MEMORANDUM 

September 18, 2009 

To: Glen Canyon Dam Adaptive Management Program - Technical Work Group 

From: Matthew E. Andersen, Biology Program Manager 

Subject: Fall Steady Flows Science Plan 

We are in receipt of comments on the subject plan prepared by four different agencies (Grand 

Canyon National Park, Bureau of Reclamation, Arizona Game and Fish Department, and 

Western Area Power Administration). A number of individual reviewers obviously reviewed the 

document carefully and provided many constructive comments. We appreciate their efforts and 

have endeavored to be as responsive as we can to their suggestions and requests. 

We received some comments asking us for more efforts to integrate results from the projects 

described in the plan. We think that there are some meaningful lines of integration that should be 

pursued and so will try to highlight those in the next iteration of the plan. Perhaps the most 

important example of integration is a project that is not discussed in this plan: the ecosystem 

modeling project described in the FY 2010-11 work plan ((R12.P1.10). We expect this to be a 

valuable effort and encourage reviewers and stakeholders interested in this issue to review that 

project in the work plan. 

Some reviewer comments requested that the document include a focus on hypothesis testing. We 

believe that making changes to the document to include hypothesis testing is unnecessary. 

Further, refutation of hypotheses might not be achievable given the limited time frame of the 

experiments. We (or others) could likely develop many alternative hypotheses to be tested, but it 

is not obvious what would be gained. We believe that the presentation of monitoring results by 

indicating the likelihood of one alternative or another is much more reflective of natural 

variability, and therefore more useful to scientists, managers, and decision-makers. We believe 

that it will be better to monitor the results in a way that seeks to observe and describe 

complicated responses rather than just seeking resolution of binary alternatives. 

One comment we received, in particular, we found difficult to respond to because it was vague 

and unnecessarily long, reviewing some of the history of flow experiments. Our emphasis in 

using this table format is to encourage reviewers to focus comments on what they believe is 

United States Department of the Interior 

U.S. GEOLOGICAL SURVEY

SOUTHWEST BIOLOGICAL SCIENCE CENTER

GRAND CANYON MONITORING AND RESEARCH CENTER

2255 NORTH GEMINI DRIVE, MS-9394 

FLAGSTAFF, ARIZONA 86001

928 556-7094 Telephone

928 556-7092 Fax
2

wrong with the document (not what they think is wrong with other program aspects) and 

suggesting how we might alleviate their concern. When reviewers don’t provide a concise 

comment, and ideally a suggested response, it is difficult for us to provide a concise response. 

We can bring this comment up for discussion in the TWG meeting for additional review, if 

desired. 

One reviewer suggested that we send a revised document to the Science Advisors for another 

review by that body. A second review is outside of the scope of the protocol for the Science 

Advisors who are already quite limited in their review activities by both time and budget 

constraints. We believe that the current revision is responsive to the Science Advisors and so a 

second review by them is unnecessary. If the TWG continues to find they have concerns over the 

plan we recommend additional consultation between TWG and GCMRC, rather than seeking to 

involve a third party in the debate. 

We very much appreciate the time of the agency reviewers as so many of the comments received 

were useful and are likely to help improve the document. We will endeavor to incorporate the 

comments as quickly as we can and will then distribute to TWG for another review. We look 

forward to discussing this plan with the TWG and also with one of the Near Shore Ecology 

investigators (Korman) at the next TWG meeting. 
Page 1 

Fall Steady Flows Comment Table Document Title: Study Plan: Fall steady flows Document Date: September 2, 2009

Comment 

Number 

Page Line Reviewer Name Affiliation Reviewer 

Comments (Be specific) 

Identify Action Requested 

Response Requested 

GR

1 na na Capron WAPA Line numbers. It would be helpful if the line 

numbers ran throughout the document, having them start over at 1 on each page can get confusing. 

continuous numbering 

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mi

2 na na Capron WAPA Synthesis. The document lacks a coherent synthesis 

which integrates the different lines of data in order to show how information will be used to answer critical questions (e.g., SSQs). It is of little utility to merely list the SSQs each project is related to and then leave it at that. What is missing is the description of how they will be answered and to what extent and likelihood they can be answered. What lines of evidence will be used to answer each one. It would be helpful describe these linkages in a section of its own, so that when this project is completed reviewers can then compare the results to what was expected to be completed. This would then lead to a logical progression of future recommendations. It is difficult to have any confidence that this work will lead to answers to our critical questions. A variety of data streams are being collected, but there is no synthesis of how these data will be used to test hypotheses. This plan appears to be more of a compliance document, a response to a biological opinion, and not a science plan. Missing is the criteria for success or failure and how key information will be interpreted. For example, a decision matrix could be constructed which would show how different conclusions might be integrated to support recommendations for future study (e.g., longer steady flow tests, different seasons). The ultimate question (from the biological opinion) is whether this scientific test will result in benefits to native fish (i.e., humpback chub). What 

are the key variables that will be considered to 

Add a section of text 

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determine whether impacts were likely or unlikely? 

3 na na Capron/LaGory WAPA Scientific Approach. What is generally missing 

from GCMRC science plans is a scientific approach to hypothesis testing. For example, this plan provides background information on nonnative catches, nonnative control efforts, and then talks about potential strategies. It might be beneficial for 

GCMRC to replace Dr. Coggins with a biometrician that would be available to GCMRC to construct science plans that are designed around hypothesis testing and designing plans to answer critical questions, illustrate how that will be done, and how information will be synthesized and what analytical techniques will be used to do that synthesis. The elements of the study plan are not sufficiently integrated in this plan to demonstrate that they address the effects of fall steady flows. The plan should be more clearly hypothesis driven and a description should be provided as to how each element will address these hypotheses or subsets of hypotheses. 

Modify Y W

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4 na na LaGory WAPA In general, the presentation of the SSQs, RINs, EINs, 

etc. does little to show how the proposed research will address those questions. Certainly, the proposed research will not address the questions fully, but there is no presentation of the linkage between the research and the questions. A better approach would be explicit statements of hypotheses that are being 

tested by the research. 

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tqndrAfsctc

5 na na LaGory WAPA The argument (stated on page 9) for using the same 

flow level (10,000 cfs) each year during the experiment has a number of problems associated with it. It is stated that the question of greatest interest is whether or not steady flows in the fall have a positive impact on the recruitment of juvenile humpback chub, and that using the same flow level 

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each year will greatly simplify interpretation of the information. The authors call secondary the questions regarding the degree of nearshore warming at different temperatures and habitat selection at different flows. It is likely that there will be tradeoffs between habitat availability, primary and secondary productivity, and water temperature at different flow magnitudes. There will also be uncontrollable antecedent effects resulting from the number and condition of fish at the beginning of the steady flow period each year and flow and sediment conditions earlier in each study year. It seems more important to understand how flow magnitude affects the environmental variables and relationships that affect recruitment. A number of short-term targeted experiments (e.g., flow manipulations) to help understand these relationships (e.g., habitat availability and nearshore warming at different flows) could aid in the interpretation of any observed trends in recruitment. 

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6 na na LaGory WAPA The conceptual model (Figure 3) is useful for helping 

frame the research. Bioenergetics modeling should also be considered to help focus research on those variables that are likely to have the greatest influence on humpback chub recruitment. Modeling should use appropriately conservative assumptions to determine the possible magnitude of effects. Measurements could then focus on the effects of flow on physical and biological conditions identified as most important (e.g., depth, volume, temperature, turbidity, food availability) in nearshore habitats used by young humpback chub. 

Wrpiopf

7 na na LaGory WAPA The discussion of transition flow experiments should 

focus on the questions or hypotheses being addressed. These questions will help focus the experiments to be conducted. The BO text provided on page 9 is fairly general and refers to “detrimental effects to fishes and food base for fish.” From this text it is not clear if the only effect of interest is related to food base or whether or not other effects (e.g., fish stranding, changes in habitat availability) are of interest. The discussion in the study plan 

Prdapii
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regarding examining the effects of changing from fluctuating to steady flows or providing a higher base flow at the end of August seems premature until it is better understood what questions are of interest and what if any effects are likely. Some questions can be addressed, at least to some extent, without elaborate experiments that target the transition period. Habitat availability during transitions could be examined using information on channel morphology to determine the availability of habitats at different flows and fluctuation patterns using computer simulations. It seems likely that any reduction in flow (whether fluctuating or steady) would result in a decrease in primary productivity. Any transitioning may only decrease the rate at which these changes occur. Food base measurements that are currently being made and that would be made during the steady flow period should provide the information needed without the need for any specific experimentation. 

8 na na LaGory WAPA The approach described on pages 13 and 14 outlines 

the overall study elements, but never clearly identifies what the results of the fall steady flow experiments will be compared to. 

Wcci

9 na na Palmer WAPA The Nature of the Experiment 

The experiment for which this science plan has been developed – whether low volume steady flows during the months of September and October will 

improve the abundance of HBC in the mainstem of the Colorado River in the Grand Canyon – has been viewed by some as being an experiment with a duration that is insufficiently short to make an adequate scientific determination as to the effect of steady flows on the Grand Canyon HBC population. On the other hand, in the Summer of 2000, a steady flow experiment was conducted with a six month duration. Beyond the direct research costs of approximately $4 million dollars, the experiment costs an additional $32 million in indirect costs associated with maintaining federal power contractual obligations. This prompted one Grand Canyon scientist to declare the 2000 year experiment 

Mbt
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as the most expensive field experiment on record. The result of this expensive experiment – in terms of abundance of HBC - was scientifically – mixed. Therefore, there is some sense to conducting a steady flow experiment that is intended to be less expensive and less disruptive in order to determine if steady flows from Glen Canyon Dam are worthy of further investigation. We are sympathetic with the position of some scientists that the experiment, as described by the BiOp, is less than what may be needed to draw a robust scientific conclusion regarding the relationship between HBC abundance and steady flows. We suggest instead, a science plan that includes the gathering and evaluation of data that – given the evidence – would lead an astute scientist to conclude that more steady flow experiments are likely to lead to significant improvements of numbers of HBC in the mainstem of the Grand Canyon or that they are not and given the expense of this type of operation, should be abandoned in favor of other actions that provide “more bang for the buck”. 

10 na na Palmer WAPA Transition Flows 

Based on e-mail communication between Western and Reclamation, a major consideration of transition flows is the stranding of HBC in pools that do not connect with the Colorado River at low flows. While the “stranding” issue was not mentioned in the BiOP, it appears to be a major component of the development of the transition pattern from August to September in 2009. As backwaters are relatively few in the Grand Canyon below the LCR and stranding in standing pools separated from the mainchannel is easily observable, we suggest that the science plan gather the observational data to “put this issue to bed”. This would mean identifying backwaters of interest and observing and quantifying the number of HBC stranded in pools after the transition. Also, the numbers should be analyzed as to its import relative 

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to the entire population. The ultimate fate of these fish, if found, should also be determined. 

e

11 5 14 Capron WAPA It would be beneficial to include a stand-alone 

section describing the key results of the 2008 steady flows research. Results from that are sprinkled about in this plan, but there is no overall description of the LSSF and key results (Ralston 2009). You could also include the steady flows from 05 in there as well. The results of the 2000 LSSF should really drive this plan, but it seems to be less integrated than that. 

Summarize results from 2008 

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12 5 13 Capron WAPA This is an abrupt transition from the BiOp discussion 

to the previous experiments and studies. What may be missing is a more detailed explanation of the current plan. For example, using the SSQs, what are the critical questions we are trying to answer with these fall steady flows – this may require some new SSQs derived from the BiOp. Then, discuss the historical experiments and explore how that 

information may relate to the questions we are looking to explore in this experiment. Then, later on the plan can tie the expected results back to the SSQs and current knowledge. 

Add a section of text 

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u

13 6 34 Capron WAPA The statement “increasing recruitment after about 

1998”. Is this referring to the 1998 year class which would have recruited in 2002 (roughly) or the 1994 year class which recruited in about 1998? This terminology is often used in this way -- please be more precise. For example, if it is the 1998 year class, then they would have been juveniles during the 2000 LSSF and may have benefitted from those conditions. If it is the 1994 year class, then any benefits of the LSSF would not have been felt until after their recruitment event. 

Clarify Y A

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14 7 1-4 Capron WAPA Awkward sentence, this could be rewritten to be a bit 

more clear. 

Clarify Y A

15 7 23-29 Capron WAPA Trout results of growth rates from Korman and 

Campana may not be translated to HBC or other native fishes downstream of Lees Ferry. This important caveat does not appear to be described in this document. It should also be addressed in Project 4. These results may only apply to trout in Lees Ferry and may not be applicable to other fishes (e.g., native fish) in other reaches of the mainstem. 

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adilLr

16 7 31-42 Capron WAPA It is unclear why this section starts with the premise 

that a constant discharge would increase food resources, when the next section seems to provide 

evidence to the contrary. This approach would fit better if the entire document was designed around hypothesis testing, but it isn’t written like that and this section seems to move in that direction. This should be rewritten to include the following line of thinking: steady flows could either increase or decrease productivity or result in changes in draft rates that could combine in a complicated way to alter the short term amount of drifting food available to consumers. For example, primary and secondary production could increase under low flows, but with reduced sloughing could actually result in less drift in the short term, and vice versa. 

Rewrite section 

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GR

17 7 43-44 Capron WAPA It appears the changes in temperature were under 

constant flow conditions? Please clarify. And if so, we’re any experiments combined to alter both flow and temperature? 

Clarify Y T

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18 8 G Capron WAPA These results are very helpful in this document. N A19 9 36 Capron WAPA The question of transition flows appears to be 

focused on the impacts of moving from a high volume month with fluctuating flows to a low volume month with fluctuating flows. However, the current research plan proposes to test the impacts of a transition flow when going from fluctuating flows to steady flows. Under these conditions, the transition flow study is hopelessly confounded. It is not possible to answer the question being asked these conditions. When operations change from fluctuating flows to steady flows, it involves two changes: no fluctuations, and flows which leave the varial zone above the new steady water level for two months. The transition study was a question of going from August high fluctuations to September low fluctuations - only one change, the location of the varial zone. Thus, the premise of the original question is illogical under this flow condition. When steady flow operations remove any varial zone in September, the research that results would be 

Clarify Y T

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comparing apples to oranges. The varial zone from the high volume month would still be above the new wetted zone, but the new wet zone would only be exposed to steady flows and not fluctuations. This could have substantial impacts on the response of the new wetted zone, growth rates, and food transport rates. Thus, logically we have two separate questions from the BiOp; (1) what is the effect of moving from a high volume month with fluctuations to a low volume month with fluctuations, and (2) what is the effect implementing steady flows in September and October. These two tests cannot be overlaid. A better approach would be to test some of these questions in laboratory conditions ss described in the Loyolla results on page 8. Flow has a big impact on growth rates and likely on sloughing and the availability of food in the water column. More consideration is needed here and perhaps a recognition that this question cannot be answered with the current flow regime. The question is probably most likely addressed via the experimental stream efforts at Loyolla. In summary, it is not scientifically possible in the field to test the fall transition question while implementing steady flows. GCMRC might collect data but it is likely to be irrelevant to the effects which would occur during normal operations when moving between two months, each with fluctuating flows. 

20 9 19-34 Capron WAPA This paragraph argues against implementing lower 

flows to increase backwater area based on changing sediment conditions between years. But then includes a statement that negates this information with “regardless” and offers to look at lower flows anyway. In another section of the document under experiments the document states: 

“The number and size of backwaters has greatly 

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diminished since the March 2008 High Flow Experiment (Kennedy, 2008-2009, personal observations). In April 2008 immediately after the High Flow Experiment there were at least 6 large backwaters between the Little Colorado River and Lava Chuar, which represents the study reach for the Near-Shore Ecology Project, and they were all present across the full range of April flow fluctuations. Presently, there is only 1 backwater in this reach that is present across the full range of flow fluctuations that occurred in July 2009 (Yard, July 2009, personal observations).” -- so this seems to be contradictory. Perhaps inclusion of these backwater observations here would clarify the situation more for the flow choice being made and not include a statement about changing this approach. 

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21 10 21-36 Capron WAPA These proposals do not remove the confounding 

issue, which is going from fluctuating flows to steady flows. The issue these proposals deal with is the other confounding variable of going from a lower limit of 12,000 cfs to 10,000 cfs. The only way to deal with the fluctuating issue is to change operations in the end of August to fluctuations which include a varial zone mostly below the previous varial zone – this is the issue described in the BiOp and that has been discussed historically. However, if this is attempted over these dates, it could have profound implications to the starting conditions of the fall 

steady flows. Thus, it may not be possible to truly address the key questions here under this flow regime, we cannot adequately alter flows in this short period in a way which we can follow the effects. We would propose that GCMRC explore other months/times of the year to test the transition flow question. Sometime in May or June might be appropriate to initiate a short term test which looks only at changes in the varial zone when moving from high volume fluctuations to low volume fluctuations. This is a test that could be easily designed. It is unclear at this point how season would confound the test if the “transition” at question always occurs from 

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August to September. But at least in this approach you would be looking at the key question of the transition period. 

ttrp

22 10 38 Capron WAPA The 7-day approach seems reasonable, but we would 

propose that during this transition that fluctuations cease and BOR implements a linear flow decline over the 7-days. This will slowly dewater shoreline and may perhaps provide a stronger cue to fish to move with a new base flow condition. It also might offer some opportunities to track primary production as flows dewater the varial zone. This could provide some insight into the transition flow question, but only in part. 

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gBttrp

23 10 38-46 and 

beyond 

Capron WAPA Again, the premise of this approach if flawed. The 

text which begins here and continues to the next page indicates those confounding variables but GCMRC is appears reluctant to admit that although we would like to study these transitions, it really isn’t an answerable question giving these flow conditions. Another option is to use flows in a different month, perhaps much earlier in the year to test the transition issue (as described above under #19). The scientific question is whether by moving the varial zone dramatically from one month to another, are there biological consequences – primarily in primary and secondary production and habitat availability for fish. 

Reconsider Y W

gBttrp

24 11 38-39 LaGory WAPA The focus on “process-level measurements” is a 

good one. 

Comment N A

25 12 Fig 3 Capron WAPA As complicated as this looks, some links are missing. 

The diagram that C. Walters could develop using ecopath might be a better description of linkages and energy transfer. A link is missing between nearshore habitat availability and juvenile and adult native fishes. Perhaps this figure is being used to help inform the ecopath simulations? 

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26 13 12 Capron WAPA Separate “otolithdaily” into two words. Edit Y A27 13 3-5 Capron/LaGory WAPA This statement that strongly positive recruitment 

trends from cohorts spawned during 2008-2012 would “provide compelling evidence that steady flows in September and October benefit humpback chub” is not necessarily true. Such an observation might support the hypothesis, but there are many other factors that could result in the same 

observation. HBC have been increasing at about 8-10% per year since 2002/2003. The trend may even be showing signs of increasing over the last two years. In part this may be due to recent translocations which may be resulting in higher growth rates and higher survival rates than the larger LCR population. Regardless, this sentence used in the document doesn’t seem reasonable. To determine if the fall 

steady flows had an effect we would need to look closely at the NSE study to see if growth rates increased during this time (otoliths or other methods), and try to track survival rates of tagged fish. If survival rates appear to increase for these year classes and we can demonstrate substantially increased growth rates this may provide some evidence for cause/effect. Yet, this is still all confounded by the nonnative removal program which could have a substantial effect by reducing predation on juvenile HBC. It is hard to see how this array of treatments can be disentangled. 

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28 13 15-25 LaGory WAPA This discussion of the effects of flow on piscivory 

focuses on primary effects (e.g., short term effects on predation rates) and does not acknowledge that longer term, population-mediated effects could occur. Even if steady flows did not affect predation rate directly in the short-term, these same flows could result in increases in predator populations over the longer term that could ultimately affect those rates. 

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nct

29 13 38-41 Capron WAPA This sentence references work by Korman, but then 

goes on to discuss a paper not by Korman (Gloss and Coggins), and then states that these papers included conclusive evidence on the relationship of dam operations to fish vital rates, specifically survival. The Korman and Campana paper looks at habitat use 

by age-o trout and may have found increased otolith growth rate on Sundays in one year but not the other, however this didn’t appear to result in a statistically significant effect in somatic growth rates. Thus, this 

sentence appears to go beyond the results of these papers. Plus, this section expands the results to “fish” but the research was only on trout -- we don’t know that these results seen with Lees Ferry trout will be translated to HBC or other native fish. “Fish” should be changed to trout. 

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30 14 1 Capron WAPA Is it correct that the water temperature proposal is 

still unfunded? Any chance GCMRC can find funding for this? 

Consider Y T

addlw

31 14 15-22 Capron WAPA The plan should provide more explicit descriptions 

of each SSQ and how the research/data will be used to respond to them and the results are expected. It is of little utility to see a list of the SSQs which relate to a research topic and not describe how the research is intended to answer them. 

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papdrS

32 17 25-35 LaGory WAPA This task statement as written is to “investigate 

sampling methods,” but the text describes 

measurements of effects not tests of methodologies. 

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ppa

33 17 41-42 LaGory WAPA What are “unstable habitat types?” Are these related 

to flow changes or habitats that change between years because of unstable sediment substrates (e.g., 

sand bars)? The text predicts that use of these habitats will increase during the fall steady flow period when flows are stabilized, but if these “unstable” habitats are within the varial zone, they would not be available for use during the steady flow period. 

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csbcpa

34 17 44-45 LaGory WAPA The basis of the prediction for increased growth and 

survival resulting from the predicted change in habitat use is not clear. Please explain. 

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cwomst

35 18 13-15 LaGory WAPA It is not clear how otoliths from native fishes would 

be used to investigate “habitat use and origin of fish.” Please explain. 

Clarify Y A

cmeudpa

36 20 32 LaGory WAPA Describe the “routine monitoring efforts” that will be 

used as the basis of the stock assessment. 

Clarify Y A

cdG

37 23 34-35 LaGory WAPA These measurements of production and drift should 

provide useful information for examining the effects of fall steady flows. 

Comment N A

38 25 1-7 LaGory WAPA This discussion about the relevance of studying the 

Lees Ferry foodbase seems contrived. Since the “food web structure in Lees Ferry is considerably 

different than around the Little Colorado River confluence,” any results of the study may have little relevance to humpback chub. I would recommend implementing measurements around the Little Colorado River in this first year of study rather than 

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waiting for the Lees Ferry results from this first year. 

39 28 1-9 LaGory WAPA It is not clear how the rainbow trout work at Lees 

Ferry “will help inform native fish collected at downstream locations.” It seems likely that any rainbow trout response would be quite different from that of humpback chub. This study does not seem to address the effects of fall steady flows on humpback chub. 

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wruh

General Kubly BOR This document seems to portray that its 

development was spurred by requirements of the 2008 environmental assessment and biological opinion on operation of Glen Canyon Dam. While we appreciate the value of integrating ongoing studies to assess the effects of prescribed flows, and have supported doing so for the 2000 LSSF and the 1996, 2004, and 2008 HFEs, we do not know of a requirement in either of the referenced EA and BO compliance documents to develop this science plan or to single out the effects of fall steady flows. We question the interpretation that it is required, because it may have the unintended effect of suggesting that the Bureau of Reclamation or Fish and Wildlife Service is promoting parsing of the annual hydrograph, whereas our intent is to study resource responses to the entire hydrograph, including MLFF, HFE and FSF flows, both within and among years. It is for this reason that we have structured our request for the Nearshore Ecology study to concentrate on comparisons and contrasts among the effects of these different flow regimes. 

Accept/Reject for all 

Yes for all A

cpBA

General Kubly BOR We are not sure whether the added text beginning 

on p. 9 (see GCMRC memorandum on changes made) satisfies the Science Advisors concern that a comprehensive experimental design is missing from the Fall Steady Flow plan. The plan still appears to us largely as an amalgamation of preexisting studies, with limited change to those study designs to provide the comprehensive approach requested by the Science Advisors. We do not, however, want to prejudge the Science Advisors 

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response, so we advocate that they be allowed to speak for themselves in a follow-up review of the document. 

awaAopWhwn(

1 2 12-16 Kubly BOR We do not think there is a disconnect with the 

sediment work. The nearshore ecology conservation measure (see p. 11 of the biological opinion and pp. 15-18 of this document) does identify connections between flows and physical parameters in nearshore habitats, some of which are founded in fine sediments. We anticipate that the physical and biological responses within and among these habitats will be determined in large part by how habitat geometry changes in response to differing flow regimes. Thus, there is anticipated to be a strong connection between the physical and biological responses. This relationship is identified in the nearshore ecology study, which is incorporated into the fall steady flows science plan. 

Ash2(f

2 4 8 Kubly BOR Change “has proposed” to “is” since steady flows 

are being released from Glen Canyon Dam. 

A

3 4 10 Kubly BOR Insert “partially” between “to” and “mimic”. A

4 12 Kubly BOR This line contains the first use of the word 

“juvenile”. Since this term can have different meanings, in terms of life stage and size of fish, we suggest defining here the range of sizes included in the term. 

A

4 4 13 Kubly BOR Make “ecosystem” plural. A5 4 21 Kubly BOR Remove “the” from before “Reclamation”. A
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6 4 22-25 Kubly BOR Both the EA and BO make it clear that MLFF 

flows are part of the experiment, i.e. interjecting HFE and FSFs within MLFF may change the resource responses to MLFF, and thus the entire hydrograph should be looked upon as the experiment, not just the two components identified in this plan (see the first general 

comment above). 

AmtbmaF

7 4 26-29 Kubly BOR As we understand it, the concern with transition 

flows across months is not limited to the effect of “a change in the lower limit of discharge”. It includes the (downward) change in maximum flows and the day to day rate of change in both minimum and maximum flows. Also, the Service has pointed out that the best, but not only, example for this concern for monthly transitions is the August to September transition, i.e. other 

monthly transitions also are of interest to them. 

WgBttrp

8 5 26 Kubly BOR Epilimnion thickness also can affect temperature 

of release water. 

A

9 6 3-6 Kubly BOR Are there empirical measurements that have been 

made of residence time, or these qualitative statements concerning backwaters and low-angle shorelines. We recall that Ralston (2006) found a wide variety of warming rates among backwaters, the implication being that variation in backwater geometry could play a large part in determining water temperature response. Did we get that right? 

WrbrfaioasapWrhihwtWaw
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dapmcov

10 6 23-24 Kubly BOR Should this question not then be one of the major 

driving science questions for the NSE and FSF studies? 

W

11 7 23-24 Kubly BOR Were otoliths used to measure growth in both the 

HBC (above paragraph) and RBT examples? If not, it is not clear how the two examples can be correctly contrasted. 

Wpceaipmntbfn

12 7 45 et seq Kubly BOR Were the volumes of water the same that were 

used for the different experiments? And were there any portions of the algae that were subjected to drying by the fluctuating flows? Seems that these conditions would have to be taken into account to make the comparison? 

Tiivvtdeura

13 8 43-65 Kubly BOR Are HBC strictly drift feeders? Are there any 

ontogenetic changes in their mechanism of food 

procurement? Also, it seems that these comparisons are predicated on there being an autotrophic and autochthonous base for production. Is that borne out by the food base studies? 

Hfbddtre
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ftaafc

14 9 6-8 Kubly BOR Yes, but recruitment rate relationships with 

environmental conditions may well be confounded by having different conditions in the years leading to recruitment. And it may not be possible to control the hydrology to ensure that within year, or year to year, conditions are the same. If so, are there other demographic or individual measures that could be used for the assessment? 

Mpcepeppftonct

15 9 19-21 Kubly BOR Doesn’t the nearshore GIS habitat work lend itself 

to this kind of quantitative analysis? Also, since backwaters are formed in fine sediments, doesn’t the underlying geometry change over time and thus change the relationship between backwater area and discharge? 

Wmwg

16 9 33-34 Kubly BOR Are these relationships quantified, i.e. could we 

model the effect of “further increases”? 

Wmwg

17 14 7-10 Kubly BOR See our earlier comment (# 1) re: nearshore 

ecology requirements for rearing habitat, including those situated in fine sediment, evaluation. 

Ar

2 7 Bill Persons AZGFD “Four existing projects are collecting data that will be 

used to determine whether biological resources benefitted from these flows”. This is a pretty strong statement, and I’m concerned that the rest of the document doesn’t provide this much certainty that we will be able to determine if resources benefited from the flows. Can it be toned back a little? Don’t want 

to give the impression that this is an experiment 

Revise Yes A
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designed to study impacts on biological resources, rather an attempt to learn from flows imposed on the program. Perhaps “collecting data that will be used to assess possible impacts of these flows on biological resources”. 

2 18 Bill Persons AZGFD Recommendation for comparable flows (10,000 cfs) 

across years is good. 

A

2 26 Bill Persons AZGFD Good, suggest you spell out the proposed flows. Is it 

7 days of transition flows? 

As

9 16 Bill Persons AZGFD Good to recommend some consistency in flow 

volumes for Sept and October across years. 

A

10 10 Bill Persons AZGFD Good acknowledgement of complexity and 

shortcomings of experimental flow design, esp. regarding ability to assess impacts on HBC and algae production. 

A

11 6 Bill Persons AZGFD You state that transition experiments would need to 

be longer than 7 days in duration if managers wish scientists to determine the increase in algae production that occurs with an increase in the lower limit of discharge. If the transition period is only 3 days, does it argue against doing the algae work because it is likely to be inconclusive? 

YtdsudsgBfe

12 Bill Persons AZGFD Should there be a line between nearshore habitat 

availability and juvenile native fish? (Yes I did look at the figure!). 

Y

13 5 Bill Persons AZGFD Delete phrase “compelling evidence”. If HBC 

recruitment from cohorts spawned during 2008-2012 are strongly positive, it will “provide insights” but I wouldn’t prejudge interpretation of results to be compelling. Don’t sell this experiment as something it likely is not, in other words acknowledge that it will be difficult to assess direct impacts of Sept-Oct stable flows to HBC. In earlier versions of the plan, I believe the Center suggested that it would be difficult, if not impossible, to discern the impact of a two month flow treatment on long lived species such as fish. I would rather see an expression of the 

Revise Yes A

t
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uncertainty around these research projects than statements that may give some stakeholders the hope that the question of steady flows will be answered once and for all with this experimental design. 

27 Bill Persons AZGFD 2nd paragraph from end of page. I think the 

statement that catch rate indices may not be adequate... is correct, but don’t think it belongs in this document. We can certainly update the stock assessment model, and that could be in the methods/tasks. 

Revise Yes A

tmf

Bill Persons AZGFD Comment and suggestion of Science Advisors (p. 9 

of their review) that GCMRC expressed concerns over the timing and period should be a focused subject of the knowledge assessment in 2010-11. 

A

1 13 15-21 Brian Healy NPS – 

GRCA 

The plan cites the results of the unpublished trout foraging ecology study (Yard and others) as a reason to dismiss the need for further study of the interactions between native/non-native fish. I would urge GCMRC to publish those results, as they may be critical in supporting additional non-native species management activities within GRCA. 

Publish trout foraging ecology study 

Thcothof repuwdo

2 13 2-5 Brian Healy NPSGRCA GCRMC requests that the steady flows for September and October currently planned 

(or proposed?) for 2008 - 2012 be maintained, which the best available science indicates may not result in benefits to HBC (as opposed to steady flows earlier in the year). GCMRC states that "if HBC recruitment trends from cohorts spawned during 2008-2012 are strongly positive this will provide compelling evidence that steady flows in September and October benefit humpback chub." Given other confounding factors, it seems unlikely that this conclusion could be drawn. Another question that should be addressed is what 

Identify where/how the effects of nonnative fish removal would be addressed. 

Mprcaecprecprprfofl(ichtri
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effect other management activities (mechanical removal) may have on HBC recruitment. 

3 19-

22 

General comment 

Brian Healy NPS - 

GRCA 

Comments on Project 2 - Stock Assessment of GRCA Native Fish

The continued assessment of native fish populations and how management activities impact population dynamics is a cornerstone of adaptive management in GRCA. Assessing the status of HBC populations, and how variability in populations and recruitment is tied to the operation of GC dam and other management activities are high priorities. The primary SSQ 1-1 will evaluate how populations are linked to tributary and mainstem fish production, and how production is tied to mainstem conditions, however it seems that only one tributary, the LCR, will be addressed. While the LCR is the top priority, it would be helpful to understand the fish population dynamics and role of other tributaries in native and non-native fish production. Also, the design needs to incorporate an analysis of how mechanical removal may influence HBC populations, so that speculation in interpreting results can be minimized in the future. 

Cdostof exmbeantritimtimreasthreinecprth

4 21 NA Brian Healy NPS - 

GRCA 

The evaluation of how population estimate techniques may be used for other native species (bluehead and flannelmouth sucker), would also be of assistance in determining how well the Park is meeting its management goals for native species. 

Wby exthsocoW
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mwjuinna

5 21 NA Brian Healy NPS - 

GRCA 

Page 21- in support of implemented and planned HBC translocations, and also to comply with recommendations of the PEP, monitoring efforts should be expanded in the mainstem sooner than 2011, as proposed by this plan. A goal of the translocation projects may be to augment HBC numbers in aggregations, and without baseline aggregation data, it will be difficult to assess whether goals are obtained. 

Consider reinitiating or expanding mainstem monitoring sooner than 2011. 

Wm20exmsureFimspat