Fish and the cold

Pumpy · 11-13-2010, 01:27 PM

How do freshwater fish stay alive and well when the pond or lake that they live in freezes over. Does anyone understand how exactly that works?

paloma · 11-19-2010, 09:29 AM

According to Harley Hahn the fishes lives a normal life under the ice when the pond or lake freezes over:

"Now, think of what happens to a pond or lake as the temperature cools and the water begins to freeze. As ice crystals form, they float to the surface of the water. Eventually, the entire surface freezes over, covering the bulk of the water underneath, which is still liquid. Once the ice forms, it acts as insulation, helping to retain heat in the liquid below.

Thus, unless the temperature is extremely low for a very long period of time, the water below the ice does not freeze, although the ice may grow thicker. In a normal winter, the cold does not last long enough to freeze all the water, so the fish are able to live just fine until the coming of spring warms the surface and melts the covering of ice."

JimBarb · 11-21-2010, 09:25 AM

I'd be guessing that vegetation in the water, on the bottom, would provide the oxygen and nutrients for the fish?

Having been ice-fishing a few times, it's always amazed me that a 2-ft hole in the ice can let you catch a skein for dinner.

Dougdad · 12-14-2010, 11:19 PM

You are in fact correct Jim, the plants provide oxygen, as do the streams and creeks that flow into and out of the lakes. Most lakes have a few springs also and this to creats flow, which creates oxygen, flows from springs also help to warm the water in the immediate area because most flows run at a constant temperture year around. A certain amount of air is also trapped under ice do to waves caused by the wind untill the lake is well frozen over. The water never really sits still, it is always sloshing around. A shallow lake may suffer a freeze off on occasion if the winter is very harsh. Another thing is the fish go into a slower life style, sitting very still, almost dormient for very long periods of time, kind of like an animal that hibernates, their system slows down, using food and oxygen at a slower rate. Cool ay?

Joe S. · 01-03-2011, 05:46 PM

The main issue for the survival of the fish is to have sufficient oxygen. They can survive lots of temperature fluctuation, but if the oxygen supply is cut off, they die.

11-13-2010, 01:27 PM	#1
Pumpy Member Join Date: Nov 2010 Posts: 42	Fish and the cold How do freshwater fish stay alive and well when the pond or lake that they live in freezes over. Does anyone understand how exactly that works?

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11-19-2010, 09:29 AM	#2
paloma Senior Member Join Date: Feb 2010 Posts: 100	According to Harley Hahn the fishes lives a normal life under the ice when the pond or lake freezes over: "Now, think of what happens to a pond or lake as the temperature cools and the water begins to freeze. As ice crystals form, they float to the surface of the water. Eventually, the entire surface freezes over, covering the bulk of the water underneath, which is still liquid. Once the ice forms, it acts as insulation, helping to retain heat in the liquid below. Thus, unless the temperature is extremely low for a very long period of time, the water below the ice does not freeze, although the ice may grow thicker. In a normal winter, the cold does not last long enough to freeze all the water, so the fish are able to live just fine until the coming of spring warms the surface and melts the covering of ice."

11-21-2010, 09:25 AM	#3
JimBarb Member Join Date: Nov 2010 Posts: 33	I'd be guessing that vegetation in the water, on the bottom, would provide the oxygen and nutrients for the fish? Having been ice-fishing a few times, it's always amazed me that a 2-ft hole in the ice can let you catch a skein for dinner.

12-14-2010, 11:19 PM	#4
Dougdad archeryaddict Join Date: Nov 2010 Location: Marion Michigan Posts: 40	You are in fact correct Jim, the plants provide oxygen, as do the streams and creeks that flow into and out of the lakes. Most lakes have a few springs also and this to creats flow, which creates oxygen, flows from springs also help to warm the water in the immediate area because most flows run at a constant temperture year around. A certain amount of air is also trapped under ice do to waves caused by the wind untill the lake is well frozen over. The water never really sits still, it is always sloshing around. A shallow lake may suffer a freeze off on occasion if the winter is very harsh. Another thing is the fish go into a slower life style, sitting very still, almost dormient for very long periods of time, kind of like an animal that hibernates, their system slows down, using food and oxygen at a slower rate. Cool ay?

01-03-2011, 05:46 PM	#5
Joe S. Member Join Date: Dec 2010 Posts: 93	The main issue for the survival of the fish is to have sufficient oxygen. They can survive lots of temperature fluctuation, but if the oxygen supply is cut off, they die.