Extreme Measures
(Video)
Humans and Salmon
(Video)
Producing Salmon
(Video)
Restoring Streams
(Video)
Salmon's Journey
(Video)
Salmon in the Ecosystem
(Video)
Download and ShareMost salmon are anadromous, meaning they are born in freshwater, migrate to the sea where they live for most of their lives, and then return to freshwater streams to spawn. Adult salmon stop feeding when they enter fresh water and survive on stored body fat. Salmon return to the streams where they were born for the spawning process, with some species, such as Sockeye and Chinook salmon, traveling up to 1,000 miles to spawn. Researchers believe salmon use their sense of smell to help locate their home streams.
To begin the spawning process, the female salmon lays her eggs in a redd (nest), up to 18 inches deep, which she digs in the gravel stream beds with her tail. After a male fertilizes the eggs, the female covers the hole and digs a new one, where she deposits more eggs. This process continues until she has laid all her eggs. Females can lay up to 8000 eggs and deposit their eggs in up to 7 different holes. After spawning, all male and female Pacific salmon die within a few weeks.
The number of wild salmon in the Pacific Northwest has decreased dramatically over the past 200 years due to a combination of natural and human-related factors. Many species of salmon in the Pacific Northwest are listed as threatened or endangered on the Endangered Species List. In the Colorado River, the salmon population is approximately 3% of what it was in the early 1800s. Some factors posing threats to salmon are rising stream and river temperatures, due to climate change; natural predators; pollution; overharvesting (through commercial fishing, etc.); and dams on rivers, which obstruct passage to spawning areas.
In order to increase the number of wild salmon, scientists have created fish hatcheries in the Pacific Northwest, to produce and raise millions of salmon each year, which are then released into the wild. The hatcheries take adult salmon from spawning grounds, remove eggs from the female salmon, fertilize them with milt (white liquid containing sperm), and incubate the eggs in plastic bags and PVC pipes. After about a year or more, they release the salmon into the wild. After these salmon are released, they are considered part of the wild salmon population.
NARRATOR: For most of their life, salmon travel the North Pacific, foraging the ocean’s rich food supplies.
When a mysterious inner signal draws them back to the coast... they gather at the mouths of their respective home rivers…before turning upstream.
They come in waves, obsessively seeking the streams – often the very gravel beds – where they were born.
DAVID DUNCAN: It’s this orgy of abundance.
For some, home is the coastal rain forest…
For others, it’s a high desert canyon…
And for Idaho’s endangered sockeye, home is deep in the continent’s rugged alpine interior.
Past eight giant dams…
Countless false turns…
Idaho sockeye remain insistent on the unique chemical signature of Redfish Lake – a cold water womb in the Sawtooth Mountains, named for the colorful fish that once spawned here in the tens of thousands.
After excavating a gravel nest… they set the next generation on its way.
Soon after, they die.
DAVID DUNCAN: It’s amazing what they do in order to reach these birth houses of these beautiful wilderness streams, eastern Oregon, eastern Washington, Idaho streams. They give up their lives to put thousands of these little glowing red balls into the stone spine of this continent. It’s this luminous ball. It looks backlit, it looks like the sun. In cold stone, cold water, they find a fire that creates life.
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