Back in the 60's and 70's it wasn't environment advocates or bunny huggers wading around the marshes picking up dead ducks and geese to find what was killing off waterfowl it was duck hunters. Lead poisoning was a real problem in some areas.
Yes the swans do get necropsied to determine what the cause of death. For many years that area also had a few pheasant release sights and one of the major roosting areas for swans was on the receiving end of a trap range. The pheasant release sights had corn planted on them that was left standing for waterfowl also. Other birds die in the area also but aren't near as visible as the swans and the swans have a number of people that monitor them.
Yes lead stays in the enviroment a long time but for the same reason you have to dig for gold and can pan it, lead is heavier than sand , gravel and mud and with wave action and current settles deeper every time it moves. It doesn't take long for lead shot in shallow waters to work it's way out of reach of birds.
I've been hunting ducks for 58 years now and most of it with a double gun of one kind or another. Back in MN we shot steel for nearly 10 years before it became a national mandate and the first couple of years I shot a Marlin 120 Skeet gun until the SKB 100 26" IC and MOD proved to handle and ounce of steel 4's just fine and was my goto duck gun until just a few years ago when the hammer guns of my youth called to me.
Shooting steel isn't a big deal, people just need to learn the limitation and abide by them and them it will kill just as good as lead. Instead of taking the shot when you think you can kill them let them make another pass and take them when you know you'll kill them. I'd much rather go home with four ducks than splash down 10 and only retrieve 7. I still count any un-retrievable duck in my bag.
You can call me a nut case but lead ingestion in waterfowl was a real problem in certain areas.
When hear someone say they quit duck hunting because of steel shot , they weren't really a duck hunter and were just looking for a reason to quit. If they made me hunt ducks with an arrow on a string so I wouldn't pollute with wads and shot and could retrieve every duck I hit I'd still be duck hunting. Heck back in the day I used to hitch across Wisconsin with my old hammer gun strapped to my duffle to hunt ducks in the river bottoms near Lacrosse and cut classes at college to get in on the evening flight of woodies on a local beaver pond. As a kid my dad would drop me on the river in one town and I'd float the river down to the next town stuff my gun in the bushes and hike to the tavern in my IKE jacket and hip boots to call dad and have him pick me up.
