[env-trinity] Message from Arnold Whitridge transmitting messagefrom Doug Schleusner

Thu Mar 25 13:49:35 PST 2004

More natural history:

Spring juvenile coho populations in the mainstem Trinity fluctuate
radically, with about half the young salmon in the area above Rush Creek
composed of coho in about one out of three years, and only a handful of
coho in other years.    Coho are  the fish most disposed to stranding,
since they occupy still backwater areas as well as the full range of
chinook habitat.   If this is a low coho year, seeing few coho stranded
really isn't encouraging, because although you won't lose many, there
aren't  many to lose.

A drop from 2,000 to 300 cfs in mid-March will necessarily eliminate many
thousands of chinook, and in a good coho year many thousands of coho.  It
is doubtful that any isolated fish will survive through April, or that any
ramping rate can be devised that would lessen the effect.  The logical
problem with slowed ramping rates is that while they allow more time for
fish to swim out of potential isolation areas, they allow the same amount
of time for fish to swim into potential isolation areas.

Population effects of the recent flow blip may be negligible, because a lot
of the the fish that were present at 2,000 cfs had survived only because of
the higher flows, and dropping flows to preordained levels will change
little in the long run.  To put it another way, when you make the river
smaller during the rearing season, there isn't room for all the fish that
were there when it was running high, and it doesn't matter whether they are
stranded or simply crowded out into undesirable areas.  If there were
enough water to hold flows at 2000 cfs until mid-May, when almost all the
natural chinook and coho have left the upper river,  there would be no
stranding and no loss of habitat.

Andrew Hamilton
US Fish and Wildlife Service
(916) 414-6540

                      "George Kautsky"                                                                                        
                      <hupafish at pcweb.net>                        To:      "Tom Stokely" <tstokely at trinityalps.net>,          
                      Sent by:                                    "env-trinity" <env-trinity at velocipede.dcn.davis.ca.us>      
                      env-trinity-bounces at velocipede.dcn.         cc:      Joel Green <jagreen12 at pcweb.net>,                  
                      davis.ca.us                                 salmon at pelicannetwork.net, Paul Petros <ppetros at pcweb.net>  
                                                                  Subject: RE: [env-trinity] Message from Arnold Whitridge    
                                                                  transmitting   messagefrom Doug Schleusner                  
                      23-03-2004 10:35 AM                                                                                     

Arnold and others, I wish to inform preliminarily as to our observations at
Junction City Juvenile screw-trapping site.  My field biologist noted today
that captures are much lower than typically observed for this week in prior
years.  That is, the flood of hatchery steelhead and coho have not arrived
yet at JC as anticipated.  He further states that he has heard accounts of
large pods of juveniles holed up in vicinity of the old Lewiston Bridge.
We should have preliminary tabulations for J.C. screw trap completed by
early next week and will distribute them to coop agencies.

Regards,
George Kautsky
Hoopa Tribal Fisheries
(530)625-4267 ext 15
      -----Original Message-----
      From: env-trinity-bounces at velocipede.dcn.davis.ca.us
      [mailto:env-trinity-bounces at velocipede.dcn.davis.ca.us]On Behalf Of
      Tom Stokely
      Sent: Monday, March 22, 2004 9:23 AM
      To: env-trinity
      Cc: salmon at pelicannetwork.net
      Subject: [env-trinity] Message from Arnold Whitridge transmitting
      messagefrom Doug Schleusner

      awhitridge at snowcrest.net wrote:

      TAMWG and TMC,

      My e-mail capabilities currently exceed those of some entire Interior

      Department agencies, so I've been asked to circulate a message from
      the
      TRRP office.  As background, there was concern that the recent
      rampdown of
      Lewiston releases from 2000 cfs to 300 cfs would strand some juvenile

      fish.  To minimize stranding, Central Valley Operations modified the
      rampdown schedule as suggested by scientists who were meeting to
      discuss
      the annual flow schedule, but there were nevertheless some reports of

      stranding, including stranding of young coho.  Doug Schleusner
      reports
      (March 19):

      "Branch Chief Daryl Petersen and two other biologists (Mike Kelly,
      NOAA
      Fisheries; Loren Everest, Forest Service) floated the Trinity from
      the
      hatchery to Bucktail, and stopped at 5 sites where stranding had been

      reported or historically has occurred. Stranded salmon were observed
      at all
      sites, but most were chinook, with some coho (native) observed at one

      location. It appears that at these sites there is still enough
      surface flow
      to allow some fry to move back into the main channel, or the pools
      are
      large enough to allow fry to rear and survive until the spring flow
      releases begin to ramp up in late April or early May.  Mike Kelly
      will
      document their observations in more detail and contact other
      observers down
      river; a report is expected by next Monday or Tuesday. At this point
      it
      does not appear necessary to mobilize a rescue effort or take actions
      other
      than continuing to monitor the situation."

      Arnold Whitridge_______________________________________________
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