Results - Fish
This section of the Results addresses fish; it is organized as follows::
The Effect of Actions on Environmental Attributes
Future Phases of The Framework Processes—Assessment and Subbasin Planning
Columbia River Basin Scale Analysis
Under Section A, Framework, we show how proposed actions affect environmental attributes and discuss the resulting change in biological performance. In the section on Validation, we present data to confirm our assumption that the EDT model results for the Current Potential provide a reasonable estimate of fish abundance in the basin. Sections C through G provide a summary of chinook model results for the Historic Potential, the Current Potential, and each of the three alternatives.
The Framework process was designed to help the region develop
a collective vision and approach for fish and wildlife recovery in the Columbia
River basin. The Framework is based on the following premise:
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Actions are designed to affect environmental attributes in a manner that changes biological performance to better meet basin goals. |
In short, the Framework provides an explicit linkage between the basin vision, biological performance, and actions needed for achieving the performance (Figure IV.A.1).
In this section, we use the results of the analysis to demonstrate how we filled in the linkages connecting actions, environmental attributes, and biological performance, with data.
The Effect of Actions on Environmental Attributes
The actions included in the analysis alternatives can be classified roughly into what is referred to in the region as the 4-Hs: habitat, hydrology, harvest, and hatcheries. We included three of the Hs in each of the alternatives—the amount and intensity of application for each of these actions, however, varied by alternative. For example, Alternative 2 emphasized hydrology actions and habitat work, while Alternatives 5 and 6 relied heavily on habitat actions focused in the tributaries. The fourth H, harvest, was set at zero for all alternatives in order to more clearly highlight effects of the other three Hs. The change in the environmental attributes described below is heavily influenced by the actions inherent in each alternative.
The change in each of the 45 environmental attributes resulting from implementation of the alternatives is shown in Figure IV.A.2. The values in Figure IV.A.2 represent the amount of change expected from the Current Potential. The values apply only to the freshwater rearing phase of the chinook life cycle and, thus, emphasize spawning egg incubation and juvenile rearing conditions in the tributaries. We present model results incorporating the marine component of the species life cycle later in the report.
In Figure IV.A.2, data are presented in a consumer report type format where ○ indicates less than 20 percent improvement, ◐ is 20 percent to < 40 percent improvement, and ● is 40 percent or higher improvement. A close examination of the data presented in Figure IV.A.2 shows that there was little change (<20 percent) in the majority of the environmental attributes modeled.
The lack of significant change could be the result of any of the following conditions:
· The alternative did not include strategies designed to affect the attribute.
· The strategy was ineffective or had little effect on the attribute.
· A problem did not exist with this attribute (i.e., no impact on fish survival).
· The quality of the data was too coarse to detect a change (especially true for the habitat type data).
In the EDT methodology, the exact cause for a lack of change observed in some of the environmental attributes would be determined during the diagnosis phase of the analysis. However, we did not complete a diagnosis for this analysis, as it was not needed for meeting the study objectives and was not applicable for the particular analytical process employed. We discuss this issue in more detail at the end of this section.
Of the 45 environmental attributes modeled, seven generally showed a change of greater than 40 percent for most alternatives. These seven attributes are:
1. bed scour
2. fine sediment
3. riparian function
4. temperature monthly maximum
5. embeddedness
6. turbidity
7. woody debris
The exact percent change in the attributes from the Current Potential is shown by alternative and province in Table IV.A.1. It should be noted that local biologists reviewed the first four attributes listed above as part of the coarse screening process. Thus, the quality of the data is substantially improved for these four environmental attributes and may explain why these attributes had the greatest effect on model results.
The data presented in Table IV.A.1 and Figure IV.A.2 demonstrate that the actions did indeed have a large effect on many of the environmental attributes given the assumptions (rules) inherent in the analysis. Later in this report we will show how these changes can be used in setting biological objectives for the basin and individual provinces.
In summary, the rationale linking actions to environmental attributes is established and documented in this step of the analysis. What is yet to be demonstrated is whether the change in the environmental attributes resulted in increased biological performance.
This question is answered in the paragraphs below.
The goal of changing the landscape is to increase the productivity of the species dependent upon that landscape. In the Framework, it is assumed that as the landscape changes, productivity also changes. In other words, an improvement in fish habitat should result in an increase in fish survival and eventually abundance. In the previous section we showed how the landscape, as represented by the environmental attributes, changed under each alternative. We now show how this change affected biological performance.
The data in Figure IV.A.3 summarize the change in freshwater habitat productivity assumed to occur in the Columbia River basin with the implementation of the three analysis alternatives[1]. As noted previously, freshwater productivity consists primarily of the egg incubation and juvenile rearing life stages. Therefore, the productivity term in Figure IV.A.3 represents the average number of juveniles (per 1,000 eggs) that would survive to the smolt stage with the removal of all density dependent survival factors.
With the completion of this step of the analysis we have filled in the linkages connecting actions, environmental attributes and biological performance (Figure IV.A.4). Whether the biological performance is sufficient to meet the vision described for each alternative can only be determined by looking at the overall increase in chinook performance resulting from the implementation of each.
In the EDT method fish performance is described in terms of productivity, abundance, and life history diversity. Obtaining estimates for these three parameters requires that the complete life cycle of the species be modeled. The results of the chinook life cycle analyses are presented in Sections C through G.
Before we describe how chinook performance has changed in the basin over time, and could change in the future with the implementation of each alternative, we finish this section with a discussion regarding the diagnosis phase of EDT.
The steps in a standard EDT analysis are depicted in Figure IV.A.5. In this typical approach, the diagnosis step is completed prior to the identification of treatments (actions)—the logic in EDT is that you cannot identify and prioritize effective treatments until after you determine (diagnosed) what the problems are!
In the Multi-Species Framework analysis, treatments (actions) were constructed without the benefit of a completed diagnosis. We assumed that the stakeholder groups submitting the alternatives had sufficient knowledge of the basin to develop a suite of actions, or at least an approach, that would be relatively effective at addressing basin ills—thereby achieving their identified basin goals. This assumption is likely correct for actions dealing with the hydroelectric system and hatcheries, but probably less so for habitat. To be effective, habitat actions must be precisely located on the landscape. The scale (how much) of the habitat action is also very important in determining overall biological and cost effectiveness.
Modeled habitat treatments were constructed at the 6-HUC scale, with the only location criteria being whether the land was in public or private hands. Habitat treatments were, therefore, based more on policy concerns than on biological effectiveness. This may explain why some environmental attributes showed little difference between the Current Potential and the three analysis alternatives. Habitat actions could have been selected to address problems identified if a detailed diagnosis similar to the one shown below for the Deschutes River, Oregon (Figure IV.A.6) had been done first.
The data in Figure IV.A.6 show the relative change in attribute effects on salmonid (spring chinook) survival in stream reaches of the Deschutes River (Mobrand 1999). The data is presented in a consumer report type format for easy interpretation. The larger and darker the circle, the bigger the impact the attribute has on salmon survival. For example, the attribute having the largest effect on chinook survival in the Lower Deschutes River mainstem is pathogens.
For the Deschutes analysis, once the major problems were identified, the next step in the diagnosis was to determine precisely where in the Lower Deschutes River mainstem the problems occur.
Locating the problems requires examining the data at a finer scale. Figure IV.A.7 shows the resulting attribute data by river mile for both the lower river and key tributaries. These data indicate that the attributes of habitat diversity, oxygen, pathogens, predation, sediment load, and temperature had the largest effect on salmon productivity.
We can see the size of the effect the key environmental attributes are having on salmon survival in Figure IV.A.8. The data show that overall productivity in this reach has decreased from 60 percent to 39.4 percent dependent on the life stage examined.
Once we have identified the problems and their location, the next step in the diagnosis is to determine the increase in survival that would occur if we could treat the problems successfully. This information is also presented in Figure IV.A.8 and summarized here for convenience:
· Potential percent change in productivity = 2.1 percent
· Potential percent change in NEQ = 9.4 percent
· Potential percent change in diversity = 10.7 percent
In short, the successful treatment of the problems identified would result in about a 10 percent increase in salmon abundance in the basin.
The diagnosis is typically completed for all stream reaches analyzed in the basin of interest. The results of the diagnosis allow us to identify the problem, its location and effect on survival (by life stage), and the resulting increase in survival from the elimination of the problem. In addition, the diagnosis also provides us with the ability to prioritize reaches for treatment. The information needed to prioritize reaches is shown in Figure IV.A.8 under the following headings: Productivity Rank, Average Abundance Rank, and Life History Diversity Rank. In this example, the lower river received an abundance rating of 5, a diversity rating of 11, and a productivity rating of 13. In other words, there are only four reaches in the basin where effective treatments result in larger increases in abundancy; 10 that see larger increases in diversity; and 12 for productivity. Any proposed fish enhancement plan for the basin should emphasize and prioritize treatments in the highest ranked reaches. Such an approach would result in a program that is more effective from both a biological and cost perspective.
The major point the reader should come away with from this discussion is that the diagnosis is the key component required for developing effective fish recovery and enhancement strategies in any basin. It is in the diagnosis phase that the environmental problems are identified, ranked according to their impact on salmon survival, and prioritized for treatment. The diagnosis is the tool used for focusing our actions on improving the key environmental attributes driving biological performance in the basin. The change in these key environmental attributes then become the biological objectives to be monitored over time for quantifying the effectiveness of our actions.
Although a diagnosis was not performed as part of this analysis, it is envisioned that it will be completed in the last stage of the Framework process: subbasin planning. In the absence of a detailed diagnosis, the discussion presented in the model results section will focus primarily on outcomes at the basin and province scales and not at the subbasin level.
As noted previously, we assumed that the data incorporated into this analysis were sufficient for estimating fish performance at the basin and province levels. To confirm this assumption, we compared EDT model results of chinook production for the Current Potential (Moderate worldview) with chinook counts at Bonneville, Priest Rapids, and Ice Harbor Dams for the years 1988-1997 (ODFW and WDFW 1998). The results of this comparison analysis are shown in Figure IV.A.9, Figure IV.A.10, and Figure IV.A.11.
The comparison analysis shows that EDT chinook estimates for the Current Potential fell within the 10-year range at all three projects. EDT estimates of the number of chinook arriving at Ice Harbor Dam were at the upper end of the dam count data. These results were deemed reasonable given the quality of the data available for the coarse screening analysis, the assumptions inherent in the analysis, and the fact that data quality will be improved as the Framework process proceeds to the next two stages of the analysis: Assessment and Subbasin Planning.
Once we determined that the results obtained for the Current Potential were reasonable, we used these as the basis for developing the alternatives and calibrating the worldview model runs (Methods). It should be emphasized that the EDT model results presented from this point forward will not include ocean or mainstem harvest effects on adult returns unless otherwise noted. This step was required in order to make the results for all conditions (Historic Potential, Current Potential, and Alternatives 2, 5, and 6) comparable. This is especially true when comparing alternatives to the Historic Potential, which represents historical conditions prior to European influence (i.e., no or limited ocean harvest). Again, all model results represent an estimate of chinook production with the elimination of all human harvest effects.
Future Phases of The Framework Process—Assessment and Subbasin Planning
The validation discussion above shows that the accuracy of EDT estimates of chinook production varies dependent on the dam’s location in the basin, which corresponds to different provinces (Figure IV.A.9, Figure IV.A.10, Figure IV.A.11).
This outcome was expected and planned for in the Framework process. The developers of the Framework envisioned that the analysis would be undertaken in a series of steps wherein each step the quality of the data would be improved. The steps identified were Step 1–Derived Data, Step 2–Course Screening, Step 3–Assessment, and Step 4-Subbasin Planning (Figure IV.A.12). The results presented in this report are for Step-2 Course Screening and should be treated as if the analysis were 50 percent complete.
In the Assessment phase of the process, we envision that the data used in this analysis will be refined at a finer geographic scale within the subbasins. The improved data quality will provide regional managers with an understanding of the core problems within the subbasins and watersheds. The Assessment phase will therefore provide decision-makers with the ability to prioritize watersheds for more detailed assessments at the watershed scale. These more detailed assessments will be undertaken during the Subbasin Planning phase of the analysis.
We anticipate that data quality will improve substantially during Subbasin Planning, as biologists with local knowledge and expertise fill in missing Level 2 attributes, confirm attribute ratings, and adjust ratings based on site-specific data at the stream reach level. Once the data have been updated, biologists would then perform the diagnosis to determine basin ills and develop the treatments needed to effectively cure these ills.
To determine the level of chinook production possible in the basin, we need an estimate of the Historic Potential—the assumption being that the basin, as a whole, cannot sustain natural production levels higher than what occurred historically. Because there is a great deal of uncertainty inherent in any exercise attempting to estimate fish abundance over 150 years ago, we used the assumptions present in the three worldviews to develop a range of possible historic chinook production levels (Figure IV.A.13 and Figure IV.A.14).
The data in Figure IV.A.13 show that the Historical Potential production of the basin could range from a low of 2.0 million under the Technology Optimistic worldview to 4.6 million for the Technology Pessimistic worldview. In general, under all worldviews total chinook production consisted of approximately 50 percent falls, 33 percent summer/falls, and 17 percent springs.
For the historical analysis, we modeled only those stream reaches downstream of Chief Joseph Dam (Columbia River) and Hells Canyon Dam (Snake River) approximately 5,540 total stream miles.
Thus, the abundance estimates do not include stream reaches above these fish blockages.
The difference between the worldview abundance estimates lies in the assumptions inherent in each. In the Technology Pessimistic view of the world, both freshwater and ocean habitats are assumed to be much more productive than they are in the Technology Optimistic worldview. This difference is important because it defines the overall production potential of the basin, relationship between current and historic run size, and expected improvement in chinook production possible from the implementation of the three analysis alternatives. The Historic Potential defines what is possible to achieve through future actions. The bigger the difference between Historic and Current Potentials, the greater the opportunity for improvement.
Historic Potential chinook productivity and life history diversity under the three worldview assumptions are shown in Table IV.A.2. As you can see from the data presented in this table, productivity is highest under the Technology Pessimistic worldview, and lowest for the Technology Optimistic. Life history diversity is the same for all worldviews (i.e., 100 percent), meaning that the full range of life history patterns modeled was possible under the Historic Potential.
Productivity is important because it is a measure of the ability of a species to rebound when population size is reduced. The very high productivity values shown for the Technology Pessimistic worldview indicate that chinook populations would respond rapidly as we improve habitat conditions throughout the basin. In contrast, the lower productivity values associated with the Technology Optimistic worldview indicate that fish response to similar actions would be more gradual. The time component is important for determining how many years may be needed to observe or directly measure the effects our actions have on chinook performance. Future research and monitoring programs focused on determining the effectiveness of proposed actions would therefore need to consider the element of time in their design.
Life history diversity is important because it represents the multitude of pathways through space and time available to, and used by, a species in completing its life cycle. Populations that can sustain a wide variety of life history patterns are likely to be more resilient to environmental change. Diverse life history patterns dampen the risk of extinction or reduced production in fluctuating environments (den Boer 1968).
The information presented in this section described a possible range of historic chinook performance for the Columbia River basin under different worldviews. In the next section we describe how historic chinook production varied in the five provinces analyzed.
We developed estimates of chinook Historic Potential
performance for five Columbia River Basin provinces (Figure
IV.A.15). The
Columbia Gorge, Columbia Plateau, Columbia Cascade, Blue Mountains and Mountain
Snake Modeling results are summarized by province, race, and worldview in
Table IV.A.3. Because the discussion points presented above for the basin level
analysis also apply at the province level, they are not repeated here. Instead,
we use the data in Table IV.A.3 for the Moderate worldview to quickly summarize
the key results.
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The key biological performance results for the Historic Potential province analysis (under the Moderate worldview) are as follows: · Total historical abundance potential of chinook in the Columbia River Basin is highest in the Columbia Plateau (57 percent) and lowest in the Columbia Gorge (three percent) · The Columbia Plateau has the highest level of historical spring chinook abundance at 39 percent, with the least amount of production occurring in the Columbia Gorge (six percent) · Summer/fall chinook abundance is greatest in the Columbia Cascade (51 percent) and lowest in the Blue Mountain (three percent). · Historical fall chinook abundance is highest in the Columbia Plateau (86 percent) and lowest in the Columbia Gorge (four percent). · Similar to the basin analysis, productivity estimates vary by worldview, with Technology Pessimistic producing the highest values. |
Now that we have presented what we believe to be the range of possible Historical Potential chinook production for the basin, the next step in the analysis is to describe what the Current Potential production of the basin is today.
As was the case with the Historic Potential analysis, there is considerable uncertainty regarding the Current Potential chinook production of the Columbia River Basin. There are two schools of thought on this topic, which we refer to as the Technology Pessimistic and the Technology Optimistic worldviews. Under the first worldview, current freshwater habitat conditions are poor in comparison to the historic conditions. The degradation in habitat is a direct result of human impacts. The Technology Optimistic worldview on the other hand states that the human effects on habitat is less severe and that Historical Potential chinook production in the basin was much lower (i.e., 2.0 million versus 4.6 million).
To account for this uncertainty, we used the assumptions
present in the worldviews to estimate a range for the current production
potential (Current Potential) of the basin. In this section the results of this
analysis are presented at the basin, province, and ESU levels.
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In estimating a range for the Current Potential: 1. Abundance numbers represent the number of adult chinook surviving to the spawning life stage. Thus, any mortality due to mainstem dam passage and pre-spawning mortality has already been subtracted from the totals. 2. The Current Potential represents the number of adults that can be produced under current habitat, hatchery, and hydro conditions and operations. 3. Ocean and Columbia River mainstem fisheries have been eliminated in all model runs. Model results are therefore an estimate of the number of adult chinook expected to return with the elimination of harvest. The removal of harvest was needed in order to make a more valid comparison between Historic Potential (no harvest) and Current Potential. 4. The adult data presented in the tables are classified into two groups: natural and hatchery. The natural group consists of both wild and hatchery fish that spawn in the wild. 5. Life history diversity and productivity values apply only to natural populations. |
Figure IV.A.16 shows the impact of eliminating harvest on the number of hatchery chinook adults returning to the basin. As you can see from this figure, eliminating harvest increases the number of adults returning to the basin, and the level of increase is dependent on the worldview. Again, in order to make a fair comparison between the Historic Potential and Current Potential of the basin, harvest has been eliminated from the analysis.
Columbia River Basin Scale Analysis
Estimates of Current Potential chinook hatchery and natural production for the basin under each worldview are summarized in Table IV.A.4 and shown graphically in Figure IV.A.17. The data in Figure IV.A.17 indicate that, Figure IV.A.16. Total number of hatchery chinook salmon returning to the river, with and without ocean and mainstem harvest.
Dependent on worldview, total chinook production potential ranges from approximately 206,000 to 340,000. Natural chinook represent between 127,000 (~62 percent) and 150,000 (~44 percent) of total production for the Technology Pessimistic and Optimistic worldviews, respectively. For these same worldviews hatchery fish constitute 38 percent (79,000) and 56 percent (190,000) of all chinook production, respectively. These results are consistent with the assumptions inherent in each worldview, i.e., hatchery fish do better under the Technology Optimistic set of assumptions than under the Technology Pessimistic set.
In Figure IV.A.18 we show Current Potential chinook production of the basin relative to the Historic Potential. This comparison shows that regardless of the worldview examined, current chinook abundance is less than ~17 percent of Historic Potential.
Note that the Historic Potential is different for the three worldviews. The Technology Pessimist estimates Current Potential at four percent of a larger number, and the Technology Optimist sees it as 17 percent of a smaller number.
These results were expected, as the analysis was undertaken in order to develop an effective approach for recovering chinook populations whose numbers are so low that they have been listed under the Endangered Species Act (ESA). We present and discuss model results by ESU later in this report.
Chinook productivity has also decreased substantially from the Historic Potential (Table IV.A.4). For example, spring chinook productivity under the Moderate worldview historically ranged from approximately 22 to 28, now it ranges from three to nine dependent on province (Moderate assumptions). The reduction in productivity means that chinook populations would recover more slowly when population abundance is reduced. Actions that increase productivity would therefore decrease the amount of time required for chinook populations to meet recovery objectives.
The life history diversity index value for summer/fall, fall, and spring chinook have dropped from an unweighted average of about 100 percent, to 33 percent, 37 percent and 61 percent, respectively (Table IV.A.4- Moderate). The large drop in life history diversity makes these populations less resilient to environmental change, thereby increasing their risk of extinction. Actions designed to increase life history diversity would help to reduce this extinction risk.
In Table IV.A.4 the reader will also see data presented on the number of fish populations present in the basin today. These data indicate that a number of populations are no longer present under the Current Potential. Under the Moderate worldview set of assumptions the number of populations have been reduced from 65 under the Historic Potential to 48 under the Current Potential. These data do not necessarily indicate the loss of a unique stock, but instead reflect a decrease in fish distribution and habitat. For example, due to the construction of the Pelton Round Butte Hydroelectric Complex (Deschutes River, OR), spring chinook no longer have access to the Crooked River and Metolius River. Modeling results therefore show a loss of two populations in the Deschutes River Basin (Columbia Plateau province).
The results presented in this section show that current chinook abundance, productivity, population numbers, and life history diversity in the Columbia River Basin have been severely reduced in comparison to the Historic Potential. In the section below we describe how chinook performance has changed over time in the five provinces.
Modeling results for each of the five provinces are also summarized in Table IV.A.4. Because the discussion points presented above for the basin level analysis also apply at the province level, they are not repeated here. Instead, we simply use the Moderate assumption data in Table IV.A.4 to quickly summarize the key biological performance results obtained at the province scale.
The change from historical for each of the environmental attributes modeled is presented in Table IV.A.5. The data in Table IV.A.5 represent the number of instances (data points) where the current value for the attribute exceeds the historical value. For example, there were 90 instances where the bed scour attribute was rated worse than historic conditions in the Blue Mountain province.
The environmental attributes affect tributary freshwater habitat productivity[2]. It should be noted that the habitat environmental attributes were not included in this table, as a change in habitat diversity may have either positive or negative effects on chinook performance. Additionally, you will note that there is no data for some of the attributes listed in Table IV.A.5. This is due to the fact that there was no or little difference between the Current Potential and the alternatives (icing), or that the attribute has yet to be rated (e.g. fish pathogens).
The resulting change in tributary freshwater habitat from the Historic Potential to the Current Potential for each province is presented in Table IV.A.6. The freshwater productivity index values presented in the table represent the average number of yearling juveniles (per 1,000 eggs) that would survive to the smolt stage with the removal of all density dependent survival factors.
The key results embedded in this table are presented below in bullet format. Unless otherwise noted, the discussion is based on the results presented for the Moderate worldview.
· For Historic Potential the highest quality freshwater habitat was found in the Mountain Snake, followed by the Columbia Cascade, Blue Mountain, Columbia Plateau, and Columbia Gorge.
· In contrast, the highest quality habitat for the Current Potential is present in the Mountain Snake, followed by the Columbia Gorge, Columbia Cascade, Blue Mountain, and finally the Columbia Plateau.
· Freshwater habitat productivity values for the provinces are currently 20 percent-60 percent of their Historic Potential.
The data in Table IV.A.6 indicate that actions tied to improving habitat conditions in the tributaries have the potential to improve productivity significantly.
The five Evolutionary Significant Units (ESUs) included in this analysis are identified in Table IV.A.7. Modeling results for each of the five ESUs are summarized in Table IV.A.8. Because the discussion points presented above for the basin level analysis also apply at the ESU level, they are not repeated here. Instead, we use the data in Table IV.A.8 to quickly summarize the key biological performance results obtained at the ESU scale.
Differences among ESUs in the patterns of change from
Historic Potential suggest different sensitivities and/or causes of decline
among ESUs.
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The historic potential abundance by ESU is shown in Figure IV.A.19. The key biological performance results for the Current Potential ESU analysis are as follows: · All ESUs have been reduced to less than 10 percent of Historic Potential abundance. · ESU-14 has experienced the greatest loss of abundance potential – it is currently at only one percent of Historic Potential. · Current Potential productivity ranges from 11 percent of Historic Potential for ESU-13 to 30 percent for ESU-12. · Life history diversity ranges from a high of 84 percent of Historic Potential for ESU-13 to 16 percent for ESU-14. |
EDT modeling results for Alternative 2 are presented in this section. Results are described at the basin, province, and ESU geographic scales. We also use the Framework graph presented earlier in this report to show the linkage between Alternative 2 actions, environmental attributes, and biological performance.
For review purposes we have listed below the major actions included in Alternative 2 to improve chinook performance in the basin. These actions are as follows:
1. The breeching of John Day and the four lower Snake River hydroelectric projects.
2. Implement hatchery supplementation program and improved hatchery rearing techniques to increase the quantity and quality of fish returning to the basin.
3. A moderate improvement in freshwater tributary habitat—habitat actions were applied with equal intensity on both public (2) and private lands (2).
4. As is the case with all alternatives, ocean and mainstem harvest has been eliminated in Alternative 2.
The effect that the combined actions had on the environmental attributes and the resulting biological performance (chinook abundance) is shown graphically in Figure IV.A.20. The values in the environmental attributes table represent the percent improvement over Current Potential resulting from the implementation of the alternative. The biological performance figure shows the percent improvement in natural chinook abundance for all races combined. The percent values presented by race show the proportion that each contributed to the entire total. The reader should be aware that the Hydro and Hatchery related environmental attributes were not included in this chart due to space constraints. However, the change in these attributes does have an effect on resulting biological performance for each alternative. In a later section of this report we will identify these attributes and show how they could be used in establishing biological objectives for each alternative.
The increase in freshwater habitat productivity under this alternative is shown in Table IV.A.9. The percent change in freshwater productivity over current (Moderate) varied from 25 percent for the Mountain Snake to ~112 percent in the Columbia Plateau. For all provinces combined, freshwater productivity increased by an average of ~61 percent. Whether or not Alternative 2 habitat actions would actually achieve this level of improvement would be dependent on the region’s ability to successfully implement the actions and their eventual effectiveness.
However, the reader should note that the environmental data driving these productivity values would be reviewed for accuracy during the assessment and subbasin planning phases of the Framework process. The incorporation of more accurate data may change estimates of resulting productivity significantly.
In Table IV.A.10 we present a summary of modeling results for Alternative 2. The data in this table include information on abundance, productivity, life history diversity, number of natural and hatchery fish, and number of populations[3].
Alternative 2 is expected to increase chinook abundance over the Current Potential from 164 percent to 381 percent dependent on the true state-of-nature (worldview) (Figure IV.A.21). This alternative provides the greatest increase under the Technology Pessimistic worldview and the least amount of change under the Technology Optimistic set of assumptions.
The percent change from current for both natural and hatchery production for this alternative is shown in Figure IV.A.22. The data in this figure indicate that natural production increases from 219 percent to 494 percent, hatchery production from 120 percent to 197 percent, dependent on worldview.
The proportion of natural and hatchery fish produced for each
worldview is presented in Figure
IV.A.23. Note that the proportion of hatchery
fish increase in the Technology Optimistic worldview due primarily about the
assumption regarding hatchery fish fitness and post-release survival.
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Alternative 2 performs best when the following assumptions about the state-of-nature are correct: · The current juvenile transportation program is ineffective, · Current in-river juvenile migration survival rates are low, · Freshwater habitat degradation is high, · Hatchery fish fitness is low, and · Ocean survival rates are high. |
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The key biological performance results for the Alternative 2 province analysis are as follows: · The largest increase over current for natural chinook abundance potential occurs in the Blue Mountain province (665 percent). Although all actions inherent in the alternative affect total abundance, the majority of the increase can be attributed to the dam removal strategy. · Natural production increases the least in the Columbia Cascade (139 percent). This result is not surprising as many of the actions inherent in this alternative (e.g., dam removal) were designed to help Snake River chinook. · The largest increase in hatchery fish abundance occurs in the Blue Mountain (249 percent) followed closely by the Columbia Cascade (242 percent). · Alternative 2 increases chinook productivity in all provinces for all races. The largest increase in productivity occurs for spring chinook populations in the Mountain Snake (193 percent) the lowest for fall chinook in the Columbia Plateau (two percent) · Life history diversity also increases in each province for all races. The Columbia Plateau life history diversity value for summer/fall chinook shows the greatest increase moving from a nine percent value under the Current Potential to ~66 percent. · The number of viable populations increases from 48 under the Current Potential to 60. |
Chinook productivity under this alternative increases by the amounts shown in Figure IV.A.24. These data indicate that average (weighted) spring chinook productivity increases from 70 percent to 106 percent, summer chinook from 75 percent to 157 percent, and fall chinook by six percent to 10 percent dependent on worldview. The small increase in fall chinook productivity results from the large influence the already productive Columbia Plateau population (Hanford Reach) has on model results. Of the ~303,000 natural fall chinook produced under this alternative, 262,000 are produced in this province. Again, increased productivity would improve the species’ ability to rebound when population size is reduced to low numbers.
The life history values for each race and worldview are also presented in Table IV.A.10. Overall, spring, summer and fall chinook diversity values increased dramatically for most provinces and worldviews. Populations that can sustain a wide variety of life history patterns are likely to be more resilient to environmental change, which in turn should reduce their risk of extinction.
Under Alternative 2 the number of viable populations, in comparison to the current, increases by 12 to 14. For example, for the Moderate worldview spring, summer, and fall population numbers increase by five, three, and four respectively. As was noted previously in the discussion on Current Potential model results, the increase in viable populations generally results from an increase in range or habitat usage as new habitat becomes available from actions such as dam removal.
Modeling results for each of the five provinces are also summarized in Table IV.A.10 by race and worldview. Because the major points presented for the basin level analysis also apply at the province level, they are not repeated here. Instead we use a series of tables and figures to highlight the key biological performance results obtained at the province scale (Figure IV.A.25 and Table IV.A.11). Unless otherwise noted, the discussion will revolve around model results for the Moderate worldview. We will compare worldview modeling results for this and the other alternatives when we discuss uncertainty later in the report.
The results presented in this section indicate that
Alternative 2 increased chinook abundance, productivity, and life history
diversity substantially in all provinces modeled. We next examine how chinook
performance changes under this alternative at the ESU level.
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The key biological performance results for the Alternative 2 ESU analysis are as follows: · All ESUs improve significantly in abundance, productivity and life history diversity. · ESU-15 sees the greatest improvement, recovering 31 percent of the lost abundance potential, and 27 percent of the productivity loss. · ESU-12 benefits less than the other ESUs under Alternative 2, with less than 10 percent recovery of abundance and productivity losses. |
Modeling results for each of the five ESUs are also summarized in Table IV.A.12. Data in this table represent the percent of chinook production loss recovered by ESU for Alternative 2. By loss we mean the difference between Historic Potential and Current Potential described in the previous section. Because the major points presented for the basin level analysis also apply at the ESU level, they are not repeated here. Instead we use a series of tables and figures to highlight the key biological performance results obtained at the ESU scale. Unless otherwise noted, the discussion will revolve around model results for the Moderate worldview. We will compare worldview modeling results for this and the other alternatives when we discuss uncertainty later in the report.
The results presented in this section indicate that Alternative 2 increases chinook abundance, productivity, and life history diversity substantially in all ESUs modeled.
EDT modeling results for Alternative 5 are presented in this section. Results are described at the basin, province, and ESU geographic scales. We also use the Framework graph presented earlier in this report to show the linkage between Alternative 5 actions, environmental attributes, and biological performance.
For review purposes we have listed below the major actions included in Alternative 5 to improve chinook performance in the basin. These actions are as follows:
· Eliminate juvenile transportation program during the spring and early summer juvenile migration period.
· Increase mainstem Columbia River average spring and summer flows by as much as 12 percent.
· Increase juvenile in-river survival through the addition of state-of-the-art surface collection/bypass systems at mainstem projects and increased spill.
· Use hatchery supplementation and improved hatchery facilities and rearing practices to increase the quantity and quality of fish returning to the basin.
· Improve freshwater habitat on both public and private lands. Habitat actions were assigned an intensity value of 2 for private lands, and a 3 on public lands.
As is the case with all alternatives, eliminate ocean and mainstem harvest.
The effect that the combined actions in Alternative 5 had on the environmental attributes and natural chinook biological performance is shown graphically in Figure IV.A.26. The values in the environmental attributes table in this figure represent the percent improvement over Current Potential. The biological performance chart shows the percent improvement in natural chinook abundance for all races combined. The percent values presented for each show the proportion that each race contributed to the entire total.
The reader should be aware that the Hydrology and Hatchery related environmental attributes were not included in this chart due to space constraints. However, the change in these attributes does have an effect on resulting biological performance for this and other alternatives. In a later section of this report we will identify these attributes and show how they could be used in establishing biological objectives for each alternative.
The increase in freshwater habitat productivity under this alternative is shown in Table IV.A.14. The percent change in freshwater productivity over current (Moderate) varied from 31 percent for the Mountain Snake to ~134 percent in the Columbia Plateau. For all provinces combined, freshwater productivity increased by an average of ~61 percent[4]. Whether or not alternative 5 habitat actions would actually achieve this level of improvement would be dependent on the region’s ability to successfully implement the actions and their eventual effectiveness. However, the reader should note that the environmental data driving these productivity values would be reviewed for accuracy during the assessment and subbasin planning phases of the Framework process. The incorporation of more accurate data may change estimates of resulting freshwater habitat productivity significantly.
In Table IV.A.14 we present a summary of modeling results for Alternative 5. The data in this table include information on chinook abundance, productivity, life history diversity, number of natural and hatchery fish, and number of populations[5].
Alternative 5 is expected to increase chinook abundance over Current Potential from 114 percent to 216 percent dependent on the worldview examined (Figure IV.A.27). This alternative provides the greatest increase under the Technology Pessimistic worldview and the least amount of change under the Technology Optimistic set of assumptions.
The percent change from current for both natural and hatchery production for this alternative is shown in Figure IV.A.28. The data in this figure indicate that natural production increases from 90 percent to 245 percent and hatchery production from 133 percent to 167 percent.
The proportion of natural and hatchery fish produced for each worldview is presented in Figure IV.A.29. Note that the hatchery fish component increases as the worldviews change from Technology Pessimistic to Technology Optimistic. This increase is a direct result of the higher hatchery post-release survival assumptions used in the Moderate and Technology Optimistic worldviews. For example, the post-release survival values used for hatchery fish under the Technology Pessimistic, Moderate and Technology Optimistic worldviews are 15 percent, 30 percent and 60 percent, respectively[6].
Chinook productivity under this alternative increases by the amounts shown in Figure IV.A.30. These data indicate that average (weighted) spring chinook productivity changes from 43 percent to 77 percent, summer chinook from 32 percent to 76 percent, and fall chinook by -1 percent to four percent depending on the worldview.
The life history values for each race and worldview are also presented in Table IV.A.14. Overall, spring, summer and fall chinook diversity values increased for all provinces under all worldviews. Populations that can sustain a wide variety of life history patterns are likely to be more resilient to environmental change, which in turn should reduce their risk of extinction.
Under Alternative 5 the number of viable populations, in comparison to the current, increases from 48 to 58 (Table IV.A.14-Moderate). The majority of the population gains come from the Columbia Plateau province.
Now that we have seen how Alternative 5 affected chinook production at the basin level we next to see how each of the provinces fared.
Alternative 5 Modeling results for each of the five provinces are summarized in Table IV.A.14 by race and worldview. Because the major points presented for the basin level analysis also apply at the province level, they are not repeated here. Instead we use a series of tables and figures to highlight the key biological performance results obtained at the province scale. Unless otherwise noted, the discussion will revolve around model results for the Moderate worldview.
The results presented in this section indicate that Alternative 5 increased chinook abundance, productivity, and life history diversity substantially for most provinces and races modeled. We next examine how chinook performance changes under this alternative at the ESU level (Figure IV.A.31, Table IV.A.15).
Modeling results for each of the five ESUs are summarized in Table
IV.A.16. Data in this table represents chinook response to the actions of
Alternative 5 as the percent of the loss recovered. By loss we mean the
difference between Historic Potential and Current Potential described in the
previous section. Because the major points presented for the basin level
analysis also apply at the ESU level, they are not repeated here.
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The key biological performance results for the Alternative 5 ESU analysis are as follows: · All ESUs increase in abundance under Alternative 5. · ESU-11 sees the greatest improvements, recovering 24 percent of abundance losses and 20 percent of productivity losses. · ESU-12 improves in abundance, but decreases in productivity. The reason for this is that as previously unsustainable life history pathways are restored, the mean productivity of the ESU as a whole decreases slightly. |
EDT modeling results for the Alternative 6 are presented below. Results are described at the basin, province, and ESU geographic scales. We also use the Framework graph presented earlier in this report to show the linkage between Alternative 6 actions, environmental attributes, and biological performance.
For review purposes we have listed below the major actions included in Alternative 6 to improve chinook performance in the basin. These actions are as follows:
· Maximize juvenile transportation for both spring and summer migrants
· Reduce spring flows; increase summer flows
· Eliminate spill when river conditions permit at all juvenile collector projects
· Improve freshwater habitat on both public and private lands. Habitat actions were assigned an intensity value of 1 for private lands, a 3 for public lands
· Use hatchery supplementation and improved hatchery facilities and rearing practices to increase the quality of the fish released.
·
As is the case in all alternatives, ocean and mainstem
harvest was eliminated for analysis purposes.
The effect the combined actions in Alternative 6 had on the environmental attributes and chinook biological performance is shown graphically in Figure IV.A.32. The values in the environmental attributes table in this figure represent the percent improvement over the Current Potential. The biological performance chart shows the percent improvement in natural chinook abundance for all races combined. The percent values presented for each show the proportion each race contributed to the entire total. The reader should be aware that the Hydro and Hatchery related environmental attributes were not included in this chart due to space constraints. However, the change in these attributes does have an effect on resulting biological performance for this and other alternatives. In a later section of this report we will identify these attributes and show how they could be used in establishing biological objectives for each alternative.
The increase in freshwater habitat productivity under this alternative is shown in Table IV.A.17. The percent change in freshwater productivity over current (Moderate) varied from 26 percent for the Mountain Snake to ~82 percent in the Columbia Plateau. For all provinces combined, freshwater productivity increased by an average of ~44 percent[7].
Whether or not Alternative 6 habitat actions would actually achieve this level of improvement would be dependent on the region’s ability to successfully implement the actions and their eventual effectiveness. However, the reader should note that the environmental data driving these productivity values would be reviewed for accuracy during the assessment and subbasin planning phases of the Framework process. The incorporation of more Framework process incorporation of more accurate data may change estimates of freshwater habitat productivity significantly.
In Table IV.A.18 we present a summary of modeling results for Alternative 6. The data in this table include information on chinook abundance, productivity, life history diversity, number of natural and hatchery fish, and number of populations[8].
Alternative 6 is expected to increase chinook abundance over current from 107 percent to 122 percent dependent on the worldview examined (Figure IV.A.33). This alternative provides the greatest increase under the Technology Optimistic worldview and the least amount of change under the Technology Pessimistic set of assumptions.
The percent change from current for both natural and hatchery production for this alternative is shown in Figure IV.A.34. The data in this figure indicate that natural production increases from 69 percent to 89 percent and hatchery production from 133 percent to 164 percent.
The proportion of natural and hatchery fish produced for each
worldview is presented in Figure
IV.A.35. Note that the hatchery fish component
increases as the worldviews change from Technology Pessimistic to Technology
Optimistic. This increase is a direct result of the higher hatchery
post-release survival assumptions used in the Moderate and Technology
Optimistic worldviews. For example, the post-release survival values used for
hatchery fish under the Technology Pessimistic, Moderate and Technology
Optimistic worldviews are 15 percent, 25 percent and 60 percent, respectively[9].
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Alternative 6 performs best relative to the others when the following assumption about the state-of-nature are correct: · The current juvenile transportation program is effective, · Current in-river juvenile migration survival rates are high, · Freshwater habitat degradation is low, · Hatchery fish fitness is high, and · Ocean survival rates are low. |
Chinook productivity under this alternative increases by the amounts shown in Figure IV.A.36. These data indicate that average (weighted) spring chinook productivity changes from 39 percent to 70 percent, summer chinook from 18 percent to 30 percent, and fall chinook from one percent to negative five percent, depending on worldview.
The life history values for each race and worldview are also presented in Table IV.A.18. Overall, spring, summer and fall chinook diversity values increased for all provinces under all worldviews. Populations that can sustain a wide variety of life history patterns are likely to be more resilient to environmental change, which in turn should reduce their risk of extinction.
Under Alternative 6 the number of viable populations, in comparison to the current, increases from 48 to 57 (Table IV.A.18). The majority of the population gains come from the Columbia Plateau province.
Now that we have seen how Alternative 6 affected chinook production at the basin level we next to see how each of the provinces fared.
Alternative 6 Modeling results for each of the five provinces are summarized in Table IV.A.18 by race and worldview. Because the major points presented for the basin level analysis also apply at the province level, they are not repeated here. Instead we use a series of tables and figures (Figure IV.A.37 and Table IV.A.19) to highlight the key biological performance results obtained at the province scale. Unless otherwise noted, the discussion will revolve around model results for the Moderate worldview. We will spend more time highlighting the differences in worldviews for each alternative in the uncertainty section of this report.
The results presented in this section indicate that Alternative 6 increased chinook abundance, productivity, and life history diversity substantially for most provinces and races modeled. We next examine how chinook performance changes under this alternative at the ESU level.
Modeling results for each of the five ESUs are summarized in
Table IV.A.20. Data in this table represent the percent of chinook production
loss recovered by ESU for Alternative 6. By loss we mean the difference between
Historic Potential and Current Potential described in the previous section.
Because the major points presented for the basin level analysis also apply at
the ESU level, they are not repeated here. Instead we use a series of tables
and figures to highlight the key biological performance results obtained at the
ESU scale. Unless otherwise noted, the discussion will revolve around model
results for the Moderate worldview. We will compare worldview-modeling results
for this and the other alternatives when we discuss uncertainty later in the
report.
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The key biological performance results for the Alternative 6 ESU analysis are as follows: · ESUs 11,14, and 15 increase in abundance and productivity under Alternative 6. · ESU-12 sees little or no improvement under Alternative 6. · ESU-11 benefits the most among the ESUs, recovering 15 percent of lost abundance potential and 12 percent of the productivity loss. |
Relative to the other alternatives analyzed, Alternative 6 provides relatively limited benefits under the Moderate worldview. If the Technology Optimistic worldview better represents the true state of nature, then Alternative 6 will compare much more favorably with the other alternatives. There is further discussion about the consequences of uncertainty about the true state of nature in the uncertainty section below.
[1] The data for the Current and three alternatives are based on the Moderate set of analysis assumptions.
[2] Because of the presence of dams in the mainstem Columbia and Snake Rivers, mainstem habitat was treated (rated) differently than tributary habitat. Juvenile and adult survival through the mainstem was based on NMFS and PATH survival data, flow and juvenile travel time relationships, and predation information.
[3] Population numbers increase either when actions in the alternative allow fish access to previously blocked habitat (extends range) or when an existing population’s productivity value exceeds 1.0.
[4] This is an unweighted average for all provinces combined.
[5] Population numbers increase either when actions in the alternative allow fish access to previously blocked habitat (extends range) or when an existing population’s productivity value exceeds 1.0.
[6] These post-release survival values are for hatchery fish reared using innovative hatchery practices.
[7] This is an unweighted average for all provinces combined.
[8] Population numbers increase either when actions in the alternative allow fish access to previously blocked habitat (extends range) or when an existing population’s productivity value exceeds 1.0.
[9] These post-release survival values are for hatchery fish reared using innovative hatchery practices.