The state and City of Seattle are again catching sockeye in the Cedar River, just about under the Interstate 405 bridge in Cedar River Park, part of an ongoing effort to preserve sockeye runs.

Last week, crews with Seattle Public Utilities and the state Department of Fish and Wildlife installed a fish weir, basically a flat fence that spans the river and directs salmon of all species to a large holding area.

From there, the male and female sockeye are separated and hauled by tank truck to a sockeye hatchery at Landsburg upriver, where they are spawned manually, their lifecycle completed.

All returning coho and Chinook salmon are allowed to migrate upriver.

The trapping begins right after Labor Day, in order to catch the earliest parts of the sockeye run. Typically, the weir will remain in place into November.

This is the second year the weir was installed in the river next to Carco Theater. Prior to that, it had been at Cavanaugh Pond upriver since 1992.

So far, the outlook isn’t good for catching a lot of sockeye. In fact, the run hasn’t been strong for the last three years, said Gary Sprague, the Landsburg mitigation manager for Seattle Public Utilities. Poor survival of young sockeye in the ocean is the likely cause, he said.

This year’s run is forecast at about 22,000 sockeye, smaller than last year’s run of about 34,000 fish.

“Unfortunately, it’s even smaller that last year’s,” he said.

Near-record high flows last winter wreaked havoc on the river and the salmon redds or nests. The flooding also damaged the weir.

“It hurt everything,” he said, including the Chinook, which got “hammered.” The Chinook are struggling to maintain a presence in the Cedar. The state is seeing a smaller return of Chinook, too, Sprague said.

On the bright side, early signs indicate that coho salmon “are coming back strong,” which could be a “good indicator” for other species, such as sockeye, Sprague said. However, coho only spend one year in the ocean, he said. Sockeye spend two or three years in the ocean.

The goal is to trap 2,200 sockeye this fall, about 10 percent of the run.

Last year, the river and hatchery produced about 1.6 million sockeye fry. The year before that, the production was estimated at 15 million to 20 million sockeye.

Sockeye typically return to their home rivers in three- or four-year cycles. They will spend their first year in Lake Washington, before heading out to the Pacific Ocean. Then they return to the lake and wait until drawn upriver, often by a rainstorm.

Seattle and the state have made some changes to the weir this year. A big one is a new gate that will allow for easier passage of the Chinook salmon, which are bigger than sockeye.

Last year, crews had to remove parts of the weir so the Chinook could pass; they had been congregating below the weir, slowing their migration.

“It wasn’t ideal for the fish or easy for us,” Sprague said.

So, now there’s a gate on the north side of the river – its deepest part – where the Chinook tend to favor.

The gate easily closes when the weir is “fishing,” typically eight to 16 hours a day and easily closes when all fish have free passage upriver.

Another “big improvement” for the crews and the sockeye is the new access road that ends directly at the river’s edge. Now, with the new access, crews only need to haul the sockeye 20 feet to the waiting tank truck. Before, it was up a slippery, muddy slope 300 feet to the truck.

Once again, Sprague is warning that onlookers stay off the weir, which is made of piping, and don’t throw anything on it.