Submitted by Nathan Bolls

If you want to “save 15 percent or more on car insurance, you…” That’s what you do! If you are a fish living in a place that enjoys four distinct seasons, you adapt. That’s what you do! We tough, adaptive Midwesterners may now enjoy a moment of silent smugness.

Having certain addictions, I went fishing on Monday, 23 November 2015. I sought not fins, but fact. My heavy duty spinning rod outfit was rigged with thermometer and bobber, set to measure water temperature in the piscine world of Bayer Pond. The meter, cast out twenty feet south of the east fishing pier, read 42 degrees Fahrenheit at a depth of three feet. Submersed in this water in our street clothes, we would last only a few minutes. Both water and fish will get much colder. The air temperature was 64 degrees.

Watching us succumb, the resident fish would simply do their thing: swim by or float nearby. They are active 24/7/365 1/4th. Taking into account all of the world’s fish species that endure significant water temperature variations, the picture is very complex. But, as Don Rasmussen mentioned in his “Outdoor Encounters” article in the 5 November 2015 Messenger, the Bayer Pond fish are slowing down and eating less.

Our fish, although now adapting to lower water temperatures, will remain active. The suggestion, not yet thoroughly investigated, is that each fish species makes some shifts, physiologically, to different enzymatic pathways to maintain a somewhat lower, but adequate, metabolic rate and activity level. The reaction rate of any given enzyme is both extremely temperature-sensitive and can function only within a temperature range specific to that enzyme. People who ice fish for the first time often are amazed at how active are the fish they pull up through that hole in the ice. Is that cool, or what?!