>conflict
There is no conflict.
If some fish breeder's pond is being ravaged by otters, they can easily fence in their property. It's not the otters' fault if they refuse to do that.
As for the anglers, they have absolutely nothing to complain about.
1) The "problems" supposedly caused by otters in the ecosystem are either made-up or not caused by otters
2) Pollution and structural developments are causing far bigger problems for fish populations than otters
3) Otters need the fish to live, anglers just need it for their boomer hobby
4) Otters were there for millions of years, when did anglers get there?
I hope I answered all your questions.