Waning of plankton food web in the upstream region of the Cochin backwaters during the southwest monsoon
DRS at CSIR-National Institute of Oceanography
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Title |
Waning of plankton food web in the upstream region of the Cochin backwaters during the southwest monsoon
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Creator |
Jyothibabu, R.
Madhu, N.V. Martin, G.D. Aneesh, C. Sooria, P.M. Vineetha, G. |
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Subject |
Aquatic Communities
Phytoplankton Trophodynamic cycle ISW, India |
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Description |
Heterotrophic bacteria (0.2-2 ?m), pico-phytoplankton (0.2-2 ?m), nano-phytoplankton (2-20 ?m), micro-phytoplankton (>20 ?m), heterotrophic nanoflagellates (2-20 ?m), and micro-zooplankton (20- 200 ?m) present in the Cochin backwaters were quantified during the Southwest Monsoon High fresh water influx during the period transformed the Cochin backwaters into an extensive fresh water zone with high levels of nutrients (nitrate av 20 ?M; phosphate av 3 ?M), which favoured high phytoplankton abundance (av 31 � 9 x 104 No L-1) and chlorophyll a (av 5.2 � 3.2 mg m-3) Autotrophic pico-plankton and nano-plankton contributed the majority (av 69 � 16%) of the total chlorophyll a while heterotrophic bacteria was found to be high throughout the study area (av 3 � 0.6 x 108 No L-1) Abundance of heterotrophic nano-flagellates and micro-zooplankton were markedly lower in the freshwater dominant region (av 0.5 � 0.3 x 106 No L-1 and av 3 � 1 No L-1) as compared to the downstream region (av 6 � 3 x 106 No L-1 and av 3222 � 3619 No L-1) This clearly indicated a weak microbial food web in a major part of the Cochin backwaters during the Southwest Monsoon The ecological implication is that it leads to inefficient transfer of bacterial and pico/nano-phytoplankton biomass to higher trophic levels This study provides further evidences to our earlier observation that most of the heterotrophic bacteria and phytoplankton carbon in monsoonal estuaries gets transported to the coastal regions during the Southwest Monsoon.
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Date |
2016-08-30T10:59:27Z
2017-09-30T03:12:38Z 2016-08-30T10:59:27Z 2017-09-30T03:12:38Z 2015 |
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Type |
Journal Article
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Identifier |
Indian Journal of Geo-Marine Sciences, vol.44(8); 2015; 1145-1154
0379-5136 http://drs.nio.org/drs/handle/2264/7684 |
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Language |
en
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Relation |
Indian J Geo-Mar Sci
SCI |
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Publisher |
CSIR-NISCAIR
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