Winter kills in Indiana or anywhere?

I'm curious if any of you midwesterners have heard any reports of fish kills lately.
I saw [and got embroiled in] a thread elsewhere about "winter kill".
I vehemently denied a fish kill could be winter kill as the photos showed a pond with either no ice or very thin, clear ice.
The only winter kill I ever see is when very thick ice and snow blocks all light and the plants die and rot, consuming the oxygen.
A state official emailed the poster that there had been several fish kills and they were all winter kill.
Any thoughts?

I'm curious if any of you midwesterners have heard any reports of fish kills lately.
I saw [and got embroiled in] a thread elsewhere about "winter kill".
I vehemently denied a fish kill could be winter kill as the photos showed a pond with either no ice or very thin, clear ice.
The only winter kill I ever see is when very thick ice and snow blocks all light and the plants die and rot, consuming the oxygen.
A state official emailed the poster that there had been several fish kills and they were all winter kill.
Any thoughts?

The thick ice and heavy snow are the causes I am familiar with around here. I do recall several years ago however, seeing news footage from Texas I think, when they had a particularly cold cold spell. They showed ponds with lots of dead fish that were unable to cope with either the low temperatures or the suddenness of the temperature change. The ponds never got more than a thin layer of ice either, but I think they still refered to it as a "winter kill". Where was the pond in question? It may just be a regional difference in the definition of a "winter kill".

The thick ice and heavy snow are the causes I am familiar with around here. I do recall several years ago however, seeing news footage from Texas I think, when they had a particularly cold cold spell. They showed ponds with lots of dead fish that were unable to cope with either the low temperatures or the suddenness of the temperature change. The ponds never got more than a thin layer of ice either, but I think they still refered to it as a "winter kill". Where was the pond in question? It may just be a regional difference in the definition of a "winter kill".

Oops, I guess I should have paid more attention to the title, I see that it was in Indiana.

Oops, I guess I should have paid more attention to the title, I see that it was in Indiana.

I'm in northern Indiana and yes this was a problem this winter up until the thaw. If some ponds have not completely thawed their owners may see dead fish after ice out. In fact, I lost some bluegills in one of my production ponds. However it wasn't that bad as I had seined most of them out last fall and only lost those I failed to seine out. However I came close in my biggest pond as my D.O. levels dropped to just over 3.0 ppm and were headed farther down. I immediately cut a large hole in the ice and inserted my 1/2 hp. surface aerator. It opened up a larger 20 by 30 foot hole and eventually we had a thaw and the pond is now ice free for the most part. I dodged a bullet!

Usually I'm able to keep snow off in strips to keep photosynthesis going but this winter I had deep snow over thin ice and wasn't able to. I also had water under the snow. The combination of deep snow and opaque ice was bad news this winter. I will be going back to installing a shallow water diffuser before next winter in combination with keeping snow off the ice. I have to much invested to lose my prize fish that I sell.

Here's a clip of fish coming up for oxygen in a pons that had dropped to 1.8 ppm. (Biologist told me they came over and took a D.O. reading) The ice fishermen said as soon as they made a hole the fish came up to the hole. This was in a pond at the Tri-County Fish and Game preserve in Kosciusko County.

http://s364.photobuc..._013109_001.flv

As far as southern fish losses with little or no ice I do know the subspecies of bluegill known as the coppernose bluegill is sensitive to low temps or quick temp changes as are the Florida strain bass. I've even had northern fish die, although not a massive fish kill, from quickly falling temps.

Edited by az9, 14 February 2009 - 11:39 PM.

Usually I'm able to keep snow off in strips to keep photosynthesis going but this winter I had deep snow over thin ice and wasn't able to. I also had water under the snow. The combination of deep snow and opaque ice was bad news this winter.

You may have solved the mystery for me.
I still think our fish out here are hardier when it comes to surviving under ice. We'd have no fish left if they died so easy from one slightly colder than normal winter.

I have a couple thoughts, but others probably understand this better than me.

• Whether the pond is natural or man-made may make a difference - flows in man-made ponds are often less (percentage-wise) than in natural ponds, resulting in less oxygen-rich water entering the sytem.
• A rapid spring turnover (which I suppose could happen even in February if the temperatures and wind were right) can often kill fish
• Eutrophic systems are particularly prone to low oxygen issues as algae and plant matter decay. Plant matter still decays in winter, albeit much more slowly.

I have a couple thoughts, but others probably understand this better than me.

• Whether the pond is natural or man-made may make a difference - flows in man-made ponds are often less (percentage-wise) than in natural ponds, resulting in less oxygen-rich water entering the sytem.

Yes, reduced flow will be significant, depth as well. Less flow, less depth = less oxygen.

A rapid spring turnover (which I suppose could happen even in February if the temperatures and wind were right) can often kill fish

Ponds deep enough to turn over are usually deep enough to minimize winter kill. The vulnerable ponds are the very shallow ones which will be 32 F right to the bottom. In fact, ice here can be 15 inches thick , 2 feet or more a little further north. In other words, if the pond is two foot deep, it could be ice right down to the mud.

Eutrophic systems are particularly prone to low oxygen issues as algae and plant matter decay. Plant matter still decays in winter, albeit much more slowly.

Yes, those are typically the ponds that suffer winter kill. The decaying plant matter is only intensified when thick ice and deep snow blocks light and the few green plants die.

I have a couple thoughts, but others probably understand this better than me.

• Whether the pond is natural or man-made may make a difference - flows in man-made ponds are often less (percentage-wise) than in natural ponds, resulting in less oxygen-rich water entering the sytem.
• A rapid spring turnover (which I suppose could happen even in February if the temperatures and wind were right) can often kill fish
• Eutrophic systems are particularly prone to low oxygen issues as algae and plant matter decay. Plant matter still decays in winter, albeit much more slowly.

Good points. Ponds tend to be more eutrophic and due to lower volume will turn over faster. I also used to live in northeastern Mass and many of the lakes (ponds I guess as many Bay staters call lakes ponds) I fished were deep and not that productive. The more water volume the more cash to reserve in the bank (oxygen in the water) before ice out occurs.

Ponds deep enough to turn over are usually deep enough to minimize winter kill. The vulnerable ponds are the very shallow ones which will be 32 F right to the bottom. In fact, ice here can be 15 inches thick , 2 feet or more a little further north. In other words, if the pond is two foot deep, it could be ice right down to the mud.

I can see a pond being 32 to the bottom if it's 2 feet deep and the ice is 2 feet deep, but once I started taking temp measurements under the ice with a very accurate expensive probe I was flabbergasted to see how quickly water temps rise under the ice. I routinely have 35 F. temps just under my ice. I've also seen 41 F. water on the bottom vs. the textbook 39 F. Maybe the bottom is heating the water slightly?

I can see a pond being 32 to the bottom if it's 2 feet deep and the ice is 2 feet deep, but once I started taking temp measurements under the ice with a very accurate expensive probe I was flabbergasted to see how quickly water temps rise under the ice. I routinely have 35 F. temps just under my ice. I've also seen 41 F. water on the bottom vs. the textbook 39 F. Maybe the bottom is heating the water slightly?

There are several factors at work there.
For one, water at it's most dense is 39F. That means as water cools, it sinks when it reaches 39 F. Ponds that are deep enough will have a layer of 39 F at the bottom, presuming no other variables are at work.
Other variables would include springs which may bubble up at 50 F, currents moving the water, dark colored substrates absorbing sun light on a sunny day etc.
Shallow ponds without springs or current can be chilled by the outside temps to the point where there is no 39 F water left anywhere. If that keeps up long enough, it will freeze solid to the mud.

Just think, if ice didn't float, and 39 F degree water didn't sink, ponds would freeze from the bottom up and fish could not exist.

Just think, if ice didn't float, and 39 F degree water didn't sink, ponds would freeze from the bottom up and fish could not exist.

Hooray for hydrogen bonds!

There are several factors at work there.
For one, water at it's most dense is 39F. That means as water cools, it sinks when it reaches 39 F. Ponds that are deep enough will have a layer of 39 F at the bottom, presuming no other variables are at work.
Other variables would include springs which may bubble up at 50 F, currents moving the water, dark colored substrates absorbing sun light on a sunny day etc.
Shallow ponds without springs or current can be chilled by the outside temps to the point where there is no 39 F water left anywhere. If that keeps up long enough, it will freeze solid to the mud.

Just think, if ice didn't float, and 39 F degree water didn't sink, ponds would freeze from the bottom up and fish could not exist.

I'm aware of that but I'm just surprised when I find 41 at the bottom vs. 39 which is supposed to be the densest. My pond is not spring fed.