Question

How does the anomalous expansion of water help aquatic life?

Answer 1

The anomalous expansion of water helps preserve aquatic life during very cold weather. When the temperature falls, the top layer of water in a pond contract becomes denser and sinks to the bottom. A circulation is set up until the entire water in the pond reaches its maximum density at 4°C. If the temperature falls further, the top layer expands and remains on the top till it freezes. Thus even though the upper layer is frozen, the water near the bottom is at 4°C and, hence the fish can survive in it easily.