The wonder and eco-importance of Pacific salmon
Once every four years, millions of salmon — including sockeye (red), king (chinook), silver (coho), pink (humpback), and keta (dog) species — return home to Pacific Coast rivers ranging from Washington State through British Columbia and Alaska.
Scientists still know little about how salmon navigate the open ocean, identify their native river or stream, find their way to within feet of their birth, and change color as they enter fresh water.
We do know that these enigmatic fish are responsible for the gigantism associated with the towering coastal rain forests of Alaska and British Columbia.
Salmon are the reason the region’s grizzly bears, who gorge on the fatty fish ahead of their long, winter nap, often top 1,000 lb.
The creatures that feed on dying salmon carry nitrogen into the forests, fertilizing the surrounding trees and allowing Sitka spruce to reach more than 20 stories into the sky.
The effect of this natural fertilizer on trees is so dramatic that scientists can tell how well a salmon run is doing simply by looking at the surrounding forest.
It's hard to overstate the importance of these keystone species to trees and wildlife, including birds, bears, and wolves ... and to coastal peoples for whom the fish are a vital food and cultural touchstone.