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Wildlife Spotlight: Chinook Salmon (Oncorhynchus tshawytscha)

By Stefan Marti
Published: May 2007

Chinook salmon in a river.

Chinook salmon. Credit: NOAA

With salmon, it gets tricky with the names: Chinook, Coho, Sockeye, Humpy, Chum—or king, silver, red, pink and dog. And some call Chinook tyee salmon, or Columbia River salmon, or chub or hook bill or black-mouth salmon.  No matter what you call them, their journey from small mountain streams to the open ocean and back again to spawn and die is an amazing tale of nature. 

Chinook salmon are the largest of all salmon, averaging 30-40 pounds, with the heaviest weighing over 120 pounds.  They are typically around 33-36 inches in length, but can reach nearly 60 inches.  The fish are blue-green on the back and top of the head with silvery sides and white bellies.  On the upper half of their body, they have black spots.

Life Cycle

Chinook range from Central California to Alaska and across the Pacific from Russia to Japan. They are born in fresh water rivers, and after a few months, head down stream toward the ocean as smolts.  The young fish spend several months feeding and hiding in estuaries before heading out to sea to mature. Generally, Chinook salmon spend 1 to 6 years in the ocean, then return to natal streams to spawn.  After they spawn, they die.

salmon at different stages in life.There are different seasonal "runs" in the migration of Chinook salmon from the ocean to freshwater, even within a single river system. These runs start when adults begin their upriver journey to spawn.

Adult females will lay eggs in deeper water with larger gravel, where the current is cool with a good flow (to supply oxygen).  After laying eggs in a redd (or nest), adults will guard the redd from 1 to 4 weeks before dying.  A few months later, depending upon water temperatures, the eggs will hatch. They young feed on terrestrial and aquatic insects, amphipods, and other crustaceans.

As the time for migration to the sea approaches, juveniles lose their vertical bars and spots useful for camouflage. They then gain the dark back and light belly coloration used by fish living in open water. Chinook salmon seek deeper water, avoid light, and their gills and kidneys begin to change so that they can process salt water.  As adults, they prey on other fish.

Destroying their Waterways

For the past two centuries, humans have had a devastating impact on salmon and their waterways. Dams and mining structures have cut off miles of spawning and rearing habitat.  Agriculture, town developments, and a growing human population have depleted water levels, causing river temperatures to rise and oxygen levels to decline. 

Along with this destruction, diseases and liquid waste from densely packed fish farming pens have impacted wild salmon stocks.  For this reason, many chefs, restaurants and fish markets are encouraging people to buy and eat wild salmon, not farmed.  Celebrity-chef Alice Waters and some 200 chefs in 33 states are calling on Congress to protect river habitats and deprioritize hydroelectric dams that cramp Northwest salmon's style.

"Wild salmon is one of the unique, authentic heritage foods of the Pacific Northwest," reads a letter that the cooking coalition presented to legislators yesterday. "It represents perhaps our country's last great wild meal."

The "Vote With Your Fork" campaign hopes to focus attention—both public and congressional—on the controversial dams that have gummed up the Northwest's Klamath and Snake rivers, and on Alaska's Bristol Bay, where a proposed humongous gold and copper mine threatens a plentiful fishery.

When it comes to salmon, the nation's best chefs are fighting to restore wild salmon habitat.  As Waters says, "Eating wild salmon can connect you in a beautiful way to the sea."