I admit it, I was a little concerned when I noticed a site called Sexyloops.com linking to the ISW. No worries though - it's all about the flyfishing. Always good to see the angling aficionados taking an interest.
Update: As an anon commenter points out below, those fly fishers and anglers certainly do care about invasive species issues. Check out this post, this one and this one about the invasive freshwater algae known as Didymo.