A South Fork Nooksack River hatchery program that took juvenile chinook salmon into “protective custody” no longer has to collect broodstock as fry to raise in captivity before spawning them.
Not only are the adult offspring of the captive broodstock returning to the Lummi Nation’s Skookum Creek Hatchery each fall, but so are some of the offspring of their offspring – second-generation adults. Plus, there is genetic evidence that some of the hatchery-origin chinook have successfully spawned in the river and produced natural-origin offspring.
“The South Fork Nooksack watershed had the largest natural escapement in recent history,” said Tom Chance, Lummi salmon enhancement program manager. “We had record numbers of redds in 2016 and 2017, and it appears 2018 redd counts may surpass these two previous years according to preliminary data.”
All of the hatchery releases from 2017 and 2018 were the progeny of adult fish that returned to the South Fork Nooksack River, rather than captive brood.
“We are in the process of increasing salmon production throughout the Nooksack and Samish river watersheds,” said Merle Jefferson, director of the Lummi Natural Resources Department. “The success of the Skookum Creek Hatchery chinook is playing an important role in helping to increase abundance of wild fish and providing fishing opportunity to tribal fishers.”
South Fork chinook were teetering dangerously close to extinction, with fewer than 100 adult fish returning to their spawning grounds in the early 2000s. The decline is a result of increasing water temperatures, decreasing water flows, and the ongoing destruction and degradation of habitat.
The captive broodstock program was developed in partnership with Lummi, the Nooksack Tribe, Washington Department of Fish and Wildlife, and the National Oceanic and Atmospheric Administration (NOAA).
Starting in 2007, the partners collected juvenile chinook salmon in beach seines and DNA-tested them to confirm their stock identity. Some of the captive broodstock were raised in fresh water at the state’s Kendall Creek Hatchery, and others were transferred to the NOAA Manchester Research Station, where they were reared in salt water.
Once the chinook matured, they were spawned. In 2011, the first batch of about 1,900 of their offspring were released. By 2016, when more than 360,000 smolts were released, enough adult chinook were returning that captive broodstock were no longer needed.
In 2018, the hatchery released nearly 790,000 chinook, with an eventual goal of releasing 2 million. The plan is to release 1.5 million from the Skookum Creek hatchery, and to take 500,000 in the pre-smolt stage farther up the South Fork in hopes that they will return there to spawn.
“We estimate roughly half of the returning adult females released from the hatchery program as juveniles are spawning naturally in the South Fork, which is exactly what we want,” Chance said.
In addition to the larger adult chinook, some second-generation hatchery fish have started returning to the Lummi Nation’s Skookum Creek Hatchery. Photo: Kari Neumeyer