Take a walk down to the creek today on a cold January day. Snow is falling and the temperatures have dropped below freezing. So how cold is Floyds Fork? This USGS graph shows the current temperature readings from the gauge station on Floyds Fork near Fisherville. While the air temperature has plunged way below freezing, the water temperature is maintaining a higher temperature just above freezing.
So why isn’t the creek frozen? One reason is that the moving water in the creek keeps the water molecules agitated and prevents them from sticking together. It is a common misconception that moving water doesn’t freeze, but this was proven wrong during the recent Polar Vortex when Niagara falls froze solid.
You may wonder where the aquatic creatures go during these frigid days of winter. They don’t build fires and curl up with a good book and a cup of hot cocoa like we may do to escape the cold. The fish who live in the streams of Kentucky are very well adapted to sustain seasonal temperature changes. Fish descend into the bottom of streams and lakes where the warmer water is in winter. Density of warm water is higher, causing it to sink to the bottom in winter. This is the same reason that ice cubes float in a glass of water.
Fish are cold-blooded or poikilothermic, meaning that their body temperatures vary with the surrounding temperature. During the cold of winter fish become less active. They find little pockets out of the way of fast moving water where they can stay still and conserve energy. As their metabolism slows, they eat less and wait out the coldest part of winter.
Some fish such as rainbow trout (pictured above) prefer very cold water and may be found throughout the water column even in the midst of winter. This is because these trout are native to cold mountain streams. They are not native to Kentucky, but are stocked by Kentucky Fish and Wildlife in Floyds Fork, William F. Miles Angler Lake, and William F. Miles Green Heron Lake in the fall and early spring (click here for the stocking schedule). Trout offer a fun fishing experience for anglers and then those who are not caught or eaten by herons and other animals naturally die-off during our warm summers when water temperatures climb.
If you can brave the cold, now is a great time for trout fishing and to enjoy the quiet beauty of winter in The Parklands. For more information about fishing in The Parklands, visit http://www.theparklands.org/Things-To-Do/Fishing
Story by Hannah Graham, Interpretive Ranger for The Parklands of Floyds Fork. This story is a feature topic for the Wednesday Wonders program held in the PNC Achievement Center weekly, centered on early-childhood education.