I guess that's one way to look at it.
Me... I ain't buyin' it.
They aren't late.
It's simply a reflection that the earliest component of the run has been systematically wiped out over the past four decades. The only remaining healthy component of the run is the late piece.... the fish returning the last few days of July and into August. Because these fish are genetically programmed to return later, they bear negligible to ZERO in-river exploitation because the king salmon fishery ends on July 31.
I can't stress enough a concept I have called "the window of vulnerability".... the time frame that a returning Kenai king is susceptible to the fleet. Some fish return earlier or spend most, if not all, of their in-river adulthood in the open fishing zone. (Think mainstem spawners!) Fish genetically programmed with that life history are a poor fit for the prevailing in-river conditions... they never leave the open fishing zone unless it's in a cold dark aluminum box!
A king salmon returning to the Kenai river has only two chances for a free pass.
1) A trib spawner that's lucky enough to make it to sanctuary water before being caught.
2) A mainstem spawner that returns late enough that it has little to no exposure to the fleet.
Early run trib spawners that dilly dally in the mainstem prior to committing to their chosen trib can have upto 8 weeks exposure to the fleet. An early-timed mainstem spawner also has the deck seriously stacked against it because its window of vulnerability may well be its ENTIRE adult stream-life. These fish have borne disproportionate exploitation for as long as I have been fishing the river, and we are seeing the fruits of four decades of that misguided harvest policy today. Among trib spawners, only those with the most expeditious migration thru the mainstem make it to sanctuary water in time. Among mainstem spawners, the front end has been systematically wiped out, the middle is on its way out, and the only fish sustaining the run today are the latest arrivals. Those late fish used to be the minority component of the run. But four decades of very un-natural selection pressures against the early and mid-timed fish have so decimated that portion of the run that the late fish have by default become the majority component.
Food for thought... and if you chew long enough, it won't take much time to sink in.
It ain't rocket science.