Sri Lanka Journal of Aquatic Sciences最新文献

{"title":"Biomarker responses of Nile Tilapia (Oreochromis niloticus) exposed to polluted water from Kelani river basin, Sri Lanka: Implications for biomonitoring river pollution","authors":"K. Ruvinda, A. Pathiratne","doi":"10.4038/SLJAS.V23I1.7551","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7551","url":null,"abstract":"Biomarkers can be considered as early warning signals for potential adverse effects on the biota. The present study examined the feasibility of using selected biomarker responses of a model fish, Oreochromis niloticus under laboratory exposure approach for identification of potential biological impacts of pollution in Kelani River. Laboratory acclimated O. niloticus were exposed under static-renewal conditions to water samples collected from selected sites of the Kelani River basin with different anthropogenic influences and biomarker responses (brain and muscle cholinesterase activities for neurotoxicity, erythrocyte micronuclei and nuclear abnormalities for genotoxicity and liver histology for hepatic damage) were evaluated at 5 and 10 days of exposure. Exposed water was physico-chemically characterized using standard analytical methods. The results revealed that exposure of O. niloticus to the water from selected polluted sites which included canals and canal confluences resulted in significant increases (p","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"39 1","pages":"105"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86201428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Length-based variations in deposition of chitin in the exoskeleton of Penaeus monodon and P. indicus","authors":"Bimba R. Wickramasinghe, P. Cumaranatunga","doi":"10.4038/SLJAS.V23I1.7553","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7553","url":null,"abstract":"Shrimp waste produced at the processing factories is a burden to the environment. Nevertheless, it is a raw material for extraction of chitin which is with more commercial uses. In this study chitin was extracted from shrimp waste collected from three different length ranges (5-10cm, 10-15cm, 15-20cm) of Penaeus monodon and P. indicus from a local small-scale processing factory, to determine the most suitable length class of shrimps to obtain a higher chitin yield. Dried shrimp waste was preconditioned by soaking in acetic acid, demineralized by treating with HCl and deproteinized by treating with NaOH.  Extracted chitin was odourless, and pinkish white and off-white in P. monodon in P. indicus respectively. Highest chitin yield was from the largest size range of both species, P. monodon (30.5%) and P. indicus (27.86%). Ash, moisture, fat and nitrogen of extracted chitin were 0.98%, 5.80% and 6.16 % in P. monodon and 0.98%, 5.72% and 6.22% in P. indicus of dry weight respectively, which were matched with the moisture content (5.5%), ash (0.3%) and nitrogen (6.9%) of chitin available in the market. The chitin extracted from P. indicus of 5-10 cm length range had a moisture content of 5.72% and a nitrogen content of 6.22%, which were the closest to the moisture and crude nitrogen in the pure commercial chitin. Ash content (0.98%) of all the extracted chitin were comparable to those of pure chitin. This indicates that chitin extracted from shrimp waste in the processing industry is comparable to commercially available chitin and therefore shrimp waste is a suitable source for extraction of chitin for commercial purposes.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"101 1","pages":"127"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87007610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial and chemical quality of selected dried fish varieties available in Sri Lankan market","authors":"P. Ginigaddarage, I. Surendra, W. K. S. M. Weththewa, K. Ariyawansa, J. G., Ganegama Arachchi, B. Jinadasa, K. Hettiarachchi, E. Edirisinghe","doi":"10.4038/SLJAS.V23I1.7552","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7552","url":null,"abstract":"Dried fish is one of the traditionally preserved foods in Sri Lanka.Since dried fish is often an important component of daily meal, this study was aimed to assess the quality of selected dried fish varieties in the local market. Dried fish samples of nine selected varieties were collected under three categories, viz. locally produced, imported dried fish before and after distribution to retail market. They were analyzed for microbiological and chemical parameters. Water activity of the samples was also measured. Samples were found to be negative for Escherichia coli, Staphylococcus aureus and halophilic bacteria. Aerobic Plate Count and yeast and mould count of the majority of the samples were within the acceptable limit. Histamine content exceeded 100 mg/kg level in 33% and 13% of imported and local samples respectively. Water activity of the samples was 0.05) between the analyzed parameters of all three categories.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"1 1","pages":"119"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89878914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cattle and water buffalo densities wading into small village reservoirs of Sri Lanka impact on yields on the culture-based fisheries thereof","authors":"Asanka D. Jayasinghe, J. A. Athula, S. S. Silva, Upali Sarath Amarasinghe","doi":"10.4038/SLJAS.V23I1.7547","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7547","url":null,"abstract":"This study investigated whether allochthonous inputs generated by cattle and water buffaloes grazing in the catchment or wading in the water in small village reservoirs of Sri Lanka can make a significant effect on yields from culture-based fisheries of those reservoirs. The analysis is based on limnological data of 37 randomly selected reservoirs. As culture-based fish yield data were available over the 2002 - 2003 period only for 23 reservoirs, fish yield data from seven more reservoirs were gleaned for the present analysis. Cattle and water buffalo densities (BD) in 37 reservoirs where limnological data were available, were found to be significantly correlated to the biological productivity-related parameters such as chlorophyll-a content. Culture-based fish yield in the 30 reservoirs varied from 54.6 to 1800.8 kg ha-1 and BD associated with the reservoirs studied varied from 0.90 number ha-1 to 216.25 numbers ha-1. Fish yield (FY) was significantly correlated with BD the relationship being, FY = 4.758 BD + 242.740 (R2 = 0.345; p","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"1 1","pages":"67"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89307044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the nuclear level impacts upon exposure to Bispyribac–sodium and Carbosulfan in Poecilia reticulata and Aplocheilus parvus","authors":"G. Fernando, S. Jayakody, W. Wijenayake, G. L. Galappaththy, M. Yatawara, R. Harishchandra","doi":"10.4038/SLJAS.V23I1.7549","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7549","url":null,"abstract":"Conventional chemical controlling, due to harmful effects on the environment and animal health, is less appreciated and discouraged today. The impacts to exposed organisms are multiple, but changes at nuclear level can result in long-term impacts to exposed populations. Such chemical exposure can also negatively impact fish that are intentionally introduced to aquatic systems for mosquito vector control. Hence, two types of fish, guppy (Poecilia reticulata) and dwarf panchax (Aplocheilus parvus) used for mosquito control, were tested to the sensitivity to insecticide, Carbosulfan, and weedicide, Bispyribac–sodium in the present study. Lethal average concentration (LC50)was measured for both chemicals. Gills and liver of moribund and survived fish were stained with Heamotoxyin and Eocin to determine the histological changes. Level of cell necrosis was calculated through terminal deoxynucleotidyl transferase-mediated d'UTP nick end labeling (TUNEL) method. The 96h acute LC50 value of Bispyribac-Sodium to A. parvus and P. reticulata were 1.280 mg L-1 and 2.370 mg L-1 respectively. The 96h acute LC50 value of Carbosulfan to A. parvus and P. reticulata were 0.315 mg L-1 and 0.028 mg L-1 respectively. Lamellar fusion, filament and lamellar epithelium proliferation, curling of secondary lamellae, hypoplasia and necrosis in gills were observed in treated fish. The percentage of damaged nuclei in the liver of treated A. parvus to Bispyribac–sodium indicated a significantly higher number of damaged nuclei in all treatments except in the lowest concentration (0.025–0.075 mg L-1) compared to control (P","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"1069 1","pages":"85"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77265072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heavy metal contamination status in seven fish species from reservoirs of Polonnaruwa district, Sri Lanka","authors":"H. Wijesinghe, F. Idroos, P. Manage","doi":"10.4038/SLJAS.V23I1.7550","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7550","url":null,"abstract":"Heavy metal contamination in aquatic ecosystems has become an emerging environmental issue. The stable physico-chemical properties of heavy metals could result in bioconcentration and bioaccumulation in different organs of freshwater fishes. The present study records the accumulation of Lead (Pb), Cadmium (Cd), Chromium (Cr), Copper (Cu) and Zinc (Zn) in the head, muscle and skin regions of seven fish species namely, Labeo rohita , Oreochromis mossambicus, Oreochromis niloticus, Etroplus suratensis , Heteropneustes fossilis , Oligolepsis acutipennis and Puntius dorsalis collected from Minnerya, Parakrama Samudraya and Kaudulla reservoirs in Polonnaruwa district, Sri Lanka. The results showed that both Pb and Cd accumulated in high concentrations in the head region compared to the skin and muscles of the fish samples. The highest amounts of Pb (22.44±5.48 mg/Kg) and Cd (4.98±0.86mg/Kg) were recorded from the head parts of the H. fossilis in Minneriya and O. niloticus in Kaudulla respectively, whereas the highest amount of Cr (30.87±4.51mg/Kg) was detected in head part of the O. acutipennis in Minneriya. The Cu concentration was the highest (2.92±0.001 mg/Kg) in head regions of H. fossilis from Minneriya. Zn was the most abundant heavy metal detected in the head, muscle and skin regions of fish in all three reservoirs. The highest amount of Zn (118.93±10.55mg/Kg) was detected in the head part of O . acutipennis from Minneriya. The Pb, Cd, Cr, Cu and Zn concentrations detected in the head part of popular edible freshwater species, O. mossambicus, O. niloticus and E. suratensis were higher than the provisional tolerable weekly intake (PTWI) of Pb (0.025 mg/Kg), Cd (0.007 mg/Kg), Cr (0.1 mg/Kg), Cu (3.5 mg/Kg) and Zn (7 mg/Kg) specified by the FAO/WHO. Therefore, long-term consumption of these fish species especially the head parts may lead to accumulation of these heavy metals in tissues and lead to chronic diseases which may risk the health of consumers especially in the north-central province of Sri Lanka.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"49 1","pages":"95"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90688245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zooplankton, zooplanktivorous fish and their interactions in Southeast Asian waterbodies with special reference to Sri Lanka: a review","authors":"J. Vijverberg","doi":"10.4038/SLJAS.V23I1.7542","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7542","url":null,"abstract":"Many countries in Southeast Asia have no natural lakes but reservoirs, flood-plains and rivers. The reservoirs are mainly inhabited by riverine fish species and introduced pelagic exotics. Benthivores, herbivores and detritivores dominate, whereas zooplanktivores are relatively rare (generally 4.6-9.5% of the fish community). Therefore, zooplanktivorours fish are not dominant in most Sri Lankan reservoirs and play only a minor role in the food web. In the Southeast Asian region, only small, often pelagic, zooplanktivorous fish species occur. They are either of riverine or marine origin. Observations were made that only six predominantly zooplanktivorous species viz a cyprinid from riverine origin Rasbora daniconius, a half beak from marine origin Hemiramphus limbatus, the glass perchlet Ambassis urotaenia and three freshwater clupeids from marine origin ( Clupeichthys aesarnensis, Ehirava fluviatilis, Sardinella tawilis ) inhabit the reservoirs in Southeast Asian countries such as Sri Lanka and Thailand and a lake in the Philippines. The highest percentages of zooplanktivory in the tropical region are observed in waterbodies which contain zooplanktivores of marine origin. These small pelagics are very productive, i.e., have relative high Annual Production/Biomass (P/B) ratios. P/B ratios of the small Southeast Asian pelagics ranged generally from 3-6, small clupeids showed the highest P/B ratios. Of the riverine species, R. daniconius is the most successful; it is a common species in the Sri Lankan reservoirs. This species is, however, not able to catch the small cladocerans and the cyclopoid copepods efficiently and fails completely to catch the fast moving calanoid copepods. Instead of feeding on larger zooplankton, they often feed on adult winged midges which are floating on the water surface. H. limbatus is not abundant in Sri Lankan reservoirs and its distribution is limited where only occasionally its densities are high enough to permit a profitable fisheries. Although the freshwater clupeids seem to be superior in their efficiency of collecting food organisms, their distribution is often limited. Despite their ability to build up stable and large populations in a handful of water bodies in the Philippines and Sri Lanka, they have a problem in dispersing into other freshwater lakes and reservoirs. In Thailand, the situation is different because C. aesarnensis is well adapted to riverine conditions and, therefore, present in all reservoirs with inflowing riverine habitats, but in most cases these stocks are still unexploited.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"45 18 1","pages":"3-11"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80432188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Misconceptions of mangrove ecology and their implications on conservation and management","authors":"M. Amarasinghe","doi":"10.4038/SLJAS.V23I1.7544","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7544","url":null,"abstract":"Being uniquely located in the harsh inter-tidal zone between land and sea, mangroves have long been considered mosquito-infested stinky and muddy environments, that can be made worthy only through “development” and converted to land suitable for other lucrative land uses such as coconut cultivation, homestead/ urban/ tourism related infrastructure development. Mangrove ecological research initiated in Florida in the late 60’s gave an insight over their ecological value and their potential positive influence on fisheries (secondary productivity) of estuaries and coastal waters through nutrient cycling. Apart from taxonomic and biogeographic studies, considerable research effort has since been devoted globally that has elucidated the nature of ecological functions of mangrove ecosystems ranging from primary productivity and carbon sequestration to nutrient cycling and maintenance of coastal biodiversity that has generated an invaluable knowledge base useful to draw up sustainable plans to conserve mangroves which are under heavy anthropogenic pressure. A few misconceptions however are often encountered with regard to characterization of mangrove habitats and species exclusive to them that inflict far-reaching negative impacts on mangrove conservation. This paper analyses them with the available scientific knowledge base and identifies the potential driving forces that contribute to pseudo-science that leads to eventual loss of mangroves and their invaluable ecological functions.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"12 1","pages":"29"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76249475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the retirement of an eminent scientist in fisheries and aquatic science in Sri Lanka: a personal approach","authors":"Upali Sarath Amarasinghe","doi":"10.4038/SLJAS.V23I1.7541","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7541","url":null,"abstract":"","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"40 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75071797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial data analysis for the marine fisheries and habitat management of Sri Lanka","authors":"D. Dahanayaka","doi":"10.4038/SLJAS.V23I1.7545","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7545","url":null,"abstract":"Satellite Remote Sensing (RS) can be effectively used for the fisheries applications, including stock assessment, management of marine resources and fish harvesting. Further, there is an extensive range of fisheries related applications of RS data, including identifying marine managed areas, detection of harmful algal blooms, bycatch reduction, long term monitoring of fisheries related habitat changes and control of illegal fishing. Applications on RS related to marine fisheries sector in Sri Lanka, seem to be meager. Limited studies have been conducted on the fisheries related ecosystem damage assessment using RS after December 2004 Tsunami disaster. To fulfill the gaps of research on coastal fisheries identified, the author conducted some research on habitat changes such as monitoring of land use changes and water quality at economically important estuarine environments around Sri Lanka using multi temporal satellite imageries. In these studies, several environmental issues have been addressed such as localized eutrophication, disturbance of water circulations and sudden fish kills etc. Furthermore, since satellite RS is a useful tool that could be applied for planning marine fisheries development in Sri Lanka, the National Aquatic Resources Research and Development Agency (NARA) is currently conducting forecasting of fishing ground using satellite data for off-shore/ high seas fishery, providing accurate information on large pelagic fishing grounds considering sea surface temperature and chlorophyll distribution. As illegal, Unreported and Unregulated (IUU) fishing is a serious threat to the long-term economic and environmental sustainability of Sri Lankan oceans, RS techniques exhibit great potential for supporting to develop fisheries monitoring system around Sri Lankan waters which is timely important for control IUU fishing. VIIRS Boat Detection system of NOAA and Global Fishing Watch were discussed as the possible systems that can support the future monitoring and management of Sri Lankan marine fisheries sector. This paper summarizes the present RS related applications to the marine fishery sector of Sri Lanka. Further, it also provides guidelines for sustainable management of the sector that can result from RS, and identify existing applications which can effectively support the marine fishery management of the country.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"42 1","pages":"37"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90621661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}