Floater,
As a professional photographer I on occasion find one of my photos used without my permission.

I've found over the years that a pleasant but direct letter to the individual or company that used the photo without my permission is the best way to handle this.

You might point out that although your were flattered to see your photo on the website, that you have never fished with him and feel it is a misrepresentation.

Suggest to him that as a courtesy, he might host you and your wife for a trip with him, if not please remove the photo.

Im my case, I just send an appropriate bill. Never had I have had it ignored.