In January 2014, I photographed an immature Great Blue Heron attempting to retrieve a fish that was embedded near the surface of a frozen lake. I was fascinated to observe the Heron pecking at the ice to retrieve the fish. The fish appeared to be a shad, which is a common species found in the lake. I have seen these birds catching shad before the lake froze over. Unfortunately, I never witnessed the Heron successfully retrieving the fish from the ice.
There are several potential reasons why shad might be found embedded near the surface of a frozen lake:
- Accidental Trapping: Fish might get trapped when the lake surface freezes suddenly, preventing them from reaching deeper, unfrozen water. This can happen during a quick temperature drop or strong wind event that pushes surface water against shallow areas.
- Shallow Water: In shallow areas, the entire water column can freeze solid, potentially encasing any fish present, including shad.
- Seeking Oxygen: During the winter, deep lake water can become depleted of oxygen due to decomposition processes and reduced mixing from wind and surface currents. In such cases, shad might gather near the surface ice where oxygen levels are higher, unintentionally getting frozen near the surface.
- Ice Holes: Shad may be attracted to areas with open water around ice holes created by anglers or natural phenomena. While trying to access the oxygenated water, they could become trapped in the surrounding ice as it reforms.
- Competition Among Baitfish: During the winter, competition for limited resources like oxygen and food can be intense. If shad get pushed towards the surface due to competition with other fish, they might become more vulnerable to freezing or predation.
Witnessing this Heron persistently trying to retrieve the frozen shad provided a fascinating glimpse into the challenges birds and fish face during winter months. It exemplified the drive of wildlife to take advantage of any potential food source, no matter how difficult it is to obtain.
Image Information:
- Date: 01/12/14
- Time: 09:03 AM
- Camera: Canon EOS 7D
- Lens: Canon 500mm F4
- ISO: 640
- Aperture: 7.1
- Shutter: 1/2000
- Exp. Comp.: -0.3
- Lens (mm): 500 (Fixed)
- Program Mode: Aperture Priority