Pond Boss Forums INTRO Questions & Observations Grass Carp winterkill

Hi everybody, I have a big winterkill this year and have never had one before, and was just wondering if anyone has any ideas why? My pond is 1/2 acre, 8ft deep , windmill aerated ,
built in 2008, spring fed, stocked in 2008. this year was the first year it has ever froze up solid even with the windmill. I could see the bubbles still blowing under the thin ice over it but for about 2 weeks of very extreme cold it froze solid. the fish kill consisted of 6 giant grass carp , a few big catfish, and some panfish, probably 20-30 fish total, I never seen a dead fish until now after ice out. we had a mid season rain and overflow flood of coffee colored water that raised the pond a foot and then refroze except the aerator hole, the water stay dirty the rest of the winter and still is.
Thanks for any ideas.

Welcome to the forum, PondGomer!!!

Don't be too upset...In a pond that was stocked 10 years ago, 20-30 fish dead sounds really minor, and could be mostly due to old age, and the unusual stress of ice (unusual for your pond). Chances are that you did lose several more fish (that sank and or got eaten by survivors/turtles) if you saw larger fish floating, but I still don't think I'd be too concerned given the age of the original stockers.

I'd be thankful for the grass carp going as "giants" eat almost nothing, but take up a LOT of biomass that could be used by other fish (i.e. a 40 pound Grass Carp could be 4, 10 pound bass).

The turbidity could have played a part by reducing phytoplankton and algae growth, resulting in low dissolved oxygen.....especially if you had calm wind days and your windmill became an ornament.

What are your pond hopes and goals? Where is your pond located? What all was stocked? Is it fished often or heavily?

Large catfish (over 3 pounds) compete with largemouth bass as an apex predator and are often overstocked in smaller bodies of water. Largemouth bass, unless managed fairly well, tend to overpopulate and stunt in the 10-14"/1 pound range, yet in some areas, bluegill can overpopulate and stunt. A "balanced" pond population is only really "balanced" till the first spawn.

Thanks for your input, very much appreciated!, My pond is located in the northeastern most county in Iowa, Allamakee. Goals include as good of fishery as a small pond can be while providing any other wildlife habitat, Migrating fowl, deer waterhole, swimming. I pulled about 25 hybrid bluegill a few largemouth bass and 3 perch through the ice, The perch were tossed in last spring from a river nearby prob 10 or so. most of the bass I catch are in fact 10-14 inches and always thrown back. I have never caught a bigger one, and until this year most of the fish caught were thrown back. I notice a big change in the water recently through the summer months, it turns brown until cool weather than looks healthy again. this started to happen after I dug out 3 big cattail patches. The pond was stocked heavy with catfish, bass and hybrid bluegills and (6) 1 ft long grass carp. Over the years other fish have been tossed in from various fish outings from smallmouth bass, walleye, perch , crappie, Only the perch have been recaught. Is it possible to post a picture I cant figure out how

How many catfish in the pond? You could be reaching your capacity in terms of lbs of fish. Might be a good idea to harvest some of the catfish etc...they also could be making the water more turbid.

If it were me, that's where I would start.

Here's a link to the archives that describes lots and lots of different ways to upload pics to the forum....

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92443#Post92443