Scientists are looking to develop guidelines for habitat restoration in the Pacific Northwest that can be used across comparable waterways to strengthen natural fish populations.
The Pacific Northwest and its incredible natural fish populations, once thought to be boundless, are now in the hands of researchers that are striving to find the best ways to restore habitat on more than a dozen watersheds.
Studies in Washington, Oregon, Idaho, Northern California, and British Columbia are focusing on creating strategies that will save time and money across the region in an effort to minimize wasteful initiatives and focus on ideas that work across similar habitats.
George Pess, research fisheries biologist with the National Oceanic and Atmospheric Administration said, “The overall goal is to learn enough to be smart about our restoration.” A simple plan that takes some serious effort, but one that has been in effect since the early 2000’s.
Barrier removal is one of the key methods of reopening spawning grounds once blocked by dams. The studies go further, determining whether removing the barriers, and which barriers to remove, leads fish to change when they migrate into the ocean and return as grown adults.
Restoration efforts need to ensure enough water flows through streams at critical times like spawning runs. Brian Knoth, fisheries biologist with the Idaho Department of Fish and Game has said that “last year, state workers for the first time counted steelhead spawning beds above an area where a dam had been removed”
In 2011, the U.S. reached a milestone of some 1,000 dams removed from rivers. Dams can impact clean water flow and impede fish from native spawning grounds. Also lost in the shuffle are native bear populations, insects, and the birds that feed on them.
Earth Share also said, “The dam removal will also allow tons of previously-trapped sediments to move downstream, helping to create a natural barrier against beach erosion at the river’s mouth and protecting vital clam beds”
The most ambitious project was the one that saw the Elwha River in Washington freed from the constraints of the Glines Canyon Dam in 2012. The removal of that dam is said to have increased habitat by more than 300 percent while doubling spawning areas for native salmon and steelhead above the dam’s previous location.
Guido Rahr, president of the Wild Salmon Center said about the guidelines: “It’s a terrific and much-needed project — getting a scientific basis for really teasing out the factors preventing the recovery of wild steelhead and salmon.”