Coho Salmon are a well-known and popular sport fish in Oregon. Like other salmon species, they are anadromous fish, which means they will migrate from the ocean to the tributaries of large rivers and coastal streams every fall and winter to breed. They often travel as far as 120 miles through treacherous waters filled with fishermen and hungry bears to fulfill this inherent need to reproduce. After successfully spawning, both the adult male and female die.
The fish can look remarkably different between their ocean and river phases. While living in the Pacific, the Coho Salmon has silver sides and a dark blue back. For this reason, they are sometimes referred to as “silver salmon.” When they return to freshwater rivers to spawn, their bellies will become a light rose color, changing to dark red as they age.
In Oregon, numerous hatcheries have been set up to help increase the numbers of salmon. In the last sixty years, the number of naturally breeding Coho Salmon has dropped from 400,000 to 10,000 individuals. Conservation efforts do appear to be making some difference, as the number of fish returning to Oregon rivers to spawn doubled between 2007 and 2009.
These salmon are found throughout the North Pacific Ocean from Japan to northern California. During their ocean phase, they live in large schools in the open sea. To breed, they will return to the same freshwater river where they were born.
The sharp decline in Coho population levels have been a concern to conservationists for the past decade and many programs are now in place to replenish their numbers. Their diminishing numbers are not only a problem for native wildlife which rely on the salmon as a food source, but for the salmon industry in Oregon and the larger Pacific Northwest. Many populations of this salmon are threatened or endangered, including close found along the Oregon Coast and in the Lower Columbia River. These populations are protected under the U.S. Endangered Species Act but environmental factors and habitat destruction still imperil the fish.
Photo credit: ODFW