International Research Conference of UWU-2019

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Accumulation of Proline in Plants of Mangrove and Maritime Ecosystems in Southern Wet Zone of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Jayathilake, W.W.N.T.; Nallaperuma, N.A.W.R.; Yapa, P.N.
Mangroves and maritime plants are the only halophytes living at the influence of land and sea, and occupy tropical and subtropical coastline. Mangrove and maritime communities are recognized as part of the marine ecosystem and are highly productive ecosystems. Saline habitats represent a physiological challenge for plants because of the highly negative water potential of the soil water, making water acquisition difficult. Osmotically active solutes such as mannitol, proline, glycinebetaine and triterpenoids are necessary to reduce water potential in cell cytoplasm. The present study was done with the objective of estimating the accumulation of proline in leaves of mangroves, mangrove associates and maritime plants in Southern wet zone of Sri Lanka. Proline concentrations in leaves of 12 mangroves, 5 mangrove associates and 15 maritime plants were measured by following the standard procedures with using UV/VIS spectrophotometer at 520 nm wave length. Further, proline concentrations were estimated in maritime plants of varying distances from the sea after plants were selected along the line transects of 200 m from the sea coast. Proline was accumulated in all tested mangrove, mangrove associates and maritime plant leaves with the varying concentrations. Among them significantly higher proline levels are found in the leaves of maritime plants Terminalia catappa, Flemingia strobilifera, Scaevola taccada, mangroves such as Nypa fruticans, Bruguiera gymnorrhiza and mangrove associate Anona glabra. Further, according to Pearson correlation analysis, there was no correlation observed on average proline concentration of maritime plants leaves and changing distances of 200 m from the sea coast (p= 0.477). An increment of proline accumulation was evident in majority of plant species of mangroves, mangrove associates and maritime vegetation in Southern wet zone of Sri Lanka under salt stress.
Assessment of Suspended Plastic Levels in Surface Water of Southern Coastal Belt in Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Athapaththu, A.M.A.I.K.; Athawuda, A.M.G.A.D.; Dias, P.C.B.; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.
Plastic pollution is a growing concern all over the world including Sri Lanka due to serious negative consequences. Thus, current study focused on investigation of occurrence, quantification and spatial distribution of visually observed plastics and microplastics (MPs) in surface coastal water from 12 locations (Hikkaduwa, Gallefort, Dodanduwa, Unawatuna, Weligama, Mirissa, Dickwella, Tangalle, Polhena, Rekawa, Godawaya, Hambantota) as covering 3 districts of southern coastal zone in Sri Lanka during July-December 2018. Surface water samples were collected by towing neuston, manta net (380 µm) along surface layer parallel to the shoreline using repeated measures approach. The samples were passed through 4000 µm, 500 µm and 250 µm mesh sieves and residual MPs were subjected to Wet Peroxide Oxidation protocol. Visually observed plastics and recovered MPs were observed through Trinocular Microscope, enumerated for density and confirmed by hot needle test. MPs were further sorted according to the color and shape. As results revealed, all the coastal water in sampling sites were contaminated with plastic accumulation. Overall average density of macroplastics and mesoplastics were recorded as 3.32 and 3.37 items/m³. Sampling location had no significant effect (p>0.05) on total MPs density (average total MPs density: 18.06±11.45 items/m³). Plastic accumulation sources of the affected sites were identified as harbor operational activities, residential actions and recreational events. MP debris with 0.512.00 mm consists of >65% of total number of MPs, whereas maximum size of microscopic plastic in coastal water was 11.04 mm. Fibers were the most common MPs followed by films. Blue colored and Transparent MPs were the majority of plastic items in coastal water due to prevalence of above plastic categories used in the packaging, bottles and fishing gears. In summary, southern coastal water in Sri Lanka is polluted by plastic debris and pollution control programmes are recommended by this study.
Biofouling Community Composition Along the Coast Adjacent to Colombo Port
(Uva Wellassa University of Sri Lanka, 2019-02) Marasinghe, M.M.K.I.; Ranatunga, R.R.M.K.P.
Sri Lanka is located in close proximity to the east-west maritime route with an increased risk of invasion by Non Indigenous Species (NIS) in the coastal waters. Here, Colombo port is one of the top risked ports in terms of potential NIS introductions and the presence of many introduced species remained mysterious until extensive work on biofouling community was initiated in 2014 by the authors. However, knowledge on fouling composition along the adjacent coast around the port is also scarce. Therefore, an extensive survey was conducted along the coast adjacent to the Colombo port to determine the presence and extent of dispersion of NIS. The survey was conducted during the months of May and June, 2018 in both north (Colombo port to Negombo) and south side of the Colombo port (Colombo port to Panadura). Samples were collected using belt transect (10m x 3m) covering both high tide and low tide in the selected sampling locations. Fouling organisms adhere to rocks, piers and floating objects were collected. Organisms which were already identified were recorded at the site itself and new species and any species had doubt on identification, were photographed and transported to the laboratory for further analysis. 42 species of fouling organisms were identified belonging to 7 taxonomic groups as Bryozoa (4 species), Annelida (5 species), Chordata (7 species), Mollusca (8 species), Arthropoda (10 species), Porifera (6 species), and Cnidaria (2 species). Eleven species were common to both side and altogether 24 species were found to be mutual to Colombo port and adjacent coast. Six NIS were recorded which were also observed in Colombo port revealing the presence of NIS in adjacent coast. Therefore, present findings alarm the impending risk of spreading NIS introduced to Colombo port and immediate attention must be taken to manage the existing NIS community in Colombo port as well as continuous monitoring is recommended for possible early detection of future NIS spreading.
Composition of the Faunal Community Fouling On Long-Term Test Panels Deployed in Colombo Port, Sri Lanka.
(Uva Wellassa University of Sri Lanka, 2019-02) Marasinghe, M.M.K.I.; Ranatunga, R.R.M.K.P.
Studies in biofouling on artificial substrates have been carried out globally in order to understand the community succession, mechanisms, associated invasive species as well as addressing the issues. However, in Sri Lanka, such information is very much lacking and present study is to address such knowledge gap. The study was conducted in Colombo port in four sampling locations from February 2016 to March 2017 using experimental panels. Entire set up was pulled out of the water and photographed alive during monthly sampling cycle before placing them back in the water. Species identification was done to the lowest possible taxonomic level using live photographs which were taken in the field. In the laboratory, the photographs were analyzed to determine percentage cover using Photoquad software. From the succession analysis of permanent settlement collectors, 74 different fouling organisms were recorded belonging to 8 different taxa including Bryozoans (8 species), Annelids (12 species), lower Chordates (23 species), Molluscs (13 species), Arthropods (7 species), Poriferans (5 species), Cnidarians (5 species) and Echinoderms (1 species). Among the species recorded, eleven were globally known invasive species. Furthermore, the Dendrogram derived from cluster analysis showed a close relationship among members of the fouling community. Especially among the native bryozoan Arbopercula bengalensis and tube worms (Sabellidae); whereas one cryptogenic (Celleporaria volsella) and two native (Parasmittina parsevalii and Hippoporina indica) bryozoan species also shared a close relationship among each other. Moreover, arthropods and tunicates also showed a close relationship. However, two major nonindigenous species, Schizporella errata and Mycale sp. showed noticeable deviation, indicating their exceptional solitary behavior despite the presence of other members of the fouling community.
Efficient Microorganisms for Bioethanol Production from the Natural Environment of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Jayasekara, S.K.; Abayasekara, C.L.; Ratnayake, R.R.
Sri Lanka is biologically diverse. The potential of utilizing this rich biodiversity for sustainable socio-economic development of the country is extensive. The vast microbial diversity is a key component in biological diversity. However, the industrial scale application of native microorganisms is still underutilized. The objective of this study was to explore microbial flora of Sri Lanka to isolate efficient cellulolytic fungi and ethanologenic yeast for application in bioethanol production. Fifty fungi were isolated from soil. The total cellulase activity of fungal isolates was determined to compare cellulase production. Yeasts were isolated from local fruits viz: grapes, oranges and mangoes. Ethanol production by each yeast isolate was assessed in a glucose containing fermentation medium. Detection and quantification of ethanol were done by High Performance Liquid Chromatography (HPLC) using ethanol standards. The HPLC analysis was conducted using Milli-Q water in 0.6 ml/minute flow rate as the solvent. Hi- Plex H, 300×7.7 mm column was used with Refractive Index Detector for ethanol detection. Both were maintained at 55 ˚C temperature for the analysis. According to the results, the highest total cellulase activities were given by fungal genera Trichoderma, Aspergillus and Penicillium. Trichoderma viridae was the most efficient isolate giving a total cellulase activity of 0.574 FPU/ml followed by the Aspergillus niger, being the second most efficient cellulase producer with 0.464 FPU/ml total cellulase activity. Total cellulase activity of Penicillium oxallicum was, 0.438 FPU/ml, which was not significantly different from A. niger. Among six ethanologenic yeast, the highest ethanol concentration was given by Y3 isolate as 9.651% while Y5 showed 5.84 %. All the isolates reported ethanol yields above 2%. There is a great potential of applying these efficient isolates in bioethanol production because cellulolytic fungi can degrade cellulose to release fermentable sugars for yeast.
Is the Future of Mangroves in Vidattaltivu Nature Reserve Secured? A Community Based Study
(Uva Wellassa University of Sri Lanka, 2019-02) Cooray, P.L.I.G.M.; Edison, M.; Ambegala, D.D.
Vidattaltivu is a coastal region and composed of four adjacent grama-niladhari divisions with a close knit community of about 600 families. It is located in Manthai West divisional secretariat division of Mannar District, Northern Province, Sri Lanka. Vidattaltivu has been declared as Vidattaltivu nature reserve since 2016, because of its luxurious but highly vulnerable mangrove ecosystem. Regardless, the mangrove vegetation in Vidattaltivu is still at a great risk mainly due to destruction and illegal felling of mangroves, pollution and inadequacy of management and conservation interventions.This study was aimed at understanding the community’s awareness, knowledge and perception on mangroves in Vidattaltivu and emphasizing the importance of the community involvement and participation in order to protect this valuable ecosystem for future. Questionnaire survey method was employed and a pre-tested questionnaire was distributed among 100 respondents in Vidattaltivu. The findings suggest that majority of respondents (77.86%) are having a higher degree of knowledge and awareness on mangroves but are not willing (89.00%) to take the prime responsibility to protect the ecosystem. This type of negative behavior of locals is typically encouraged by neglecting of sociological & socioeconomic factors and ignoring of suggestions & needs of local communities in planning and implementation stages of protected area management. Apart from that, the exclusion of ownership of the mangroves from local communities might have lessened their commitment towards conservation of this ecosystem. Nevertheless, the respondents showed a higher level of readiness and capacity (86.25%) towards community participation in mangrove management, which can be utilized productively in future if they are encouraged and empowered properly.
Monitoring Tributyltin (TBT) Contamination of Southern Coastal Waters in Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Bandara, K.R.V.; Chinthaka, S.D.M.; Manage, P.M.
Tributyltin (TBT) is an organotin compound belongs to the group of Persistent Organic Pollutants (POPs) and one of the active ingredient in antifouling paints used for boat hulls, docks, fish nets in order to prevent the growth of aquatic fouling organisms. The presence of TBT in the aquatic environment is extremely toxic to target and non-target organisms and it is responsible for severe sexual disorders like sex changes called imposex leading to sterile aquatic populations which lead to decline of animal diversity. According to WHO, the No Observed Effective Level (NOEL) of TBT is below 1 ngL-1. However, there are no information has been recorded regarding the TBT contamination in water and its adverse effect on aquatic organisms in Sri Lanka. Therefore, the study aims to monitor the contamination status of TBT in southern coastal area in Sri Lanka. Coastal water samples were collected from river canals, fishing harbors and river mouth along the Southern Coastal area from Dehiwala to Mirissa. TBT was extracted by using a newly optimized Solid Phase Micro Extraction (SPME) method. Hydridization process was followed for quantification by using the Gas Chromatography-Mass Spectrometry (GCMS) in parts per trillion level (ppt). Results showed that the highest TBT concentration in highly polluted Dehiwala (3.4ngL-1) and Wellawatta canals (3.4ngL-1). TBT concentrations in fishing harbors at Ambalangoda, Galle, Mirissa and Beruwala were range from 1.4 ngL-1 to 3.2ngL-1 where in Madu and Benthota river mouth were 0.8ngL- 1 and 0.9ngL-1 respectively. The recovery of the TBT extraction method was 87±0.1% for the artificial sea water. Thus, the preliminary results of the study showed that high contamination of TBT may adversely effect on marine biodiversity.
Morphological Characterization and Distribution of Lagenandra praetermissa de Wit & Nicolson
(Uva Wellassa University of Sri Lanka, 2019-02) Madola, G.K.I.S.; Yakandawala, K.; Yakandawala, D.M.D.; Karunaratne, S.B.
Lagenandra praetermissa is an aquatic endemic species distributed throughout the Wet and Intermediate zones along the rivers, streams and marshy habitats. According to National Red List 2012 the plant is listed under the “Least Concern” category. The recent field observations indicated a reduction in subpopulations and variations in vegetative morphology. Hence the present study was focused on distribution and morphological diversity of L. praetermissa which would contribute to its conservation. Field collections were made covering Wet, Dry and the Intermediate zones of the country. At least three plants were studied in detail from each population for coding morphological characters. Twenty-three qualitative and quantitative vegetative characters of individuals from 34 different subpopulations were coded into a data matrix and a morphometric analysis was carried out using the PAST software. Distribution of the subpopulations were recorded using GPS locations. Further, the soil pH and threats were also recorded for each location. Although L. praetermissa was recorded as occurring in the Kandy and Kalutara districts during the revision of the family in 1986, according to the present study they were also recorded from Badulla, Kegalle, Kurunegala, Matara, Rathnapura and Monaragala districts which extends its distribution to the dry zone. Even they exhibit a wider distribution, most of these subpopulations occur outside protected areas in polluted disturbed streams and river banks. The soil pH ranged from 4.7-6.3 which is acidic indicating the polluted nature of the habitats. The cluster analysis identified two phonetic groups, separating at a 32 distance units, while these two groups further divided into subclusters. The petiole length and the leaf laminar length were the most contributing characters. The identification of two different phenetic groups of L. praetermissa indicates its morphological diversity which needs to be further studied using molecular data to identify whether these belong to distinct groups.
A Preliminary Study of the Faunal Diversity in a Fragmented Lowland Evergreen Rain Forest Patch: Wawekele Reserve Forest, Avissawella, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Ranatunga, R.A.G.N.; Abeyrathne, P.A.B.P; Madola, G.K.I.S
The abundance of lowland evergreen forest patches within the lowland wet zone is considerably very high in Sri Lanka and they function as invaluable natural production systems through providing catchment areas for regional water sources like rivers, streams, wells etc. A preliminary study was conducted to assess the faunal diversity in the Wawekele Reserve forest area in the Southern boundary of Colombo District in Sri Lanka. This forest covers 45 ha and falls within the lowland wet zone, at an elevation of 90m120m above sea level. Approximately, 600 person hours were spent in the field over a period of six years from August 2012 to August 2018 to document freshwater fish, amphibians, reptiles, birds, mammals, butterflies and dragonflies through the visual observations following the trails and streams within day time. A total of 131 different faunal species including 08 freshwater fish species, 05 amphibian species, 15 reptile species, 64 bird species, 05 mammal species, 22 butterfly species and 12 dragonfly species were recorded from Wawekele, of which 03 freshwater fish species (37.50%), 05 amphibian species (~100%), 04 reptile species (~26.67%), 06 bird species (~9.38%), 02 mammal species (~40%), 02 butterfly species (~9%) and 02 dragonfly species (~16.67%) are endemic to Sri Lanka. Out of 131 species recorded 10 (7.63%) Near Threatened, 04 (3.05%) Vulnerable, 05 (3.82%) Endangered and 01 Data deficient (0.76%) species according to the red list of 2012 by international union for conservation of nature. This lowland evergreen forest patch is affected by noise pollution due to its locality near an urban area. Further night time observations are required to uncover the nocturnal faunal species and more detailed studies are required to formulate the better management plans for conserve this bio diversity rich forest patch.
Present Status of Export Trade of Endemic and Indigenous Freshwater Ornamental Fish Species in Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Egodauyana, K.P.U.T.; Dias, P.C.B.; Jayawardana, J.M.D.R.; Senevirathne, J.D.M.; Liyanage, N.P.P.
Sri Lankan ornamental fish export industry has developed rapidly during last decade due to high demand. Recent surveys have indicated that wild collection of endemic and indigenous freshwater ornamental fish species has caused serious conservational issues. This study aims to evaluate the present status of export trade of endemic and indigenous fish species in Sri Lanka during 2016-2017. Secondary information on type of freshwater fish species which were exported as ornamental fishes and their levels of exporting were collected from Sri Lanka Customs. Pre-tested questionnaire was used to collect data from 15 ornamental fish exporters, including the details of restricted and prohibited species and current status of the export industry. Results of the study indicated that the exportation of endemic species and indigenous species have been reduced by 43.7% and 9.4% respectively in 2017 when compared to 2016. Highest export trend were recorded on Garra ceylonensis: endemic fish species (48.7%) and Monodactylus argenteus: indigenous species (69.6%). Only 20 species of restricted freshwater fish have exported in 2016 and not reported at 2017. The major export destinations of Sri Lankan endemic and indigenous fish was USA (22%) followed by Netherlands (18%) and Australia (10%). The results of the questionnaire survey indicated that a limited number of exporters (40%) tend to export endemic fish species due to legal barriers. Further, captive breeding of Sri Lankan endemic fish varieties (Puntius titteya) outside the island may threat to the ornamental fish trade of Sri Lanka. A high proportion of exporters (80%) are over depended on the wild collection which leads to overexploitation of demanded species. Further, natural habitats of the wild population are negatively affected by deforestation and environmental pollution. Therefore, improving the captive breeding for wild catch species is important to ensure the sustainability of ornamental fish trade.
Screening the Effects of Microplastics on Selected Invertebrates along Southern Coastal Belt in Sri Lanka: A Preliminary Approach to Coastal Pollution Control
(Uva Wellassa University of Sri Lanka, 2019-02) Wijethunga, H.N.S.; Athawuda, A.M.G.A.D; Dias, P.C.B; Abeygunawardana, A.P.; Senevirathna, J.D.M.; Thushari, G.G.N.; Liyanage, N.P.P.; Jayamanne, S.C.
Primary and secondary microplastics entering into coastal and marine environment are potentially harmful to the health of aquatic organisms. Current study intended to assess plastic pollution effects on sessile invertebrates along the Southern coastal belt of Sri Lanka during July-December 2018. Twelve sampling sites (Hambantota, Godawaya, Rekawa, Tangalle, Dickwella, Polhena, Mirissa, Weligama, Unawatuna, Gallefort, Dodanduwa and Hikkaduwa) with different anthropogenic activities were selected as representing 03 districts (Hambantota, Matara, Galle) of Southern province. Biodiversity survey was conducted to identify prevalence of natural inhabitants in selected regional coasts and 03 dominant coastal mollusks: Saccostrea cucullata (Rock Oyster), Littorina sp. (Periwinkle) and Patella sp. (Limpets) were selected for screening microplastics accumulation level. Alkaline digestion protocol was identified as the most suitable procedure for microplastics extraction considering plastics recovery rate and digestion efficiency of flesh. Randomly collected, pooled biological samples (N=20-2) were subjected to KOH digestion and resultant microplastics were verified using hot needle test. As results revealed, all 03 invertebrates were contaminated with microplastics accumulation at average rates of 7.2-2.8counts/g in all sampling sites. Majority of contaminated microplastics were filamentous types (>90%) followed by rod shapes (1%). Microplastic accumulation rate varied significantly according to the type of species (p<0.05) due to differences of their feeding mechanism. Further, filter feeding organisms (Rock Oysters) were highly susceptible in accumulation of microplastics (7.24.1counts/g) in their bodies, while plastic accumulation rate was highest in oysters from Hambantota. Microplastic accumulation rate of mollusks was not significantly different according to the sampling site due to closer proximity (p>0.05). Tourism, unsustainable coastal fishery and harbor operational activities were identified as key factors affecting on higher plastic pollution level on Southern coast. Current study reflects negative aspect of plastic pollution on intertidal organisms.
Species Limits in Curvularia: Updated Backbone Phylogeny and Fresh Collections from Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Ferdinandez, R.S.K.H.S.; Udayanga, D.; Deshappriya, N.; Munasinghe, M.L.A.M.S.; Manamgoda, D. S.
The genus Curvularia comprises of fungal species frequently encountered as saprophytes, endophytes and pathogens. Both living and dead weeds as well as crops are well known for the survival and completion of life cycles of Curvularia in nature. Molecular phylogenetic assessments are leading to precise identification of species in this genus from closely related taxa since morphological identification alone is often insufficient for species discrimination. Updated molecular phylogeny with all the existing Curvularia species is essential in order to infer phylogenetic relationships for freshly collected strains. The major objective of this study is to assess the evolutionary relationships of species of Curvularia collected from Poaceous crops and related weed hosts in Sri Lanka incorporating them in an updated backbone phylogeny with all of the available ex-type Curvularia sequences. Fresh collections were made from selected Poaceous weeds, rice and maize crops and morphological characters were assessed based on microscopic imaging and culture based studies. An updated backbone phylogenetic tree was constructed based on ribosomal Internal Transcribed Spacer region and partial Glyceraldehyde 3-Phosphate Dehydrogenase using maximum parsimony, was used to place the fresh collections within the genus. In addition, Phylogenetic Informativeness (PI) profiling test was performed to evaluate the informativeness of loci at species level phylogenetic discrimination. The PI profiling proved that the GPDH is the highest informative locus among the loci compared for this genus. The fresh collections of Curvularia from local study sites which were incorporated in the current phylogeny were grouped within several different clades such as geniculata-clade, hominis-clade and lunata-clade, emphasizing the existence of diverse array of species among fresh collections. Therefore, it is vital to collect more samples from both crops and weed residues in order to establish impact on these pathogens on crops and to understand their host range and shifting patterns of life modes.
Study on Diversity and Abundance of Cetaceans off Mirissa, Southern Coast of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Senadeera, S.K.; Thilakarathne, E.P.D.N.; Liyanage, U.S.P.K.
Sri Lanka is rich with marine cetaceans (whales, dolphins and porpoises) and mainly whale watching industry has immensely developed in Mirissa, Southern coast of Sri Lanka. But up to date surveys on cetacean populations in Southern marine water is in unsatisfactory level. Hence, a shipboard survey to identify their diversity and abundance was conducted in Southern marine water off Mirissa for 48 days during August - December 2018. 5 baleen whales (suborder Mysticeti) and 8 toothed whales (suborder Odontoceti) were recorded during the survey period (13 total species). Blue whale (Balaenoptera musculus) was the most common type of baleen whale with 443 sightings in 80010´- 80046ˊ E ,05055ˊ- 05017ˊN and 1 - 3 range was their pod size. In addition to that, 60,4 and 3 sightings of Bryde’s Whales (Balaenoptera edeni), Fin whales (Balaenoptera physalus) and Ormura Whales (Balaenoptera omurai) were recorded respectively. Spinner Dolphin (Stenella longirostris) was the highest abundant toothed whale type with 2765 sightings. In addition to that, 571 of Bottlenose Dolphin (Tursiops truncatus), 125 of Stripped Dolphin (Stenella coeruleoalba), 75 of False Killer Whale (Pseudorca crassidens), 54 of Rissos Dolphin, (Grampus griseus), 30 of Pilot whale (Globicephala macrorhyncus), 7 of Killer Whale (Orcinus orca), 6 of Sperm whale (Physeter macrocephalus) and 3 of Humpback Whale (Megaptera novaeangliae) were sighted. As per whale watcher’s data, Humpback Whales were recorded in Southern coast after 2015. Since the whale watching industry in Southern coast is mainly rely on Blue whale population, they are highly vulnerable group from whale watching, shipping and fishing activities. Results provide important information on the conservation status of cetaceans. Therefore, a powerful management measure is highly needed for the conservation of cetacean populations and the sustainability of whale watching industry.
Zooplankton Studies in East Coast of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2019-02) Koshika, K.; Wimalasiri, H.B.U.G.M.; Jayasinghe, R.P.P.K.; Guruge, K.P.G.K.P.
Zooplankton plays a vital role in marine environment by transferring the energy to higher trophic levels through the food web. However, the studies on zooplankton in the coastal water of Sri Lanka especially in the East coast are deficient. The present study was conducted to investigate zooplankton abundance in East coast of Sri Lanka in marine resources survey using the Research Vessel: Dr. Fridtjof Nansen during June to July 2018. Twenty-five samples were obtained from five transects using WP2 plankton net with 180µm mesh size. The samples were collected vertically from 30 m, 100 m and 200 m depths. In the laboratory; zooplankton was identified to the lowest possible taxonomic groups using standard keys and counted. The results revealed that zooplankton are dominated by the Phylum Arthropoda (63%), followed by Chordata (20.6%), Sarcomastigophora (7.4%), Chaetohnatha (4%), Cnidaria (2.5%), Annelida (1%), Echinodermata (0.4%), Mollusca (0.4%) and Ciliophora (0.2%). The highest (13053.57 m-3) and lowest (5747.43 m-3) abundance were recorded at transects near Mullaitivu and Batticaloa respectively. The study showed that there was no significant difference (p>0.05) of the abundance of zooplankton among the sampling stations. However, abundance of the zooplankton between shallow and offshore sampling stations were significantly different (p <0.05). The abundance of zooplankton at the depth of 100 m indicated an increasing trend towards Batticaloa. Offshore (100 m and 200 m) zooplankton abundance (2697 m-3) at 30 m depth was higher than the abundance of nearshore samples (1298 m-3). This study revealed that there are spatial variations of zooplankton in East coast of Sri Lanka and it may affect the fish production in the area. Therefore, further comprehensive studies on zooplankton are recommended to find out the possible reasons for such variations which could be useful in managing the marine environment.

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