Forest Preserve District of Cook County, Illinois
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Fish Smother Under Ice

Clayton F. Smith, President
Roberts Mann, Superintendent of Conservation
February 1, 1945
Nature Bulletin No. 1


Grown-ups, who used to kive on a farm or in a small town, are fond of  talking about the old-fashioned winters "when I was a boy" and the  winters that grandpa used to tell about.  Well, one would have to go  back a long, long time to find a winter as severe as this one.


Lakes and streams breathe the same as living things.  When they are  covered with ice and snow they cannot get air and they much hold their  breath until the ice thaws.  While they are holding their breath the  oxygen in the water is gradually used up by the living things sealed up  in it -- fish, plants "bugs", snails, and hosts of microscopic life.  If the  ice lasts long enough, these living things die one after another as each  kind reaches the point where it cannot stand any further oxygen  starvation.  Sometimes temporary relief is given by rains and melting  snow that bring fresh, serated water under the ice, but no method of  artificial respiration has been found that works.  Sometimes, too, when  water plants get enough sunlight through clear ice they produce small  amounts of oxygen and delay the suffocation of the fish, etc.; but when  snow and cloudy ice cuts off the light this does not happen.

On December 8, all of the sloughs, ponds, streams and small lakes in  the Cook County forest preserves froze over tight.  Two days later this  was followed by almost a foot of snow.  Since then the ice has frozen  thicker and thicker, and several more heavy snows have fallen.  For  eight weeks there have been no rains or snows to bring in oxygen, and  the fish in most of these waters are already dead or dying.

During the last half of January, inspections were made through holes  chopped in the ice and in occasional bits of open water at dams.  We  found large numbers of dead fish of all common kinds.  At the  McGinnis Slough Waterfowl Refuge near Orland Park, which has 314  acres of shallow water, numbers of black bullheads and golden shiners  were found dead, but no live fish of any kinds.  Since these species will  live with less oxygen than most fish, it is presumed that the kill is  practically complete and may reach 100 tons.  As many as 50 tons may  have died in the 190 acres of water in the Skokie Lagoons in the  northeastern corner of the county, although a few are still finding  enough oxygen to stay alive where a little water pours over the low  dams that separate the lagoons.  Here the main part of the kill was  good-sized largemouth bass, crappies and bluegills, along with  moderate numbers of large carp.  The kill in the DesPlaines River also  seems to be practically complete.  At Dam No. 1, near Wheeling, large  numbers of medium-sized carp are being hauled away for chicken and  hog feed, while a flock of herring gulls feed on those that are not frozen  solid.  No dead fish have been found in 55-acre Maple Lake near  Willow Springs, probably because it is deeper and its oxygen reserves  are greater.


A lot of kind people are afraid the birds will starve this winter and  should be fed.  There's no harm and you'll get a lot of fun in feeding  the juncoes, the sparrows, and the few songbirds -- such as the robin  and the cardinal -- that sometimes stay here all winter:  PROVIDED  you put hte feeding board or hopper up where the cats can't lie in wait  to pounce on the birds that come there.

But feeding grain on the ground to pheasants, qualis and other birds out  in the country or the forest preserves is really unnecessary and can be  dangerous to the birds if always done in the same place.  Not only cats  but hawks, owls, weasels and foxes soon learn to hide near such feeding  stations to catch and devour the birds as they come there.

Besides, such feeding isn't really necessary.  We walked through the  deep snow over several hundred acres of our forest preserves the other  day.  We found a network of tracks made by pheasants, quail, rabbits  and dogs, as well as a few other animals.  Whenever there was a clump  of burdock (that weed with the big, broad leaves, and the burrs that  stick to your clothes), the pheasants had reached up and pecked all the  seeds out of the burrs.  The same thing had happened to the ragweed,  the giant ragweed (or "horse-weed") and a lot of other weeds that have  a lot of fat seeds.  And you could see the tracks of the small birds that  had cleaned up what the pheasants had scattered.  Birds know how to  take care of themselves in the wild.

Weeds, even if they do not have pretty flowers, have a very real  purpose and value in nature.  The field mice get most of what the birds  don't get.

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