So if you have a clean shallow pond with lots of plants but no leaves in the botton, no fish and there is no snow cover on the ice - it's OK not to keep a hole open in the ice.

Now if this was fron the US, the only thing missing would be that the charity was given a million dollar grant to fund their study.
sam -- just sitting here watching it snow...

Thanks Sam - got my chuckle for the day :)

Gahhhh!

I have a 1300 gallon pond in three pools, that smallest is about 300 gallons. The minimum depth in pools is about 14 inches. We turn the pump off when it starts to freeze, so the pools are not connected.

In the middle pool, we have the majority of the fish about 40, some as long as 8", this pool is about 600 gallons and about 20" deep.

We have mature trees around the pond and try as you will you can not avoid having leaves in the bottom of the pond.

We live in Indiana and the pond freezes over every winter. Based on the thickness when it breaks up in the spring the ice gets about 6" thick. In the seven years we have had the pond, we have not lost a fish in any of the three pools. We do nothing special, no holes in the ice or remove the snow cover.

In nature fish have lived for millions of years with no one to break the ice in their ponds and they have survived.

Good point knuttle. You must be doing something right! :) And I mean that as a compliment! The one year my pond froze over for several weeks I lost 1/2 of my fish, and that was only 4 or 5 4"-5" goldies in 28" of what I thought was pretty clean water.

Unfortunately, try as we may, we cannot re-create nature in our man-made ponds. So each of us do what we can, or are willing, or are able to do to help minimize unpredictable Mother Nature's effects.

I used to watch the water near our house in Wisconsin with fascination since growing up in W.Va. I had never seen ice that amounted to anything. Along the sides of ponds and streams there would be rocks and logs, tree roots and debris. There is no such thing as a straight line anywhere that is more than a few feet long. I also watched things around the yard that were visible from my greenhouse where snow could be four and five feet deep just an inch or so from the glass but the snow and ice never touched the glass. DH thought I was crazy to take walks in such conditions but it was fascinating. If I saw a rock that had been covered by new snow the night before, the snow that had been in direct contact had been melted away. If the rock was in contact with water, there would be a gap that had appeared as the rock released stored heat and melted the ice. Wherever there was a clump of plants in the water there would be the same kind of gap. it rarely took long for such a gap to form. I had a large rock garden and it was around the rocks that you would find open ground for the first time. I had shredded leaves in black plastic bags and the ice and snow melted all around them very quickly because the rotting leaves in the bags put out lots of heat.
What I am suggesting is that a pond that has rocks showing around the pond edges may have those same gaps I observed. That would be evidence that some gas exchange is taking place despite the depth of the ice. The gap might be the thickness of a sheet of paper and it would still work.

Exactly! Natural ponds/lakes always have openings somewhere, though there are instances where even large bodies of water suffer fish kill if they are shallow and have low oxygen levels.

Yes!
i totally agree with Knuttle, You do not need to do any hole in the snow cover of your pond or pool for the fish to survive but again it depends on the species of the fish.
some fish got the capability to survive in freezing water and some do not.

Really depends on your fish load (and yes, species) and debris in the pond.

"So if you have a clean shallow pond with lots of plants but no leaves in the botton, no fish and there is no snow cover on the ice - it's OK not to keep a hole open in the ice."

This isn't ever gonna happen in my pond... :)

Question- I have lived for 10 years with a pond in my back yard. Every year it freezes solid enough to skate on. This year, even thought the temperature is way below freezing for weeks, there are air holes in the pond -everywhere. They also are in different locations every day. What is causing this? Turtles? Muskrats? fish?

Teresa: do you have any seals in the pond? They like to change their breathing holes to keep the polar bears wondering where they will show.

I don't have a guess why you get ice holes.

Here in LI NY my pond just froze over solid, my 2nd year of keeping the fish there overwinter. A few days ago on last check I could still see my air bubbles inside (all I run is air, no pump in 200 gallons). So this morning there I was battery drill in hand making a new hole for a new air pump and bubbler. Ice was thick, maybe 3 inches (double last year). I also stuck an unused aquarium heater to blast a larger hole so I can get a larger bubbler thru the ice.

Sam got it in one....
"So if you have a clean shallow pond with lots of plants but no leaves in the bottom, no fish and there is no snow cover on the ice - it's OK not to keep a hole open in the ice"......

Keep in mind also that over in the UK they are having an exceptionally cold winter this time around. Normally their garden ponds, even the natural ponds, would have no more than an inch of ice on them for a day or two over a winter. It is not the norm for them over there to have the prolonged extremely cold winters we can have in N. America. The UK is warmed (or at least were, before the climate upset)and the temperatures kept mild by the flow of the Gulf Stream crossing the Atlantic ocean. So long cold winters do not happen too often, though there are exceptions from time to time.

From what I have read on this pond forum and my own experiences, over many years concerning this subject, is that there have been more loses of fish and frogs in unvented ponds, than in ponds that were vented, by either the the use of an air pump bubbling or a water pump roiling the surface water or an electric trough de-icer.

Sleepless points out the fact that some natural and even man/woman made garden ponds, having the capability to allow for venting of gases by their design and structure.

Sheepco points out that there are also fish losses reported about, even in natural ponds, that become frozen over. Whereas Knuttle and Rosesecretgarden do not choose to vent their ponds and all is well in their situation.

I once had an 18 inch deep pond that was debris free starting off the winter but because of a loose hose connection on my bubbler system, it froze solid,leaving only about about four inches of water at the bottom of the pond.
There were three or four fish frozen dead into the ice halfway down. In the bottom few inches of water were the rest of the fish, hale and hearty, just waiting for the spring sunshine to thaw out their icy covering.

Who can really say what is the best or safest way to go for the fish and frogs?

My thoughts are, why take the chance on losing fish (unless you don't really care)! I go with doing a clean-out of the junk and leaves in the late fall. Installing an air bubbler or a water moving pump or an electric de-icer ( you choose) then cover or net the pond over to keep the debris and leaves out and that should do the trick.
I would hate to see all my fish floating dead in the springtime because I took a gamble on whether or not to vent the pond.
Just my opinion.
"Horton"