International Journal of Modern Science and Technology Vol. 1, Issue 2, May 2016. Page 69-79. http://www.ijmst.co/ ISSN: 2456-0235 Research Article Assessment of water quality along the coast of Arabian Sea S.P.R. Kalaikathir 1, S. Begila David 2* 1Department of Chemistry, Womens’ Christian College, Nagercoil – 629 001. India. 2PG and Research Centre in Chemistry, Scott Christian College (Autonomous), Nagercoil – 629 003. India. *Corresponding author’s e-mail: [email protected] Abstract The present work was focused on the spatial and temporal variations of the coastal water quality from six shores along southwest coastline in Arabian sea in Kanyakumari District,Tamilnadu, India. The surface temperature was found varied from 21.2°C to 28.1°C, pH was varied from 7.66 to 8.9, conductivity, TDS, DO, CO 2, Alkalinity and nitrate remains almost same in all places in a particular season. Turbidity was ranged between 2 NTU to 11 NTU and maximum in Kanyakumari in all seasons. The observed DO was above 5 mg/l. Minimum BOD was observed in the present study. Carbon dioxide was found varied from 8 ppm to 25 ppm. Total alkalinity values lie within the maximum permissible limit. Both gross alpha and gross beta count were maximum in Muttom coastal water. Nutrient nitrate varied from 2 g/l to 4 g/l. Phosphate was much higher in Muttom in summer season. Sulphate was higher in Kanyakumari and Thengapattanam coast which indicates anthropogenically affected water quality. Keywords : Coastal water; Alkalinity; Turbidity; Spatial and temporal variation. Besides the natural changes which bring Introduction about variation in physical and chemical Water is one of the most important and parameters of water, human interventions also abundant compounds of the ecosystem. All create powerful disturbances on the marine living organisms on the earth need water for environment. The maximum production was their survival and growth. About 71% of the reported nearer to the coasts, within 50 m depths world we live in is occupied by oceans. The and gradually decreasing seaward (Nair et al., oceans cover 361 billion sq. km of earth and 1973). The valuable resources are exploited by contain 1368 billion cubic kilometers of water. fishing which is one of the major man made The Indian Ocean extends from Antarctica to the activities in the sea (Jennings et al., 2001). continent of Asia including the Red Sea and 'These differing atmospheric regimes produce Persian Gulf. The Arabian Sea and South China drastic physical, chemical and biological Sea are marginal seas. Compared to the open changes in the water column (Banse et al., 1959; ocean systems, the coastal region exhibits Pankajakshan et al., and Ramaraja et al., 1987). environmental gradients occurring spatially and A series of studies have been conducted on the temporally on micro or macro-scale. Estuarine physico - chemical parameters of the open and coastal waters always maintained an Arabian Sea (Jayaraman et al., 1959; Banse et intimate relation with the developmental al., 1959; Rao et al., 1984) south west coast of activities of man. Marine pollution is one of the India is well known for its surface production most serious problems of environment that poses compared to the other coasts. a major threat to the human health. Around the An integrated study of physico-chemical world, pollution has increased in prevalence by parameters has not been carried out so far along the growing industrialization and the population these regions, which lead to take up this study. explosions (Kennish et al., 1997). Seawater With a view to delineate environmental changes resources are considered to be one of the major of such a vulnerable region, detailed chemical components of environmental resources that are oceanographic studies have been undertaken to under threat either from over exploitation or monitor water quality of coastal waters of south pollution (Efe et al., 2001). west coast of Kanyakumari District.. The survey ©International Journal of Modern Science and Technology. All rights reserved. 69 Kalaikathir and Begila David, 2016. Water quality assessment along the coast of Arabian Sea provides important background information for the rich variety of fishes. Kanyakumari necessary for the study of the coastal processes. district was one of the worst affected districts in The objective of this study is to evaluate the India in the tsunami that ravaged the coasts of chemical oceanographic parameters of the various countries in South and South East Asia, coastal waters of Arabian sea in Kanyakumari on 26 December 2004. Since this district is district in Tamilnadu at different seasons to located at the extreme south of the Indian understand the probable changes that may arise subcontinent, the coastline is formed nearly by in the coastal waters based on the behavior of three seas; the Arabian Sea, the Indian some of the parameters like pH, Temperature, Ocean and the Bay of Bengal while the main part Turbidity, Conductivity, Total dissolved solids, of the coast of Kanyakumari district faces the Dissolved oxygen, Biological oxygen demand, Arabian Sea. Alkalinity and radioactivity and nutrients nitrate, The present study was carried out in six phosphate and sulphate. coasts such as Kanyakumari (place 1) which is an important tourist centre, Manakudy (place 2, Materials and methods Chothavilai (place 3, Muttom (place 4), Colachel Kanyakumari District is one of the 32 (place 5) and Thengapattanam (place 6). districts in Tamilnadu. It is located at the Manakudy, Muttom and Colachel coast are southernmost tip of peninsular India. It is predominantly occupied by fishermen. sometimes referred to as “land’s End’. It lies Thambaraparani river confluences with the between 77 ο 15’ and 77 ο 36’ of the eastern Arabian Sea near Thengapattanam. The Valliar longitudes and 8 ο 03’ and 8 ο 35’ of the collects the drainage from P.P. Channel and its northern latitudes. Its south eastern boundary branches and confluences with the Arabian Sea (coastal) is Bay of Bengal, while on the south near Manavalakurich which is nearer to Muttom. and south west, the boundaries are the Indian Manakudy estuary formed by the confluence of Ocean and Arabian Sea (Fig. 1). Since this river Pazhayar in between East and West district is located at the extreme south of the Manakudy villages. Pambarestuary confluences Indian subcontinent, the coastline is formed near Colachel. The present study was carried out nearly by three seas; the Arabian Sea, the Indian over a period of 12 months from June 2014 to Ocean and the Bay of Bengal while the main part May 2015. of the coast of Kanyakumari district faces the Arabian Sea. The Arabian coast is well known Fig. 1. Map showing the locations of the selected shores from where the sampling was done ©International Journal of Modern Science and Technology. All rights reserved. 70 Kalaikathir and Begila David, 2016. Water quality assessment along the coast of Arabian Sea Throughout the study period sampling of (Sundaramanickam et al., 2008). During the water was carried out on a monthly basis on the study period surface water temperature varied first week of every month between 6 am to 8 am. from 21.2 to 28.1. The minimum surface water Each sampling stations were visited monthly and temperature was recorded during winter and six samples of surface seawater were collected maximum was recorded during summer. All the from different locations of the same coast. station showed similar seasonal changes. Surface However, the locations for the collection of water temperature is influenced by the intensity samples in a particular coast were fixed. In the of solar radiation, evaporation, fresh water influx present study 12 months have been divided in to and cooling and flow from adjoining waters four seasons prevailing in this region viz (Govindasamy et al., 2000). monsoon (June to August), postmonsoon Table 1. Sea surface temperature of seawater (September to November), winter (December to from different coasts of Arabian Sea in February) and summer (March to May). Kanyakumari District. Values expressed are Sea water samples were collected every mean±SD month with a clean plastic can from six different Post stations. Samples for nutrient analysis were Place Monsoon Winter Summer collected in pre-cleaned polythene bottles. monsoon Preservation and transportation of the water 1 23.1±0.2 25.6±0.1 21.2±0.3 26.8±0.1 samples to the laboratory were as per standard 2 24.4±0.1 26.2±0.1 21.4±0.3 27.6±0.2 methods. Some physical parameters like 3 24.7±0.3 26.1±0.3 21.8±0.2 27.2±0.2 seawater temperature, pH, conductivity and 4 24.5±0.1 26.8±0.2 22.7±0.1 28.1±0.1 turbidity were measured directly in the field 5 using portable multi parameter analyzer. 24.2±0.2 25.3±0.1 21.8±0.4 27.8±0.3 Parameter TDS was determined gravimetrically. 6 23.4±0.4 25.9±0.3 21.5±0.1 27±0.3 Samples for DO and BOD were collected in pH BOD bottle and analyzed later. Carbondioxide and total alkalinity are estimated volumetrically. Ocean acidification is the ongoing decrease Nitrate, sulphate and phosphate are estimated in in the pH of the Earth's oceans, caused by the the laboratory by following standard methods uptake of carbon dioxide (CO2) from the (Grasshoff et al., 1999). Radioactivity was atmosphere (Caldeira et al., 2003). Between measured by alpha and beta counting system. 1751 and 1994 surface ocean pH is estimated to The analytical procedures for all parameters have decreased from approximately 8.25 to 8.14. were adopted from APHA and Trivedi and Goel Increasing acidity is thought to have a range of (1986).