I am not a pro but IMHO it is not the fish.

Do you have subsurface water entering the pond in the eroded areas? This might cause the undercuts as well as the turbidity. Do you have a high water table, spring, etc in that area?

What kind of crawfish do you have? A burrowing species?

Last edited by Bill D.; 10/16/15 05:17 PM. Reason: Clarification

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