Question

Regarding the Epilimnion layer, which of the following statements is correct?

1. It is the bottom-most layer of the lake, characterized by cold, nutrient-poor water.
2. The Epilimnion is the upper layer of the lake, containing freely circulating warm water.
3. It is well-aerated primarily due to decomposition processes occurring at the bottom.
4. The Epilimnion is well-lit but typically poor in dissolved oxygen.

• A. All
• B. ii only
• C. iii only
• D. iv only

Answer 1

Answer:

B. ii only

• The Epilimnion constitutes the uppermost layer of a thermally stratified lake.

• This layer is characterized by warm water that circulates relatively freely, largely due to wind action and photosynthetic activity.

• It receives ample sunlight, making it well-lit and suitable for phytoplankton growth.

• The oxygen levels in the Epilimnion are generally high, supported by both oxygen production from photosynthesis by aquatic plants and algae, and by atmospheric exchange facilitated by wind mixing.