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Indian Journal of Geo-Marine Sciences (IJMS) >
IJMS Vol.40 [2011] >
IJMS Vol.40(4) [August 2011] >
| Title: | Influence of river influx on phytoplankton community during fall inter – monsoon in the coastal waters off Kakinada, east coast of India |
| Authors: | Sooria, P. M.
Reny, P. D.
Jagadeesan, L
Nair, M. |
| Keywords: | Phytoplankton community
Size variation
River influx
Salinity
Nitrate
Coastal water off Kakinada
Bay of Bengal |
| Issue Date: | Aug-2011 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Significant changes
in phytoplankton community structure were observed in the coastal waters off
Kakinada
(Bay of Bengal) during fall intermonsoon (October) of 2006 and 2007. River
influx was more in October 2007 compared to those in October 2006. Phytoplankton
showed marked changes in composition and abundance between the two periods of
observation. Abundance was considerably higher in October 2007 (av. 150.9 ±
54.8 X 103 cells l-1)
compared to that of October 2006 (av.7.9 ± 4.8 X 103 cells l-1). Phytoplankton community was formed by larger diatoms in October 2007,
dominated by Hemidiscus
hardmannianus and Ditylum
brightwellii (300-500 μm in diameter) whereas in October 2006 smaller
diatoms such as Lioloma elongatum (2
- 4 μm), Thalassiossira subtilis (15
- 32 μm) and T. favus (60 - 140 μm) dominated. Both H. hardmannianus and D.
brightwellii occurred in bloom density throughout the study area (av.>
50´103 cells l-1). Agglomerative hierarchical
cluster analysis of phytoplankton species abundance showed two well separated
clusters (similarity ≤ 10 %) for 2006
and 2007. It reveals the variation in community structure between the two
periods of observation. Multidimensional scaling of species abundance
superimposed on scaled values of salinity and nitrate has shown that the
community shift was directly related to
environmental factors. Coastal
waters of western Bay of Bengal receive high freshwater inputs, particularly
during the southwest monsoon and the internal variations observed in the
Coastal waters of Kakinada could as well be relevant to the entire east coast
of India. |
| Page(s): | 550-558 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1033 (Online); 0379-5136 (Print) |
| Source: | IJMS Vol.40(4) [August 2011]
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