Question

A recent case study conducted in the Edulabad Water Reservoir (EBWR) has shown that the accumulation of heavy metals in fishes is more in the pre-monsoon season than the monsoon season. Which of the following statements supports the seasonal change in accumulation?

• A. Increased acidic condition of the water
• B. Decreased acidic condition of the water
• C. Increased temperature of the water
• D. Decreased temperature of the water

Answer 1

Answer: (B), (C)

The correct options are
B Decreased acidic condition of the water
C Increased temperature of the water

$\bullet$ The study on seasonal variation in the accumulation of heavy metals in the Edulabad Water Reservoir (EBWR) concluded that the accumulation of heavy metals is more during the pre-monsoon season than the monsoon season.
$\bullet$ This conclusion can be supported by the following points (i) The pH of the water during the pre-monsoon season is alkaline precipitating the metals to form an insoluble toxic metal oxide that cannot be degraded by the fishes. (ii) Temperature of the water is high during the pre-monsoon season. Higher the temperature of the water lesser the dissolved oxygen available. This in turn increases the rate of assimilation that results in the deposition of these insoluble metal oxides in the liver and kidney.