“Out There” is a column by Ed McMackin
A big, little world beneath the ice
When boating or canoeing on a shallow, mirror-surface lake, one can see a whole different world below a perfectly calm surface. Often one finds themselves looking down on a “forest” of plants, of various heights and structures.
Some of the plants have a likeness to tall slender spruce trees that taper to the top, and that you would find in the sub-alpine forests of our Kootenay Mountains. Other plants are bent over, looking like sapling trees bent under the weight of snow.
Then there is, to use ecological terms, the under-story and ground-cover, and many more types of vegetation. Some of the aquatic plants you might see in summer produce a showy flower that sticks above the water’s surface. There is a knot-weed, tagged “Lady’s Thumb” and one with a yellow flower, called “Bladder-wort”, with air-filled bladders that keep the plant somewhat afloat. Looking further one might find white water-buttercups, yellow water-buttercup and water lilies.
An underwater forest can be best viewed in summer, in calm, mirror-like conditions. An aid to under-water viewing is a wood box, with a glass bottom. Holding the glass bottom of the box just below the water’s surface reduces glare and ripple or wave action.
Comparable, but much more interesting, is viewing the underwater world through a surface of crystal clear ice, which one can sometimes safely walk on, if about two or more inches thick. (Test the ice first with the end of a hockey stick or hiking pole and stay close to shore). To have optimum clarity the water surface must have frozen before any snow fell on it or in it. When I have looked down through the ice, at the underwater forest, I have found it much the same as when viewed just before freeze-up.
Once when I looked down, from a canoe, into nearly frozen water, I saw what appeared to be a squaw-fish. It was sitting motionless, as if suspended. It may have moved an inch or two when I thumped the canoe. Only rarely, at this time, have I seen a dragonfly nymph clinging to a plant. Small animal life in the water is much more plentiful than what meets the naked eye, even in the height of summer.
Most of what we would observe in late spring and early summer would have survived the winter in the egg, nymph or even adult stage. A productive lake, or pond, can teem with young of many kinds of insects. With some visual helpers, we might find innumerable smaller denizens like amoebas, parameciums, cyclops, water-bears and so forth.
It is safe to say there are greater numbers of creatures in a healthy pond or lake than there are on the surrounding land. Land creatures depend directly or indirectly on the life in the water for food. If there is no life in the pond there is a much-reduced amount of life on the surrounding land. The healthy and natural pond could be said to be a “breadbasket”.
The variety and numbers of animal and plant life in a pond depends on the character of the pond, water movement, source, mineral content, temperature and turn-over. Have you ever thought of what would happen if ponds froze from the bottom up?
Water has a special feature that protects pond life in winter, ensuring that aquatic plants and animals survive to the next season. When water cools down near the freezing point, it expands, becoming less dense, causing it to rise to the pond’s surface, replacing the warmer, more dense water on the surface which sinks to the bottom.
As the less dense, cooler water freezes further, it stays on the surface as ice insulating the water below, protecting the pond life during winter, freezing conditions. During severe winters shallow ponds often freeze to the bottom. Still, some creatures and plants may survive. My students once collected dried mud that had frozen. Mixed with a little water in a screened jar, one of the student’s samples, after several weeks, “hatched” an adult mosquito.
An old Indian in the Bella Coola area once told a distant cousin of mine, that he found frozen fish in a glacier. On putting them in cold water they revived. Also, in a glacier, a swarm of grasshoppers were found frozen in the ice. I can, perhaps, explain how the grasshoppers got up there but I am challenged with the fish story. Perhaps the fish froze in an alpine lake that later became part of the glacier.
Closing this peek into life under winter’s ice certainly doesn’t mean the end of the story. There are more life processes and creatures in that world of cold water, mud, rocks, dead and living plants, than what meets the eye.
Obvious are the muskrats, mink, otters, pollywogs, tadpoles, frogs, leeches, mollusks, and, perhaps, the young of diving beetles, whirligigs, water-scorpions, giant water bugs, flies and mosquitoes. Protected under that covering of ice, natural processes and life are preserved for the spring. And, you want an early spring?
