How Do Fish Live in a Frozen Pond?
How Do Fish Live in a Frozen Pond? Anyone who has fished through a hole in the ice knows that many fish are active in the winter. Usually, what we call a frozen pond is one whose surface is frozen.
This sheet of ice helps keep the water below from freezing, allowing fish to live in the pond during the winter. Fish are cold-blooded. In general, their body temperature is much the same as that of the water around them.
Some of them can become very cold without being harmed. They can live comfortably in the water of a pond in summer, or under the ice when the pond freezes over in winter. Fish can survive under the ice of a pond or lake for a few months.
In the fall, they feed heavily, storing up food energy to survive until spring. The fish may not find much to eat under the ice, but they will not need much food.
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 sheet of 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 meters, temperatures are cold and stable, but food is scarce.
As a result animals have adapted to this situation by growing more slowly. There are other dangers that fish face in freezing waters – like death. The body fluid of an ordinary fish can solidify if the temperature of the surrounding water drops below -5 °C.
So Arctic and Antarctic fish have adjusted to their surroundings in an interesting manner. Certain species of cod, flatfish have a reduced metabolic rate and produce antifreeze molecules called glycoprotein to reduce the freezing point of their body fluids.