Thorney Channel
I'll try to get some photo's the next time I'm down there ( within a few days ) - my boat's out of the water at the moment, but when re-launched in March I'll photo the Emsworth side ( where I'm convinced there's nothing ) and go down the Thorney Channel & see if there's anything to photograph; of course by then everyone will probably have forgotten this !
I suppose the real people to ask would be the local pro' fishermen; not a very approachable lot, and if asked questions they'll probably think they're being accused of something, or that there's money to be made out of it.
I do know the pub they tend to use ( The Bluebell, Emsworth, which is actually a very nice pub ) so I suppose I might have to visit 'for research purposes' !