Frigid weather…ice sculptures sparkling off the waterfalls…a stream flowing through the snow. A winter wonderland created in your own backyard. But wait, you cannot see anything under all that ice. Is everything OK down there?
Understanding what happens to your aquatic life makes it easier to be at ease in the winter until spring comes again.
First of all, your aquatic plants go into a dormancy state. Dormancy is a state in which there is metabolic inactivity. For plants it is temporary phase they go in during the winter. They stop growing and conserve their energy until the water temperatures start rising again.
This is a natural process plants go through to survive, so trimming them off in the Fall does not hurt them.
Some plants such as the Lotus do however need to be lower in the pond so that the tubers do not freeze.
You may think your fish have disappeared but they only go to the bottom of the pond in the winter seeking warmer water. Fish slow down and try to stay concealed in the warmest parts of the water.
Fish are poikilothermic animals (in other words cold-blooded). Their body temperatures are regulated by the surrounding temperature of the water. In the winter, the warmest part is the bottom layers of the pond and sometimes you will see fish line up in rows. They are trying to fit in as many into the warm pocket of water as possible.
Fish go into a state of torpor (a semi-hibernation state). Torpor is a shorter phase of being than hibernation. They experience reduced body temperatures, slower metabolism, slow reaction time, reduced breathing rate and other body functions. Therefore, you do not want to feed your fish as they cannot digest foods. During this state, the fish conserve their energy by slowing down.
Do not chop or bang the ice on the pond’s surface as the vibrations can harm the fish when they are in hibernation. Also do not add any salt treatments as the salt will actually lower the water temperatures even more.
That explains plant and fish, but what about the frogs and turtles?
Frogs are found in almost all types of extreme environments. They have learned to adapt nicely. Frogs use hibernation to survive the cold winter temperatures. In a state of hibernation an animal’s metabolism slows down drastically. They can literally sleep the winter away as it conserves its body’s energy. In the Spring it ‘wakes up’.
Aquatic frogs hibernate under water. They need to be near oxygen-rich water and spend most of its winter just lying on the bottom of the pond. Frogs do not freeze even though ice crystals can form in their body cavity and under their skin. A high concentration of glucose in their vital organs keeps them from freezing. Their breathing can stop and heart stop beating so that they seem dead.
However when water temperatures rise, they thaw out, their heart starts beating and they start breathing again. So in the spring when you have ‘dead’ frogs in the pond you might want to give them a little more time to see if they hop away.
Turtles are ectothermic animals that get their body heat from the air, water and ground. Aquatic turtles hibernate in the bottom of the pond. They snuggle deep into the debris in the bottom. They prefer being buried. They let themselves get cold and as a result their bodies slow down and do not eat anymore. Their hearts slow down so that they only beat once every several minutes. They stop breathing through their lungs. They need very little oxygen to survive. They get their oxygen from the water. Oxygen actually enters their bodies through specialized skin cells that are in the tail. They ‘breathe’ through their tails! They can do this for several months at a time. When spring comes, the turtles will warm back up and again seek warm places to bask in the sun!
Since water is a good insulator and retains heat better than other environments it is a great place for your aquatic life to hang out until spring. So no worries…it’s Mother nature taking care of her creatures!
Sleep tight little creatures till next spring!