We have a large 2 acre land locked pond in which the deepest point is approx 13 ft. It is stocked with carp, large mouth bass, perch, and blue gill, and sunfish. We are located in the Fingerlakes of NY and we just had the coldest harshest winter on record. Temperatures were constantly below 0 with many days that were as cold as -15 below. Upon recent thawing we discovered 100s of dead fish all along the pond edges Including the 3 carps and many small fish. Could the pond have frozen solid? Or could many fish have been oxygen depleted? Or could they have been poisoned by their own gases?

Sorry to hear about your losses. I'd imagine you are not alone after the winter you guys have had.

In principle the lake could have frozen solid, though I doubt it and almost ceratinly the fish will have died due to oxygen depletion in the water. Ice limits gas exchange with teh atmosphere and O2 depeletion is exacerbated if there is snow lying over the ice too (blocking the light prevents any plant photosynthesis that might otherwise replenish some dissolved O2).