Pond Boss Forums INTRO Questions & Observations trying to prevent winter fish kill

Here in Michigan the ice has been thick since christmas, when the snow would pile up I would shovel two big rinks to let some sun in & some fun skating. Since the snow storm that blasted through the snow is very deep with a 6 inch slush ice layer then the bottom 9 inches of clear ice. Today I cut three large openings with a chainsaw to open the pond up, saw a few dead quarter sized fish. Dreading another fish kill.

Should be getting a lot of melt this week. We hit a high of 48 Sunday. I went down by the Muskegon River and it is filling right up. Supposed to hit the 50's this week, and three days of rain. Hopefully things will clear up quick and all is not lost.

The warm up is at good time for our pond, I'm glad I cut the holes in the ice when it was freezing. The warm sunny days keeps them open, The rest of the pond has 6 inches of honeycome ice then 9 inches of clear usually it takes a while to melt through. We have aeration but only in the deep parts, this next year we want to install some aeration in the shallows for winter.

I have a pond just over an acre with some areas over 10 ft deep. I had a winter fish kill with most fish that I see being CC, BG, and RE, with a few dead LMB as well. We had snow covered ice for a long time, so deminished DO is the likely cause. The total number of fish that I can see is under 50, but some are laying on the bottom in the shallow water (which is quite clear) so more are certainly laying on the bottom in deep areas. My question is whether or not I likely lost any of these species completely? I have caught members of each of these species that are larger than any of the ones that I can see are dead, and there were very many small fish swimming in the shallows in fall, few of which I see dead. Any thought are greatly appreciated.

RAH, the larger the fish, the more suceptable they seem to winterkill. I doubt that you have lost all of one species, but probably the larger of each species.

Do you run an aerator during the winter?

I still have 6" of ice on my pond, the top 5" is milky white. We just got 5" of snow Thursday night and another 1" last night. I was fortunate that Cecil let me borrow his O2 meter this winter. I kept tabs on the O2 for a study that Dave Willis is doing on groundwater ponds. I monitored my pond and 4 others that are also groundwater ponds. Some aerated, some not. I didn't run the aerator in my pond this year for the study, and had a low O2 reading in the high 5mg/l range near the bottom in 11' of water. The lowest high reading was in the 8 mg/l range up right below the ice. My pond is less than an acre now due to the drought we've had here in late 2010. With the snow cover and thick ice, it is apparent that sunlight getting thru the ice helps O2 levels under the ice more than you think. If shoveling off the snow or running an aerator is not an option, then I would look into running a pump (even off of a generator for a day) to pump water on top of the ice to melt the snow, allowing more sunlight thru the ice.

I am surprised not to see the larger fish dead, although a few 18" CC are dead; no large bass are dead, and medium and some small BG are dead. Maybe the big ones sank. We had ice covered with snow for a long time, but there is some open water now and things are expected to warm up soon. The ice was not safe to go on to clear the snow. I have never had a fish kill in the past 8 years since the pond was dug and stocked. I think that raising the drain 6" last year, combined with the drought, added too much vegetation to the water after the water reached full pool this winter. Fortunately, the water did not drop much during the drought, but it did not fill either. I am restoring a lot of habitat and do not want to have ongoing pond maintanence, so the fish are on their own. I am hoping that I did not lose the paddlefish added last fall, but I am not hopeful. I think they need higher oxygen compared to the other fish. Time will tell.

I used to just remove snow from the surface of my ponds until I had a winter where the ice was thin with early season heavy snow. Couldn't get on the ice to remove the snow and the heavy snow cracked the ice from its weight, brought up water, and created slush, which refroze. After that I've used an aerator ever since. I have an added negative to losing fish in that I make part of my living selling them. Not only monetarily but one fish kill would put me back a few years as I'd have to build up my age classes again.

For those of us that get significant snow in the winter, even if it's not every winter, I would strongly suggest investing in a small compressor and running a separate short airline and diffuser in winter.