[env-trinity] Trinity River spawning survey update for week September 23 to 27

[Chamberlain, Charles]

Our latest weekly report from the Trinity River Salmon Spawning Survey is
available from the home web page of the Arcata Fish and Wildlife Office:
 http://www.fws.gov/arcata

Crews this week surveyed from Lewiston Dam to Pigeon Point.  We mapped 225
redds and encountered 56 carcasses.  The figure below is clipped from our
report linked above.

[image: Inline image 1]

We aim to survey reaches 1-7 (Lewiston Dam to the Pigeon Point Access) and
reaches 9 and 10 (Big Flat Access to Cedar Flat Access) for the week of
September 30 to October 4 - if the federal government doesn't shut down!


*Fun fact for the week...*
Did you know?…. the typical shape of a salmon’s nest (redd) increases the
flow of water through the gravel and across the eggs deposited within?
 Much like an airfoil influences air pressures flowing across its surfaces,
the shape of a redd with a pit upstream and mound downstream influences
localized pressures of flowing water.  More water is forced through the egg
pocket in a redd than would be if the eggs were buried in the same gravels
at the same depth in an unmodified surface.  This increased flow improves
oxygen levels within the egg pocket and helps disperse metabolic wastes
generated by the developing embryos.

Talk to y'all soon (I hope!),
Charlie

Charles Chamberlain
Supervisory Fish Biologist
U.S. Fish and Wildlife Service
Arcata Fish & Wildlife Office
1655 Heindon Road
Arcata, CA 95521

Charles_Chamberlain at fws.gov<https://mail.google.com/mail/?view=cm&fs=1&tf=1&to=Charles_Chamberlain@fws.gov>
Phone: (707) 825-5110    Fax: (707) 822-8411
www.fws.gov/arcata/fisheries
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