[env-trinity] Mainstem Trinity River spawn survey update for November 17 to 21, 2014

Chamberlain, Charles charles_chamberlain at fws.gov
Fri Nov 21 20:34:56 PST 2014


Hello Trinity River followers,
The US Fish and Wildlife Service along with the Yurok Tribe, California
Department of Fish and Wildlife, US Forest Service, and Hoopa Valley Tribe
have another weekly update for our Trinity River mainstem spawn survey
posted on the Arcata Fish and Wildlife Fisheries webpage.
http://www.fws.gov/arcata/fisheries

Our crews mapped 487 redds and 2,956 carcasses in the Reaches from Lewiston
Dam to Pigeon Point, and Hawkins Bar to Weitchpec.  Spawning in the up
river reaches is begging to be dominated by Coho Salmon.  Chinook Salmon
are going strong in the river downstream of Hawkins Bar.  The graph below
is clipped from our weekly report (limited to the river upstream of Cedar
Flat).

[image: Inline image 1]

*Did you know*.... the genetics of wild salmon populations are shaped by the
environments they evolve in?  Unique regions throughout the range of
Pacific salmon challenge survival in different ways and salmon evolve to
meet those challenges.  In the Klamath Basin here near the southern end of
the range for Chinook Salmon, salmon are better equipped for warm water
temperatures than many populations to the north.  *Ceratonova shasta* is a
fish parasite common in the Klamath Basin and is relatively rare in many
other places.  While *C. shasta* can significantly impact juvenile salmon
survival in the Klamath in some years, fish from other basins where *C.
shasta* is not endemic are *much* more susceptible as they haven't evolved
to meet that particular challenge.  To lose a population of salmon is to
lose centuries or millennia of evolutionary adaptation to a particular
region or location.  Given a chance, fish continue to adapt to shifting
environments, restored conditions, and changing flow and climate regimes.
For example, Chinook Salmon from the Sacramento River system in northern
California were introduced to New Zealand between 1901 and 1907.  From
genetics highly suited to the Sacramento River system, that population has
hence evolved and developed traits that are more suitable for rivers of New
Zealand (Quinn et al. 2001).  Left to evolutionary devices, wild Trinity
River salmon populations will continue to evolve and adapt to capitalize on
changing Trinity River environments and meet its challenges.



Quinn, T. P., M. T. Kinnison, and M. J. Unwin.  2001.  Evolution of chinook
salmon (*Oncorhynchus tshawytscha*) populations in New Zealand: pattern,
rate, and process.  Genetica 112-113: 493-513


Talk to you next week.  Have a great Thanksgiving!
Charlie

Charles Chamberlain
Supervisory Fish Biologist
U.S. Fish and Wildlife Service
1655 Heindon Road, Arcata, CA 95521
http://www.fws.gov/arcata/fisheries
(707) 825-5110
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