Bloom of Hemidiscus hardmannianus (Bacillariophyceae) and Its Impact on Water Quality and Plankton Community Structure in a Mangrove Wetland

An intense monospecies bloom of the centric diatom Hemidiscus hardmannianus (Greville) Mann. (Bacillariophyceae) occurred in the coastal waters of Sundarban mangrove wetland, India on 22 July, 2010. The species was abruptly flourished (mean density 8.86 × 106 cells/L) resulting intense green coloration of water. The greatest impoverishment of diversity and density of phytoplankton, micro- and mesozooplankton community was observed during the bloom. The phytoplankton community showed an extreme reduction in diversity (12 species to one) and sharp decrease in standing stock (12.84 × 103 to 8.86 × 106 cells/L) during this period. The late bloom condition coincided with sudden and huge arrival of a clupoid fish Hilsa ilisha which forms the most potential fisheries in Sundarban deltaic region. An attempt has been made to correlate the satellite remote sensing-derived information to the bloom conditions. The MODIS-Aqua derived chlorophyll and TMI satellite derived sea surface temperature and wind speed maps have been interpreted.

[1]  A. Alimov.  Changes in the structure of animal communities accompanying eutrophication and pollution of aquatic ecosystems , 2010, Doklady Biological Sciences.

[2]  Suna Zhang,et al.  Mesoproterozoic Calymmian Tintinnids from Central China , 2009 .

[3]  W. Verstraete,et al.  Initial community evenness favours functionality under selective stress , 2009, Nature.

[4]  Asokkumar Bhattacharya,et al.  Water quality management in the lower stretch of the river Ganges, east coast of India: an approach through environmental education , 2007 .

[5]  D. Beigt,et al.  Temporal variability of diversity and biomass of tintinnids (Ciliophora) in a southwestern Atlantic temperate estuary , 2005 .

[6]  S. K. Sasamal,et al.  Asterionella blooms in the northwestern Bay of Bengal during 2004 , 2005 .

[7]  Shailesh Nayak,et al.  Cover: Remote sensing of Trichodesmium blooms in the coastal waters off Gujarat, India using IRS‐P4 OCM , 2005 .

[8]  Xabier Irigoien,et al.  Phytoplankton blooms: a ‘loophole’ in microzooplankton grazing impact? , 2005 .

[9]  N. Godhantaraman.  Seasonal variations in species composition, abundance, biomass and estimated production rates of tintinnids at tropical estuarine and mangrove waters, Parangipettai, southeast coast of India , 2002 .

[10]  H. Claustre,et al.  Microzooplankton diversity: relationships of tintinnid ciliates with resources, competitors and predators from the Atlantic Coast of Morocco to the Eastern Mediterranean , 2002 .

[11]  T. Smayda,et al.  What is a bloom? A commentary , 1997 .

[12]  H. Müller,et al.  Maximum growth rates of aquatic ciliated protozoa : the dependence on body size and temperature reconsidered , 1993 .

[13]  D. Lynn,et al.  Global Production of Heterotrophic Marine Planktonic Ciliates , 1991 .

[14]  A. Subramanian,et al.  Mass mortality of fish and invertebrates associated with a bloom of Hemidiscus hardmannianus (Bacillariophyceae) in Parangipettai (southern India) , 1985 .

[15]  P. Verity,et al.  Relationships between lorica volume, carbon, nitrogen, and ATP content of tintinnids in Narragansett Bay , 1984 .

[16]  W. Thomas,et al.  Occasional blooms of phytoplankton during summer in Saanich Inlet, B.C., Canada , 1977 .