3 and E-6 contents of raw fillets were 43.2610.55, 29.9011.26, 26.3111.65, 15.4311.17 and 10.8810.53%, respectively. Frying led to exchange of fatty acids between the tilapia fillets and cooking oils. As a result of interactions, PUFA, E-6 and PUFA/SFA ratio of samples fried in soybean and sunflower oil significantly increased while the amounts of SFA decreased (P<0.05). Frying had a negative effect on the E-3, EPA and DHA amounts in all fried samples. E-6/-3 ratio was optimum in soybean oil fried samples while sunflower and coconut oil fried samples values were not in the recommended level to health. Frying with coconut oil showed high SFA, MUFA and low PUFA levels among all samples. in concern to sensory results, both sunflower and soybean oil-fried samples obtained positive results. By considering all the facts, soybean oil can be considered as the best cooking oil to fry tilapia fillets. Keywords: Tilapia, Deep frying, Soybean oil, Coconut oil, Fatty acids
Effectiveness of Ultraviolet Filtration of Incoming Sea Water for Controlling Vibrio spp. in Shrimp Hatcheries in North Western Province
(Uva Wellassa University of Sri Lanka, 2016) Pathirana, I.P.D.H.; Rajapakshe, R.M.G.N.; Jayamanne, S.C.; Ranathunga, R.M.N.P.K.
Vibrio spp. are natural micro flora that presence in marine waters are one of the main factors which responsible for larval mortality of penaeid shrimp. To avoid bacteriological problems, shrimp hatcheries adopt extensive water treatments which include effective ultraviolet filtration. But there the effectiveness of UV filters is a considerable problem. Therefore effectiveness of UV filtration of incoming sea water for controlling the Vibrio spp. and the management procedures that can be implemented for improving the efficiency of UV filters were studied. Ten shrimp hatcheries out of forty seven hatcheries in north western province of the country were selected. Sea water samples were taken before and after the UV filtration and were subjected to the Total Vibrio Count (TVC) test. Thiosulfate Citrate Bile salt Sucrose (TCBS) agar was used as the culture medium and pH, salinity, Ammonium-N, Nitrate-N, Nitrite-N were checked. Questionnaire survey was also conducted for collecting information regarding water treatment systems, disinfection procedures and the factors affecting on the efficiency of UV filters. According to this study there is a significant difference by considering the TVC among hatcheries and between the TVC of sea water before and after UV filtering. It was observed that salinity and pH have no significant effect on the TVC. According to questionnaire survey, although each hatchery uses the UV bulb capacities which are relevant to the water flow rates by considering the water usage volume, the effectiveness of UV filtration is not in an efficient level when comparing the mean values of TVC of sea water before and after UV filtering. According to Chi square Goodness of fit test, availability of charcoal filters, maintaining the records of hours of UV filter operation, replacing UV bulbs after its life time and routine changing of filter media in sand, charcoal and cartridge filters have significant impact on the TVC of UV filtered water. Therefore productive maintaining of the filter system is very important for the effectiveness of UV filtration. Keywords: Water quality, Shrimp disease, Bacteriological problems, Water treatments, UV filters
Efficacy of Aloe vera Against Aeromonas hydrophila in Gold Fish (Crassius auratus)
(Uva Wellassa University of Sri Lanka, 2016) Dissanayaka, D.M.S.G.; Jagoda, S.S.S de S; Wijesundera, R.R.M.K.K.
Sri Lanka is a pioneer county of ornamental fish industry. Guppy, Goldfish, Swordtail, Moly are some fresh water fish species which have high export potential. Disease is one of the major constraints to the development of the ornamental fish industry and bacterial infections are very common in ornamental fish. Herbal medicines have become cheaper and better alternatives to antimicrobial drugs to treat bacterial infections in fish. Therefore, this experiment was conducted to determine the efficacy ofAloe vera for gold fish growth and against artificially injected A. hydrophila. A. hydrophila was isolated from a septicaemic fish and the identity was confirmed through conventional bio chemical tests and Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR¬RFLP). Fresh and mature A. vera leaves were used for the experiment. Antibacterial efficacy ofA. vera was tested in in- vitro by using A. vera supernatant. To examine in- vivo antibacterial efficacy, A. vera supernatant was combined with commercial fish feed and three different A. vera concentrations, i.e; 250 g/kg, 500 g/kg and 750 g/kg were used with a control. According to the results, there was a positive effect of A, vera against A. hydrophila in-vitro. Original A. vera supernatant had the highest inhibition zone in-vitro. Inhibition zone diameter was decreased with increased dilution. When consider about the in- vivo method, a noticeable increase in body weight and Feed Conversion Efficiency was observed as the A. vera concentration in feed goes up, though the values are not statistically significant. Different levels of mortalities were observed in all groups, but the highest mortality within the observed period was recorded in control group and the lowest in the group fed with highest A. vera concentration. Keywords: Bacterial infections, PCR- RFLP, Feed conversion efficiency, Antimicrobial drugs, Ornamental fish industry.
An Evaluation on Fisher Women Contribution for Household Economy in North-western Province of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2016) De Silva, D.W.L.U.; Sandaruwan, K.P.G.L.; Wimalasena, H.D.
The fisheries sector is concerned as a sector that has high gender discrimination all over the world because it is highly dominated by males. However, a fishery woman provides a significant contribution for the wellbeing of their family which is not clearly visible. This study was conducted to assess the level of contribution of fishery women to the family economy. The study was carried out in North western province (NWP) and relevant data were gathered by administrating a pre tested questionnaire during the year 2014. The total sample was 197. Data were analyzed using SPSS ver.20. Although women engagement in active fishing at the sea was nil, with aquaculture marginal (only 2%) they provide supportive services such as net clearing and sorting of fish. These services are not earned direct income but save Rs. 25,492 for their family in a year. Dried fish production and selling as well as fresh fish selling were major income earning activities of fishery women in NWP and earned annually Rs. 5,460 and 10,920 respectively. Hence, fisher women have contributed Rs. 41,872 annually to their family income by cash or non-cash form. Keywords: Barriers, Empowerment, Economic contribution, Fisher women, North western province
Examine the Appropriate Ovulation Time to Determine Latency Period of Golden Tinfoil Barb (Barbonymus schwanenfeldii) Using OvaprimTM
(Uva Wellassa University of Sri Lanka, 2016) Isharini, W.A.U.; Epasinghe, E.D.M.; Karunaratne, T.A.D.W.; Adikare, A.M.A.N.; Liyanage, N.P.P.
Fertility of the Golden Tinfoil Barb is very low when they are subjected to induced breeding practices. The research was carried out to determine the appropriate ovulation time for maximizing the fertility rate of Golden Tinfoil Barb, Barbonymus schwanenfeldii. Induced spawning of Barbonyms schwanenfeldii was conducted at different Ovaprim (sGnRHa and Domperidone) dose and latency period combinations to observe the appropriate ovulation time to increase the fertility. For the purpose, three doses of Ovaprim (0.4, 0.6 and 0.8 mL/kg of body weight) and three latency periods (4, 6 and 8 hours) were considered in nine combinations. Males were injected with half of dosage from female. Induced of breeding was carried out in the hatchery and same water source was used for maintaining the equal condition. After the injection, biopsy tests were performed for all the females after 4, 6 and 8 hours from the injection to detect the moment of ovulation. After eight hours, mean egg diameter was 982.81 ± 48.49 vm, germinal vesicle had broken down, follicle had already removed and ovulation had occurred. When ovulation was observed, hand stripping and then artificial fertilization was carried out. One hour after fertilization, between 40 and 60 eggs of three samples were taken from the hatching jar for each dosage and eggs were counted to calculate percentage of fertilization. Although all ovulation times were recorded in approximately eight hours after the injection, the recorded fertility rates were different. 4% fertility rate was recorded with the 8 + 2.0 hours in 0.4 mL/kg, while it was 80% with the 8 ± 0.5 hours in 0.6 mL/kg of Ovaprim and fertility rate was 52% when 8 ± 0.5 hours in 0.8 mL/kg. The highest fertility rate was recorded in 0.6 mL/kg of dosage. Although 8 ± 0.5 hours ovulation time was recorded in 0.6 mL/kg and 0.8 mL/kg of body weight of female, their fertility rates were different. Keywords: Fish breeding, Egg diameter, Hand stripping, GnRH, Fertility rate
Identification of Factors Affecting the Survival of Lobster Exports Industry in Sri Lanka with Special Reference to Spiny Lobster
(Uva Wellassa University of Sri Lanka, 2016) Chamodika, L.P.S.; Jayamanne, S.C.; Duminda, T.G.A.
At present there are five main species of Spiny Lobsters exported from Sri Lanka. There are controversial findings regarding lobster resource and it is required to know the current status of the lobster resource in Sri Lankan oceanic waters. Thereby the status of lobster fishery and exports industry as well as the factors affecting the survival of lobster exports industry in Sri Lanka are required to be identified. The present study was carried out to fulfill this requirement. Questionnaires and direct interview methods were used to obtain the relevant information from the exporters, lobster fishermen, lobster purchasing centers and collectors. Lobster export data and catch data were analyzed by using MS Excel. Information related to legal aspects and other stock assessment projects related to lobsters were obtained from Ministry of Fisheries and NARA. Currently, Panulirus longipes is the mostly exported lobster species and it accounts for 30.4% of total lobster exportation. Panulirus ornatus is nearly overexploited. Panulirus polyphagus has completely vanished from Sri Lanka. Panulirus ornatus fetch the highest price in the export market (US$ 701Rs. 8200 per Kilogram). Highest lobster production and export quantity as well as the highest export value were earned in 2013. Availability of the lobsters in the ocean around Sri Lanka, laws and regulations, political influence, Scuba divers & other recreational divers, problems faced by the lobster fishermen, problems faced by the exporters, illegal activities done by fishermen, collectors and exporters are the factors affecting the survival of lobster exports industry in Sri Lanka which were identified from the present study. Some of these factors affect positively on the survival of lobster exports industry while other factors affect negatively on the survival of this industry. Relevant authorities should take steps to protect this lobster resource while providing opportunities to the fishermen, exporters and local consumers to use the resource in a sustainable manner. Keywords: Lobster export industry, Lobster production, Stock assessment
An Investigation of the Economic Impact on Fishing Communities in Mannar District Caused by Illegal Fishing by Indian Trawlers in Sri Lankan Waters
(Uva Wellassa University of Sri Lanka, 2016) Sosai, B.M.K.; Wickramaratne, I.U.; Jayamanne, S.C.
Mannar district is located in the Northwestern Sri Lanka (8° 52' 0" N, 80° 4' 0" E). Thalaimannar, Pesalai, Vankalaipaadu, Erukkalampiddy, Pallimunai, Panankaddikoddil, Thalvupadu in Mananr District were selected for the study. Primary data were collected through a questionnaire survey and direct interviews with fishing community leaders, officials of department of fisheries, fishing agents and traders. Information on fishing season (charts), monthly income, the relative impact of Indian trawlers on village fishing activity, direct and indirect losses to the ancillary service sectors in each village, the quantities of fish and fish species caught by Indian trawlers and the number of Indian trawlers and their annual production were obtained. Secondary data was gathered through research papers, publications and internet. Gathered data were analysed with three approaches i.e. Approach A: Direct losses due to Indian trawlers harvesting Mannar's marine resources, (estimated daily and annual direct losses were Rs.54.4 million and Rs.6955.2 million, respectively) Approach B: Indirect loss due to Mannar fishermen by not being able to harvest Mannar's marine resources (estimated annual indirect losses were Rs.425.63 million), Approach C: Direct losses due to the destruction of fishing gears (Rs. 2, 56, 18,750), Approach D: Direct and indirect losses for ancillary service sector (Rs.24, 59,400 and Rs.24, 59,400 respectively). Data were analyzed using MS Excel 2010. Indian trawlers fish in the northern Palk Bay and south of Gulf of Mannarall year round, while they trawl Pesalai, Vankalaipadu, Erukkalampiddy and Pallimunai in northern coast of Mannar from May to October. Further, Panankaddu koddil and Thalvupadu, located in Southern Mannar were trawled from November to April. Mechanized trawling has been banned by Tamil Nadu State Government for 45 days a year, therefore illegal trawl fishing stops in between March to April (about 45 days). In this study it was found that Thalaimannar (with idela location for fishing), Peasalai and Vankalaipaadu villages were highly affected. Vankaalaipaadu fishery activities mainly depend on gill net. It was found gill net fishing activity was affected by trawler activity. Five other villages faced less loss due to the operation of trawlers, because fishery activities carried out only for six months using variety of fishing gears. Keywords: Mannar district, Indian Trawlers, Coastal fishery, Gill net, Economic Impacts.
An Investigation on Total Catch, Catch Composition, Catch Quality Variation Based on Different Effort Levels in Multiday Boats in Kalutara District
(Uva Wellassa University of Sri Lanka, 2016) Fernando, A.W.K.; Gunawardane, N.D.P.; Wickramarathna, I.U.; Jayamanne, S.C.
Deep sea fisheries commenced in late 1980s and introduction of Multiday boats with modern technologies (GPS, SSB radio, Freezer unit, Fish detecting sonar) and synthetic nets increased the pelagic fish production. The multi-day boats in operation today are of several types, varying according to their length and the degree of sophistication. Those vessels use several types of fishing gears based on their preference and also fishing duration also differ with those boats. Fishermen have their own selections on those variables according to their knowledge, experience to maximize their catch with good quality by applying minimum effort.This study was carried out to identify the deep sea fishery trends and optimum efficiency levels in Kalutara fishery district using landing statistics (Catch) and fishing inputs (effort) and to give recommendation on management of Kalutara fishing fleet. In this study, total catch per fishing trip and species wise catches taken as output data and gear type, fishing trip duration, boat length, facility level, no. of crew and boat capacity are taken as input data. Parallel organoleptic survey of fish catch was conducted to measure the quality level of fish. The study found that only the gear type is significantly affecting total catch per trip and other five factors (Boat length, Boat capacity, No. of crew, Trip duration, and Facility level) do not affect the total catch per trip. Three types of fishing gear including longline, gillnet and ring net and combination of gears was used basically and the catch composition of the single species catch is not significantly affected by gear type. Longline, gillnet and ring net when taken individually, significantly affects the species catch variation. The fish quality is significantly affected by total catch, trip duration, and boat capacity while not significantly affected by gear type and facility level. So according to the study it can be recommend that gear combination (better to use Longline cum Gill net) is the most suitable fishing method as it gives high fish catch (2427 236) with medium quality (1.8571 0.1650) fish and more emphasis should be given on fish quality improvement in Beruwala fishery harbor. Keywords: Deep sea fishery, Multiday fishing vessels, Catch, Fishing effort, Fish quality, Fisheries management
Possible Effects of Climate Change Driven Sea Level Rise on Small Islet Complex of Negombo Lagoon Sea Entrance with Respect to Mangrove Floral Community and Fisheries
(Uva Wellassa University of Sri Lanka, 2016) Silva, E.N.S.; Liyanage, N.P.P.; Jayamanne, S.C.
The climate change driven long term sea level rise by global warming will be a potential threat to the islet system of Negombo lagoon sea entrance which is a unique Eco geographic feature of the Sri Lankan coastline. The study was carried out to identify both ecological and socioeconomic impacts by long term sea level rise on this islet system of Negombo lagoon as a fisheries hub and ecologically important mangrove forests to the country. Three possible sea level rise scenarios by year 2100 were developed based on Intergovernmental Panel on Climate Change (IPCC) forecasts of sea level rise through Representative Concentrative Pathways (RCPs'). Inundation patterns due to sea level rise for the islet complex was projected. As ecological impacts, pneumatophore heights of Sonneratia spp. and Avicennia spp. for its distribution and inundation percentage along the Siriwardene mangrove forest due to sea level rise by 2100 were calculated. A timeline analysis for Munnakkarai islet was conducted to understand the socioeconomic significance for two selected shorelines at Munnakkarai islet with an emphasis to fisheries activities. Results have expressed that percentage land loss of Munnakkarai islet due to sea level rise scenarios I, II and III are respectively 18.21% 27.54% and 42.20% by year 2100 and projected loss of pneumatophore distribution for the scenarios I, II and III were respectively 79.7% , 99.2 % and 100%. There is a possibility of displacement, effect on fisheries and species loss in this islet complex by year 2100 due to the loss of pressure on mangrove outskirts of the island where they are possible nursery grounds of economically important fish and shellfish. In conclusion, current study has predicted negative ecological and economic impact for the islet complex due to climate change driven sea level rise by year 2100, emphasizing immediate requirement to overcome global warming nationally and internationally. Keywords: Global climate change, Sea level rise, Lagoons, Fisheries, Mangroves
Preliminary Study of Bioluminescence Species in the Southern Bay of Bengal
(Uva Wellassa University of Sri Lanka, 2016) Wimalasiri, H.B.U.G.M.; Jinadasa, S.U.P.; Dissanayake, D.C.T.; Weidemann, A.; Wijesekera, H.
Marine organisms ranging from bacteria to fish make their own chemically induced light called bioluminescence, it is used to hunt, frighten predators, attract mates, communicate, or camouflage them. The bioluminescence phenomenon was studied in the southern Bay of Bengal during August 2015 onboard R/V Roger Revelle operating from Colombo, Sri Lanka. The intensity of light produced by bioluminescence spices was measured using Recoverable Bathy Photometer (RBP). The RBP recorded light intensity while free falling at a speed of about 1-1.5 m/s. Several RBP profiles in the upper 200 m were collected at six different sites encompassing a region 5 - 8N, 85.5 - 88.5E. All samples were collected in the night time to minimize interferences from other light sources. Zooplankton samples were collected using 150 1.11T1 mesh size plankton net from each location to identify light producing zooplankton species. The RBP measurements showed the existence of bioluminescent organisms in all the sampling locations and high light intensity was found up to 150-200 m water depths. Sapphirina sp belonging to the family Sapphirinidae of phylum Arthropoda was identified as one of the light emitting zooplankton species. Studies are underway to examine the luminous substances, and vertical and spatial distribution of these species, especially around Sri Lankan coastal waters. Key words: Bioluminescence, Recoverable bathy photometer, Zooplankton, Bay of Bengal.
A Preliminary Study on Absorption of Heavy Metal (Lead) From Synthetic Waste Water Using Mullet (Mugil spp.) Fish Scales
(Uva Wellassa University of Sri Lanka, 2016) Herath, H.M.S.S.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
Heavy metals are relative dense metals present in earth crust that are in high accumulation level in water bodies. Among several technologies to remove these heavy metals, biosorption is a novel concept that use in waste water facilities. This study was carried out tofind the feasibility of using mullet (Mugilidae spp.) fish scales as a biosorbant and find the best cost effective form of mullet fish scales to absorb heavy metal (Pb) in synthetic waste water.The effect of oven drying conditions, particle size, and dosage of fish scales and pH for the absorption of heavy metal (Pb) absorption were investigated by Atomic Absorption Spectrophotometer (AA240, 283.33 nm, Varian., Australia). The reusability was investigated with the use of nitric and hydrochloric acids. The highest mean absorption results were obtained for 3 g (98.70 0.73) of damaged 1-2 cm2 size (92.03 ± 0.51) with oven drying conditions of 80°C (99.10 ± 0.52) for 24 hours (93.93 ± 2.38). All parameters were indicated that there was a significant difference among the treatments (P < 0.05). In addition to that, absorption was not depended on pH and reusable ability was high with the nitric (19.83 ± 5.66) compared to hydrochloric acid (3.09 ± 0.37). But in cost effective manner new fish scales were more applicable. The observed reason for the efficient biosorption from the fish scales were the crystal structure, chemical composition of hydroxyapatite with porous structure and the highly ordered three dimensional structure of collagen. This research revealed that, there is a high potential to use mullet fish scales as a biosorbant for treat waste water in wastewater treatment facilities and it is a rapid, cost effective and high efficient biosorbant among other biosorbants. Keywords: Heavy metal, Biosorption, Cost effective, Hydroxyapatite, Collagen
Strategies to Reduce Larval Cannibalism of Pangasius stitch!
(Uva Wellassa University of Sri Lanka, 2016) Thilakarathna, W.M.W.S.; Epasinghe, E.D.M.; Karunaratne, T.A.D.W.; Adikari, A.M.A.N.; Liyanage, N.P.P.
Ornamental fish industry is the most significance income earning approach in Sri Lankan economy. Pangasius sutchi (Thai pangus) is considered as the most popular ornamental fish species. In their early larval stage, they show cannibalistic behaviour which leads reduction of population. Then experiment was conducted to reduce the larval cannibalism of larvae within first 72 hours because it has been identified as the critical period of their cannibalistic behaviour. Therefore several types of feed, feeding frequencies and stocking densities were tested. We investigated the effect of two different types of feed(Artemia and Moina),three different feeding frequencies (3hr,4hr,5hr)and three different stocking densities(60.90.120)one square feet can hold 80 larvae and 22"x 10x 10glass tank can hold approximately 94 P.sukhi larvae. Each tank was randomly assigned to one of the treatment. At the end of the experiment numbers of survivals were calculated to determine the cannibalism rate. Five fish from each tank were sampled to measure body length. Then numbers of average body length were recorded. Data were statistically analized by using MINITAB 17 software. Significance levels were calculated to determine whether there is any relationship or not. Results showed that the feed types were not significantly (p>0.05) affect the survival rate and it only affected the body length. Feeding frequency was significantly (p<0.05) affected the survival rate and not affected the body length. And also results showed that stocking density affected the survival rate significantly (p<0.05) and not affected significantly for body length of larvae. Final results indicated that highest mean survival rate was recorded with 60 stocking density whereas lowest survival rate was recorded in 120.highest mean body length was recorded with the Artemia feeding with 3hour feeding frequency. Keywords: Cannibalism, Feeding frequency, Stocking density, Artemia, Moina
A study on shelf life of export oriented fresh chilled Yellowfin tuna loins in relation to histamine content
(Uva Wellassa University of Sri Lanka, 2015) Arachchige, T.R.K.; Jayamanne, S.C.; Amarasinghe, K.
Sri Lanka has become a leading country which produces Yellowfin tuna (Thunnus albacores) and other large pelagic species in the Indian Ocean. (Indian Ocean Tuna Commission, 2011). To meet export market, maximum histamine content of the product should not exceed 50 ppm (Food and Drug Administration, 1998). Seafood processing factories guarantee a shelf life of 14 days for the product fresh chilled Yellowfin tuna loin, even though shelf life of different Yellowfin tuna loin batches is varied. Shelf life can be exceeded or not exceeded 14 days in different batches. These batches represent Yellowfin tuna received from different fishing harbors in different proportions. According to the fishing harbor environmental factors and practices followed by fishermen can be varied. There is evident that depending on the nature of the environment, different proportions of decarboxylase positive bacteria would be present in water and external fish tissue, and therefore the level of histamine and other toxigenic amines formed in fish tissue would not be uniform (Yoshinga and Frank, 1982). This research is to identify whether these fishing harbors have an effect on the shelf life of fresh chilled Yellowfin tuna loin in relation to histamine content. Methodology The study was carried out at SGS Lanka (Pvt) Limited, Colombo 02. The sample collection and background study of fresh chilled Yellowfin tuna loin exportation was done at Global Seafoods (Pvt) Limited. Three repeated experimental trials on histamine analysis of Yellowfin tuna loin samples were conducted during a time period of 42 days. Storage time period of each set of samples for an experimental trial was 14 days. Selected fishing harbors were Beruwala, Tangalle, Chilaw, and Trincomalee. Yellowfin tuna loins of Grade A and B were selected from each fishing harbor. All collected samples had an on-broad freezing time period, which was varied between 18 - 22 days. Labeled and vacuum packed samples were stored at 0 C, in the fresh chilled condition. Histamine analysis was carried out from the time period of zero day of storage to 14 days of storage. Histamine was analysed using flurometric method according to the AOAC official methods of analysis. Data collected from the three experimental trials were analysed using Minitab 14 statistical software. Descriptive statistics of means, Standard deviation, two-way ANOVA and one way ANOVA with tukey’s pairwise comparison was applied in analysing the results. A significance level of 5 % was used. Result and Discussion Histamine content was increased with storage time period in each and every sample. The increment pattern of Yellowfin tuna loins received from four selected fishing harbors of Grade B did not show any significant difference (P>0.005). It was concluded that there was an effect from fishing harbor on average histamine content of Yellowfin tuna loins within fish grade A (P<0.005). Further analysis of one way ANOVA with tukey’s pairwise comparison revealed that Trincomalee fishing harbor had the least contribution for histamine formation.

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