Sumouli Roy,Rina Paladhi,Abhijit Mitra,



Digha coast,Nitrate and Phosphate,Aila,COVID lockdown,


West Bengal is a maritime state in the northeastern part of the Indian subcontinent with a coastal area of 10,158.22 sq. km. The coastal region consists of the Digha coast, which is noted for its tourism and fish landing activities. We highlight in this paper, a load of nitrate and phosphate during premonsoon in the aquatic phase of Digha for more than three decades (1984 – 2020) to observe the trend of these two variables, which are important components of sewage. A uniform increase in the concentrations of the nutrients is observed except in the years 2009 and 2020. A sudden peak observed for both the nutrients during 2009 may be attributed to Aila, a super cyclone that hit coastal West Bengal on 25th May 2009. The dip in the levels of nutrients during 2020, may be the effect of the COVID lockdown phase in the state during which all the tourism and fish landing activities were completely paralyzed.


I. Agarwal, S., Mitra, A., Pal, N., Zaman, S., Pramanick, P., Mitra, A., “Perturbation in Dissolved Oxygen trend due to Super Cyclone Aila in the Lower Gangetic Delta Region”, Journal of Environmental Science, Computer Science and Engineering & Technology, vol. 4, no. 4, pp: 939-943, 2015
II. Chaudhuri, A., Mitra, A., Trivedi, S., Gupta, A., Choudhury, A., “Phosphate and Nitrate status in the east coast of Indian Subcontinent”, Seminar on Our Environment: Its Challenges to Development Projects, American Society of Civil Engineers – India Section, Kolkata, 1994
III. Choudhury, A. K., Pal, R., “Phytoplankton and nutrients dynamics of shallow coastal stations at Bay of Bengal, Eastern Indian coast”, Aquatic Ecology, vol. 44, pp: 55–71, 2010
IV. CPCB, “Municipal sewage pollution along Indian coastal waters” Central Pollution Control Board, Delhi, 2002
V. Haggard, B. E., Stanley, E. H., Storm, D. E., “Nutrient retention in apoint-source-enriched stream” Journal of the North American Benthological Society, vol. 24, pp: 29–47, 2005
VI. Howarth, R. W., Marino, R., “Nitrogen as the limiting nutrient for eutrophication in coastal marine ecosystems: evolving views over three decades”, Limnology and Oceanography, vol. 51, pp: 364–376, 2006
VII. Jayachandran, P. R., Bijoy Nandan, S., Sreedevi, O. K., “Water quality variation and nutrient characteristics of Kodungallur-Azhikode Estuary, Kerala, India” Indian Journal of Geo-Marine Sciences, vol. 41, pp: 180-187, 2012
VIII. Klaus, K., Pat, H., “Disposal of sewage to the ocean’a sustainable solution?”, Marine Pollution Bulletin, vol. 33, no. 7-12, pp: 121-123, 1996
IX. Lawal, I., Ahmed, A., “Physico-chemical parameters in relation to fish abundance in Daberam Reservoir, Katsina State, Nigeria”, Department of Biology, Faculty of Natural and Applied Sciences, Umaru Musa Yar’adua University, Katsina. Katsina State, Nigeria, 2014
X. Luger, M., Brown, C., “The impact of Treated Sewage Effluent on Urban Rivers”, An ecological, Social and Economic Perspective., 1999
XI. Mitra, A., “In: Sensitivity of Mangrove ecosystem to changing Climate”, Publisher Springer, India, DOI: 10.1007/978-81-322-1509-7, ISBN 978-81-322-1508-0 (Hardcover), 978-81-322-2882-0 (Softcover), pp: XIX 323, 2013
XII. Mitra, A., “Mangrove Forests in India”, Publisher Springer, Cham, DOI:, ISBN 978-3-030-20594-2 (Hardcover), 978-3-030-20595-9 (eBook), pp: XV, 361, 2020
XIII. Mitra, A., Banerjee, K., Sengupta, K., “Impact of AILA, a tropical cyclone on salinity, pH and dissolved oxygen of an aquatic sub-system of Indian Sundarbans”, National Academy of Science Letters, India, vol. 81 (Part II), pp: 198-205, 2011
XIV. Mitra, A., Halder, P., Banerjee, K, “Changes of selected hydrological parameters in Hooghly estuary in response to a severe tropical cyclone (Aila)”, Indian Journal of Geo Marine Sciences, vol. 40, no. 1, pp: 32-36, 2011
XV. Mitra, A., Sengupta, K., Banerjee, K., “AILA and its impact on Gangetic delta”, Environment Watch – A Newsletter of Indian Chamber of Commerce, pp: 5-6, 2009
XVI. Mitra, A., Zaman, S., “Basics of Marine and Estuarine Ecology”, Publisher, Springer New Delhi, DOI:, ISBN 978-81-322-2705-2 (Hardcover), 978-81-322-3819-5 (Softcover), pp: XII 483, 2016
XVII. Nielsen, S. L., Sand-Jensen, K., Borum, J., Geertz-Hansen, O., “Phytoplankton, nutrients and transparency in Danish coastal waters”, Estuaries, vol. 25, pp: 930–937, 2002
XVIII. Strickland, J. D. H., Parsons, T. R., “A practical handbook of seawater analysis. 2nd (Ed.)”, Journal of the Fisheries Research Board of Canada, vol. 167, pp: 1-310, 1972
XIX. Sulaiman, A., Attalla, E., Sherif, M. A. S., “Water Pollution: Source and Treatment”, American Journal Environmental Engineering, vol. 6, pp: 88–98, 2016. doi: 10.5923/j.ajee.20160603.02
XX. Young-Jin, S., Rousseaux, P., “An LCA of alternative wastewater sludge treatment scenarios”, Resource, Conservation and Recycling. (Elsevier Science), 2001
XXI. Zaman, S., Agarwal, S., Mitra, A., Amin, G., Pramanick, P., Mitra, A., “Impact of Aila on the Dissolved Oxygen level in the Indian Sundarbans region”, Journal of Energy, Environment and Carbon Credits (STM), vol. 5, no. 3, pp: 1-4, 2015

View Download