> ![](media/image1.wmf){width="0.875in"
> height="0.8680555555555556in"}**UNITED STATES DEPARTMENT OF COMMERCE**
>
> **National Oceanic and Atmospheric Administration**
>
> NATIONAL MARINE FISHERIES SERVICE
>
> Northwest Fisheries Science Center
>
> 2725 Montlake Boulevard East
>
> SEATTLE, WASHINGTON 98112-2097

**MEMORANDUM**

Date: January 8, 2007

From: Interior Columbia Technical Recovery Team

To: NMFS NW Regional Office, co-managers and other interested parties

Subject: Scenarios for MPG and ESU viability consistent with TRT
viability criteria

# 

**[Purpose and Scope]{.underline}**

Clearly, the overall goal of recovery planning is to achieve a condition
for an ESU where it no longer needs protection under the ESA because it
is no longer in danger of extinction or likely to become endangered
within the foreseeable future. The ICTRT (2005, 2006) viability criteria
recommend that all Major Population Groups (MPGs) in the ESU must be
viable before the ESU can be considered at low risk of extinction and a
candidate for delisting. Because of the importance of the MPG in
determining overall ESU viability, we are providing more focused
interpretation and application of ICTRT MPG-level viability criteria. In
this memo, we provide, for each MPG in the Interior Columbia recovery
domain, a discussion about the combinations of populations that would
meet the ICTRT MPG-level recovery criteria if those populations achieved
low risk status. We also provide some recommendations and considerations
that recovery planners could use to prioritize populations for meeting
viability criteria within an MPG. However, in most cases where there are
multiple possible combinations of populations that could achieve MPG and
ESU viability, we do not provide a single set of populations. Likewise,
we did not develop a "least-effort" scenario for achieving MPG
viability. While we considered providing such a population set, we
concluded there were multiple ways to identify a "least-effort" scenario
technically and that scenario would also involve social, economical, and
political considerations that are outside of our purview. We do provide
some discussion about ways in which populations could be prioritized for
recovery efforts.

The "TRT-recommendation" included in this memo for each MPG is a
description of populations that, when those populations achieve viable
status, would meet the minimum MPG-level viability criteria. The
populations included in each recommendation or viable-MPG scenario were
selected based on unique characteristics (e.g. run timing, populations
size, genetic characteristics), major production areas in the MPG, and
spatial distribution of the populations. [Importantly, although not all
populations in a MPG need to meet TRT viability criteria under most
viable-MPG scenarios, it is strongly advisable to attempt to improve the
status of more than the minimum number of populations to a low-risk
(viable) situation.]{.underline} There are two primary reasons for this:

First, based on current population dynamic theory, the TRT has
recommended that all extant populations be maintained with sufficient
productivity that the overall MPG productivity does not fall below
replacement (i.e. these areas should not serve as significant population
sinks). Thus, it would be highly risky to allow the status of any
population to degrade. In fact, many populations will need to be
improved from their current status to be regarded as "maintained. " As a
rule of thumb, the TRT believes that populations that fall within cells
adjacent to those that we regard as viable in our risk matrix (Figure 1)
can be regarded as "maintained." We will provide further discussion of
this issue in a forthcoming update to our viability document.

Figure 1. Matrix of possible Abundance/Productivity and Spatial
structure/Diversity scores for application at the population level.
Percentages for abundance and productivity (A/P) scores represent the
probability of extinction in a 100-year time period. Cells that contain
a "V" are considered viable combinations; "HV" indicates Highly Viable
combinations; "M" indicates combinations that can be regarded (as a rule
of thumb) as "maintained." The darkest cells represent combinations of
A/P and SSD at greatest risk.

+-----------+---------------+----------+--------+----------+---------+
|           |               | *        |        |          |         |
|           |               | *Spatial |        |          |         |
|           |               | Str      |        |          |         |
|           |               | ucture/D |        |          |         |
|           |               | iversity |        |          |         |
|           |               | Risk**   |        |          |         |
+-----------+---------------+----------+--------+----------+---------+
|           |               | **Very   | *      | **Mo     | *       |
|           |               | Low**    | *Low** | derate** | *High** |
+-----------+---------------+----------+--------+----------+---------+
| **Abu     | **Very Low**  | **HV**   | **HV** | **V**    | M       |
| ndance/** |               |          |        |          |         |
|           | (\<1%)        |          |        |          |         |
| **Pro     |               |          |        |          |         |
| ductivity |               |          |        |          |         |
| Risk**    |               |          |        |          |         |
+-----------+---------------+----------+--------+----------+---------+
|           | **Low**       | **V**    | **V**  | **V**    | M       |
|           |               |          |        |          |         |
|           | (1-5%)        |          |        |          |         |
+-----------+---------------+----------+--------+----------+---------+
|           | **Moderate**  | M        | M      | M        |         |
|           |               |          |        |          |         |
|           | (6 -- 25%)    |          |        |          |         |
+-----------+---------------+----------+--------+----------+---------+
|           | **High**      |          |        |          |         |
|           |               |          |        |          |         |
|           | (\>25%)       |          |        |          |         |
+-----------+---------------+----------+--------+----------+---------+

Second, although the possible population sets suggested in this memo
would meet TRT recovery criteria for the ESUs, achieving recovery for
those populations will likely require attempting recovery in more than
just those populations because of the uncertainty of success of recovery
efforts. For example, if there is an 80% chance that recovery will be
successful in each of a set of three populations identified, there is an
overall 51% probability of recovering three populations if recovery
efforts are limited to those three populations (McElhany et al. 2003).
To have more than a 95% probability of recovering three populations in
this case would require attempting recovery of six populations. [A
low-risk strategy will thus target more populations than the minimum for
viability.]{.underline}

**[Prioritizing Populations within Scenarios]{.underline}**

Prioritizing populations is by its nature, a technical and policy
exercise. In this memo, we provide descriptions of scenarios that would
meet TRT biological viability criteria. Because these are not, in most
cases, a single scenario, we also identified a number of additional
factors that could be considered by recovery planners choosing which
populations to target in order to meet MPG viability criteria:

-   Current status of the population -- Recovery planners should
    consider the current condition of the population with respect to all
    four VSP parameters. Those that are closest to viability criteria
    currently may require less effort (but the remaining factors should
    also be considered.)

-   Biological feasibility -- This is closely tied to the current status
    of the population, but includes considerations, for example, of
    whether particular actions can produce the needed change. It also
    includes considerations for density-dependence --for example, would
    the required change be feasible, given current spawner or juvenile
    capacity?

-   Political/social/economic feasibility -- Obviously, some recovery
    actions are constrained by non-biological factors. These may make a
    population less or more attractive to serve as a low-risk/viable
    population than it would be by strictly biological criteria.

-   Hatchery practices affecting the population -- hatchery practices
    and diversity criteria in some locations may be in conflict. This
    may affect the choice of populations.

-   Monitoring history -- Some populations have an extensive history of
    monitoring data, while others have very little. It may cost less in
    dollars and effort to determine that a population has met viability
    criteria with substantial existing monitoring data.

-   Presence of multiple species in an area that would benefit by the
    same actions. Populations may rise in importance when more than one
    species of concern is in the area, and actions would achieve
    efficiencies of effort.

**[MPG-level scenarios consistent with TRT criteria for each
ESU]{.underline}**

To achieve viable ESUs in the Interior Columbia, the TRT recommends that
all extant MPGs meet MPG-level criteria. We, therefore, present
combinations of populations within MPGs that would meet viability
criteria. For each MPG, we first present the "menu" of populations that
would meet our criteria. We then discuss population-specific
characteristics or conditions that should be considered when choosing
among populations in that menu. Finally, we provide a reduced set of
populations that we recommend meet our criteria. We will be providing
additional information about the IC-TRT's recommended approaches to MPGs
that include populations that have been extirpated in another memo.

In this document, we identify recommendations and scenarios that are
consistent with our criteria.

***A. Snake River spring/summer chinook salmon ESU***

For the Snake River spring/summer chinook salmon ESU to meet TRT
viability criteria, each of the MPGs should meet the scenarios described
below:

[1. Lower Snake MPG]{.underline}

Component populations:

  --------------------------------------- -------------- ----------------
                                          Size Category  Life History
                                                         Type

  Tucannon River                          Intermediate   Spring

  Asotin Creek (functionally extirpated)  Basic          Spring
  --------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Two populations must meet viability criteria, one of which must meet
    high viability criteria

Considerations:

-   Asotin Creek population is functionally extirpated. Treatment of
    extirpated populations is discussed more thoroughly in the
    accompanying memo. However, our general recommendation is that
    extirpated populations be included in the total number of
    populations in the ESU (for calculating minimum number of
    populations in the MPG), but that the initial focus of recovery
    efforts be put on extant populations, with scoping efforts for
    re-introductions conducted concurrently.

TRT Recommendation:

  ------------------------------- ---------------------------------------
  Highly Viable:                  Tucannon River (receives initial focus)

  Re-considered for               Asotin Creek
  reintroduction as recovery      
  efforts progress:               
  ------------------------------- ---------------------------------------

[2. Grande Ronde/Imnaha MPG]{.underline}

Component populations:

  ------------------------------------------ -------------- ---------------
                                             Size Category  Life History
                                                            Type

  Wenaha River                               Intermediate   Spring

  Minam River                                Intermediate   Spring

  Lostine/Wallowa Rivers                     Large          Spring

  Lookingglass Creek (functionally           Basic          Spring
  extirpated)                                               

  Catherine Creek                            Large          Spring

  Upper Grande Ronde                         Large          Spring

  Imnaha River                               Intermediate   Spring/Sum

  Big Sheep Creek (functionally extirpated)  Basic          Spring
  ------------------------------------------ -------------- ---------------

Basic application of TRT criteria:

-   Four populations must meet viability criteria, one of which must
    meet high viability criteria

-   Population in the Imnaha River has a unique life history strategy;
    this must meet viability criteria

-   Two of the three Large populations must meet viability criteria

Considerations:

-   Lookingglass Creek and Big Sheep Creek populations are functionally
    extirpated.

-   Distributing viable "Large" populations throughout the sub-basin is
    preferable to having them clumped or contiguous.

-   There is the potential for Imnaha to be isolated.

-   Wenaha R. is most downstream, providing connectivity with other
    MPGs.

-   Wenaha R. and Minam R. populations are currently the most unaffected
    by hatchery fish. Hatchery supplementation programs are ongoing in
    the Imnaha, Wallowa-Lostine, Catherine Creek and Upper Grande Ronde
    populations.

-   Minam R. and Wenaha R. populations have little spatial structure or
    diversity impairment. They may be candidates for high viability
    status.

TRT Recommendation:

+-------------------------------+--------------------------------------+
| 1 Highly Viable and 3 Viable: | Imnaha River                         |
|                               |                                      |
|                               | Lostine/Wallowa River                |
|                               |                                      |
|                               | Catherine Creek OR Upper Grande      |
|                               | Ronde R.                             |
|                               |                                      |
|                               | Wenaha R. OR Minam R.                |
+-------------------------------+--------------------------------------+
| Maintained:                   | All remaining extant populations     |
+-------------------------------+--------------------------------------+

[3. South Fork Salmon MPG]{.underline}

Component populations:

  ----------------------------------------- -------------- ----------------
                                            Size Category  Life History
                                                           Type

  Little Salmon River (includes Rapid       Intermediate   Spring/Sum
  River)                                                   

  South Fork Salmon River                   Large          Summer

  Secesh River                              Intermediate   Summer

  East Fork South Fork Salmon River         Large          Summer
  ----------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Two populations minimum must meet viability criteria, one of which
    must meet high viability criteria.

-   Little Salmon River (as the only spring/summer life history).

-   One Large population (East Fork South Fork or South Fork) must meet
    viability criteria.

Considerations:

-   The Little Salmon's size category is largely driven by small,
    adjunct tributaries. These adjunct tributaries are also the only
    places where the spring life history is represented in the
    population. If this was not the case historically (i.e. if these
    fish are a result of hatchery production or not representative of
    the historical condition), the importance of maintaining that life
    history is somewhat less.

-   Little Salmon River population is greatly influenced by Rapid River
    hatchery production and releases.

-   Ongoing supplementation exists in EFSF population (Johnson Creek).

TRT Recommendation:

  ----------------------------------- -----------------------------------
  1 Highly Viable and 1 Viable:       Two populations in the main South
                                      Fork basin.

  Maintained:                         All remaining extant populations
  ----------------------------------- -----------------------------------

[4. Middle Fork Salmon MPG]{.underline}

Component populations:

  ---------------------------------------- -------------- ----------------
                                           Size Category  Life History
                                                          Type

  Middle Fork Salmon below Indian Creek    Basic          Spring/Sum

  Big Creek                                Large          Spring/Sum

  Camas Creek                              Basic          Spring

  Loon Creek                               Basic          Spring/Sum

  Middle Fork Salmon above Indian Creek    Intermediate   Spring

  Sulphur Creek                            Basic          Spring

  Bear Valley/Elk Creek                    Intermediate   Spring

  Marsh Creek                              Basic          Spring

  Chamberlain Creek                        Intermediate   Spring
  ---------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Five populations must meet viability criteria, one of which must
    meet high viability criteria.

-   Big Creek is required by size criteria.

-   Two of three Intermediate populations (Middle Fork Salmon above
    Indian Creek, Chamberlain Creek, or Bear Valley Creek) must meet
    viability criteria, to meet size criteria.

Considerations:

-   Chamberlain Creek falls in a significant geographic position --
    providing connectivity between MPGs.

-   Chamberlain Creek has unique, apparently persistent genetic
    characteristics.

-   Marsh Creek is somewhat less isolated, and overall a larger
    production area than Sulphur Creek.

-   Upper Middle Fork mainstem is composed of a number of small
    tributaries (rather than a core, contiguous spawning area).

-   Several populations have potential to achieve Highly Viable status
    because of high quality habitat.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 4 Viable:     | Big Creek                         |
|                                   |                                   |
|                                   | Chamberlain Creek                 |
|                                   |                                   |
|                                   | Bear Valley Creek                 |
|                                   |                                   |
|                                   | Marsh Creek                       |
|                                   |                                   |
|                                   | Camas OR Loon Creek               |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+

[5. Upper Salmon MPG]{.underline}

Component populations:

  -------------------------------------------- -------------- --------------
                                               Size Category  Life History
                                                              Type

  North Fork Salmon River                      Basic          Spring

  Panther Creek (extirpated)                   Intermediate   Spring

  Lemhi River                                  Very Large     Spring

  Salmon River mainstem, below Redfish Lake    Very Large     Spring/Sum

  Pahsimeroi River                             Large          Spring

  East Fork Salmon River                       Large          Spring/Sum

  Yankee Fork                                  Basic          Spring

  Valley Creek                                 Basic          Spring

  Upper Salmon River mainstem, above Redfish   Large          Spring
  Lake                                                        
  -------------------------------------------- -------------- --------------

Basic application of TRT criteria:

-   Five populations must meet viability criteria, one of which must
    meet high viability criteria

-   Pahsimeroi River has the only extant summer life history strategy,
    and thus must meet viability criteria

-   Three Very Large or Large populations (Lemhi R., Pahsimeroi, East
    Fork Salmon R., Salmon River mainstem, above and below Redfish Lake)
    must meet viability criteria

-   One Intermediate or larger population (Panther Creek is the only
    Intermediate population) must meet viability criteria.

Considerations:

-   Lemhi historically may have had summer chinook production.

-   Panther Creek is extirpated and is the only intermediate population;
    a large population could be substituted for it.

-   Lemhi provides important connectivity to other MPGs, as a large,
    downstream population.

-   Upper Salmon mainstem population is at the geographic "end" of the
    ESU and MPG.

-   Valley Creek had historically larger production than most Basic
    populations.

-   North Fork is the most downstream population. However, fairly few
    data are available, and substantial anthropogenic effects to
    population and habitat.

-   Yankee Fork is currently occupied by non-native stock.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 4 Viable:     | Lemhi R.                          |
|                                   |                                   |
|                                   | Pahsimeroi R.                     |
|                                   |                                   |
|                                   | East Fork Salmon River            |
|                                   |                                   |
|                                   | Upper Salmon River                |
|                                   |                                   |
|                                   | Valley Creek                      |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+

*B. Snake River Steelhead DPS*

[1. Lower Snake MPG]{.underline}

Component populations:

  --------------------------------------- -------------- -----------------
                                          Size Category  Life History Type

  Tucannon River                          Intermediate   A-Run

  Asotin Creek                            Basic          A-Run
  --------------------------------------- -------------- -----------------

Basic application of TRT criteria:

-   Two populations must meet viability criteria, one of which must meet
    high viability criteria

Considerations: (none)

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 1 Viable:     | Tucannon River                    |
|                                   |                                   |
|                                   | Asotin Creek                      |
+-----------------------------------+-----------------------------------+

[2. Clearwater MPG]{.underline}

Component populations:

  ---------------------------------------- -------------- ----------------
                                           Size Category  Life History
                                                          Type

  Lower Clearwater                         Large          A-Run

  South Fork Clearwater                    Intermediate   B-Run

  North Fork Clearwater (extirpated)       Large          

  Lolo Creek                               Basic          A&B-Run

  Selway River                             Intermediate   B-Run

  Lochsa River                             Intermediate   B-Run
  ---------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Three populations must meet viability criteria, one of which must
    meet high viability criteria.

-   Lolo Creek has the only A and B life history, and must meet
    viability criteria.

-   Two Large or Very Large populations (North Fork Clearwater, Lower
    Clearwater, Lochsa or Selway) must meet viability criteria.

-   One additional Intermediate or larger population must meet viability
    criteria.

-   At least one A-run and one B-run population must meet viability
    criteria.

Considerations:

-   TRT criteria for size and life history cannot be met with three
    populations; four are necessary.

-   Lochsa River is more accessible than the Selway River for data
    collection.

-   North Fork population is extirpated.

-   A/B life history (as seen in Lolo) may be less important than
    ensuring that both A-run and B-run fish are present.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 3 Viable:     | Lower Clearwater                  |
|                                   |                                   |
|                                   | Lolo Creek                        |
|                                   |                                   |
|                                   | 2 of: Selway River, Lochsa River, |
|                                   | SF Clearwater                     |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+

[3. Grande Ronde MPG]{.underline}

Component populations:

  --------------------------------------- -------------- ----------------
                                          Size Category  Life History
                                                         Type

  Lower Grande Ronde mainstem             Intermediate   A-Run

  Joseph Creek                            Basic          A-Run

  Wallowa River                           Intermediate   A-Run

  Upper Grande Ronde mainstem             Large          A-Run
  --------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Two populations must meet viability criteria, one of which must meet
    high viability criteria.

-   Grande Ronde upper mainstem must meet viability criteria, as the
    only Large population.

Considerations:

-   The Lower mainstem or Joseph populations would contribute to spatial
    structure in the lower portion of the MPG.

-   Wallowa includes multiple core areas, some unique habitat
    characteristics (Eagle Caps), but does support a hatchery (with
    little straying).

-   Joseph Creek population is somewhat smaller than the others and has
    the least hatchery influence.

-   Lower Grande Ronde population receives hatchery releases.

-   Upper Grande Ronde population currently receives no hatchery
    releases.

-   Joseph Creek may be a candidate for High Viability status.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 1 Viable:     | Upper Grande Ronde                |
|                                   |                                   |
|                                   | Joseph Creek OR Lower Grande      |
|                                   | Ronde                             |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+

[4. Salmon River MPG]{.underline}

Component populations:

  --------------------------------------- -------------- ----------------
                                          Size Category  Life History
                                                         Type

  Little Salmon and Rapid Rivers          Intermediate   A-Run

  South Fork Salmon River                 Intermediate   B-Run

  Secesh River                            Basic          B-Run

  Lower Middle Fork Tributaries           Large          B-Run

  Upper Middle Fork Salmon River          Large          B-Run

  Chamberlain Creek                       Basic          A-Run

  Panther Creek                           Basic          A-Run

  North Fork Salmon River                 Basic          A-Run

  Lemhi River                             Intermediate   A-Run

  Pahsimeroi River                        Intermediate   A-Run

  East Fork Salmon River                  Intermediate   A-Run

  Upper Salmon River                      Intermediate   A-Run
  --------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Six populations must meet viability criteria, one of which must meet
    high viability criteria

-   One of the Large populations (Upper Middle Fork OR Lower Middle Fork
    Tributaries) must meet viability criteria

-   Four additional Intermediate or larger populations must meet
    viability criteria (all remaining except Secesh and North Fork
    Salmon River)

-   At least one A-run and one B-run must be represented

Considerations:

-   South Fork Salmon is the only B-run, intermediate sized population,
    has no hatchery influence

-   Spatial structure should be strongly considered in the choice of
    populations in this large MPG -- those that meet viability criteria
    should be spread across US, MF and SF and lower Salmon

-   A-run populations made up 2/3 of the total populations in this MPG.
    Where possible, maintaining the distribution of A and B run
    populations would most closely mirror historical (lower-risk)
    conditions

-   Upper Salmon, EF, Lemhi, Pahsimeroi, Little Salmon/Rapid all have
    some hatchery influence. This tends to be out of MPG -- e.g.
    Dworshak B, Hells Canyon A.

-   Little monitoring on any of these populations except Rapid River

-   Secesh, South Fork, Chamberlain and Upper Middle Fork all have no
    history of hatchery influence, and are relatively natural systems.

TRT Recommendation:

+---------------------------+------------------------------------------+
| 1 Highly Viable and 5     | Upper Middle Fork                        |
| Viable:                   |                                          |
|                           | Chamberlain                              |
|                           |                                          |
|                           | South Fork Salmon                        |
|                           |                                          |
|                           | 2 Additional Intermediate or Large       |
|                           | populations                              |
|                           |                                          |
|                           | 1 Additional population of any size      |
+---------------------------+------------------------------------------+
| Maintained:               | All remaining extant populations         |
+---------------------------+------------------------------------------+

[5. Imnaha MPG]{.underline}

Component populations:

  -------------------------------------- --------------- ----------------
                                         Size Category   Life History
                                                         Type

  Imnaha River                           Intermediate    A-Run
  -------------------------------------- --------------- ----------------

Basic application of TRT criteria:

-   One population must meet viability criteria

TRT Recommendation:

  ----------------------------------- -----------------------------------
  Highly Viable:                      Imnaha River

  Maintained:                         N/A
  ----------------------------------- -----------------------------------

[6. Hells Canyon MPG]{.underline}

Component populations:

  ------------------------------------- -------------- ------------------
                                        Size Category  Life History Type

  Hells Canyon                          \-             \-

  Powder River (extirpated)             \-             \-

  Burnt River (extirpated)              \-             \-

  Weiser River (extirpated)             \-             \-
  ------------------------------------- -------------- ------------------

Considerations:

-   With the possible exception of several small tributaries in Hells
    Canyon, this MPG is largely extirpated. Fish that are currently
    occupying those small tributaries may be the only remnants of this
    MPG . A key research need is to determine whether these are remnants
    or hatchery strays. If they are remnants, emphasis should be placed
    on recovering this population. The other extirpated populations are
    addressed in the accompanying memo.

C.  *Snake River fall chinook salmon*

[1. Snake River Mainstem MPG]{.underline}

Component populations:

  ------------------------------------- --------------- -----------------
                                        Size Category   Life History Type

  Lower Mainstem                        Small~FC~       \-

  Marsing Reach (extirpated)            Large~FC~       \-

  Salmon Falls (extirpated)             Large~FC~       \-
  ------------------------------------- --------------- -----------------

Basic application of TRT criteria:

-   Two populations must meet viability criteria, both of which must
    meet high viability criteria

Considerations:

-   Two upstream populations are extirpated

-   The two upstream populations were historically the most productive

-   Additional information about the TRT recommended approach to
    consideration extirpated areas in recovery planning is presented in
    the accompanying memo. We recognize that there are significant
    difficulties in re-establishing fall chinook populations above the
    Hells Canyon complex, and suggest that initial effort be placed on
    recovery for the extant population, concurrently with scoping
    efforts for re-introduction. As recovery efforts progress, the risk
    and feasibility associated with opening this area to fall chinook
    can be re-assessed.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| Highly Viable:                    | Lower Mainstem                    |
|                                   |                                   |
|                                   | Marsing Reach OR Salmon Falls     |
+-----------------------------------+-----------------------------------+
| Re-considered as recovery efforts | Marsing Reach or Salmon Falls     |
| progress:                         |                                   |
+-----------------------------------+-----------------------------------+

D.  *Snake River sockeye salmon*

[1. Stanley Lakes Basin]{.underline}

Component populations:

+------------------------------------------+------------+--------------+
|                                          | Size       | Life History |
|                                          | Category   | Type         |
+------------------------------------------+------------+--------------+
| > Redfish Lake                           | \-         | \-           |
+------------------------------------------+------------+--------------+
| > Alturas Lake (extirpated)              | \-         | \-           |
+------------------------------------------+------------+--------------+
| > Pettit Lake (extirpated)               | \-         | \-           |
+------------------------------------------+------------+--------------+
| > Yellowbelly Lake (extirpated, and of   | \-         | \-           |
| > uncertain historical status)           |            |              |
+------------------------------------------+------------+--------------+
| > Stanley Lake (extirpated, and of       | \-         | \-           |
| > uncertain historical status)           |            |              |
+------------------------------------------+------------+--------------+

Basic application of TRT criteria:

-   The IC-TRT required 2/3 of the populations in ESUs with only one MPG
    to meet viability criteria. This value (2/3) was chosen as a number
    that was substantially greater than half, with the intent of
    mitigating for the small number of MPGs with increased numbers of
    populations. However, there is great uncertainty around the
    proportion or number of populations that would adequately mitigate
    risk. With such a small number of populations in this MPG,
    increasing the number of populations will substantially reduce the
    risk faced by the ESU. Our next update to our viability criteria
    will explain the rationale for this recommendation more thoroughly.

-   

Considerations:

-   Four of five populations are entirely extirpated

-   Sockeye are currently maintained in a captive broodstock program,
    and are at extremely high risk

-   Additional information about the TRT recommended approach to
    extirpated areas will be forthcoming.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 2 Highly Viable and 1 Viable:     | Redfish Lake                      |
|                                   |                                   |
|                                   | Alturas Lake                      |
|                                   |                                   |
|                                   | Pettit Lake                       |
+-----------------------------------+-----------------------------------+
| Re-considered as recovery efforts | Yellowbelly Lake                  |
| progress:                         |                                   |
|                                   | Stanley Lake                      |
+-----------------------------------+-----------------------------------+

*E. Upper Columbia spring chinook salmon*

[1. East Cascades MPG]{.underline}

Component populations:

  ----------------------------------------- ------------- ----------------
                                            Size Category Life History
                                                          Type

  Wenatchee River                           Very Large    Spring

  Entiat River                              Basic         Spring

  Methow River                              Very Large    Spring

  Okanogan River (extirpated)               Basic (U.S.   Spring
                                            only)         
  ----------------------------------------- ------------- ----------------

Basic application of TRT criteria:

-   Three populations must meet viability criteria, two of which must
    meet high viability criteria

Considerations:

-   Okanogan River population is extirpated

-   Additional information about the TRT recommended approach to
    extirpated areas will be forthcoming.

-   An additional recommendation to moderate risk for an ESU with only
    one MPG was to require at least 2 populations to meet highly viable
    status (\<1% extinction risk for abundance and productivity). The
    lowest risk scenario for the ESU would be for the two very large
    populations (Wenatchee and Methow) to meet highly viable status.
    Entiat cannot reach these standards due to its inherent spatial
    structure and the Okanogan population has been extirpated

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 2 Highly Viable and 1 Viable:     | Wenatchee River (highly viable)   |
|                                   |                                   |
|                                   | Entiat River                      |
|                                   |                                   |
|                                   | Methow River (highly viable)      |
+-----------------------------------+-----------------------------------+
| Re-considered as recovery efforts | Okanogan River                    |
| progress:                         |                                   |
+-----------------------------------+-----------------------------------+

F.  *Upper Columbia steelhead*

[1. East Cascades MPG]{.underline}

Component populations:

+---------------------------------------+-------------+----------------+
|                                       | Size        | Life History   |
|                                       | Category    | Type           |
+---------------------------------------+-------------+----------------+
| Crab Creek (anadromous component      | Basic       | (Summer A)     |
| functionally extirpated)              |             |                |
+---------------------------------------+-------------+----------------+
| Wenatchee River                       | I           | Summer A       |
|                                       | ntermediate |                |
+---------------------------------------+-------------+----------------+
| Entiat River                          | Basic       | Summer A       |
+---------------------------------------+-------------+----------------+
| Methow River                          | I           | Summer A       |
|                                       | ntermediate |                |
+---------------------------------------+-------------+----------------+
| Okanogan River                        | I           | Summer A       |
|                                       | ntermediate |                |
|                                       |             |                |
|                                       | (Basic for  |                |
|                                       | U.S.        |                |
|                                       | portion     |                |
|                                       | only)       |                |
+---------------------------------------+-------------+----------------+

Basic application of TRT criteria:

-   Three populations must meet viability criteria, two of which must
    meet high viability criteria

-   Two large populations must meet viability criteria

Considerations:

-   The anadromous component of Crab Creek was likely historically less
    robust than those of other populations

-   The Okanogan population includes some territory in Canada -- for
    U.S. purposes, this population should meet requirements of a "Basic"
    population within the U.S., or "intermediate" if status within both
    countries is considered

-   An additional recommendation to moderate risk for an ESU with only
    one MPG was to require at least 2 populations to meet highly viable
    status (\<1% extinction risk for abundance and productivity). The
    lowest risk scenario for the ESU would be for the two large
    populations (Wenatchee and Methow) to meet highly viable status. The
    Entiat and U.S. Okanogan cannot meet high viability criteria due to
    their inherent spatial structure, and the anadromous component of
    Crab Creek has been functionally extirpated.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 2 Highly Viable and 1 Viable:     | Wenatchee River                   |
|                                   |                                   |
| Maintained:                       | Methow River                      |
|                                   |                                   |
|                                   | Entiat River                      |
|                                   |                                   |
|                                   | Okanogan River                    |
|                                   |                                   |
|                                   | All remaining extant populations  |
+-----------------------------------+-----------------------------------+
| Resident component                | Crab Creek                        |
|                                   |                                   |
| maintained/reconsidered as        |                                   |
| recovery efforts progress:        |                                   |
+-----------------------------------+-----------------------------------+

*Mid-Columbia steelhead*

[1. Cascades Eastern Slopes MPG]{.underline}

Component populations:

  ------------------------------------------ -------------- ----------------
                                             Size Category  Life History
                                                            Type

  White Salmon River (functionally           Basic          Unknown
  extirpated)                                               

  Klickitat River                            Intermediate   Summer/Winter

  Deschutes River Eastside                   Intermediate   Summer

  Deschutes River Westside                   Large          Summer

  Crooked River (extirpated)                 Very Large     Summer

  Fifteenmile Creek                          Basic          Winter

  Rock Creek                                 Basic          Summer
  ------------------------------------------ -------------- ----------------

Basic application of TRT criteria:

-   Four populations must meet viability criteria, one of which must
    meet high viability criteria

-   Fifteenmile Creek is the only winter population, and thus must meet
    viability criteria

-   One Large or Very Large populations must meet viability criteria.
    Deschutes River Westside is the only extant population meeting that
    size requirement.

-   In addition, two Intermediate populations must meet viability
    criteria.

Considerations:

-   White Salmon is functionally extirpated. It is blocked by a dam
    three kilometers upstream, and has been the recipient of abundant
    hatchery releases from the Skamania stock.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 3 Viable:     | Fifteenmile Creek                 |
|                                   |                                   |
|                                   | Deschutes River Westside          |
|                                   |                                   |
|                                   | Klickitat River                   |
|                                   |                                   |
|                                   | Deschutes River Eastside          |
+-----------------------------------+-----------------------------------+
| Maintained:                       | Rock Creek                        |
+-----------------------------------+-----------------------------------+

[2. John Day MPG]{.underline}

Component populations:

  ------------------------------------------ -------------- ---------------
                                             Size Category  Life History
                                                            Type

  Lower John Day River                       Very Large     Summer

  South Fork John Day River                  Basic          Summer

  Middle Fork John Day River                 Intermediate   Summer

  North Fork John Day River                  Large          Summer

  Upper John Day River                       Intermediate   Summer
  ------------------------------------------ -------------- ---------------

Basic application of TRT criteria:

-   Three populations must meet viability criteria, one of which must
    meet high viability criteria

-   Two population in the Large or Very Large size category (Lower John
    Day and North Fork John Day) must meet viability criteria

-   One additional population in the Intermediate (Upper John Day and
    Middle Fork John Day) category must meet viability criteria

Considerations:

-   Lower John Day River population provides an important spatial
    structure component, as the most downstream population

-   North Fork John Day is strong candidate for High Viability status,
    as it currently appears to be at low risk.

-   South Fork John Day is the smallest of the populations

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 2 Viable:     | North Fork John Day River         |
|                                   |                                   |
|                                   | Lower John Day River              |
|                                   |                                   |
|                                   | Middle Fork John Day OR Upper     |
|                                   | John Day                          |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+

[3. Walla Walla-Umatilla MPG]{.underline}

Component populations:

  ---------------------------------------- -------------- ----------------
                                           Size Category  Life History
                                                          Type

  Willow Creek (extirpated)                               

  Umatilla River                           Large          Summer

  Walla Walla River                        Intermediate   Summer

  Touchet River                            Intermediate   Summer
  ---------------------------------------- -------------- ----------------

Basic application of TRT criteria:

-   Two populations must meet viability criteria, one of which must meet
    high viability criteria

-   One Large or Very Large Population (Umatilla River) must meet
    viability criteria

Considerations:

-   Willow Creek population has been extirpated

-   Some hatchery influence exists throughout the Walla Walla, Touchet
    and Umatilla populations.

-   Current status suggests that the Walla Walla is closer to meeting
    viability criteria than the Touchet.

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 1 Viable:     | Umatilla River                    |
|                                   |                                   |
|                                   | Walla Walla River OR Touchet      |
|                                   | River                             |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+

[4. Yakima MPG]{.underline}

Component populations:

  -------------------------------------- --------------- ----------------
                                         Size Category   Life History
                                                         Type

  Satus Creek                            Intermediate    Summer

  Toppenish Creek                        Basic           Summer

  Naches River                           Large           Summer

  Upper Yakima River                     Large           Summer
  -------------------------------------- --------------- ----------------

Basic application of TRT criteria:

-   Two populations must meet viability criteria, one of which must meet
    high viability criteria

-   One Large or Very Large (Naches or Upper Yakima) population must
    meet viability criteria

Considerations:

-   Having populations at upper and lower ends of the drainage would
    contribute to a robust spatial structure for the MPG

TRT Recommendation:

+-----------------------------------+-----------------------------------+
| 1 Highly Viable and 1 Viable:     | Naches River OR Upper Yakima      |
|                                   |                                   |
|                                   | One of the remaining three        |
|                                   | populations                       |
+-----------------------------------+-----------------------------------+
| Maintained:                       | All remaining extant populations  |
+-----------------------------------+-----------------------------------+