St. Nicholas/Volume 32/Number 3/Nature and Science/Fish
Fish Suffering for Lack of Air
I once observed a singular incident on a marsh near Lake Ontario. Some French Canadians had cut a hole through the ice, which was quite a foot thick, and bullheads were swarming to the surface of the water in such quantities that they were being shoveled out on the ice. I believe this was against the law, for as soon as the men had secured all that they could carry they hurried away. But still the fish swarmed to the surface, struggling with one another to get to the air.
On recounting this observation to a man who has made a study of fish, he told me that the fish were suffering for want of pure air to breathe.
Dr. H. M. Smith, who has studied the habits of fish, writes regarding this observation:
This same freezing over must occur every winter, but it is only in severe winters that the fish are really suffocated. This lack of air under the ice is to some extent compensated for by the hibernation of some fishes, but in shallow water the ice is likely to form on the bottom (“anchor-ice.”), and the fish are then readily killed.
Dr. Smith has also sent ns the following quotation explaining that a fish, though living inthe water, requires the same kind of air that we do.
By means of their gills fish breathe the air dissolved in water. The oxygen consumed by them is not that which forms the chemical constituent of the water, but that contained in the air which is dissolved in the water Fishes transferred to water from which the air has been driven out by a high temperature, or in which the air absorbed by them is not replaced, are soon suffocated. They require aërated water to maintain life, and they take it in constantly through their mouths and expel it through their gills, retaining the air. It follows that if the water in a lake should be completely cut off from contact with the air long enough to exhaust the supply of air, the fish in the lake would die. It would take a severe and pretty long-continued freeze to accomplish this, but it might happen, and doubtless has frequently happened, with a small body of water.