UNDERWATER WINTER: Changes

When winter comes, the surfaces of ponds freeze over, but life goes on – underneath the frosted veneer. Well, this week, we’ll have a sneak peek beneath the frozen surface, and see how winter transforms the underwater life of a pond. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.

ambience dripping water

Peter Marchand is a visiting biologist with the Colorado College in Colorado Springs. He explains that once a lid of ice forms on a pond or a lake, that ecosystem is effectively cut off from the outside.

“The world underneath that ice becomes cold, but very stable. Temperatures no longer fluctuate — they remain, in fact, within a very narrow range, from about 32 degrees right under the ice to 39 degrees at the pond bottom. There’s no longer currents of water, and there’s no longer any input of oxygen into the pond except that which might enter via a stream flowing into the pond. Once the ice cover is established on a lake, the resources of the pond or the lake are set for winter. And it’s upon those resources that all life in the pond must survive now for the duration of winter.”

Such drastic change effects the animals that make their homes beneath the ice.

“Life slows down considerably. The organisms that inhabit the pond, the fish, the salamanders, are slowed to a degree where many of them move only with some difficulty.”

“Interestingly, other fish in the same pond increase their rate of metabolism so that they remain active all winter long.”

More on winter ponds in future programs. Pulse of the Planet is presented by the American Museum of Natural History. I’m Jim Metzner.


Peter J. Marchand is the author of Life in the Cold, 3rd edition, published in 1996 by University Press of New England, Hanover, NH. ISBN 0-87451-785-0

UNDERWATER WINTER: Changes

When ponds freeze over, life goes on, amidst this major transformation of the ecosystem.
Air Date:01/19/1998
Scientist:
Transcript:

When winter comes, the surfaces of ponds freeze over, but life goes on - underneath the frosted veneer. Well, this week, we'll have a sneak peek beneath the frozen surface, and see how winter transforms the underwater life of a pond. I'm Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.

ambience dripping water

Peter Marchand is a visiting biologist with the Colorado College in Colorado Springs. He explains that once a lid of ice forms on a pond or a lake, that ecosystem is effectively cut off from the outside.

"The world underneath that ice becomes cold, but very stable. Temperatures no longer fluctuate -- they remain, in fact, within a very narrow range, from about 32 degrees right under the ice to 39 degrees at the pond bottom. There's no longer currents of water, and there's no longer any input of oxygen into the pond except that which might enter via a stream flowing into the pond. Once the ice cover is established on a lake, the resources of the pond or the lake are set for winter. And it's upon those resources that all life in the pond must survive now for the duration of winter."

Such drastic change effects the animals that make their homes beneath the ice.

"Life slows down considerably. The organisms that inhabit the pond, the fish, the salamanders, are slowed to a degree where many of them move only with some difficulty."

"Interestingly, other fish in the same pond increase their rate of metabolism so that they remain active all winter long."

More on winter ponds in future programs. Pulse of the Planet is presented by the American Museum of Natural History. I'm Jim Metzner.


Peter J. Marchand is the author of Life in the Cold, 3rd edition, published in 1996 by University Press of New England, Hanover, NH. ISBN 0-87451-785-0