Benthic macroinvertebrates diversity in Kokkilai Lagoon A preliminary

Benthic macroinvertebrates diversity in Kokkilai Lagoon: A preliminary survey EMM-2020 Centre for Environmental Studies University of Peradeniya Hettige. N. D. 1, * & Wickramaarachchi, W. D. N. 1 *Environmental Studies Division, National Aquatic Resources Research and Development Agency (NARA), Crow Island, Colombo 15, Sri Lanka INTRODUCTION Kokkilai Lagoon is an estuarine lagoon which is located in Mulathivu and Trincomalee Districts, North East of Sri Lanka. The Lagoon and its vicinity is one of the oldest protected areas in Sri Lanka having been declared a sanctuary on May 18, 1951, almost 59 years ago. The natural productivity and rich diverse resources of gives economic values to the lagoon (Krishanthan et al. , 2015). However, there were few studies conducted on aquatic biodiversity in northeast lagoons. RESULTS AND DISCUSSION A total of 1769 individuals of benthic macroinvertebrates belonging to three phyla (Mollusca, Annelida and Arthropoda), four classes (Gastropods, Bivalves, Polychaeta and Crustaceans) and 24 families were recorded from Kokkilai Lagoon. Class gastropods were found to be abundant in the total composition of benthic macroinvertebrates and nine families of gastropods were recorded. Littorinidae were the most abundant gastropod (67. 44%) family followed by Cerithiidae (8. 14%) and Haminoeidae (4. 75%) from the total abundance of benthic macroinvertebra [VALUE]% [VALUE]% Littorinidae Naticidae Neritidae Tellinidae Cerithiidae Dentallidae Cardiidae [VALUE]% Donacidae [VALUE]% Acmaeidae Mytilidae Arcidae Nassariidae Solenidae Thiaridae [VALUE]% Cyrenidae Veneridae Dentaliidae The Shannon index has been a popular diversity index in the ecological literature. It is used to determine the diversity of the biota. Veneridae Mytilidae Among the eight bivalve families recorded, Veneridae was the most dominant family (4. 58%). Four families of Polychaeta namely Nephtyidae, Nereididae (0. 40%), Pilargidiidae and Opheliidae were detected and Penaeidae, Gammaridae and Balanidae (0. 17%) were identified among crustacean families. Composition of Polychaeta Composition of Crustacea METHODS REFERENCES [VALUE]% The study was conducted in October 2017 and sediment samples were collected from nine randomly selected sampling sites in the Kokkilai Lagoon. Opheliidae 0. 11% Penaeidae Balanidae Gammaridae 0. 17% Sediment samples were collected using grab sampler [VALUE]% Haminoeidae Due to their high biodiversity, very limited mobility, relatively long life cycle, bottom-dwelling nature and their immense sensitivity to changes in their environment, macroinvertebrates can be used as ideal bioindicators for aquatic environments (Selvanayagam & Abril, 2016; Sharma et al. , 2013; Dacayana et al. , 2013; Tampus et al. , 2012; Jun et al. , 2012; Flores & Zafaralla, 2012). The main objective of this study is to identify the diversity of benthic macroinvertebrates in Kokkilai Lagoon. [VALUE]% Cerithiidae [VALUE]% Nephtyidae [VALUE]% Nereididae [VALUE]% Balanidae Pilargidiidae 0. 06% Polychaeta The overall Shannon diversity index of the lagoon was 1. 41. It is indicated that comparatively low diversity. Collected sediment samples were preserved using 70% Alcohol Sediment samples were wet sieved Shannon score does not take into account the sensitivity of taxa that were found. The Shannon score would be good because of a high abundance and even distribution of many pollutant tolerant taxa. However, Hawke, (1978) reported that diversity indices are good for indicating physical and toxic pollution which stress most species in a community without encouraging replacement species. He warns that high diversity does indicate good quality water but low diversity may not necessarily indicate low quality. ACKNOWLEDGEMENT Diversity index of macroinvertebrates was calculated. After separation benthic macro invertebrates were sorted and identified using standards guides This index confirmed that the aquatic health of lagoon is in moderately poor condition and low species diversity of the lagoon. Furthermore, the lagoon is dominated by the class gastropod. The findings of the study can be used as baseline data of the aquatic biodiversity of the lagoon. Composition of bivalve Composition of Gastropods 2. 88% Benthic macroinvertebrates are invertebrate organisms visible to the naked eye that live in aquatic water bodies as well as in, on or near the bottom of aquatic sediments (Aweng et al, 2012). CONCLUSIONS National Aquatic Resources Research and Development Agency and International Union for Conservation of Nature, Sri Lanka (Grant No. 2017/1. 17) is gratefully acknowledged for awarding a research grant. Aweng, E. R. , Suhaimi, O. , Nur Izzati, S. , Suhaimi, E. , & Nur Izzati, O. (2012). Benthic macroinvertebrate community structure and distribution in Sungai Pichong, Gunung Chamah, Kelantan, Malaysia. American International Journal of Contemporary Research, 2(1), 163– 167. Retrieved from www. aijcrnet. com Dacayana, C. M. L. , Hingco, J. T. , & Socorro, M. M. L. D. (2013). Benthic macroinvertebrate assemblage in Bulod River, Lanao del Norte, Philippines. Multidisciplinary Studies, 2(1), 2350– 7020. https: //doi. org/10. 7828/jmds. v 2 i 1. 398 Hawke, H. A. (1978). Invertebrate indicators of river water quality. In Proceeding of Symposium on Biological Indicators of Water Quality (pp. 12– 45). Tyne: University of Newcastle. Selvanayagam, M. , & Abril, R. (2016). Use of Benthic Macro Invertebrates as a Biological Indicator in Assessing Water Quality of River Puyo, Pastaza, Ecuador Mariadoss. American Journal of Life Sciences, 4(1), 1– 12. https: //doi. org/10. 11648/j. ajls. 20160401. 11 Krishanthan, G. , Thiruchchelvan, N. , and Mikunthan, G. (2015). Pedestal Study for Diversity of Fishes, Crabs and Shrimps in Kokkilai Lagoon of Sri Lanka, Advances in Biological Research, 9 (1), 49 -52. Sharma, S. , Dubey, S. , Chaurasia, R. , & Dave, V. (2013). Macro-invertebrate community diversity in relation to water quality status of Kunda River (M. P. ), India. Discovery Publication, 3(9), 40– 46. Tampus, A. D. , Tobias, E. G. , Amparado, R. F. , & Sinco, A. L. (2012). Water quality assessment using macroinvertebrates and physico-chemical parameters in the riverine system of Iligan City, Philippines. Advances in Environmental Sciences Bioflux, 4(2), 59– 68