In a deep, clear pool in a coastal Alaska stream, a large school of Dolly Varden rest almost motionless near the bottom. A giant, bright silver fish fins lazily at the tail of the pool, dwarfing the smaller char. It's a 15-pound summer steelhead, fresh from the sea. The steelhead trout is actually a rainbow trout that has adopted a different life history and has spent most of its adult life in the open ocean.
Steelhead are often classified as to the time of year they return to their natal stream, either spring, summer or fall. Regardless of when they return to freshwater, all steelhead spawn during the spring months, usually about mid-April through May to early June.
Steelhead may spawn more than once, while Pacific salmon spawn only once and then die. Many steelhead do die after spawning once, but about 30 percent return to sea and live to spawn again. Males do not survive spawning as well as females, and generally the larger and older females survive better than the smaller and younger ones. After spawning, the ragged and spent steelhead, sometimes called kelts, move slowly downstream to saltwater, and the vibrant spawning colors return to a bright silvery hue as their depleted stores of fats are restored. Most steelhead that repeat spawn come back annually but some may skip a year before returning to spawn.
After hatching out in the gravel of freshwater streams, juvenile steelhead may grow to be 2- or 3-inches by their first fall. Juvenile steelhead typically spend two to five years in freshwater before moving to the ocean in the springtime. Once in the food-rich marine environment steelhead can grow an inch per month. Most steelhead spend two or three years in the ocean and will travel hundreds of miles before returning to their natal stream to spawn.