Elwha River Recovery Following Dam Removal
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- Опубліковано 21 сер 2024
- Mike McHenry, fish biologist for the Lower Elwha Klallam Tribe, tells the continuing recovery to the Elwha River and its native fish following removal of dams that blocked the river flow and fish passage for over a century.
Backwater juveniles hatched from local gravels, are slow water specialists preferring deeper pools, backwaters, lakes, beaver dams, hiddeb within the vital cover, and it sounds like the dwd, boulder cover, high oxygen content slower moving waters and wetlands great cohort survival until outmigrants at sizes of out migration period. Smolting at between 1 and two years within the saline, brackish estuary is crucial, and the sizes of these for surviving oceanic endeavors and returning to spawn higher in the watershed.
Barriers may include waterfalls, log jams, or other major obstacles.
That Diversity is inherently a driver for Salmonid Speciation from Headwaters to Estuarine thee mouth whereby such Species over Riverine Habitat Use. Other Anadromous Species and Ocean going Organisms should be considered essential to overall Elwha integrity.
My understanding was that the Elwha had a unique strain of Chinook that tended to grow rather large. Their larger size would seem to help then get past the canyon easier. Do you think that the main source of Chinook being hatcheries might be why they are not making past the canyon much?
In Britain the data shows that hatched Atlantic Salmon do very poorly, having appalling survival rates and not being so vigorous working up river. A hatchery programme did save the only UK population of river running Char.
Best I've been able to figure is that there was a spring chinook run- I'm not clear if those genetics exist in the river anymore or if the strain that was "maintained" by the hatchery has the potential to produce spring returners.
www.science.org/doi/10.1126/science.aba9059
So spring chinook is determined by single gene. More discussion of the article:
www.fisheries.noaa.gov/feature-story/small-genetic-difference-determines-chinook-salmon-migration-timing-new-study-shows
It would seem reestablishment of a spring chinook run in the Elwha would be dependent on strays from elsewhere on the coast.
Sorry, Coho are the slow water Specialists as juveniles, and gaining necessary size before ex-migration to the Ocean as that is a major survival threshold.
Removing the dams is great for fish. Slade Gorton not getting his way is great for schadenfreude.