Knocking on the Door of an Icy World

by | Dec 31, 2023 | Animals, Reflections & Celebrations

   Hello Ice, my cold hardened one.   Your beauty and chill is hard to take, yet there are hidden gems in all natural wonders.  It is difficult to resist the temptation to “break the ice” with a rock, a stick or with one’s foot.  I admit that I threw a few rocks onto the icy surface of the lake just to observe the phenomenon of the them bouncing and sliding across the ice.

   But what happens to the life within a lake once the ice has formed in winter? 

   The temperature of the water throughout the seasons effects the density of water resulting in lake stratification.  During the summer, lakes have a warmer layer at the top, due to the amount of sunlight warming the surface water which is less dense than deeper water.  However, during the winter the warmest layer of water is usually at the bottom of a lake, while the top layer is subject to colder temperatures including freezing.  

  Many animals such as amphibians, reptiles, and fish live in the lower levels of a lake where the temperature tends to be warmer in a large, deep body of water while the surface of a lake may be frozen over. 

Brumation occurs in reptiles and amphibians in the winter and is similar to the deep state of inactivity that some mammals go through during hibernation (such as ground squirrels and marmots).  However, reptiles and amphibians can wake up and move around occasionally during brumation. Some frogs burrow at the muddy bottoms of lakes, obtaining oxygen through their skin.  While aquatic turtles obtain oxygen through their cloaca (butts) during brumation.

   Native fish are adapted to surviving throughout the winter by moving into the deeper, less dense water of a lake and by going into a state of torpor (reduced metabolism and activity).  Some cold-water fish have anti-freeze proteins in their bodies that prevent ice crystals from forming in their tissues. 

   So, there can be plenty of life “pausing” at the bottom of a frozen lake in the winter through a variety of amazing adaptions.  In retrospect, tossing the rock onto the surface of the frozen lake likely created a loud sound which may have caused some alarm or curiosity for the inhabitants of the lake that might have been alert enough to notice it.

    From the world of brisk winter air, to the world of cold and frozen water, I toss these stones in peace, as sound waves echo across the division of these worlds atop the ice.  Reminding the lake life that mobility is afoot above for some, and that the seasons will soon bring warmth and animation!