With a low return of summer-runs forecast, Washington fishery managers are closing the Green-Duwamish to steelhead retention to try and ensure enough broodstock are collected.
The rule change announced today takes effect June 2, when season opens between Harbor Island and the Headworks Dam deadline.
In 2015, after a winter with little snowpack and a hot start to the year, low flows and high water temperatures killed at least 34,000 young steelhead being reared at Soos Creek Hatchery, half of all those set for release in 2016, WDFW reported at the time.
The Green-Duwamish has produced angler harvests of as many as 711 summer-runs in 2013 to as few as 67 in 2015, the last year figures were available for.
The system is one of the last three consumptive summer steelhead fisheries in Pugetropolis.
The others are the Skykomish and the North Fork Stillaguamish.
A sea lion was spotted in the upper Duwamish earlier this month.
Managers say they will reopen retention once eggtake goals are met. Steelhead are defined as rainbows 20 inches or longer.