Influence of allochthonous input on autotrophiceheterotrophic switch-over in shallow waters of a tropical estuary (Cochin Estuary), India

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dc.contributor.author Thottathil, S.D.
dc.contributor.author Balachandran, K.K.
dc.contributor.author Gupta, G.V.M.
dc.contributor.author Madhu, N.V.
dc.contributor.author Nair, S.
dc.date.accessioned 2008-06-04T04:24:15Z
dc.date.available 2008-06-04T04:24:15Z
dc.date.issued 2008
dc.identifier.citation Estuarine, Coastal and Shelf Science, vol.78(4); 551-562p.
dc.identifier.uri http://drs.nio.org/drs/handle/2264/1087
dc.description.abstract Bacterial productivity (BP) and respiration (BR) were examined in relation to primary productivity (PP) for the first time in a shallow tropical ecosystem (Cochin Estuary), India. The degree of dependence of BP (6.3 199.7 mu g C L sup(-1) d sup(-1)) and BR (6.6 - 430.4 mu g C L sup(-1) d sup(-1)) on PP (2.1–608.0 mu g C Lsup(-1) d sup(-1)) was found to be extremely weak. The BP/PP (0.05-8.5) and PP/BR (0.02-7.9) ratios widely varied in the estuary depending on the season and location. There was a seasonal shift in net pelagic production from autotrophy to heterotrophy due to terrestrial organic matter input through rivers which enhanced the bacterial heterotrophic activity and very high pCO sub(2) (106-6001 mu atm) levels. The heterotrophic zones were characterized by low PP but high bacterial production and respiration leading to oxygen undersaturation and exceptionally high pCO sub(2). We propose that the CO sub(2) supersaturation caused by increased bacterial respiration (in excess of PP) was a result of bacterial degradation of allochthonous organic matter. This indicates that sources other than planktonic compartment need to be explored to understand the C-cycling in this estuary. These results are of particular relevance to tropical ecosystems in general, where the bulk of world's river discharges occur.
dc.language.iso en
dc.publisher Elsevier
dc.rights Copyright Elsevier[2008]. It is tried to respect the rights of the copyright holders to the best of the knowledge. If it is brought to our notice that the rights are violated then the item would be withdrawn.
dc.subject primary productivity
dc.subject bacterial productivity
dc.subject CO2 supersaturation
dc.subject tropical estuary
dc.title Influence of allochthonous input on autotrophiceheterotrophic switch-over in shallow waters of a tropical estuary (Cochin Estuary), India
dc.type Journal Article


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