[env-trinity] Willow Creek Trapping Summary
Bill_Pinnix at fws.gov
Tue Apr 22 14:48:14 PDT 2008
Willow Creek Downstream Migrant Trap Site
2008 In-Season Trapping Update –April 22, 2008
Synopsis: The 2008 Downstream Migrant trapping season at the Willow
Creek Trap Site (river kilometer 34) is being conducted jointly by the
USFWS Arcata Fish and Wildlife Office (AFWO) and the Yurok Tribal
Fisheries Program (YTFP) on the mainstem Trinity River near Willow
Creek, California. The season began March 13, 2008 with the
installation of one trap. A second trap was installed March 15, 2008,
and a third trap was installed March 27, 2008.
This summary includes data from March 13th, 2008 through April 16th,
2008 and is presented as raw catch. No expansions have been calculated
at this time. Data entry is not complete for Julian Week 15 and 16,
April 9th to April 22nd. Heavy debris load from floating algae have
occasionally resulted in null sets, causing less than 21 trap days (3
traps x 7 days) in some weeks. This accumulation of algae in the rotary
screw traps is a relatively new phenomenon for the Trinity River, and
has necessitated increased trap checks at night as well as during the
day. See attached catch summary for details of this narrative.
Raw daily catches of Chinook salmon (Oncorhynchus tshawytscha) have been
captured each day sampling has occurred and most have been
young-of-the-year (YOY), with a higher than normal catch of age 1+
natural Chinook salmon. Weekly mean Fulton’s K values of YOY Chinook
salmon began the season lower than 1.0 with an increase in condition to
greater than 1.0 in Julian Week 15. Age-0 Chinook salmon being captured
are quite small (< 50mm) and many are just buttoning up.
Raw daily catches of steelhead (Oncorhynchus mykiss) smolts (age 1+)
have been increasing as the season progresses. Steelhead smolts
captured JW 11-16 had weekly mean Fulton’s K values slightly higher than
1.0. Steelhead YOY have not shown up yet in the catches, as they
usually emerge from the gravel later in the season. Normal peaks in YOY
steelhead catch occur in mid-June to early July.
Raw daily catches of coho salmon (Oncorhynchus kisutch) are low compared
to the past 5 years, especially for natural smolts. Weekly mean
Fulton’s K value of natural coho salmon smolts were higher than 1.0 in
If you have any questions regarding this summary, don't hesitate to
contact Bill Pinnix at (707) 822-7201.
(See attached file: WCT_CatchSummary_4_22_08.pdf)
1655 Heindon Rd
Arcata, CA 95521
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 15685 bytes
Desc: not available
Url : http://www2.dcn.org/pipermail/env-trinity/attachments/20080422/e8b461d0/WCT_CatchSummary_4_22_08.pdf
More information about the env-trinity