RESEARCH ARTICLE Inventi Rapid: Water & Environment Vol. 2012, Issue 1 [ISSN 2229-7766] 2012ewe039, CCC: $10 © Inventi Journals (P) Ltd Published on Web 19/12/2011, www.inventi.in INTRODUCTION Water quality deals with the physical, chemical and biological characteristics in relation to all other hydrological properties. Any characteristic of water that effects the survival, reproduction, growth and production of aquaculture species, influences the management decisions, causes the environmental impacts or reduces the product quality and safety can be considered a water quality variable. Other factors being the same, aquaculture species will be healthier, production will be more, environmental impacts will be less and quality better in culture systems with “good” water quality than in those with “poor” water quality 9 . Water quality provides current information about the concentration of various solutes at a given place and time. Water quality parameters provide the basis for judging the suitability of water for its designated uses and to improve existing conditions. For optimum development and management for the beneficial uses, current information is needed which is provided by water quality programmers 16 . Unequal distribution of water on the surface of the earth and fast declining availability of useable freshwater are the major concerns in terms of water quantity and quality 8 . Rivers are subjected to various natural processes taking place in the environment, such as the hydrological cycle. As a consequence of unprecedented development, human beings are responsible for choking several lakes to death. Storm water runoff and discharge of sewage into rivers are two common ways that various nutrients enter the aquatic ecosystems resulting in the pollution of those systems 33&2 . Rivers and lakes are very important part of our natural heritage. They 1 PG & Research Department of Zoology, Khadir Mohideen College, Adirampattinam - 614 701, Thanjavur Dist, Tamil Nadu, India. E-mail: athimaha@yahoo.co.in *Corresponding author have been widely utilized by mankind over the centuries, to the extent that very few, if any are now in a natural condition 15 . A continuous monitoring of water quality is very essential to determine the state of pollution in our rivers. This information is important to be communicated to the general public and the Government in order to develop policies for the conservation of the precious fresh water resources 3 . However, there is no published periodical report on hydrochemistry, particularly in Kumbakonam area. In that context, the present study was carried out to assess seasonal variation of the water quality parameters in Cauvery delta region Kumbakonam, Tamil Nadu, India. MATERIALS AND METHODS Description of Study Area Kumbakonam in Thanjavur district is located at 10º 59 north latitude and 79º 23 longitude. It is about 131 kms from Chennai on the north, 40 kms from Mailaduthurai on the cast 40 kms from Thiruvarur on the south and 40 kms from the Thanjavur on the west. India, along the certain holy river-edge settlements have grown into religious centers or holy cities. Kumbakonam is one such city in Tamilnadu, along the Cauvery River; located in the delta between the Cauvery and its tributary Arasalar. The city has developed in the delta between the Cauvery River to the north and the Arasalar River, to the south and has a gentle slope from north-west to south-east. In the present context, there are vast agricultural wetlands to the north and south of planning area, with the rivers. Cauvery is a seasonal river of Tamil nadu. Water of cauvery is used for drinking and irrigation purposes in Kumbakonam region of Tamil nadu. Cauvery originates in Karnataka at Talakaveri, in Kodagu and flows down through Kushal Nagar, Srirangapatna, and Shivanasamudram before reaching Hogennikal and Srirangam in Tamilnadu. In erode in Tamilnadu two more tributaries join it – Noyyal and Amaravathi. In Trichirapalli, it branches out in to Coleroon and Cauvery. Cauvery again divides in to Arasalar and Cauvery at Papanasam, near Kumbakonam. Cauvery further fans out into 32 branches and all these further branch off into a number of small streams and falls into the Bay of Bengal at the historical place of Poompuhar or Kaveripoompatinam about 13 km north of Tharangampadi. Sampling and Analysis of Water In the present study, seasonal variations in physical and chemical parameters of river Cauvery were studied at Kumbakoam about 35 km from Thanjavur dt, Tamil Nadu. The sampling started on January 2010 and continued up to January 2011.The study period consists of 12 months. The river Cauvery there are three sampling station designated as station I (upstream of the river) station II (mid stream of the river) and station III (down steam of the river) were established for sampling purpose. Water samples were collected from three locations on monthly basis using a standard water sampler. At each station three samples were collected from 1/3, 1/2, and 2/3 width of the river along transect and mixed together to obtain a composite sample. All the samples were collected from the upper 15cm of the water surface and stored in polyethylene bottles fitted with screw caps. At the time of sampling, the air and water temperature were recorded by using alcoholic bulb and digital thermometer. Light penetration was recorded with the help of sacchi disk. Determination of pH and conductance were all so performed on site using portable meters (Henna pen type, Portugal). While all other parameters were analyzed by following standard methods given in APHA 5 and Trivedy and Goel 34 . These parameters were compared with the water quality standards to indicators to indicate probable pollution in river. RESULTS AND DISCUSSION Data of the physicochemical parameters of the river Cauvery for a period of one year (Jan 2010 to Jan 2011) are presented in the Table 1, 2 and 3. The mean and range values of physic- chemical parameters are listed in the Table 4. Presence of nutrient in water is judged on several factors among the various physicochemical, biological and biochemical factors are considered as most vital factor which indicates oxygen level, ionic status and biological activity in water respectively. The distribution of nutrients in River Cauvery at three stations presented in Fig 1-3. The water temperature was ranging from 25°C to 32°C during the study period. The minimum water temperature (25°C) was observed in October at station1 and maximum temperature (32°C) was observed in June at station 2. The mean value of temperature observed to be 28.23°C, 28.61°C and 28.69°C for the S1, S2 and S3 respectively. Temperature is an important biologically significant factor, which plays an Seasonal Changes in Distribution of Nutrients in River Cauvery at Kumbakonam in Tamil Nadu, India G Annalakshmi 1 , A Amsath 1 , A Maharajan 1* , Abstracts: Physico-chemical studies were conducted in river Cauvery situated in Kumbakonam, Tamil Nadu, India. The study was conducted from January 2010 to January 2011. The present paper deals with nutrient status in Cauvery river, for this three stations were selected for the sampling methods i.e., S1, S2 and S3 the main aim of the study was to determine the nutrient status of Cauvery River and the suitability of the water for domestic and other purposes, in the light of water quality criteria prescribed by WHO standards. The parameters analyzed were water Temperature, pH, dissolved oxygen, Free CO2, Calcium, Magnesium Sodium, potassium, Ammonia, Nitrate, Nitrite, Phosphate, Sulphate and Silicate. The results indicated that most of the physico-chemical quality parameters of River Cauvery were within the WHO limits for drinking water and, therefore, may be suitable for domestic purposes. However, nutrients levels were low during the study period and did not give any clear seasonal variation. The results revealed that the values of Nitrate and Phosphate do not compile with WHO standards. Water quality assessment of delta regions of Cauvery River revealed slightly contamination from anthropogenic activities. Key Words: Seasonal variations, distribution of nutrients, river Cauvery.