[env-trinity] Iron Gate: If the dam is removed, the fish hatchery would b...
FISH1IFR at aol.com
FISH1IFR at aol.com
Thu Feb 16 17:45:33 PST 2012
In a message dated 2/16/2012 5:24:33 P.M. Pacific Standard Time,
t.schlosser at msaj.com writes:
The Biological Assessment on the Preferred Action of Interior's EIS on
Klamath points out that total chinook returns to the river will decline
substantially after PacifiCorp stops replacing the IGH output. See e.g., pages
214-15 of _this._
(http://klamathrestoration.gov/sites/klamathrestoration.gov/files/Klamath%20BA_%20Final%20_10-03-11.pdf)
PacifiCorp is obligated to replace IGH chinook output for 8 years after
removal of IGD but no party has agreed to fund or provide replacement
production after that.
_http://www.heraldandnews.com/news/article_cdf4af6e-586b-11e1-8b2e-0019bb296
3f4.html_
(http://www.heraldandnews.com/news/article_cdf4af6e-586b-11e1-8b2e-0019bb2963f4.html)
Colleagues...
The Biological Assessment appears to be incorrect on this point. The
projected increase in chinook runs size after dam removal and KBRA benefits is
not "hatchery dependent" because it was assumed that, after stabilizing
reintroduced populations, that Iron Gate Hatchery would close. Here is my
reply to Tom Schlosser noting this problem from another forum:
*******
Interesting, but [your assumption that fish numbers would decline after dam
removal] is based on some false reasoning.
You should be aware that the DEIS Salmon Production Model was run with the
assumption of NO Iron Gate Hatchery production at all, to be
conservative... and still comes up with the 83% production increase you cite, at least
for fall chinook. The note [above] is not in fact based on that fact, so you
are assuming a double subtraction that cannot mathematically be made.
In addition, hatchery fish have notoriously lower survival rates in the
natural environment than wild fish as they have become "hatchery dependent"
even on the genetic level. There have been (literally) hundreds of studies
verifying this phenomenon, and the Klamath Iron Gate Hatchery is no
exception. Genetic drift to make a fish more genetically fitted to hatchery life,
but less fitted to life in the wild, has been demonstrated to occur (at least
with steelhead, but no reason to think it is not broadly applicable to
their cousins) within just one or two generations!
In addition, hatchery fish are typically released at sizes larger than
native wild fish (since they are well fed their whole lives in the tanks), and
so predate on the wild smolt stocks -- hence, any introduced hatchery
stocks can in fact REDUCE productivity of the wild stocks, resulting in a
partial cancellation of any additional hatchery benefits in terms of sheer
escapement numbers. In some studies, such as in the Alsea River, the more
hatchery fish were introduced the LESS the ultimate adult escapement from that
brood year -- in other words, there was a negative correlation! This is
apparently because the larger hatchery juveniles simply ate up many of the wild
juveniles in the short-term, but themselves had much lower overall survival
rates over their entire lifecycle in the long-term -- so more of them just
flat out died in the ocean and from larger predators than would have
occurred had there been no hatchery "supplementation" to begin with.
You can check with the authors of the Chinook Production Model for
verification of how the modeling was done, i.e., without assuming any hatchery
production as a conservative assumption. As to the other flaws in assuming that
hatchery supplementation can replace a healthy wild stock with impunity,
there are literally hundreds of such studies in the literature that any
salmon biologist would help you locate, though it would take some legwork.
As is usually the case with biology, its all a LOT more complex than at
first cut. But by and large, your juxtaposition of the two statements below
and your conclusion from that that the end result of dam removal will be
FEWER salmon in the river because of the loss of IGH production is simply not
true so far as I am aware of the science and modeling done.
PS: The adult hatchery fish returns to the Iron Gate Hatchery in 2009, I am
told, was 12,263 adult chinook. This is far below the 53,400 number as
estimated IGH returns on which the note below was based. If, then, the dam
removal and re-established above-dams fall chinook runs had instead been in
place that year (for comparison), an estimated 41,000 would have been coming
in with an IGH loss of only 12,263 -- a net GAIN of over 28,700 adult
spawners! This is of course also simplistically assuming a one-to-one
replacement, without any negative hatchery-wild interactions. So you see, it all
depends on how and what you count, what your baselines are, and what data-years
you are averaging from -- and what hatchery-wild interactions you count
and how you count them, or simply ignore.
Hatchery programs also are expensive (and subject increasing to state
budget cuts) and sometimes just flat out fail, from disease or human error. So
relying on hatchery production always carries its own risks. These too have
to be considered.
-- Glen Spain
And in a later email exchange in which Tom asked for some citations to the
fact that the Chinook Model was run without reference to any hatchery
impacts, I responded as follows:
In a message dated 2/9/2012 9:05:00 A.M. Pacific Standard Time,
t.schlosser at msaj.com writes:
I agree with many of your generalizations about hatcheries. Can you point
me to where it is made clear that the DEIS modeling assumes no IGH
production.
Tom... Surely.... One can start here:
"Anticipated removal of the dams, combined with restoration of aquatic
habitats as anticipated in the KBRA, is predicted to increase the median
annual production of adult Chinook salmon, in the absence of hatcheries, by an
average of 83 percent for the years after dam removal (see Figure 4.1-25).
The Chinook salmon ocean commercial and sport harvests are forecasted to
increase by an average of 50 percent, the inriver tribal harvest would increase
by an average of 59 percent, and the in-river recreational fishery would
increase by an average of 9 percent in those years following dam removal
(2021 to 2061)." SDOR pg. 86 of text (emphasis on key phrase added)
Then looking to the Source Document, which is:
Forecasting the response of Klamath Basin Chinook populations to
dam removal and restoration of anadromy versus no action
---- Noble Hendrix (2011)
"ABSTRACT: Two alternative actions are being evaluated in the Klamath
Basin: 1) a No Action Alternative (NAA) and 2) removal of four mainstem dams
(Iron Gate, Copco I, Copco II, and J.C. Boyle) and initiation of habitat
restoration in the Klamath Basin under a Dam Removal Alternative (DRA). The
decision process regarding which action to implement requires annual forecasts
of abundance with uncertainty under each of the two alternatives from 2012
to 2061. I forecasted escapement for both alternatives by constructing a
life-cycle model (Evaluation of Dam Removal and Restoration of Anadromy,
EDRRA) composed of: 1) a stock recruitment relationship between spawners and
age 3 in the ocean, which is when they are vulnerable to the fishery, and 2)
a fishery model that calculates harvest, maturation, and escapement. To
develop stage 1 of the model under NAA, I estimated the historical stock
recruitment relationship in the Klamath River below Iron Gate Dam in a Bayesian
framework. To develop stage 1 of the model under DRA, I used the predictive
spawner recruitment relationships in Liermann et al. (2010) to forecast
recruitment to age 3 from tributaries to Upper Klamath Lake, which is the
site of active reintroduction of anadromy. I also modified the spawner recruit
relationship under DRA to include additional spawning capacity between
Iron Gate Dam and Keno Dam. In order to facilitate the comparison of the two
alternatives, I used paired Monte Carlo simulations to forecast the levels
of escapement and harvest under NAA and DRA. Median escapements and harvest
were higher in DRA relative to NAA with a high degree of overlap in 95%
confidence intervals due to uncertainty in stock-recruitment dynamics. Still,
there was a 0.75 probability of higher annual escapement and a 0.7
probability of higher annual harvest by performing DRA relative to NAA, despite
uncertainty in the abundance forecasts. The median increase in escapement in
the absence of fishing was 81.4% (95% symmetric probability interval
[95%CrI]: -59.9%, 881.4%), the median increase in ocean harvest was 46.5% (95%CrI:
-68.7, 1495.2%), and the median increase in tribal harvest was 54.8%
(95%CrI: -71.0%, 1841.0%) by performing DRA relative to NAA (estimates provided
for model runs after 2033 when portion of the population in the tributaries
to UKL are assumed to be established and Iron Gate Hatchery production has
ceased)." (emphasis added)
And to get even deeper into the methodology of the Chinook abundance model:
"I also calculated the percentage increase in abundance for each paired
iteration as (DRA – NAA)/NAA * 100%, which provided a quantitative estimate
of the difference in abundance. There were three periods that could have
different relative levels of abundance under DRA versus NAA: the period
between model initiation and dam removal (2012- 2020); the period after dam
removal but with active reintroduction in the tributaries to UKL (2021-2032);
and the final period when the population in the tributaries to UKL are assumed
to be established and Iron Gate Hatchery production has ceased
(2032-2061). (Hendrix, (2011), pg. 17 -- emphasis added)
I will spare you all the equations.... I can digest Bayesian functions but
they do give me indigestion unless I follow them with a quick glass of
wine (grinning). But from the above it is pretty clear that the Chinook
production estimate modeling for the DRA scenario was all done without reference
to any IGH fish as a potentially confusing factor in the final time frames,
i.e., after dam removal.
=============================================
Glen H. Spain, NW Regional Director
Pacific Coast Federation of Fishermen's Associations (PCFFA)
PO Box 11170, Eugene, OR 97440-3370
O:(541)689-2000 -- Fax:(541)689-2500
Email: fish1ifr at aol.com
Home Page: _www.pcffa.org_ (http://www.pcffa.org/)
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