The fish hatchery uses a high steel mesh fence around the rearing ponds and has the netting attached to the top of the fence. It is a closed system with gates for entry. Of course they are a government agency and can spend tax dollars. It sounds like you have a fairly large pond and it would be expensive to close in. You would have to place netting around as well as over the pond.
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"I would not be an old man if I had not been an armed young man." JTJ
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