As with most wildlife in the winter months, fish activity slows down and many pond owners may wonder where they disappear to during these long months.
Fish metabolism slows to a crawl in the winter. However, fish are always adventitious eaters and will snag a quick meal if it is available. That is why ice fisherman still are able to catch fish in the winter.
Otherwise, fish simply expend very little energy and therefore do not need much food to sustain life through the winter. You could say that they are in semi-hibernation, but are still alert to activity around them.
However, frogs and turtles will sink to the bottom and hibernate in the muck for the winter.
All of these animals do need liquid water to persist in the winter. If the water freezes solid, fish, frogs and turtles will all die. Be sure that your pond is a minimum of 3 feet deep in the Midwest and deeper as you move north.