The bad news everyone had been waiting for on the Kenai River came late Thursday.

Sport fishing for late-run Kenai king salmon is being shut down in the river, according to the Alaska Department of Fish and Game, and the consequences will ripple out into Cook Inlet to force closure of some commercial fisheries as well.

At one minute after midnight Friday, the river will close for kings for the rest of the year, the agency announced. The sport fishery closure, according to the state Board of Fisheries management plan, also triggers closures of commercial setnet fisheries on beaches along the east shore of Cook Inlet and forces the boats of drift gillnetters farther offshore.

The Commercial Fisheries Division of Fish and Game issued an emergency order closing "set gillnetting in the Kenai, Kasilof and East Foreland Sections of the Upper Subdistrict until further notice. In addition, the drift gillnet fishery in the Central District of Upper Cook Inlet is closed within one mile of the Kenai Peninsula shoreline north of the Kenai River and within one and a half miles of the Kenai Peninsula shoreline south of the Kenai River.

The problem for everyone is a weak return of late-run Kenai kings. Though the commercial fishermen are targeting red salmon, which appear to be coming back strong, their bycatch of king salmon is high enough that biologists have concluded that if their nets were left in the water, the weak king run would suffer.

As the situation stood Thursday, only about 8,000 of a needed minimum of 15,000 spawning fish are in the river, and the latest computer projection -- based on modeling of past runs -- puts the expected return at 13,000 to 14,000 fish even with further catches eliminated.

On Sunday, the situation looked better. More than 1,000 kings passed the sonar counter in the lower river that day. The big bump came after setnetters were ordered to fish shallower nets along the beaches. Some scientists believe the kings, which move deeper in the water column, can swim beneath those nets.

But no firm cause-and-effect relationship has been established between shallower nets and lower king catches, and with heavy commercial salmon fishing taking place offshore in recent days, the hopes that a closure could be avoided faded after Sunday's big school of fish swam upriver.

The Monday count was only 371 kings. It increased to 463 on Tuesday and bumped up to 717 on Wednesday, but the way things look now, some 1,000-fish days are going to be needed to make the minimum spawning goal.

Catch figures estimate about 2,400 kings have been killed to date; 534 of those were kept by anglers or died after being released in the catch-and-release fishery, according to Fish and Game's Division of Sport Fish data. Commercial fisheries reported a total kill of 1,833 kings -- about 85 percent of them caught in a couple hundred setnets.

The sport fishery closure will be a blow to a multimillion-dollar Kenai tourism industry, much of which revolves around sport fishing. But it is not a massive blow. The king season normally closes in a week anyway, and a good run of red salmon has kept anglers flocking to the Kenai.

The news is probably worse for setnetters. It ends their season just as red salmon appear to be storming the beaches, and it comes just days after a Superior Court judge overturned Lt. Gov. Mead Treadwell's attempt to block voters from deciding on whether setnets should be banned on the Kenai and in other urban areas.

Backers of the initiative to ban the nets plan to start gathering signatures soon with an eye to getting a vote on the ban on the Alaska ballot in 2016. Many in the state are angry at what they see as an unfair division of the kings between a handful of setnetters and tens of thousands of anglers.

Contact Craig Medred at craig(at)alaskadispatch.com