Pond Boss Forums INTRO Questions & Observations wierd observation

We had a cold, very cold Dec. here in central Ohio. My 3 year old, 1 1/2 acre pond froze over for much of Dec. (4 inches to be exact.) Today, after a period of warm weather,40-60 degrees, I walked around my pond with my new puppy.( Half coyote- half golden retriever. It is mostly open water again. I found it wierd that I saw so many fry and minnows on the shore line. I have a heavy fathead minnow pop. Some of them had the shape of small bluegills also. DEC.30th????? The other very upsetting observation that I noted was 10 to 12 adult, large bluegills dead on the edge of the water. Is this alot? and is it winter kill? No other dead fish noted. I have a water way that I diverted around my pond. I have a valve that I can let water in as needed. Would you open up the valve and let water in. The pond is full, but I thought that it may contain O2. Help please, I thought that bluegills would be the strongest fish in the pond.Tom

Tom:

I don't think it is unusual to see BG fingerlings clear down in size to so small that they're unrecognizable in the Winter. With spawning taking place throughout the Summer and some BG just being slow growers, we enter Fall with pretty much every size smaller BG present, and then they hardly grow at all during the Winter.

WRT possible Winterkill. I don't remember if you aerate. I don't think we have had enough ice cover to deplete the O2 so far this year ( based on the reassuring info posted here by Ted Lea, et al. Maybe you had more snow cover on top or for longer than I did.

Did you only find large BG dead? I think the larger fish suffer from low O2 before the small ones of the same species.

Tom :

Look at this link as it has pics. of 2 yoy BG from last week ,with Bill's estimate of age. Theo is right on all sizes of BG this time of year. We have many like the small one that are almost clear when in the water. Did you pick up the BG to see what appeared to be wrong like wounds or such. Often it is hard to tell what killed a fish.

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=7;t=000290;p=1#000004

Tom,

As stated I believe it's too early for winter kill. I'm still catching fish near the bottom of my pond and I never aerated or removed snow from the surface of the pond. That tells me oxygen levels are still fine near the bottom of my pond and should be for you too. Bottom D.O. levels are the first do go and D.O. depletion goes up in the water column over time. Something else killed your fish.

I had some dead fish before ice up this fall and some stressed fish near shore just after a really fast temperature drop and high winds. Water was open and temps were well below freezing with high winds. I believe the fish were stressed by the extremely fast dropping temps. Maybe that is what happened to you as we probably experienced the same cold front.

Tom,very very doubtful lack of DO was the case.DO in ponds with no aeration and 3-4 weeks of snow cover at 8 ft depth were still at 9ppm before this warm spell. I am in NW Ohio.I did however have some ponds 3 weeks ago without complete ice cover in windy conditions with single digit temps. This is a lot of stress.Open ice causes more harm due to cooling of bottom water in Ohio ponds.If you go a maximum of 6-8 weeks with solid snow cover then consider getting some snow off. As far as letting water in and creating horizontal current I dont think it has any advantage.As your pond gets some age and the Demand for 02 goes up you will not want snow cover for as long a period as stated above. If you are aerating assign a diffuser as a winter diffuser in a shallow end to clear some snow when physical removal is not practical.Oxygen checks today in our display ponds were at 12.18 ppm and 39.8 F at 10 ft 95% saturated. Last year with ice on/off four times I used no winter aeration in any of the ponds that we take care of.

Thanks everyone. I don't oxygenate. Just worried about the dead gills. I bet it was the rapid temp drop. As for the small fry, I just didn't think that you would see them this time of year. Thanks again, Tom