I'm thinking winterkill. I remember several small lakes (ponds, really) on the Canadian shield having only minnows in them, because any larger fish (YP, WE, NP) that get introduced into them routinely die from low oxygen under the ice. The small minnows have a lower oxygen demand and survive in breeding numbers.

Any future large fish stocking could be kept alive through some snow removal or enough aeration to keep a small area ice free.


"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
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