How the Salmon Spawn Works


Silver salmon of western North America.
Glenn Oliver/Visuals Unlimited/Getty Images

Silver salmon of western North America.

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­Many of us have grown up watch­ing nature shows that pres­ent dramatic footage of large salmon swimming and leaping heroically upstream to spawn. For many, that image is a last act of the salmon -- and not just because a bear got to the leaping fish.

Where does spawning fit into the salmon's life cycle? For most species, spawning is the final act before dying. Eggs are deposited in a redd, or gravel nest, that the female salmon has made. The embryos hatch, becoming alevins, or yolk-sac fry, and live off the yolk-sack on their undersides. When they have completely absorbed the yolk-sack, they begin to search for food as fry. After growing in freshwater, ­the juvenile salmon, known as smolts, change physically to adapt to saltwater. They lose the spotted coloring that allowed them to be hidden in a stream and become silvery to blend into the ocean. Once in the ocean, they feed and become full adults.

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A few species can spawn more than once in a lifetime. Most, however, die within a week of spawning, completely worn out from their migration and spawning efforts. Their decomposing bodies provide food for other species during the winter and help fertilize the streams.

To everything there is a season, so let's find out more about salmon seasons. Just when do the salmon spawn?

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When Salmon Spawn

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­Angle­rs prize several species of salmon. The following chart summarizes the spawn times and average size of some of the more popular types.

Salmon Spawning Times and Sizes

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Species

Spawning Season

Average Size

Pink salmon

Fall, but only every odd-numbered
year in Washington state

3 to 5 pounds (1.4 to 2.3 kg)

top weight: 12 pounds (5.4 kg)

Sockeye salmon

Fall

5 to 8 pounds (2.3 to 3.6 kg)

top weight: 15 pounds (6.8 kg)

Chum salmon

Fall

10 to 15 pounds (4.5 to 6.8 kg)

top weight: 33 pounds (15 kg)

Coho salmon

Fall

6 to 12 pounds (2.7 to 5.4 kg)

top weight: 31 pounds (14.kg)

Steelhead

Spring; summer and winter runs

8 to 11 pounds (3.6 to 5 kg)

top weight: 40 pounds (18 kg)

Chinook salmon

Fall; spring, summer and fall runs

10 to 15 pounds (4.5 to 6.8 kg)

top weight: 135 pounds (61 kg)

[source: Washington Department of Fish and Wildlife]

Save the Salmon!
In places where the salmon have become extinct, the entire ecosystem is at risk. In turn, river otter, mink, bear and eagle experience loss of population. That's part of the reason behind efforts, which started in the 1990s, to preserve wild salmon as a natural resource, after 17 stocks had become extinct. Stock varies from river to river -- all Chinook are not genetically alike. By adapting to their specific watershed, the salmon have been able to survive. Loss of a particular stock is a genetic loss [source: Washington Department of Fish and Wildlife].

Depending on the timing of the spawn, salmon may face multiple threats. Natural events can make things more difficult, too. In the summer of 2008, floods in Alaska put the king salmon population at risk. Floods usually occur late in the year, after the salmon have spawned. Earlier flooding means that eggs already deposited could be washed away. Higher, stronger water also makes it more difficult for the salmon to reach spawning grounds because the fish use more energy to fight the current. In such events, expending that energy may mean not enough energy remains to spawn. [source: Anchorage Daily News].

You've carefully chosen the right season for catching spawning salmon. But where do you go to find them? Read on to get your bearings!

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Where Salmon Spawn

Out of every 1,000 eggs laid, only about one survives to return to the home stream­ for the spawn. A large female salmon may lay as many as 5,000 eggs in multiple redds during the spawn, which can last between 30 and 40 hours. The fish you are angling for is healthy and a fighter, or it would have died sooner [sou­rce: Evergreen].

Salmon are prone to spawn in parts of the stream where the young fry can grow safely. This also ensures that the fry don't need to travel very far when looking for rearing areas. Most salmon are very adaptable to all freshwaters. They prefer clean, cool water that offers woody debris as well as clean spawning gravel. The table below shows how several species use different segments of rivers and streams. Salmon that have adapted to living in both freshwater and saltwater are called anadromous.

Pacific Salmon Species' Use of Northwest Waterways

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Species

Preferred Spawn Location

Chum

Lower reaches of small streams

Coho

Middle reaches of small streams; small tributaries of big rivers

Chinook

Mainstem and larger tributaries of big rivers

Pink salmon

Lower reaches of big rivers

[source: Washington Department of Fish and Wildlife]

Where have all the salmon gone?
In the spring of 2008, wild salmon appeared to have abandoned sections of the Pacific coast, leaving professional anglers and guides stymied. Between 2005 and 2008, the number of salmon returning to the Sacramento River dropped from more than 800,000 to below 200,000, a loss of more than 75 percent. Although researchers identified more than 40 different possible factors --from hungry sea lions to water taken out of the river for irrigation -- no one was certain of the cause [source: CBS].

­Both pink and chum salmon have adapted to migrating to saltwater immediately after hatching rather than growing in the freshwater stream as other salmon species do. This technique allows the salmon to escape the higher mortality rate suffered by the species that remain in a more varying freshwater location [source: Evergreen].

Different varieties of salmon are found on both coasts and have been introduced into other locations as well. For example, several New York state streams have been stocked with Pacific salmon, primarily Chinook and Coho [source: Moore].

What are your options for salmon fishing during the spawn? Let's move upstream to find out!

Salmon Fishing During the Spawn

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Safety Check and What's in a Name?
If you're p­lanning to fly fish in a river during the salm­on run, follow the guidelines below.­
  • Use caution and good common sense.
  • Put on a life jacket or a wader belt.
  • Carry a stick to help you keep your balance as you wade over rocks that may be slippery.
  • Wear shoes, boots or waders with spikes.
  • Use polarized sunglasses. They will help you see potential hazards as well as fish.[source: Moore]
Many species of salmon have descriptive nicknames. King salmon is another name for the Chinook, probably because they are the largest Pacific salmon. Coho salmon are nicknamed for their color, silver. So are the sockeye salmon, known as reds. Because of its structure, pink salmon are also called humpback or humpie. Chum salmon during the spawn develop something that looks like dog's teeth; thus, they are also called dog salmon [source: Washington Department of Fish and Wildlife].­­

Y­ou have two major options f­or salmo­n fishing: spin fishing and fly f­ishing. Let's look at both c­hoices to help you decide which is best for you.

If you plan to spin fish, you'll want an 8- to 9-foot (2.4- to 2.7-meter) me­dium-action graphite rod. This will allow you to keep your line off the water and also help you be aware of strikes. Use a 10-, 12- or 15-pound test line. You need at least 200 yards (182 meters) with a smooth drag on your reel. If you decide to use a leader, use two to four feet of 6- to 10-pound test. If there's clear or low water or heavy fishing pressure, use a light leader [source: Moore].

Anyone who's read the book or seen the film "A River Runs Through It" may have developed a fantasy about fly fishing. If you fit that description, here's the information you need.


­Your rod needs to be about a foot longer than one you'd use to spin fish, so roughly 9 to 10 feet (2.7 to 3 meters). Your line weights will be seven, eight or nine. Use a reel of the best quality you can afford -- fighting salmon can give the reel a beating! Make sure the reel can handle a minimum of 150 yards (137 meters) of 20-pound test backing. Fluorescent backing makes it easier to see where your fish is running, and it allows other anglers to see that you've got a fish on your line. You'll want a smooth disc drag to stop runs and wear out the salmon. Full-floating lines give you better control and work well for casting long distances [source: Moore].

In upper areas of the river, or after fish have been in the river for a few days, use smaller flies. Save large flies for lower sections of the river earlier in the run. Have three to four dozen different flies with you in different patterns and sizes. Choose flies that you can quickly tie because you'll lose a lot during the day.

Rel­ated HowStuffWorks Articles

Sources

  • Anchorage Daily News. August 5, 2008. "Floods may have frustrated interior salmon spawning."
    http://dwb.adn.com/money/story/9938218p-9858018c.html (Accessed 11/12/08)
  • CBS Evening News. "What Happened to the Wild Salmon?"
    http://www.cbsnews.com/stories/2008/03/17/eveningnews/printable3946364.shtml (Accessed 11/11/08)
  • Evergreen University. "Salmon Spawning Behavior."
    http://academic.evergreen.edu/curricular/ftts/downloads/chumsalmon2pg.pdf (Accessed 11/12/08)
  • Five Counties Salmonid Conservation Program. "Basic Salmon Life Cycle."
    http://www.5counties.org/BasicSalmonInfo800.htm (Accessed 11/11/08)
  • Moore, Paul. "Introduction to Pacific Salmon River Fishing Techniques."
    http://www.fishusa.com/FishErie/Library_One.asp?Article_ID=9 (Accessed 11/11/08)
  • Streamnet. "Interactive Salmon Life Cycle."
    http://www.streamnet.org/pub-ed/ff/factsheets/Lifecycle.html (Accessed 11/11/08)
  • Take Me Fishing. "Sockeye Salmon: Baits and Lures."
    http://www.takemefishing.org/fishing/fishopedia/species-explorer/details/bait-and-lures/fish/sockeye-salmon (Accessed (11/12/08)
  • Take Me Fishing. "Salmon, Sockeye: Fishing Methods."
    http://www.takemefishing.org/fishing/fishopedia/species-explorer/details/fishing-methods/fish/sockeye-salmon (Accessed 11/12/08)
  • Washington Department of Fish and Wildlife. "Salmon Facts."
    http://wdfw.wa.gov/outreach/fishing/salmon.htm (Accessed 11/11/08)
  • Washington Tourist. "Journey of the Wild Salmon: Spawning."
    http://www.washingtontourist.com/salmon/journey/seven.html (Accessed 11/11/08)
  • Wisconsin Department of Natural Resources. "Lake Michigan Trout and Salmon Frequently Asked Questions."
    http://dnr.wi.gov/fish/faq/troutsalmon.htm (Accessed 11/11/08)
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