Thursday, April 25, 2024

Salmon Spawning Starts New Generation at Leavenworth National Fish Hatchery

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August is an exciting month at Leavenworth National Fish Hatchery This is when our next generation of salmon gets its start. This year, 472 females and 469 males await their opportunity to spawn in the next few weeks.

We raise 1.2 million spring Chinook salmon every year for release into Icicle Creek. Releases happen in April, and the young smolt swim 500 miles downstream, through seven dams, and out into the Pacific Ocean. Half will die before reaching the sea. The other half are on their own, heading north to the Bering Sea to feed and grow for another one to four years.

Leavenworth fish are very faithful: they find their way back to the Columbia River when they feel the urge to spawn, and travel all the way upstream and through those seven dams to reach Icicle Creek and enter our holding ponds, following their acute sense of smell and their memory of the journey out. Leavenworth’s stray rate is exceptionally low.

Spring Chinook are named for their habit of returning in spring, even though they won’t actually spawn until August. This timing may seem odd—until you take a walk beside Icicle Creek right now and have a look at the low water level. Now is not the time to migrate into the high, cold streams Chinook salmon prefer. A spring arrival means there is plenty of water, and the fish can get well up into the headwaters of their preferred home stream. Then they find a cool pool, and wait.

Why not lay eggs in spring? Because summer is coming, with its high water temperatures and shallow depths. That’s a lousy time to be an egg. Laying eggs in August instead means the salmon will hatch in autumn, a better time for them to survive as temperatures cool and fall rains raise the river levels.

Our hatchery fish are almost ready to lay their eggs. On Tuesday mornings in the second half of August, the entire staff turns out to help with spawning. Unlike their wild brethren, hatchery fish will have their eggs collected in bowls. Each bowl will be fertilized with milt from two male salmon, ensuring a high degree of fertilization. The bowls are carefully driven to the nursery, where the eggs are washed and each bowl is emptied into trays designed for incubation.

Staff from the Mid-Columbia Fish and Wildlife Conservation Office (MCFWCO) take data on the spawned fish. Measurements, genetic samples, and scales are used to describe the broodstock. Additionally, each fish is put through devices that detect two types of tags that were implanted into the juvenile fish months before they were released. Coded wire tags, the width of a mechanical pencil lead, are collected and read under a microscope. Then the code is entered into a huge database that covers the entire Pacific Northwest. Passive integrated transponder (PIT) tag information is also collected. These tags can bounce back signals and help us track our fish in real time as they return.

In addition, Fish Health veterinarians and staff take measurements and biological samples. For example, liver samples can indicate whether a female salmon was infected with bacterial kidney disease (BKD). BKD can be passed down to the eggs. Since every female’s eggs are kept in a separate tray, we can go back later and remove any unhealthy eggs without infecting the other batches.

Leavenworth’s hatchery program is monitored and evaluated by the MCFWCO to make sure we get the best possible results. We want our hatchery fish to come back to our hatchery and not interbreed with wild fish. Our production staff watches over them closely, reporting any issues at once to our on-site Fish Health staff and working together to solve health problems rapidly. We support tribal hatchery programs by supplying space at our site and providing eggs during spawning season to be raised in other locations. When ocean conditions cooperate, our salmon offer commercial, tribal, and sport harvest as well as being a source of food for wildlife.

The fisheries of the Columbia River Basin are challenging to manage. Hydroelectric and irrigation dams provide low-cost electricity for industry and residents, and water for millions of acres of agricultural land, forming the backbone of our economy and keeping the cost of living among the most affordable in the nation. The economic infrastructure and our growing population put enormous pressure on our natural resources. Keeping salmon in our rivers is not easy and not without risk or cost; but it is a task that multiple partners—federal, state, and county agencies, tribes, public utility districts, cities, and communities—all work together to support. We are proud to be part of this effort. And we welcome visitors to the hatchery to learn more and, if your timing is right, to watch the spawning and welcome the next generation of salmon to Leavenworth.

You can reach Julia Pinnix, Visiter Services Manager, Leavenworth National Fish Hatchery at 509-548-2915,or Email at Julia_Pinnix@fws.gov,

12790 Fish Hatchery Road, Leavenworth, WA, 98826

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service. For more information on our work and the people who make it happen, visit www.fws.gov

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