Question

mountaineer climbing the Everest, experience the following fact explain the fact with the scientific reason: he found fishes alive below the ice​

Answer 1

There are 2 reasons for this question

1) solubility of oxygen increases as temp decreases

2)ice has maximum density  at 4C there fore the ice at 0,-1,-2being less dense than water comes to the surface and floats which acts as an insulating layer and prevents freezing below certain heights

Answer 2

Underneath the frozen upper layer, the water remains in its liquid form and does not freeze. Also, oxygen is trapped beneath the layer of ice. As a result, fish and other aquatic animals find it possible to live comfortably in the frozen lakes and ponds. ... This irregular expansion of water is called anomalous expansion.