Indian Journal of Geo Marine Sciences Vol.46 (07), July 2017, pp. 1274-1286 Spatiotemporal variation of water quality and assessment of pollution potential in Paradip port due to port activities Ranjan Kumar Mohapatra & Chitta Ranjan Panda* Environment & Sustainability Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar-751013, India *[E-mail: crpanda@immt.res.in] Received 21 January 2015 ; revised 20 September 2016 Present study focused on the evaluation of spatial and temporal variation in different bio-physicochemical parameters at ten different locations inside port harbour by applying statistical and multivariate approaches. Various physico-chemical parameters along with chlorophyll-a, phytoplankton, total viable and coliform bacteria were analysed for the harbour water throughout the year. Seasonal changes responsible for temporal variations were observed during monsoon, pre-monsoon and post-monsoon. Noticeable spatial variation was found due to port’s ongoing activities mainly at Iron ore handling berth, South Quay, East Quay, ADB-Coal berth, General cargo berth and Fertiliser berth. From the cluster and correlation analysis, greater inter dependency are found among the variables like phytoplankton, chlorophyll-a, PO 4 , NO 3 , NH 3 , TSS, Cr, DO, BOD and pH. [Keywords: Port activity, harbour water quality, spatiotemporal variation, factor and cluster analysis] Introduction Bay of Bengal (North Indian Ocean) is a unique dynamic system with reference to seasonal changes due to immense river discharges, excess precipitation and evaporation, frequent depression, wind direction and cyclones 1 . In India, Paradip Port is one of the major ports, acting as the gateway of national and international maritime trade transactions situated in Odisha coastline of Bay of Bengal. Paradip Port harbour is considered as semi-closed water body affected mainly by loading and unloading operations and nearby cargo storage heap runoff which may cause severe alteration of nearby coastal ecosystem. The chief materials handled by the port are coal, iron ore, fertilizer, petroleum products and various other minerals. The material handling through port may influence the concentration of nutrients, dissolved oxygen, chlorophyll, phytoplankton population, bacterial load, etc. It is generally agreed that, the pollution in surface water system may reach a critical level of considerable influence of tidal currents on the vertical mixing of the port water 2 . Nutrient input to the sea may occur anthropogenically or through natural physical, chemical and biological processes. In the recent years nutrient delivery to coastal areas has increased as a consequence of human activity, mainly due to agricultural practices, terrestrial and sea-based industrial runoff and sewage discharges 3 . Adjacent coastal waters are also inevitably affected by the nearby ports that can be considered as a transition zone between the natural environment and the area impaired by port activities. Sea ports are very complex systems with a broad range of environmental issues relating to water, wastewater, continual dredging, waste production, maintenance operations, recreational activity and storage, loading and unloading of raw materials and finished products 4 . Phytoplanktons are the major constituents of the sea surface water which are mainly affected by various environmental factors. Chlorophyll-a is the primary photosynthetic pigment, and its concentration is an important indicator of phytoplankton abundance in coastal waters. Higher phytoplankton count indicated as blooming stage responsible for the eutrophication condition, which could be harmful to marine ecosystems 4 . Above phenomenon occurs due to the addition or depletion of nutrient in the water system by means of port and nearby industrial