I would say that we don't have any direct evidence of it on salmon, only because they co-occur so infrequently, but there's a huge concern right now in the Miramichi because of the introduction into one headwater lake, that they will now get into the Main Wouthwest Miramichi. They do occur in the Saint John River system, where there are also salmon, but to my knowledge there has been no directed study to look at their potential impact on salmon there.
On May 19th, 2016. See this statement in context.