Peggy Bailey, age 10, of Gary, Indiana, for her question:
Where do fish go in winter?
Almost all the earth's waters teem with assorted fishes. Some thrive in icy polar seas, others enjoy life in the tropics or temperate zones. Some migrate with the seasons and when winter comes to our streams and lakes, certain fishes sink to the bottom and take a long rest.
We live in the temperate zone, where winter often freezes our lakes and streams. Under the ice, the fishes manage to survive, each in his own way. A pond rarely freezes solid and often the deeper water is not much cooler than it was during the summer.
However, the deeper levels may drop ten degrees or more when winter comes. For some fishes, this is too cool for comfort. For example, the whiskery catfish is quite sensitive to the cold. So is the bullhead. During the worst of the winter, they sink down to the bottom of their streams and go into a deep winter sleep.
Lake trout enjoy cool water and during the summer they tend to stay near the bottom, where the water is coolest. Winter suits them just fine and they range happily at all levels, from the bottom right up to just below the ice. As a rule, the whitefish prefer the medium level, about half way between the top and the bottom. There they stay active through summer and winter.
In summer we find the bass and the bluegill sunfish in the warm sunny water near the surface. They prefer warm water and are quite sensitive to the cold. When winter comes, they sink down to lower levels, where the water is a little warmer. They do not hibernate, but they do slow down and eat very little.
Altogether, more than 30,000 different fishes live in our watery world, and most of them live in the salty seas. All of them, of course, are born swimmers and many are free to roam for hundreds and even thousands of miles around the globe. Teeming schools of herring and mackerel travel far and wide in search of food. Many fishes migrate to warmer waters during the winter.
However, temperature changes in the sea are never as fierce as they are on the land. In summer the sea is somewhat cooler than the land and in winter it is somewhat warmer. The seasons there are not so hard on the fishes. And, being such good travelers, most species can migrate to the warmer or cooler seas that suit them best.
Though fishes are cold blooded creatures, many species prefer to live in polar seas. Many thrive in the Arctic, even when the surface is covered with chunks of wintry ice. Herring and mackerel, haddock and cod feast on the rich plankton off Alaska and Greenland, summer and winter. And the world's most bountiful fishing region is the chilly Humboldt current that flows from the Antarctic along the coast of Peru.