Lower Redwood Creek Juvenile Salmonid (Smolt) Abundance Project
In the turquoise waters of rivers running past the towering giants of coast redwood forest, salmon once were so abundant that some say you could catch them with your hands.
Big trees and big fish—coast redwoods and salmon —depend on each other. Redwoods help provide the cool, clear streams that salmon need, slowing erosion that would otherwise cause sediment to suffocate the fish eggs in the gravel. The great trees also shade the water, keeping them cool, and redwoods fall into streams, creating calm, deep pools where fish take refuge from predators and fast currents. In turn, salmon supply redwoods and other plants with nutrients from their bodies after they spawn and die in their native streams.
Virtually all redwood forests have (or once had) streams in which salmon run and spawn. But after 150 years of damming, water diversion, logging and development, most of these fish species face extinction.
Chinook salmon, for example, are a federally listed threatened species. Despite years of heavy logging decades ago, Northern California’s Redwood Creek supports large numbers of Chinook salmon.
Since 2004, scientists from Humboldt State University, Redwood National Park and the California Department of Fish and Wildlife have been monitoring those Chinook and other “salmonid” fish (fish in the salmon family) that live in Redwood Creek. But in 2008, a state budget crunch threatened the continuity of their research. So Save the Redwoods League stepped in with a small grant to bridge the gap, thanks to donations from you, our members.
Today the researchers have almost a decade of valuable data about Redwood Creek’s fish numbers and needs. In 2011, an estimated 148,000 juvenile Chinook were making their way down Redwood Creek to the ocean. That number is 28 percent lower than the previous seven-year average. But there’s no reason for alarm just yet, said researcher Walter Duffy of Humboldt State University. Chinook numbers vary greatly from year to year. In December, the fish deposit eggs in nests, or “redds,” and cover them with gravel. If a big winter storm comes in before those eggs hatch, it can wash the redds away, and the population tumbles.
In the long run, forest restoration efforts in and around Redwood National and State Parks should boost the Chinooks’ productivity, Duffy said. That’s because intact forests soak up water like sponges and reduce sediment in streams.
“But restoration doesn’t happen overnight,” Duffy said. “It takes a long, long time.”
That’s why we need support from you, our members to help us learn about the state of fish populations like these and to return the redwood forest and its inhabitants to health. Please donate today.
Grant Applicant Organization: California Cooperative Fish & Wildlife Research Unit (Humboldt State University)
Grantee: Walter Duffy and Michael Sparkman
Downloads: Documents and Reports