I don't know how long it takes, but I do know that swords are spawning younger and younger, and the average size has dropped drastically. That's usually a sign that a species is in serious trouble. The big adults are history and the only animals left in the gene pool are the smaller, early-maturing fish. In my lifetime, I've seen the same thing happen with stripers. When I tell people that an 18-pound bass used to be considered a schoolie, they look at me like I'm nuts. They just keep killing the big breeders, then they wonder what the hell happened.
