[env-trinity] Mainstem Trinity River Spawn survey update through October 9

[Chamberlain, Charles]

Hi all,
Our latest weekly update for the Trinity River Spawning survey is posted on
the Arcata Fish and Wildlife Office Fisheries website
http://www.fws.gov/arcata/fisheries

We surveyed from Lewiston Dam to Pigeon Point and from Hawkins Bar to the
mouth at Weitchpec this week.  Our crews mapped 351 redds and 466
carcasses.  The figure below is clipped from our report this week.  We're
still "flirting" with the blue -  Hopefully we'll be well in there in the
coming weeks.

[image: Inline image 1]


I've added a page and graph to our weekly report related to interest in the
outbreak of *Ichthyophthirius multifilis* (Ich) observed in the lower
Klamath
<http://www.fws.gov/arcata/fisheries/projectUpdates/FishHealthMonitoring/Ich%20finding%20initial%20memo%20CNFHC%209-16-2014.pdf>
this year, and the flows that were released
<http://www.usbr.gov/newsroom/newsrelease/detail.cfm?RecordID=47908> to
hopefully decrease it's severity.  From this week forward our weekly report
will include a graph like the one pasted here showing how 2014's observed
salmon pre-spawn mortality rate thus far compares to those of recent years.

[image: Inline image 2]


I won't normally paste the graph directly into these future email
announcements as two graphs makes the message size electronically large
enough to require moderator intervention for the env-trinity listserv
<http://www2.dcn.org/mailman/listinfo/env-trinity>.  The graphs will
however be included in the full weekly versions available for download on
the Arcata Fish and Wildlife Office Fisheries website.


*Fun fact for the week...  *

*Did you know*....   The proximity of where a salmon carcass is encountered
in the river to where that salmon spawned can vary greatly by sex.  A
Chinook Salmon female usually constructs a single redd to deposit her eggs
into.  After spawning she'll guard her nest until her condition
deteriorates to a point that she can no longer hold her position, and
she'll die soon thereafter.  Her carcass usually settles on the river
bottom a short distance from the redd she constructed.  A male salmon
however, often spawns with more than one female, and sometimes on redds
many kilometers apart.  He'll guard and fight for a female against other
males on the spawning grounds, but he does not exhibit nest guarding
behavior when spawning is done.  When he's completed spawning he can drift
with the river current considerable distance as his condition deteriorates
until he dies.  The location that a male's carcass is encountered on the
river bottom therefore makes for a relatively poor indicator of where that
fish spawned.  In the Trinity River, female carcasses often outnumber males
in the highest most reach from Lewiston Dam to Old Lewiston Bridge (our
survey's reach 1).  Males often outnumber females in the reach from Old
Lewiston Bridge to Bucktail River Access (our survey's reach 2) because
many have drifted there from the reach above.


Until next week,
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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