About 3,200 adult sockeye salmon, about evenly split between males and females, were collected this fall at the fish weir on the Cedar River next to the Renton Community Center and trucked to the river’s fish hatchery.

That number is considered on the low side and reflects the cyclical nature of the returning sockeye runs on the Cedar River. In the past operators of the weir have set goals close to 10,000 sockeye.

“With ocean conditions being cyclic, it’s hard to predict,” said Michael Sedgwick, a fish-hatchery specialist for the state. “As for actual numbers, it’s on Mother Nature at that point.”

The roughly 3,200 total is about 10 percent of the 33,426 adult salmon that moved through the Hiram Chittenden Locks fish ladder in Seattle, among the lowest on record since the counts began in 1972. In 2009, the total was 21,718.

The fish weir is staffed by the Washington state Department of Fish and Wildlife, in cooperation with Seattle Public Utilities, which operates Chester Morse Reservoir that provides water for the Seattle area and for fish in the Cedar.

The Muckleshoot Indian Tribe is a partner in managing the salmon resources on the river.

Trapped this fall were 1,594 females and 1,656 males at the weir, which was removed in early November. The crew tries to split the catch evenly in order to maintain genetic diversity at the hatchery upriver from Landsburg in east King County, according to Sedgwick, who oversees the fish weir.

“The fish were considered in good health,” he said, weighing between 4 pounds and 7 1/2 pounds, about average for sockeye.

A “fairly low” return was anticipated this year, Sedgwick said, and “an awesome job taking eggs” at the fish hatchery allowed the staff to meet its goal of collecting almost 4 million eggs.

But that’s still far short of the 34 million fry the hatchery must release to support a return of at least 350,000 adult necessary to have a fishery on Lake Washington. That number was reached in 2006, 2004, 2002 and 2000.

The salmon trapped this year were released as fry in 2010, 2011 and 2012. Sedgwick worked for the state in those latter two years and recalls good egg takes and fry releases.

This year’s fry will be released in 2016 before heading out to the Pacific.

Endangered Chinook salmon and coho also were trapped but they were released and some also bypassed the weir through a “tip” gate on the community center side of the river.

Sockeye also move into other rivers and streams, including Issaquah Creek, that flow into Lake Washington. Young sockeye spend about 18 months in the lake’s fresh water as part of their life cycle, before heading out to the Pacific Ocean through the locks.

It’s often the conditions that sockeye find in the Pacific that will determine how many survive to return to spawn.