I’ve never caught a Sturgeon but I do know that this is NOT a very big one. They grow much, much bigger than this specimen.
Anyway, this is a good fish story and that guy sure looks happy.
Two years back a buddy was fishing the mouth of the Merrimack in Newburyport, MA. They were fishing for stripers. They hooked up on a sturgeon. It was about this same size, six feet. It took over an hour to land. All the other boats in the area stopped fishing and pulled in their lines. It eventually tired and they got it into the boat just to take pictures like this. When they got it into the boat other boaters were yelling to get it back in the water. Apparently, it is illegal to even land them in Mass because they are so rare. You are supposed to cut the line once you realize what you have on the other end. Therefore, they certainly did not share the pictures with anyone other than friends. These guys have been fishing in the area for 30 years, and never heard of anyone ever catching one before. FYI, the Merrimack flows from the White Mountains of NH south into Mass and into the Atlantic just south of the Mass/NH border.
There is a TV show about monsters in waterways and the guy who hunts them around the world. IIRC he captured a sturfeon which was eating children!