The Columbia River Basin provides habitat
for six species of anadromous salmon: chinook, coho, chum,
sockeye, pink, and steelhead. Anadromous salmon hatch in
fresh water rivers and tributaries where they rear for a
year or two. They then migrate to, and mature in, the ocean
and return to their place of origin as adults to spawn. Salmon
live two to five years in the ocean before returning to spawning
areas.
Salmon Life Cycle & Habitat
Salmon stocks are cyclical. They rise
and fall in accordance with natural rhythms. Long-term changes
in climate, atmospheric pressure, and water temperature create
ocean conditions that are sometimes favorable to salmon survival
and sometimes not. Short-term weather patterns - hot summers
and cold winters - also affect survival rates.
It's a difficult journey from egg to
spawning adult. Only
about two percent of all salmon hatched will live to adulthood.
Many other factors reduce salmon populations-disease and natural predators such as birds, fish and marine mammals. And there are human-made
obstacles including harvesting, river blockages, pollution, and
poor habitat management. For these reasons, protection
of the relatively few adult salmon that make the arduous journey
to spawn in their natal streams and rivers is vitally important.
