Good balanced stuff as always from Bruno.This is from Bruno Broughton, it dismisses a lot of the myths spread by 'interested' parties, often with more than a hint of bias.
The only current legal deterrent is a proper fence (the right spec is detailed on the Angling Trust website). Obviously you cannot fence a river as Simon R has pointed out.
The latest legal development that I’m aware of is a concession from Natural England that they will consent the live trapping of otters that get INSIDE purpose built otter fences. NE will not accept basic stock fences or chicken wire constructions.