In fact, this to has happened to me a countless number of times. I first noticed this about 6 years back on a peninsula silver. These were also little black leeches,but I didn't think anything of them and kept the fish anyways. I have kept a few with leeches this year too and smoked them up and never have gotten sick or anything so I guess they're harmless. I think the leeches are simply feeding on the salmon because as soon as a salmon hits the freshwater, it starts the detioration process immediately and the leeches take advantage of it. I've seen this on lots of Kings and Silvers, but never on a steelhead. I find that odd. Just a really bad year for them I guess and the rivers must just be flooded with the bloody little creatures. I don't think you have to worry about the leeches as much as the worms. I did catch a bright hen silver on the Dungy about a month ago and on the outside everything seemed to be fine, but when I cleaned the fish, I noticed a large number of white pea sized eggs or something in the meat that resembled eggs, so I threw it back in the river for the birds. Anyone ever seen this or know what it is?