Look closely, you'll see it's a pretty nasty fishing hook. Its a hair rig hook, devised to trick the fish into believing it has found a piece of loose food, then when the fish swallows it the hook catches in the mouth and the fish is quite literally hooked. It is attached to a length of braided line, designed not to snap. Clearly the inconsiderate angler has just left this on the bank with the bait still attached to the hair. The duck, fortunately didn't like the bait - a boilee, and dropped it and moved on. But it would have been so easy for this to have got stuck in its beak or face, or even of one of the geese that were also feeding in the same spot.
I am a fisherman, have been since I was a kid, but I was taught to leave no rubbish and certainly no dangerous tackle on the bank. Fishing has come a long way over the years, lead weights (in small sizes) were done away with years ago when it was realised that hundreds of water birds were eating it and dying. There is no control for this. It's just mindless ignorance, or at best forgetfulness of a dangerous proportion. Oh and before you say it, it wasn't kids. I regularly see a group of adult anglers fishing at the spot with their overnight bivvy tents.
We have to take more care, all of us. It's not just fishing takcle it's rubbish of all kinds. It's poop scoop bags, left hanging from the hedges, why bother to bag your dog's crap if you intend to just throw it into a bush. I do point a finger at the authorities, be it the Forestry Commission or Yorkley Angling club as in the case of the hook. There are insufficient rubbish bins at beauty spots. I accept that mindless morons burn them but there should be more, indeed SOME at places like Cannop and New Fancy.