Where is dissolved oxygen likely to be lowest

a) At the bottom of a deep lake

b) In the fastest part of a stream

c) along the edge of a fast river

d) at the surface of a tidal pool

The answer is A. at the bottom of a deep lake (Apex)

D. and when water is hot

Rapidly moving water, such as in a mountain stream or large river, tends to contain a lot of dissolved oxygen, whereas stagnant water contains less. Bacteria in water can consume oxygen as organic matter decays. Thus, excess organic material in lakes and rivers can cause eutrophic conditions, which is an oxygen-deficient situation that can cause a water body "to die.

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water near the surface of the lake - the epilimnion - is too warm for them, while water near the bottom-the hypolimnion - has too little oxygen. Conditions may become especially serious during a period of hot, calm weather, resulting in the loss of many fish.