Pillai, V K and Ponniah, A G and Vincent, D and David Raj, I (1983) Acidity in Vembanad Lake causes fish mortality. Marine Fisheries Information Service, Technical and Extension Series, 53 . pp. 8-15.
The sudden changes of variations in the environmental and climatic patterns in an area always cause certain undesirable and unforeseen events as well as problems. Immediately after the first monsoon rains, in the third week of June, an instance of mass mortality of fishes and clams was reported from the Vembanad Lake. The report indicated that large scale mortality of several groups of aquatic organisms were occurring mainly in the southern half of the lake. The unusual phenomena might have been caused by soil acidity. Hydrogen-ion concentration of the water showed that it was in acid range. The data revealed that the effect of pH reduction seemingly influenced the eco-system only up to the middle of the lake and coming towards the mouth of the estuary the effect appeared to have got neutralized, probably due to the regular tidal action. The reason for the persisting low pH could be that the river water input into the lake after several spells of monsoons showers has not been sufficient to flush the acids produced at the water soil interface continuing for several weeks as the monsoon this season had been weak and halting in the initial period.
|Uncontrolled Keywords:||Fish mortality; Vembanad Lake; Hydrogen-ion concentration; climatic pattern; aquatic organisms|
|Subjects:||Fish and Fisheries > Fish Toxicology|
Marine Environment > Fish Mortality
|Divisions:||CMFRI-Cochin > Marine Capture > Fishery Resource Assessment|
|Deposited By:||INVALID USER|
|Deposited On:||23 Sep 2010 11:49|
|Last Modified:||05 Jun 2012 09:56|
Repository Staff Only: item control page