One good reason coho salmon fishing is so popular is that cohos are such aggressive feeders.
Known to anglers as “eager biters,” these fish we call “silvers” are relatively easy prey. We can catch silvers with many different fishing methods, which makes the pursuit of them all the more interesting. In streams, we still-fish or back-bounce with bait, we float fish with bait or jigs, we fly fish with wet flies or “on top,” we cast lures, we troll plugs. When we locate feeding coho in saltwater, we’ve found that they’ll snap at most anything we put in front of them. I once saw a hungry coho swim right up to the transom of a boat and bite a down-rigger clip.
Cohos seem to be designed for catching and eating fish, prey that requires a predator to be alert, to have fast reflexes and to respond quickly and forcefully. Being a fish eater may well be the reason that coho are such aggressive biters, even after they enter their spawning streams, when they are no longer eating. When any animal has been aggressive all its life, it’s not likely to stop being aggressive overnight.
There’s reason to believe that coho fishing is usually best early and late in the day because that’s one of their favorite times for eating. Baitfish are vulnerable during low-light conditions. It stands to reason that coho would go on the hunt during such times.
When coho enter their spawning streams, they stop feeding and their stomachs shrink. But just because they’re not eating doesn’t mean they don’t try to eat. They still have the urge. If you fish for them with bait, you’ll notice that you often hook them deep in the throat. They’re obviously trying to swallow, but their stomachs have shrunk down to where swallowing is no longer possible.
Coho eggs develop in the gravel during the winter and hatch in early spring. The embryo remain in gravel, receiving nourishment from the yolk. The young emerge from the gravel in May or June. From the time they are free swimming fry, they are voracious eaters. At first, small cohos feed mainly on plankton and aquatic insects, but they soon are eating free-floating salmon eggs and insects that fall from stream-side vegetation. By the time they reach smolt size — 4 to 6 inches long — they are regular gluttons, and are eating other fish. A study at Chignik Lake, Alaska, found that young coho were eating seven times as many sockeye fry as were the Dolly Varden char that had previously been thought to be the main culprits for eating large numbers of young salmon.
In the Kenai River, most cohos spend the first two years of their lives in fresh water before migrating to sea. They like to live along shorelines where the vegetation comes right down to the water, where the current is slow. They become territorial little ambush predators, like miniature versions of lingcod on a reef, just waiting for something live to come within reach. Like lingcod, coho will even eat their own kind.
At sea, coho eat mainly fish and squid. The amount of time cohos spend in saltwater varies. A small percentage of “jacks,” about 12 inches in length, mature and return to fresh water after 6 months or so as sea, but most coho spend about 18 months at sea. They return to their natal streams weighing anywhere from 6 pounds to upward of 30. I once heard a biologist say that a coho must have a herring hanging out of its mouth constantly, in order to gain so much weight in such a short time.
I heartily agree with the following description of silvers, found in Lineres’ and Pedersen’s book, “Alaska Fishing”: “Habits: Reckless feeder, especially fond of baitfish; easily provoked.”
These are the fish we seek, these feisty predators that yank on our lines and sometimes take to the sky when hooked, these silvery phantoms that urge us from our warm beds onto the cold river in the dark, so we can be in the “right spot” for the morning bite. These are the fish of our dreams.
Les Palmer can be reached at email@example.com.