From: tomg@hpcvxph (Thomas J. Gilg)
Subject: Re: fyi: Oregon's Anadromous Fishery
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
X-Newsreader: Tin 1.1 PL5
Date: Wed, 26 Aug 1992 00:13:29 GMT

> ... never really understood the reasoning behind the "once that
> population is gone, it cannot be revived". After all, there have
> been succesful reintroductions of land animal populations from
> captive breeding populations.

> Before you flame me ...

This is a valid question - no reason to flame anyone for asking!

The key is "Steelhead the species" vs "Steelhead, a collection of
subspecies".   I doubt we'll loose the species, but we are loosing
many of the subspecies, and that hurts for several reasons:

   1. Loss of genetic diversity.
   2. Loss of optimaly-tuned subspecies for a particular river system.
   3. Other - fishing diversity.

As an example, consider the "monster B-run Steelhead" that spawn in
Idaho's Clearwater river system.   Compared to most other steelhead
subspecies, these fish are big and know instinctively how and when
to run 800+ miles of river to spawn *most* successfully.   I suspect
the Skamania subspecies from Washington state could be successfully
planted over time, but they wouldn't enjoy the success rate that
the natives have had after hundreds or thousands of years of specialized
tuning for the Clearwater river run.

Now look at the Rogue River in southwestern Oregon.   The Rogue is famous
for its run of "half-pounders"; steelhead that went out to sea during
March and returned months later in August weighing 2-8 pounds.   This is
unusual because most steelhead spend 2 to 3 years at sea before returning.
Certainly genetic diversity, and maybe a survival adaptation for the
Rogue river system.

Throughout the west coast, steelhead subspecies become apparent as you
look at:

   1. years of freshwater residency as a parr/smolt.
   2. timing of smolt migration back to the ocean.
   3. years at sea as an adult.
   4. timing of adult migration back to spawning areas.
   5. areas of the river selected by spawning adults.
   6. tricks used to successfully navigate a particular river system.
   7. and so on....

As an example of how important tuned-genetics are, consider what man
has done recently.   When hatcheries started up some years ago, the
Skamania Steelhead subspecies from Washington State became the favorite
hatchery strain.  It came pre-tuned it seemed by mother nature as an
ideal hatchery-farm fish; its adult return time, smolt maturity time,
and smolt migration timing seemed perfect (ie, cheapest) to raise.  Last
year during Oregon's drought, the best advice I got from a fisheries
biologist was to find rivers that wern't stocked with Skamania steelhead -
it seemed the Skamania strain was susceptable to the current conditions
in Oregon.   A nearby river in the midst of many rivers with Skamania
steelhead had one of its best native/wild steelhead returns in years.

Another example of man's good intent gone crazy - hatcheries used to
calculate the number of adults they needed to produce the next years
crop.   They would then take the *first `n' returning steelhead* for
hatchery production.   Over the years, this inadvertently caused the
adult returns to become earlier and earlier.   It's not uncommmon that
hatchery steelhead now return months before the better tuned natives.

Apply the same discussion to salmon.

Ironically, the timber industry is also learning about genetic diversity
the hard way.  In NE Oregon, they logged a diverse and native collection
of pine trees, but then replated using a specific pine tree (the one with
best market value).   The mono-crop is now being over-run by pine beetles
and other critters, and the upcoming loss of timber and jobs appears to
be considerable.   Historically, the pine tree diversity and wild fires
of the area prevented such overwhelming catastrophes.

Thomas Gilg
tomg@cv.hp.com