Those sea lions have no shyness whatsoever about taking a salmon off the line, I found out.
The horsehead (grey) seals on the atlantic have been giving me some fits by eating stripers off my line, eating my fly or more commonly picking off freshly released fish.
My take on the whole seal problem (Ballard Locks, etc) is that humans create the worst of it. If there were no locks the predation would be like any other river mouth. If I didn't C&R fish in front of the seals, they wouldn't try to eat the dazed fish I release. Sure, before there were concrete walls to trap fish against they got their share of the fish, but only their share. I hated watching hershel eating just the roe out of the endangered native Cedar River steelhead! Not the sea lions fault, we gave them the all-you-can-eat buffet.
They are curious critters though. They sure know how to scare the crap out of me when I am wading far out on a shallow flat! It ruins my whole day when they play chicken with me.