Coho salmon
A silver ocean salmon that comes home each winter to the small creeks under the redwoods, turning brick-red and hook-jawed to spawn once and die.
Coho salmon at a glance
Oncorhynchus kisutch KOH-hoh SAL-mun; Oncorhynchus kisutch is on-koh-RING-kus kih-SOOCH
- Type
- Fish · salmon
- Diet
- Carnivore
- Size
- An adult coho usually weighs 8 to 12 pounds, close to a full gallon jug of milk, and grows 24 to 30 inches long, about the length of a baseball bat. A few reach 36 pounds.
- Lifespan
- About 3 years total, almost entirely split between one year in a home creek and roughly a year and a half at sea, then a final return to spawn and die.
- Conservation
- Least concern (IUCN); the Southern Oregon/Northern California Coast population, which spawns in Redwood Creek and the Klamath and Smith Rivers, is listed Threatened by NOAA Fisheries
Eats insects, small fish, krill and other invertebrates at sea
A young coho spends about a year hiding in a small forest creek, mostly eating drifting insects. At sea for about a year and a half more, it switches to small fish and krill, growing from finger-length to several pounds before heading home to spawn.
Should you worry?
Coho salmon are completely harmless. Because the local population is federally threatened, follow current fishing regulations with an adult, keep any fish wet, and never trample a redd, a gravel nest, in the shallows where coho spawn from November into February.
Stand on the footbridge over Prairie Creek in December and look down into water barely wider than a driveway. A fish that spent a year and a half in the open Pacific is down there, brick-red now, jaw hooked into a shape it didn’t have in the ocean, pushing upstream over gravel the size of peas toward the exact creek where it hatched. This is a coho salmon at the end of its life, and it came a long way to get here.
Every coho follows the same short, exact script. A year in this creek as a small fish, hiding from herons under undercut banks. A year and a half at sea, growing from finger-length to eight or twelve pounds on a diet of small fish and krill. Then the return, timed to peak in Redwood Creek in November and December, the fish turning color and shape as it swims, chrome sides fading to red, jaw curving into a hook built for nothing but holding a mate’s attention. It will spawn exactly once. Every coho salmon dies within days to weeks of doing it, no exceptions, the whole redwood-creek run keyed to one irreversible trip.
That single-shot life is also why the population here counts as threatened, in a place with limited creeks small enough and cold enough to keep working. A boot print in the wrong spot on a shallow gravel bar can crush a season of eggs before they’ve hatched, so anyone fishing here with an adult follows current rules and stays out of the reddish patches of disturbed gravel where a female has already dug her nest. Watch from the bridge instead. The fish underneath it will not get another try.
Did you know?
- Coho are also called "silver salmon" for the bright, chrome-colored sides they carry while still in the ocean, before spawning turns them red.
- A coho spends a whole year as a small fish in its home creek before ever seeing salt water, hiding from herons and larger fish under logs and undercut banks.
- The best time to see spawning coho in Redwood National and State Parks is November and December, from the bridges over Prairie Creek and Lost Man Creek.
Common questions
Why do coho salmon turn red?
It happens as they get ready to spawn. A coho that was silver in the ocean develops a bright reddish-maroon color along its sides and a hooked jaw once it reaches its home creek.
Do coho salmon die after they spawn?
Yes, always. Every coho salmon dies within days to weeks of spawning once, its whole life spent building toward that single return trip.
When can I see coho salmon in Redwood National and State Parks?
Look from November through February, with the biggest runs in Redwood Creek in November and December. The bridges over Prairie Creek and Lost Man Creek are good, easy spots to watch from.
Are coho salmon dangerous to be around?
No, they're harmless. The only real risk is to the fish. Because this population is federally threatened, avoid stepping in the gravel nests, called redds, where they've laid their eggs.