Why do aquatic species feel more comfortable in the lakes in winter than in summer?

Hello student
In cold winter months, lakes and rivers freeze over forming ice.
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.
Ice does not allow heat to pass through it easily, so the freezing of the waters below is a very slow process. At depths below 30 metres, temperatures are cold and stable, but food is scarce. As a result animals have adapted to this situation by growing more slowly.