Sudden Death of Fishes in Meghna river estuary: A First Report of Mass Fish Death in Meghna River

Abstract

Water bodies and its biodiversity are being hampered as results of water pollution. Sudden deaths of fish in the river Meghna have been observed for the last 5 years during pre-monsoon periods. This study was conducted to report the causes of sudden fish mortality in six-kilometer-wide areas of the Meghna River from Motlob Uttar Upazila of Chandpur to Gazaria Upazila of Munshiganj from March 20 to April 4, 2023. Nine types of deathfish, including bearded worm goby (Taenioides cirratus), Pama croaker (Otolithoides pama), Indian river shad (Gudusia chapra), tank goby (Glossogobius giuris.), spotted snakehead (Channa punctata), striped snakehead (Channa striata), pangas catfish (Pangasius pangasius), long-whiskered catfish (Sperata aor), Ganges river sprat (Corica soborna), etc., and other aquatic animals like Macrobrachium sp., crabs, mussels, oysters, etc., were observed in these affected areas. Key water quality parameters, including dissolved oxygen (1.0–2.5 ppm), PH (6.0–6.2), ammonia (1.6–2.1 ppm), water color, and odor, were not congenial during the mortality periods. Other parameters like temperature and alkalinity were within suitable ranges. As frequently occurs this phenomenon, further intensive investigation is required to identify the cause of sudden fish death and better management.