Ice fishermen may walk on water, but they generally take for granted the magic carpet that supports their passion. How our lakes and ponds freeze is truly amazing, counter-intuitive, and generally not understood. The entire process is dependent on water under 39 degrees behaving like nothing else in the world.
Like most matter, water gets denser and consequently heavier as it cools. Chilling top-water in a lake or pond therefore sinks to the bottom, and warmer, less-dense, lighter bottom-water rises towards the top, resulting in a total, refreshing circulation of a pond or lake. This water movement continues until all the water below the surface is about 4 degrees Celsius (39.2 degrees Farenheit). At that point, water begins to show its magical uniqueness, defying our reasonable expectations.
You’d logically think ice would form from the bottom up. But this great exception to the rule of cold affecting density is vital to both ice fishermen and all the life within our freezing waters.
For ice to freeze on the surface, all the water below it must first cool to 39.2 degrees. Very deep water sometimes never freezes because its entire column may never reach that uniform temperature. But when the entire water column does get that cold, the stage is set for an unexpected reversal.
As the surface temperature begins to get even colder than 39.2, instead of getting even more dense and heavier still, it actually begins expanding and getting lighter. At this point, very cold water amazingly starts to float on top of less cold water. As this lighter water chills further to 32 degrees (0 C), it freezes on the surface.
If ice were to form from the bottom of a lake or pond upwards, all life in that water would eventually freeze and die.
Freezing of water from the top down is critical for aquatic life to survive in brutally cold winters, since surface ice actually helps insulate and slow the cooling of the water below.
Ice fishermen don’t really need to know chemistry and properties of matter. It’s crystal clear to all of them that there’s nothing more magical than water. All that’s needed are good old-fashioned cold winters.
Shops with numbers
MassWildlife’s Bill Davis reports that 450 white-tails were checked in by muzzle-loaders in Worcester County. Wickaboag Valley Bait & Tackle checked 73; Fin & Feather Sports checked 54; Turnpike Rod & Gun 51; D&G Bait & Tackle, 44, and Ric’s Still Alive Taxidermy, 42. Thanks to the five shops that went out of their way to help us.
The park waterfowl survey is in full swing. Bill Davis reports that up to this point, 1600 mallards have been tallied at major concentration points that include Orlando’s Farm in Charlton, The Old Mill Restaurant in Westminster, Mahoney Park in Gardner, and Winterberry Farm in Dudley. If you have tallies from other artificial feeding sites, please contact District Wildlife Biologist Bridgett McAlice at (508) 835-3607.
Helping with science
Ducks Unlimited and the National Oceanic and Atmospheric Administration are now partners working to protect and restore 5,000 acres of coastal habitat for waterfowl across America. NOAA has committed $2.6 million dollars to the effort, while DU is committed to matching that amount.
DU, the world leader in wetlands conservation, was established in 1937. This year is their 75th anniversary. They’ve conserved more than 12 million acres over the years thanks to contributions and memberships. Guided by inspired and well-informed leadership, they base policy decisions on wildlife science. Their upcoming fundraisers are critical for local waterfowl and sustaining coastal habitat that has been recently ravaged by hurricanes and storm surges.
Ducks Unlimited works locally as well as in the highly productive Prairie Pothole Region - Alberta, Saskatchewan, Manitoba, North and South Dakota, Minnesota, and Iowa – where more than 75% of North America’s waterfowl are produced. Both hunters and non-hunters should join their ranks and attend their fund-raising banquets. For information on how to help, visit www.ducks.org.
You might want to unpack your fishing rods. Drift boaters on the Oswego River are reporting some of the best steelhead fishing in memory, and a 47-inch striper was just taken this month by a shore fisherman on the Housatonic.