I've seen the pic before, it's actually from the Fraser River in BC. (The Lake Sturgeon found in all the great lakes only grows to about 200 pounds max) I forget if it's a White Sturgeon or what the species is but they do get even bigger. It's hard to measure an exact weight because (at least in the US) it's illegal to fully remove them from the water. You can get pretty accurate by measuring length and girth and using a formula. There are reports (and some compelling pictures) of fish going up to 1500 pounds but the official world record is much lower since old reports are generally unreliable, the fish was protected until recently and with the no-removal rule it's impossible to weight them!
