Sorry to anyone who wanted it to be true.
With a google search, I found a site that found the true source in 2005.
http://www.hoax-slayer.com/giant-sturgeon.html

As referenced in the above webpage,
Brad Dokken of the Grand Forks Herald also got the email, found the source of the photo and also wrote an article.
I believe it was back in 06.

Also is a link to Lens Sport Fishing Adventures website where the picture was originally posted.
Take a look, it’s there. – http://www.lenssportfishing-bc.com/fish-photos2.htm