Question

Which of the following statements regarding turnover in a lake is correct?

A) Fall turnovers and spring turnovers are exactly the same.
B) In fall turnover, dense water at 4°C sinks and disturbs sediments in the benthic zone.
C) The surface water gets to 4°C only by cooling.
D) In fall turnover, dense water at 4°C rises and disturbs sediments in the benthic zone.

Answer 1

In fall turnover, dense water at 4°C rises and disturbs sediments in the benthic zone. It helps redistribute nutrients and oxygen.

Step-by-step explanation:

The correct statement regarding turnover in a lake is d) In fall turnover, dense water at 4°C rises and disturbs sediments in the benthic zone.

During the fall turnover, the temperature of the lake water cools to 4°C, causing the dense water at this temperature to sink and disturb the sediments in the benthic zone. This process helps in redistributing nutrients and oxygen in the lake.

It is important to note that fall turnovers and spring turnovers are not exactly the same. In spring turnover, the surface water at 4°C rises and disturbs sediments in the benthic zone due to the warming temperatures.