Southwest Monsoon Effect on Plankton Occurrence and Distribution in Parts of Bay of Bengal

• Main Author: M. ZAFAR
• Format: Article
• Language: English
• Published: Asian Fisheries Society 2007-07-01
• Series: Asian Fisheries Science
• Online Access: https://www.asianfisheriessociety.org/publication/downloadfile.php?id=310&file=Y0dSbUx6QTVPREkxTXpZd01ERXpOVFU0TURVeE5UZ3VjR1Jt
• ISSN: 0116-6514; 2073-3720

The present investigation was carried out for one year from March 1988 to February 1989 and focused on hydroplankton aspects in parts of Bay of Bengal. The hydrological factors were mainly governed by the monsoon and river systems flowing into the Bay. A marked seasonal fluctuation in salinity, dissolved oxygen, water temperature and suspended particles was observed, generally which was a unique feature of the northeastern coastal part of the Bay of Bengal. The higher abundance of phytoplankton was recorded in January (3332 cells.l-1) during the low turbidity and bright sunshine period. The minimum was found in August (1295 cells.l-1) when maximum rainfall and fresh water discharge were recorded. Total phytoplankton population were found to have a significant negative correlation with suspended particles at four stations in the study area (S1, r = - 0.887, P < 0.1; S2, r = -0.920, P < 0.001; S3, r = -0.807, P < 0.01; S4, r = -0.920, P < 0.001). Maximum density of zooplankton was recorded in September (326146.36 per 100 m3 ), which indicated a seasonal influence on the distribution pattern of the different groups of zooplankton. Hydromedusae, Mysids and Squilla were major indicator groups and they represented only <1% of the zooplankton population. The zooplankton abundance was not significantly correlated with phytoplankton (r = 0.24, P > 0.05).