Updated August 28, 2012 at 11 am
The National Park Service reported this week that adult Chinook (king) salmon have been seen in the Elwha River in Olympic National Park, less than five months after removal began on the Elwha Dam. According to the Park Service, the fish are the first of their kind known to enter the park through that river, since Olympic was established twenty-five years after the dam went up in 1913. (See a map of the region.)
The dam had blocked off more than 70 miles of formerly prime Elwha River habitat for the fish, which had been an important part of the local ecosystem and a key food source for local indigenous people.
As National Geographic previously reported, the Klallam Tribe still say that the Elwha River had been so full of salmon that a person could cross from one bank to the other by walking atop the thrashing bodies of fish struggling to move upstream to spawn.
According to the Park Service, Chinook were seen this week about two miles upstream from the park border by Phil Kennedy, the park’s lead fisheries technician.
Chinook salmon (Oncorhynchus tshawytscha) are the largest of the Pacific salmon, and historically entered rivers from California to Alaska, as well as in parts of Asia. Adult fish tend to range in length from 33 to 36 inches (840 to 910 mm) but may be up to 58 inches (1,500 mm). They average 10 to 50 pounds (4.5 to 23 kg), but may reach 130 pounds (59 kg). Their numbers have dropped due to loss of spawning grounds, and nine local populations are listed as threatened or endangered in the U.S.
“We knew this was going to happen and as I saw the fish roll, my heart jumped!” said Kennedy.
“The return of the salmon marks an important milestone in the restoration of the Elwha River ecosystem and a historic moment in the history of the park,” writes the NPS.
“This has been an extremely exciting summer,” said park Acting Superintendent Todd Suess.
Park biologists have been making regular surveys of the river in anticipation of the salmon’s return, after nearly a century. We had previously reported that scientists predicted the Elwha’s salmon population would likely swell from 3,000 to 400,000 after the dam came down.
This week scientists are sharing their findings and reaching out to the Olympic peninsula public during the Elwha River Science Symposium.
The Elwha Dam is the largest dam to come down in the U.S., although river advocates hope more unused structures are next. The dam, like the nearby Glines Canyon dam on the same river, is being dismantled slowly to minimize sediment problems in a process that will take up to three years to complete.
I know I’ve shared this before, but once again, the dramatic removal of the Condit Dam, also in Washington State:
Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for TheDailyGreen.com and E/The Environmental Magazine, and has written for TheAtlantic.com, FastCompany.com, PopularMechanics.com, Yahoo!, MSN, Miller-McCune and elsewhere. He is the co-author of six books, including Geothermal HVAC, Green Lighting, Build Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.