The Alaska Department of Fish and Game on Tuesday announced the season’s first commercial salmon fishing opening in a special harvest area at the mouth of the Kasilof River.

The emergency order opens set gillnetting within a two-mile area around the mouth of the Kasilof River for a 29-hour period from 6 p.m. on Tuesday through 11 p.m. on Wednesday. The emergency order also opens drift gillnetting in the area from 6 p.m. to 11:59 p.m. on Tuesday and from 5 a.m. to 11 p.m. on Wednesday.

This announcement marks the first time during the 2015 fishing season that fisheries managers will use the special harvest area to control sockeye salmon escapement up the Kasilof River. While it is technically possible to pack the 450 setnet permit holders of the east side setnet fishery into that area, the fishery can be chaotic as there are no restrictions on how far apart the nets have to be.

Commercial Area Management Biologist Pat Shields said the season is reaching a point when it can be difficult to manage the commercial fishing fleet because there are low numbers of king salmon and large numbers of sockeye salmon. Currently, setnetters are limited to 36 hours per week of fishing time.

Shields said it is difficult to control escapement within that time frame because of the speed and volume with which sockeye salmon bypass the commercial fishing fleet, personal-use fishermen and anglers on the Kasilof River.

The Kasilof Special Harvest Area is exempted from the hourly restrictions put on the rest of the setnet fishery, so managers can fish the set and drift gillnetters near the mouth of the river and control Kasilof sockeye salmon escapement without using the limited hours available for the setnetters to fish.

The 29-hour period available for setnetters to fish is longer than other fishing periods this season. Shields said it was based around the tide cycles and his tentative fishing plan for the rest of the week.

“We knew that Thursday was probably the next time we were going to fish in the regular area (available to setnetters),” he said. “So we fish until high water, slack tide on Wednesday night and then come out of the water. That will put the setnetters in the water in the Kasilof section for sure and maybe even the Kenai and East Forelands section on Thursday.”

Putting the setnetters in the special harvest area for a regular 12-hour period and then waiting until Thursday to fish was problematic, Shields said.

“We weren’t comfortable staying out of the water until Thursday morning without a fishery in the Kasilof section,” he said. “Every time we stay out of the water for at least three high tide cycles, sockeye escapement rises. Last time, we had 16,000 make it upriver.”

By Monday, more than 191,000 sockeye had been counted passing the sonar on the Kasilof River. The 10-year average of passage estimates for sockeye salmon in the Kasilof River suggests that the run is about 32 percent complete through July 6, according to the emergency order. Fishery managers are currently projecting more than 595,000 sockeye salmon could escape upstream if the sockeye salmon escapement continues at its present rate, according to the emergency order. If realized, that escapement would exceed the river’s escapement goals for sockeye.

“We’re just trying to slow the rate of escapement at this point,” Shields said.

During the 2014 fishing season, managers used the special harvest area for 17 days and commercial fishermen harvested 210,000 sockeye salmon, according to the 2014 annual fishery management report.

Some fishermen have expressed concern about the number of king salmon taken by setnetters in that area, Shields said in a previous Clarion interview.

In 2014, setnetters in that area caught about 625 king salmon according to Fish and Game data. Genetic sampling of that catch in 2013 showed that between 70-75 percent of those king salmon were headed for the Kasilof River, while the majority of the remaining king salmon were bound for the Kenai River.

“So that’s about 470 of those king salmon last year that might have been Kasilof king salmon,” Shields said in a previous Clarion interview. “Those are the types of decisions we’re faced with here. So when you look at that data you go, 470 king salmon for 200,000 sockeye salmon … that’s probably a pretty fair trade.”

Still, despite the low percentage of Kenai-bound king salmon caught in that fishery, Shields said his department was careful to consider the Kasilof River king salmon run as well when fishing setnetters in the special harvest area.

“It’s not a perfect tool and everybody recognizes that,” he said in the previous interview. “We use it realizing that we’re catching king salmon runs in there and if king salmon are weak in the Kenai River, it’s possible they could be weak in the Kasilof River. We just don’t measure them there.”

The extensive use of the special harvest area will likely dampen catches in the Kasilof River’s personal-use dipnet fishery. Shields said managers were cognizant of the negative effect on personal-use fishing in the area.

“This isn’t with intent to say ‘Oh, let’s make the dipnet fishery bad.’ This is an attempt to slow the escapement down,” he said.

Reach Rashah McChesney at rashah.mcchesney@peninsulaclarion.com or follow her on Twitter @litmuslens