http://en.wikipedia.org/wiki/Copepod
I'm by know means any expert, but this is usually claimed as being "Sea lice" Sometimes shows up on fish that have no way of getting to the salt other than taking a bus.

Very interesting, the article stated that copepods are in nearly every fresh water ecosystem as well as salt water. I took it as a given that "sea lice" on a fish meant it was in the salt recently. Wrong. Obviously many of the fish we catch in lake washington and sammamish have at one point been in the sea, but unless you are a copepod biologist good luck telling which ones truly were in the salt. So, these fish we caught were DEFINITELY kokanee then. Thanks for the info quadfather.

docshane - I had thought the same thing when I noticed this. However, there is a simple way to determine if they are sea lice or freshwater gill louse. Sea lice are brown and gill louse are white. I have caught fish with sea lice one them in Lake Washington, but never in Lake Sammamish. I think that by the time they make it through the locks, Lake Washington, the slough and into Lake Sammamish the sea lice have died and dropped off the fish. I have caught sockeye in Lake Washington that have been infected by gill louse. These are typically fish that have been in the lake for a while and have become stressed to the point that the parasite can infect the host.