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April 28-29, 2001 (WSU - Vancouver, Student Services Center) Meeting Summary Meeting Minutes Meeting Agenda Presentations Attendees view as PDF file: minutes_apr28.PDF Meeting Minutes APRIL 28-29, 2001 MODELING MEETING - TRANSCRIPT OF DISCUSSIONS DAY 1 Introduction and Welcome by Courtney Courtney introduced the concept of adaptive management, and suggested that this might be a useful approach to keep in mind during the discussions of uncertainties, particularly as these are addressed using modeling approaches. Anne Fairbrother, Parametrix Uncertainty and Risk Analysis view: parametrix.PDF Bartell: Has it been agreed on that there will be a goal of adaptive resource management? It's my understanding that there's a proposition to go ahead with the dredging. A BA was initially rendered and agreed upon - while I would certainly endorse an adaptive mgt. approach to the project, that's not my understanding of that's in fact where we are. It's my understanding that we're focusing on the quality of the technical information that went into the previous decisions that were made thus far. Can we now go back and thru the application of uncertainty principles, reevaluate that information to try to understand what an appropriate decision would be. Young: I agree with Bartell's comments that we're at a point where we're evaluating the risk portion. In fact, there was an earlier agreement to move forward thru the BA, thru the BO, into the implementation of this project. Adaptive management would be a process that could be proposed in the new BA when we consider monitoring. Boesch: I've worked in various parts of the country in coastal environments using adaptive approaches. One of the challenges in this case is that not all actions and not all risks are as controllable or versatile. In the case of fisheries mgt. and, you can adjust harvest depending on what the results are. And in the case of dams, you can control releases. But in the case of dredging, it's sort of you do it or you don't. Although I guess it's conceivable that, after the fact, if we find that the channel deepening was having effects that weren't desirable, you could let the channel fill back in. From a practical standpoint, though, it's probably unlikely. In a similar vein, some of the massive types of public-funded reconstructions -- like the Everglades, or creating new deltas in the Mississippi -- although they certainly have some adaptability after the fact, the decision to do them is a big decision that you make in the face of much uncertainty, and the alternative of undoing what you've done is not going to be there. How do you factor those kind of differences into management actions? You might say the same thing pertains in terms of reversibility of the risks. I guess the reversibility of the risks in that case, speaking in terms of the magnitude, have to play into it. Fairbrother: I would suggest that this channel deepening work that is currently going on, as well as the proposed action, is not being done in a vacuum. It's being done within the context of a lot of other management. actions that are going on in the estuary and upriver. All of those are being integrated as we look at how this next step in this action may affect the salmon. And while you can't necessarily change the physical aspects of having dredged deeper some parts of the channel, you can adjust the other management actions that are going on within the river in ways that can mitigate that action. Courtney: If the decision is made to proceed, and mitigation plans are put in place for that, and subsequently we find that our underlying assumptions were wrong and the scale of mitigation is not appropriate to offset the consequences of the action, if you don't have an adaptive framework, that's an irreversible decision. But if there is an adaptive framework, something can be done to put the system right. Whitney asked for comments on the notion of ecosystem management as it applied to the wetted margins. Fairbrother replied that this was an issue of scale - how are we defining "ecosystem,"? Are we defining the ecosystem as only within the river channel, or are we defining the ecosystem as a larger portion of the watershed? Certainly, systems interact, and there are a lot of interactions from what's happening on the land and wetted edges of the river channel with what occurs in the river channel itself. Scale continues to be part of our discussion, particularly in talking about our conceptual models. All this has to be put within the context of the proposed action - what is the connection between that action and the different parts of the system? Is there any reason to believe that that action changes other parts of the system that then feed into the river. Courtney sought feedback from NMFS, given the acknowledged need for more information. If NMFS elected to go forward with this project would adaptive management be something the agency would be interested in adopting? How does NMFS' research and monitoring interests (raised in the withdrawal letter, and shown in document 2) fit in with the idea of going back to the conceptual models? Tortorici: We need to make a determination about whether the project goes forward as a whole. Assuming that it does go forward, I think taking an adaptive management approach is the appropriate way to go, from a learning perspective. That fits into the context in the monitoring program that we had originally envisioned with the first BO, having a comprehensive monitoring program that looked at physical-biological aspects and integrate those over the short term before, during, and after construction. The caveat that I'll add to this is something that you just said Don. This is a bit different than Glen Canyon Dam. They had the luxury -- if I can use that word -- where they could be testing water from these scenarios and they could stop it and start it, and that was the beauty of what went on there. This project is a little bit different. It's more of dig or don't dig, and so I guess the piece that we need to be cognizant of is how you apply an adaptive mgt. approach to a project like this, and can we make it real, and what are we going to derive from it? So NMFS is not at all opposed to the concept of adaptive mgt. to use in this project as this project moves forward. It's really a matter of how to adapt it to the situation at hand. Fairbrother: We can distinguish "active" and. "passive" adaptive mgt. What you were just referring to was the active type of "let's try different things," and then see what happens in terms of an outcome -- truly an experimental design vs. one like this where you can't do replication, you can't start and stop and try different things. What you can do is develop your monitoring plan to refine your models and reduce your uncertainties so that the parts of it that you are managing can be changed as you move forward. And I would suggest that even if the decision is made not to move forward with this proposed action, that is a decision, and that decision also deserves monitoring and evaluation. So you would bring this into effect, regardless of which decision you make. Tortorici: I would also see this approach applied in terms of ongoing maintenance of dredging activities. So I think from a broader ecosystem perspective, it could really change the face of how we're viewing ecosystem operations. Eriksen: People are suggesting that the decision to deepen this channel is an irreversible one. I just want to point out that the locations we would have to dredge and deepen are primarily the same locations where we continually do maintenance dredging on a regular basis. So if an impact is identified, the decision is not irreversible. Many of the areas would fill back in to the current channel in just a few years. Ron Thom, Battelle Marine Sciences Lab Conceptual Model view: ronthom.PDF Bartell: Your conceptual model is important in relationship to this overall deliberation from several viewpoints. One is certainly outlining the complexity of the system and indicating what has happened historically to the system in terms of creating conditions that have either been favorable or unfavorable to the continued production of salmonids as the resource of concern. With regard to the particular decision we are assembled to address, it raises the issue of is the decision to be made primarily in terms of an incremental change to the existing condition, or is it something that has to be looked at more in the historical, comprehensive context of what's happened to the pre-settlement conditions; the notion of a sliding baseline. It certainly makes a difference in terms of what information is pertinent and how it's used in the overall decision-making process, and it seems to me that's one of the reasons why this conceptual model is very important in trying to resolve these differences of opinion. Thom: Correct me if I'm wrong, but the baseline conditions relative to this project are the present conditions. Bartell: Well there seems to be lack of agreement there. DePinto: From the point of view of a modeler, you want to ask yourself not only what the response of the system might be, but you also have to ask whether you can either model or detect that response within the context of the natural variability of the system. Regardless of what your baseline condition is, that issue has to be dealt with in terms of trying to decide what it is you want to model and what the level of resolution needs to be. Bartell: I agree with you - almost. Depending on the historical complexity of things that have changed the system from pre-settlement times, it might make it more or less -- I'd say more -- difficult to see this additional signal in terms of response from a baseline condition. Boesch: Steve (Bartell) asked about whether the historical or present condition is the baseline. Perhaps a more constructive way of looking at this with respect to some future desired future condition, is some restoration goal for the estuary. And then one can ask the question, not what is the change of an action from what the condition is today, but the degree which a change affects the attainment of a restoration goal. Does it put you closer or farther away from reaching that goal. So maybe rather than the control being the existing condition, or some pre-existing condition, some potentially, achievable desirable condition that you then have to weigh changes, actions, in terms of whether that makes attaining that goal more difficult or more achievable. Thom: That's an interesting point of view. Whether the project affects the habitat-forming processes, and how much or not, may affect your restoration goals. And if you're going to interrupt processes that affect say the formation of marshes, and formation of marshes is the thing you're trying to do in mitigation, you need to know that. Courtney: It's my understanding that the regulatory agencies have an ongoing debate about what constitutes the appropriate standard -- whether that should be a recovery standard, or no net loss of current conditions standard. That's an ongoing debate on a national scale. I think we can all agree that they may be desirable goals but its a question of whether that's the legal standard. I think we need to be cautious about trying to set new goals when that's really not our role. What we should be trying to do is evaluate potential impacts on current conditions, future goals -- lay those out, but other folks will be deciding what standard they're applying and what the law says. Boesch: Let me try to argue a little on this. It seems to me, one of the assumptions, and we have the literature which provides some evidence for it, that the estuarine condition is going to be a key factor in the long-term survivability of some of these ESUs, right? Because we had some literature which said that even if you removed the dams the population would continue to go down without also thinking about increasing survivorship in the estuary. You can argue about that, but if that is indeed a basis for a decision about endangerment in terms of the future of the stock, then one has to then ask what are those changes that will have to be made in order make that stock survivable. Then those have to be included in some sort of a vision of what that ecosystem is. And it's in that context that you can view any action as inimical to reaching that vision, or neutral, or assisting. Curtis: One the questions I have about applying some of this information is how good are the data out there for populations, densities, and abundances of some of these organisms you've identified as crucial, the deposit feeders for example. I have some feeling for how much data are out there on the salmon themselves at different stages. I know it's not all that great, but at least there's some historical info. As you worked on this, did you get a feeling for the next level of the food web -- the heterotropes and the deposit feeders. How much do we know about where we are now, where we were, and where we might be? Thom outlined some of the available data. In the conceptual model , where the lines are connected to salmon, those links are proven - the insects, the Corophium, and the Daphnia. They are found abundantly in salmonid stomachs. Things like the carbon ratios in the prey, prove that the macrodetritus is supporting the Corophium. There is no available stable carbon data. Larson indicated that the data set on benthic invertebrates was fairly good. Goldman encouraged the use of stable isotope work if it was available - it takes a lot of the uncertainty out of the food chain analysis. Dunne: When Anne (Fairbrother) was laying out the process of adaptive mgt., she said first of all you lay out your conceptual model and that allows conceptual models to be shared. My question is do the agencies share the conceptual models, or do they have any fundamental objection to its nature? Eriksen replied that the Corps found the model useful. Young stated that the USFWS had not yet the opportunity to review it. Dunne: I can't believe there hasn't been a conceptual model until now. Tortorici replied that there's been a huge amount of money focused on the more upstream portions of the system where the dams are - the big black box in all of this is the estuary. Dunne: But by 1990, there was enough in-depth research in the estuary to have a special volume of Progress in Oceanography. There must be some other attempts to do what you've done that people have been playing with as a basis, either for their objections or their plans. Among all those models are there strong differences of opinion about how this system works? Do you all share more or less the same conceptual model? Casillas: From a general perspective, I don't think there's much disagreement. The issue is how much data exist to support the underpinnings of those particular processes in this system. We don't have the information about how processes support salmon. The Progress in Oceanography volume is based on one year of data. The system is very dynamic, so it's unlikely that one year of data will characterize the system in an effective way. Dunne: What you're uncertain about are the rates of the processes that are represented by the arrows. And your saying that is it that one side of the debate estimates that a certain arrow may be either not quantitatively important, or would not be quantitatively affected by the dredging process, and the other side of the argument says we don't know that? Casillas: I think it's more fundamental than that. It's not a question of the arrows Dunne: It goes back to Anne's initial statement. She said that the process of building a conceptual model is a process of developing hypotheses about linkages. Then her diagram shows you represent those hypotheses about linkages by arrows. So presumably in Thom's conceptual model diagram, all the arrows represent is hypotheses about linkages between habitat structure and function. So why are the arrows not vital? Casillas: They are. Dunne: So you say they're vital, and the other side says -- now I'm making this up -- that we've addressed the arrows, and our estimation is that this dredging project will not impact that arrow. Is your position, now that you've stated that the arrow is important, that you don't yet know what the magnitude is and what the impact of the dredging program on the magnitude of that arrow will be? Tortorici: It could be a magnitude issue - it could be a question of whether that arrow should be included at all in the discussion. Bartlett: That really stimulated one of my earlier remarks in terms of the 'sliding baseline' because, of course, that is one of the points of criticism in the review of the original BA. If it's our charge to review the existing technical information, it really helps me to know if I'm looking at it in context of an incremental impact to the current condition, or if I'm supposed to review it in the context of the historical development of the whole estuarine system. Tortorici: In the first workshop, when Doug [Young] and I talked about the baseline, we talked about the condition of the project in the context of all that's happened to get you there and overlay the proposed action on top of that. The reason we look at that from the ESA context, is we recognize that the system is degraded; it's on a downward slope, as evidenced by the existence of threatened and endangered species. So the question becomes how will the project shift that slope at all? Is it going to make the shift more severe? Not affected? Or is there something we can do with regard to this action to allow not only the survival, but the swoop back up, allowing that line to come back up toward recovery. So when we look at a project -- not only this project, but projects in general -- we're taking a broader ecosystem perspective in which to place the project and value it. Casillas: There's a science question of comparing what we think happened historically with present conditions; the overlay, as Cathy [Tortorici] suggested. On top of that, however, is a management issue of determining the baseline. Management decides on the baseline, not science. Curtis: In terms of what would help the salmon, from reading the paper that the NMFS science center laboratory published in Science, they said if you could increase the survival in the estuary and ocean about nine percent it would stop the decline. It would do more than doing more radical things upstream. So really what I'm trying to get to is - do you know what's limiting in the estuary? What specifically affects survivability? In my view, only if we have some insight into that that tells us what to look for when we look at these physical and chemical models. Casillas: To answer your question, the answer basically is no (no information on increasing survival in the estuary). Quinn: This paper (Kareiva et al in Science) has been referred to a number of times. Initially, we need to point out that it's not for all salmonids. It's for Snake River spring/summer chinook salmon. So not all components, and not all species, and not all races. The second is it's based on a lot of data, which simply aren't presented here. I would need to see a lot more of the data before I would be willing to accept flat out that it's correct. Ed [Casillas] has made another valid point that the early ocean mortality and estuarine mortality are rolled in; there's absolutely no basis to distinguish those on the data. And a number of other assumptions are made that may or may not be true. I respect the people that did the work, but I'm not willing to simply say that we know this (important role of estuary) to be true. Sullivan: You [Dunne] were asking if anyone had been working on a conceptual model. They must have because most of this literature addresses and provides some data on most of the species. What's generally not there is the synthesis of how productivity in the estuary is driven for individual species vs. community. But it does seem like some conceptual linkages begin to pop out. Do you have a sense that there are some of the driving interactions begin to pop out from the information that's been collected, and that further information could tone down or improve those hypotheses? Or are you of the position that we simply don't know anything? Casillas: Yes, we can make some inferences, we just don't have a complete understanding. Boesch: I'd like some ground rules - you should have to tell us two things you know, before you say "we don't know"! We have a tremendous amount of information here, and it's actually quite a lot of knowledge. It's not perfect, but we ought to be looking at the key things in this body of knowledge that provide the uncertainties that we need to try to resolve to find the disputes. Broad platitudes about what we don't know and would like to know are not very helpful. Goldman: One of the things we've know for a long time is that estuaries are nutrient traps. And the behavior of the salt wedge -- it's penetration upstream -- is a very important factor in determining how this nutrient trap functions to produce the high fertility that estuaries are well known for. It seems to me that this still remains somewhat of a gap in our knowledge, combining the physical facts of the dredging -- whether it's sedimentation or allowing the salt wedge to go up further or be more concentrated in the channel -- is going to have a major impact on the analysis of whether the food chain in the estuary is going to be helped or hindered by the project. Larson: There is a lack of knowledge, but there's also a fair amount of knowledge on how these processes go on. There's a fair base of knowledge, which our EIS and BA were based on. Like Ed (Casillas) says it's not a conclusive array of knowledge, but it's still enough to move ahead with an assessment of what we feel the impacts would be. Courtney: This next presentation is a preview of where we'll be in the next workshop. I've asked the agency folks to provide just a simple summary of what we'll be exploring in considerable depth at the next meeting. Tortorici and Young Overview of Salmonid Estuarine Ecology view: salmontalk2.PDF Eriksen asked about the use of the term lower estuary. Young replied that they (NMFS and USFWS) are working from a summary of estuarine sampling for four or five years in the 1980's.. 1980 was the most focused year of work. They split their sampling up between upper estuary river in-flow areas and the lower estuary. And they looked at lateral habitats based on beach net seining. Since you can only run a beach net off a beach, the researchers considered that shallow-water habitat. And they did purse seining out in the mid-channel areas, so they were looking for areas probably greater than at least 5 meters deep when they were doing that work. Larson and Casillas discussed the use of different capture techniques for different fish types. Stream-type fish in channel margins don't show up in beach seines. Stream-type are caught with purse seines, which are used in deeper water. Fairbrother: I believe these last two presentations were very helpful. They are starting the discussion we were looking for as to how can we get boxes of information and connect arrows between structure and function, which in this case are the salmon. There are probably still question marks over the arrows, but we've heard that there's collective wisdom -- not just from the system, but from other systems -- that we can apply to this system as well, which allows us to start building those framework concepts. And as we move forward this afternoon and in the workshop two weeks from now, we'll start clarifying some of those boxes and understanding which are the big question mark arrows and which ones are smaller. But we're not entering into this whole discussion with no information, and as we go through the discussions, we start popping up little bits of new information, or different ways of looking at the information, so as Don [Boesch] was saying, if you can say two things that you know before you start putting question marks on things you don't know, what are the size of the question marks is kind of what we're trying to get at. Tortorici: In this presentation, we talked about ocean-type vs. stream-type and the fact that some of these species are spending longer in the estuary than others, but we don't want to leave you with the impression that just because a particular species is spending a shorter period of time in the estuary vs. something like a chum, that that time they're spending there is unimportant. It could be just as important for a fish that's spending three days in there for whatever critical need it may have vs. another species that's spending a month. I mean the value of that is difficult to determine. So just keep that in mind as we talk about the different ways the species are using the system. Boesch: Pursuant to that point, Cathy, one of the challenging things is that there are so many ESUs here, and if you actually had to define all of the specific habitat requirements and sources of mortality for each of them within the estuary in transition, and then try to develop a management matrix to optimize for all those... It's a fool's errand, quite frankly. What I gather is the approach in the Bottom et al. argument is that given this diversity, and that one of the management objectives is the maximum amount of diverse habitat -- I understand that and that makes some sense. But as you get into the specifics of trying to understand the vulnerabilities of these stocks, am I correct in hearing that if you had to pick one type that was particularly vulnerable that you might want to focus on in this analysis to see if the action were reducing the survivability of these populations, it would be the ocean-type chinook. Tortorici: It's such a painful discussion for NMFS in terms of which do you focus on vs. which you don't because then of course the implication is that somehow you're letting the rest of them go. We actually have talked about this internally. The issue is if you're not seeing a change in the system based on chinook and chum, it's probably going to be much more difficult to see a change based on those other species. I may be overstating this, but we probably have more information on chinook than we do on most any other species. But I think from the perspective of what we would want to do here, we'd want to look at both chinook and chum, see how the habitat changes in relation to what we're talking about, and then go from there. Hopefully, we can generalize enough to those other species so that we're not making some overleaping decision at the end that's going to place us in a difficult spot. Dunne: Cathy (Tortorici ) said that managing for genetic and life history diversity was the goal for maximizing survival and that if the project were to change conditions that might alter that range of diversity, you would have a concern. I'm trying to understand the significance of the fact that then, for example, you said there's a range of residence times for a species in the estuary. What does that range of residence times mean? Does it mean that if you took a box full of salmon -- today's salmon just coming back from the ocean -- put them at the mouth of the Columbia and then they would spend some time in the estuary, there would be a probability distribution of residence times, and that that would be because of their genetic diversity, or would it be accidental encountering of food, or is your observation comparing inter-annual variability so they come back one year and conditions are not so good so they scoot through the estuary quickly. In other words, the habitat fluctuates from year to year, do they read the habitat and decide whether to stay or not, or is it something more fundamental that will not be affected by, for example, changing flow conditions of the project? What is the observation that there's a range of residence times in the estuary mean? Tortorici: This issue of residence time is partly an environmental issue in terms of what those fish are encountering vs. an issue of their genetic component. The thought behind this is, from a survival standpoint of a species, you want to have enough plasticity in the species such that as they're encountering different conditions in the system, there's going to be a component of that species that will be able to react favorably to that and others won't. And so preserving the amount of diversity - the ability of these fish to react to changing environmental conditions -- is really what we're after. I don't know if that fully answers your question or not. We just recognize through observations of these species that they're spending various amounts of time within the system, and from a survival standpoint, that's a good thing because it allows the species as a whole to adapt to changing conditions to make sure that enough are going to get back upstream to spawn. Dunne: You said, 'We're managing for genetic diversity....' Then you said, 'If the project changes conditions in the estuary, it would affect some of these... Tortorici: Yes, because if the project is changing conditions such that habitat is changing, then those portions of the population that might have a residence time in a certain habitat type -- if that habitat is no longer there, if its limited in some way, then you've created perhaps a disadvantage for that portion of the population. It doesn't mean that, on the other hand, that another proportion of the population might be at an advantage. We can't say that for sure. Casillas: You [Dunne] were essentially asking if these fish are hard-wired for residency time. In our conceptual model, the answer is no. It's really a composite of information -- hardwire, genetic, and phenotypic expression. Dunne: I'm trying to understand the linkage. For example, if the variability were in response to let's say habitat condition, and then we get modeling done this afternoon and they say, 'Well, we can simulate through a time series of forcing conditions what the range of variability will be. If the variability of habitat condition maps into variability of residence time, then you've got a linkage. And what I'm hearing is some of that linkage, but there's a lot of unexplained variability that's interpreted to be phenotypic. In other words, you have a large component of uncertainty about how an individual fish will respond to a condition in the estuary. Tortorici: And your question is a good one because it gets to the issue of how you interpret that modeling in terms of the behavior of these fish. That's something that we struggled with in the course of this project is how changing conditions are going to impact these fish, given the 'variability' that they show in terms of behavior with residence time, for example. Dunne: The way lots of sciences deal with that as-yet irreducible uncertainty is through stochastic modeling. Of course, we don't know what decisions individual fish would make, but we know there's a probability distribution and that that probability distribution will respond to say, mean changes in the larger environmental conditions. Are those probability distributions at least known even if they're not understood? What's the basis of saying that there is variation? Are you saying, 'We know there's a range?' Or are you saying, 'There's a modal value and a range, or...." Casillas: We can document some of that. When they come in the system and when they leave the system. We have these data, but they are not complete. Karl Eriksen, U.S. Army Corps of Engineers Overview of Estuary Physical Processes Quinn: Presumably, in the ancient days it [the Columbia River estuary] was in a steady state; as much was going out as was coming in, otherwise it would've filled up, right? Eriksen: No; it was filling up. PSU is just now finishing up a study on depositional rates for the estuary. They show deposition back some 20,000 years on up to the present, with the highest rates occurring 10,000-20,000 years ago. Now it's filling slower because the hydraulics are changing and you're seeing more fine materials being carried through now than would've been in those days. But as sea level came up, the estuary filled, all the way upriver to Portland largely. Quinn: By dredging, are you accelerating or decelerating deposition? Or does it affect it? Eriksen: We can't quantify that. In the estuary, we dredge here at the downstream tip of Puget Island every year, we dredge in this area around Skamokaway about every other year, and we have a large point bar here that the channel cuts into and it continually back fills. We have a developing problem downstream of Skamokaway where sands that are washing across the shallow areas are cascading into the channel, and shoaling the south side of the channel. Most of those are dredged by hopper dredge -- we take the material and distribute it within the channel at different locations. We have a disposal island here at Pillar Rock. We dredge near that island almost every year. Most of that is going in-water because the island has hardly any capacity at all. We dredge a large amount here in the Rice Island/Miller Sands area. About half of it is pumped back up onto the Miller Sands spit, which was constructed as an environmental enhancement in the early eighties. It erodes constantly, re-deposits in the channel right about here, and we dredge it and put it back to maintain the spit. Most of the material that is removed from the system is here on Rice Island; there's about 12-13 million yards of material in storage there. We've been using it since the early eighties, so there's 20 years of material there. We have another major shoal that we dredge downstream of Astoria. All of that material goes back in the water, either down here in deep water, or over here in the north channel. So we are dealing with whatever is deposited in the channel. Most of it is bedload related, coming off the sides and into the channel. What's happening out here and in the rest of the estuary, we don't have much of an effect on. So, suspended sediment, which carries the bulk of the sand, comes through on high flows, maybe is undisturbed at all. Some of it we trap the net balances. We just don't have enough information to say we're trapping more than we would've otherwise, or we're not. Casillas: You noted that the sediment transport has dropped from the 1970's to currently from 5.3 yards to less than 1. What is your take on how that affects physical processes in the estuary? For the panel, the consideration is what is the impact on biological processes that need to be considered with that drop? Eriksen: I'm not sure. It's probably reduced the amount of deposition that's occurring throughout the estuary because there's not as much sand coming in. The estimates on fine sediments were that 30 percent of that was depositing, which is also part of the reduction. So with that kind of trapping of fine sediment probably most of the sand is being trapped as well. So annual deposition has probably gone down accordingly. The drop may be significant, and it may not. Channels are still changing and there's still bedload movement out there, both in the main channel and at least in the shallows adjacent to the main channel are still transporting sediment. Beyond that, I can't really tell you what it means. Boesch: Is there any evidence that it's maybe resulting in a reduced deposition of marsh colonization of tidal flats? Eriksen: It could be. Evidence, no, because there was no pre-development rate of in-filling, and there's been no measured rate of those created now. In theory, you'd think that that might've been one of the results, but as far as data and such, there's no basis to make the comparison. Goldman: Any data on shoaling, resulting from dredge spoils at the margins? Away from the channel? Eriksen: There's data, yes, but there's no shoaling away from the channel. We've done a number of studies over the years. A couple of the more detailed ones were on disposal sites where we went in intentionally and called "point dump". We created a mound so that we had an identifiable figure on the river bottom, and then detailed surveys on those for six months to a year to see what happened to them. Because there was a perception that material dispersed from a dump site. Well, those mounds stayed in place. There was some initial reduction in height. We couldn't track sand waves away from them and we couldn't see a shift upstream or downstream; they just dropped in surface height. It may have been settling -- we don't know for sure -- but they dropped for a couple of months, and then they just sat there. A little bit of movement, some sand waves, developed off them, but largely they were just like the rest of the bed after that. So, there were no immediate effects a distance from the disposal sites themselves. Dunne: What are the biological functions of sedimentation and sediment transport? Well, first of all you've got sand that settles onto the bed someplace so there's a burial and an accretion. You've got mobility of bedload, so you've got sand waves moving. Fine-grained sediment -- some of it settles out in quiet water. So there's a shoaling.. at least however small it is, there's a very good accretion rate. Some of that fine-grained sediment presumably has a nutrient content, right? So there's a bio-geochemical flux to that. Even before this settles out, there are patterns of turbidity, and some of that may be mineral and some organic. So there is the physics. What's the biological significance of every one of those? Can we make a list and then write on those little arrows of Anne's [Fairbrother] a biological response of each of those? Then we can ask the modelers what will be the effect of this project on each of those physical responses, and therefore, on the biological responses. Goldman: For instance, in the [San Francisco] Bay delta, the lack of transparency from sediment transports is a major factor in productivity because the nutrient levels are sufficiently high that support all the photosynthesis that the phytoplankton are able to do in their limited euphotic zone. So suspended sediment has a major impact in the Bay delta on transparency and hence productivity. Dunne: Can anyone put the biological responses on the physical responses I've just mentioned? Baptista: I'm not a biologist, but I've asked that question of biologists a number of times. Although the answers vary, the notion is that the system seems to be turbulent enough that biologists don't consider changes in turbidity a major issue, at least in the context of Cathlamet Bay and salmon survival. When we've discussed measuring physical parameters, that will help fisheries research in Cathlamet Bay, turbidity has come up frequently as one of the parameters that can be measured, but it doesn't come up constantly at the top of the priority list to be measured. It comes up as 'it would be nice to know,' but not fundamental. Dunne: So you're saying that turbidity is not thought to be a limiting factor in this system? I was also thinking of suspended particles being a food source. Is there any evidence that that's the case? Baptista: There is significant evidence that there is biological activity in the suspended sediments in the ETM, not necessarily that it affects Cathlamet Bay-type of issues. Dunne: That sounds like one of the things we'd like to ask the modelers if they can generate. Examine what this project would do to that concentration of whatever it is -- food, biological activity -- that's suspended sediments, so to speak. Baptista: There are a couple of things for context that may be relevant for you to know. First, a bank-to-bank survey of this system has not been done since the late fifties. There's been a lot of surveying done in the main channel and near the main channel, but bank-to-bank surveys have been lacking. That is actually one of the difficulties in doing modeling. Just recently, we found out that the bathymetry that we were using in our models dated back from 1953 to 1958, which is the most recent date. And there are some changes between 53 and 58. So that's one general piece of background. The other thing you should be aware of is that this system is really very turbid. When my field staff goes to the field and dives to maintain the stations, they don't operate by sight, but by touch. It's very turbid in general in the areas where we have instruments, which are really quite representative. These points don't address your question, but those are background... Dunne: So even though it's a very turbid system, the biologists still don't think that turbidity is not a limiting factor. Baptista: The changes in turbidity that will come with a small alteration of the system will be noise relative to the actual value of the turbidity (and its variance) that is already within the system. Dunne: So just going back to my list of physics, are there any other biological responses that the biologists can identify? DePinto: One of the things that was brought up in Ron (Thom)'s talk was that there seems to be sort of a shift towards more biotic solids coming from upstream. A shift toward that as a pelagic pathway for food. And so one of your items was the fine-grained biotic solids transport of the system. There seems to be a change that has occurred pre- and post-regulation, as we saw with the data. That's one thing that probably ought to be looked at. It's not just turbidity per se, but it's the kind of solids -- their size and characteristics -- that lead to that turbidity that we really need to think about if you're going to think about the effects of an action on turbidity. Dunne: So is the question then for the modelers, 'Will the deepening of the navigation channel increase the efficiency of firing the fine-grained sediment downstream and lowering the lateral diffusion? Is that a question that biologists would want to know?. Baptista: You are starting maybe too wide in your parameter list. If you think about what physical modelers can give you, you really need to start at water levels. Then velocities, then salinity, temperature, and sediments. In a system like the Columbia, I would say that modeling sediments is neither an easy proposition, or one that is going to be accomplished any time soon. I've been asking the question what is the level of interest in turbidity as a parameter? Of course, it depends on what question you're trying to answer. If you're focusing on impacts on juvenile salmon for instance, in Cathlamet Bay, the interest level has been low. Courtney: We need to hear prioritization from biologists in terms of the parameters in the model. Tortorici: What Steven [Courtney] is referring to is a conversation that we had where we prioritized the elements that would be included from the physical side in the model. We came up with five priorities... Casillas: And as Antonio [Baptista] said, turbidity is not the first thing on our list. It's there, we talk about it, but we're really not sure how to grapple with it as a concept and a feature that salmon are relating to directly. In an indirect manner, the issue may be how does turbidity represent some sets of functions that represent ecosystem function that benefits the estuary in general. In that regard, maybe ETM, and infusion of materials into the ETM, as a metric that you would monitor as one of the measures of ecosystem health that one would go after. But the connection to salmon, which is the question we are posing, turbidity per se is not high on our list, but it's on the list at some point, but we're not sure exactly how to connect it in a direct way. Bartell: If I recall from the review of the original assessment, there were some assertions made about how increased turbidity might further reduce reactive distance for visual predators. Casillas: Correct. On the extreme side, there are some behavioral issues, but if we were to look at how the project would affect turbidity, those measurements come from catastrophic events in which they determined effects when Mt. St. Helen's blew. The amount of turbidity that was in the system was well over what would normally be seen. Under those situations, they did in fact see measured reduced reactive distance and an ability to capture food. Bartell: The other issue was the location of ETM. Casillas: Right. To me, that's a general sort of question about estuarine function. Again, the linkage to salmon would be somewhat distant. One way to look at would be to say, 'If the ecosystem is operating properly, then it's to the benefit of salmon.' How we qualify and quantify that with that measurement is a bit shaky at this stage. But I would ask Karl (Eriksen )-- one of the original questions I had -- on the input of sediment and the sediment change, how do you think that affects the ETM per se? Is it driven by what's coming into the system? Do you have any sense of that? You know, the reduction we have of 5.3 to less than 1 over the past 30 years, shall we say. Do you characterize that as having some impact on the ETM, and do you know that it has or hasn't? Eriksen: No, I don't know that it's had any impact. ETM is essentially the turbulent front of the salt wedge, and it might lower the concentrations a little bit, only of sediment... Casillas: But would that be something that we want to go after as one measure from general ecosystem health? Boesch: The sediments in the ETM are basically recycled sediments, they're re-suspended sediments, they're not necessarily sediments that are being actively put out at that time. Secondly, the biological importance of the ETM, at least based on studies elsewhere, has very little to do with the fact that it's a TM. It's that the physics, which creates the ETM, also is important in aggregating larvae and food, and things of this sort, independent of what the turbidity is in that particular system. So it's a coincident thing that the physics that results in a turbidity maximum has biological significance. So, the question is, 'What do we know about the effect of changing channel morphology on the location of the ETM and the characteristics of it?' As a physical phenomenon, and not just the fact that it's high turbidity. Tortorici: When we raised those issues about the ETM, that's what we were driving at. Is a physical change in the system going to affect the ETM, and if so, in what manner, and what can we say about that? And whatever that change is, large or small, then how do we value that change as insignificant, more significant, whatever. We had taken a look at the modeling input-output table as it was being developed. If you look at the left side of the column, it talks about hydraulic parameters of concern, and I'll just read them off: Salinity, ETM, surface water elevation, depth, velocity, shear stress, suspended sediments, and temperature. In having our in-house discussions, we thought that the top five to take a look at from a modeling standpoint would be salinity, surface water elevation, depth, velocity, and temperature. And then following that, in a more nested sense, suspended sediments. Goldman: I wouldn't agree on the suspended sediments from what we've been finding in the Bay Delta. It's a major factor in the fertility of the system. I think it ought to move up in priority, right toward the top. Casillas: Did I hear you correctly? You were saying to elevate suspended sediments? Goldman: Yes. In terms of importance. One thing, you've got automatic filter feeders in there and they take in sediment, along with any organic detrital material that they can use for food. If you've got more suspended sediment, they get less nutrition as they pass food automatically through their guts. Plus the euphotic zone is so greatly reduced by turbidity.In fact the Bay Delta system, according to the most recent studies, is really limited by turbidity. Boesch: I think there's no question that primary production in this estuary is limited by turbidity, too. I guess the point in hand is the degree to which we think changing the morphology of the lower estuary by deepening it by three feet is going to change the suspended sediment distribution. Goldman: Well, I was thinking more of how much more stuff is stirred up and the fine components of it staying in suspension. It's been stated, of course, that most of what's been dredged is sand that's going to settle back out, which won't have much of an impact on turbidity. But it would be nice to know how much of the material is fine enough to stay in suspension in lower turbidity in the estuary. Dunne: Regarding this table, the third column, under modeling approach, it says connection to biota. Do you expect that to emerge from a modeling approach, or are you in a position to specify. What is it you expect will be the connection of shear stress to biota, for example? Casillas: This is developed by Karl and Rick. We've had input to it, and we tried to identify physical features we think are important that may constrain availability of salmon habitat. We were trying to help by identifying the physical features that one might want to look at as input parameters and that would help guide output parameters. The connection to the biology, we agree, is going to be the difficult one to make. Courtney: Let's save this till tomorrow (discussion of table). To some extent, I wanted to maintain your focus on trying to identify the factors we need to incorporate. I'm not trying to dissuade you in any sense from driving to that conclusion. I think you've heard that folks have been thinking about it and doing their best to prioritize parameters. Since we've got presentations and we'll get to some of that tomorrow, maybe we should focus back on salinity modeling opportunity. Rob McAdory, Overview of Corps Modeling view: CRsalt042801.PDF Goldman: Since the salinity flows go up so dramatically with low flow, what's the minimum possible flow in the Columbia? Karl: The minimum recorded was 36,000 at The Dalles, and that day had 5,000 in the Willamette, so about 41,000. Historic flow at 40,000; with regulation, even this year, they're predicting somewhere in the 70,000-80,000. Goldman: That's lower than the 120,000 in the model. DePinto: In your model, basically the outputs are salinity, tide range, and velocities. You didn't really talk about velocities. I was just wondering whether there were changes in velocities. McAdory: I didn't compare those. I could've, but I didn't. DePinto: Well the reason I ask is that while it's beyond the capabilities and the time available to actually model the sediment transport system, we might be able to get a handle on the extent to which this might impact re-suspension by looking at bottom velocities or actually calculating bottom shear stress and to see whether that changes significantly from base to plan. Not actually modeling the sediment transport, but just seeing if there are changes that are large enough to affect re-suspension. McAdory: This graphical user interface allows you to take the difference between solutions. In fact I did that this morning. So if I could find those others, I could take the difference between the two, or I could take the ones that I have and square the velocities and compare those and make some idea, depending on what you prejudice is, about sediment transport and how its related to velocity. I do have some of these old results in the can, and they could be used in that way if Karl wants to see that. Dunne: Karl [Eriksen], you began your presentation by talking about the fact that the morphology of the estuary had changed over 100 years toward closing up the north channel and focusing flow into the south channel. Now, one of the things we were given to read said that the major penetration of salt water on the flood tide comes up the north channel and spills across into the south channel. Presumably, given long enough, and I don't know what is long enough, if that north channel continues to shut off then it would spill more salty water on the flood tide into the south channel. But did you decide not to address this question of the general shifting of morphology in the estuary because now the sedimentation rate's been shut off by the dams, or what? Eriksen: No, we were trying to isolate the impact from the change in the channel depth. Dunne: Yeah, but you're doing that given today's morphology. And I'm asking the question, 'Suppose the morphology of the bottom of the estuary generally changed in the direction that you were describing at the beginning of your talk and that that impacted the flood tide salinity distributions. Could you imagine, on some time scale, and I don't know what time scale that is, that eventually you'll have a whole different bottom morphology to deal with. So during the lifetime of your channel, you'd have more saline water penetrating further up the south channel, just because you're shutting off the north channel. McAdory: What do you mean by shutting off the north channel, Karl? Did you mean it's shoaling in up here and shutting off, or are you talking about water flowing over this area up here? Dunne: I thought you said earlier that that process is continuing? Eriksen: Yes. Dunne: Then is that likely to shunt more saline water on the flood tide toward the south and have more penetration of salt water up the south channel, and if so, what's the interaction on that natural evolution of the estuary with your deepened south channel? McAdory: One thing I talked about when I was showing those movies is that you can see that right around in here, there was a spot where the salinity went down and I think what it's due to is that one of these little hills was cut down here and allowed more salinity to come up this way that otherwise would've gone this way. In fact, you saw this get a little fresher up in here, and my interpretation was in the absence of this shoal, more of it would come up this way and less that way, and make this a little bit fresher and that a little bit saltier. And that sort of gets to what you're talking about. In other words, you can change the share of salinity that goes between these two if you change their relationship. If you completely put an island here so there was no exchange this way, that might mean that more salt water got up in this way because it can't all get up in there, or it might mean less because there is a transport of salinity and water over these shoals into this area. The way it is now, it comes up and spills over in there. If you'd shut it off, it might just cause some kind of a residence in here with a lot more water coming and going. That's why you have models so you can play with that and see. But I do believe that the interaction between the salt in the north and south channel depends on these depths to some extent down here, so it's a good question. Baptista: So the discussions you're having are being based on the bathymetry that's on the screen. You have to keep in mind that what Rob [McAdory] did was a preliminary study with a preliminary resolution in the estuary. So it may be worth looking at the actual bathymetry, and you'll see that that shallow zone is actually cut through a number of small channels, and there are some differences also in Cathlamet Bay. That's useful for the process of discussion. I can bring that bathymetry up tomorrow. McAdory: The idea was that you make the same mistakes in the base and the plan, they sort of factor out, and you try to look at the differences that are represented by what you're interested in, that is, the change due to the bathymetry in the channel. Any model is going to miss some details. It's just a matter of making a decision about how close you want to get your answer to make a decision to do or not do something. Ed Casillas, NMFS Science Center Overview of the Corps' Estuarine Model view: NMFSmodelquestions.PDF Dunne: I know that reductionism gets a bad name sometimes... but, to me, your approach seems to throw up your hands and say, 'I can't isolate anything.' Casillas: I'm not referring to single projects... Dunne: A project, like dredging the channel three feet deeper, could be regarded as a single, independent factor. Casillas: In the context of how we would try to operate and to conduct the evaluation, that was the discussion of the context. Should we look at it by itself in isolation? We would say, 'No, we would want to look at what has happened in the past, how does it look like now, and what do we project in the future?' Dunne: How could you ever raise an objection to it? Casillas: I don't follow your question. Dunne: How can you raise an objection to a project without doing all those things if it's not possible to isolate a single, independent factor? It seems that taking this approach completely neuters any kind of scientific approach. We can't study everything all at once. Casillas: No, but what I'm saying is that there are certain levels of integration that we know we can work with now. Remember, this is in the context of salinity modeling as an element to evaluate this particular project. In a generic sense, we need to be much broader in our evaluations. Past evaluations have gone on ad infinitum, looking at very independent factors, trying to make projections, in a reductionist approach. The issue is when we go to the ecosystem perspective, we know that single factors aren't driving those systems so this is only pointing out the broadness of how we have to look at the evaluation not the limitation that presents a limitation to us. Dunne: In the past, people have looked at tiny incremental changes, and things have gone to hell in a hand basket. It doesn't mean automatically that, therefore, we have to try to take the opposite approach -- which is completely intractable -- which is to study everything. Casillas: No, I'm not suggesting you study everything. I'm just saying it should be broader than one thing. Dunne: Okay, how broad? What does 'taking the ecosystem approach' mean? Particularly, since you've already just referred to it in a full historical context. Casillas: From our perspective, that's what we're trying to gain -- input, information, and evaluation. One looks at constructs of the habitat that we think are important and are defined by physical attributes that define how these animals use that. And ask questions how is that going to change when we do things, or how does that change in relation to natural variation? What happens when the climate changes? What happens when you have a shift in the species composition? What happens in those sorts of contexts? Those are things that we can do and evaluate from that perspective. Dunne: Can you give me an example of where an environmental management dispute has ever been analyzed with that full panoply of analyses, and thereby, proven to be tractable? Casillas: At this stage, probably not. Dunne: And so, do we know that it's tractable to do that? It seems to me you're talking about re-creating the whole of historically-based ecology. Casillas: What we will be looking at is a process that I think will get us further than we've been. Dunne: And how much further? Casillas: In terms of characterizing habitat change, we think much further, in an integrated sense. The question will be, and we understand the difficulty is really trying to arrive at the crux of the biological consequences of those changes. That is where we all agree we will have difficulty, but we will feel much better. For instance, if the outcome in an integrative evaluation of a physical set of matrices is evaluated, and we find that there is no change by however you evaluate it, we'll feel much better from that perspective. It won't answer the question that there won't be any impact, but we'll feel much better to let the project proceed with some monitoring going on. But, on the other hand, if we in fact see some differences with an integrative set of physical attributes that we see does in fact change in response to this evaluation, or this impact, then the question becomes how do we evaluate that in a biological context. And there is no clear way yet other than to develop a weight of evidence from the information we know as to how to interpret that information. That will be arrived at probably by regional consensus of those experts who have appreciation of the problem and the situation to gain a better understanding for the agencies, then to proceed and make a decision of how they will go. Dunne: You say we're not going to get to the level of uncertainty reduction that we all feel... science just doesn't do that. Can you say these are the things we need to know before we feel better. Casillas: That's the question I've been wrestling with for this project -- how will we know if we should or shouldn't feel better? What we did in the report that we recently finished is to develop a family of curves to describe how the system responds in relation to physical features that we think are important over a variety of different conditions and ask the question, 'What has changed?' If we then impose this project on that evaluation, and ask, 'Can we see any further change, or not?' We know the system has changed through the modifications that have occurred over the past 100 years, and then we ask, 'Did it change much more when we imposed this change on it?' We can't really resolve any change with the accuracy that we have. I think at least two things: One, do we know that we can see change with the evidence that we have, which we have documented already under constraints that we've imposed, and two, that we will have evidence that no change will occur when we impose the proposed change in the system. Now the problem will be what happens if we do see further change in addition to the historical change? And that will be a dilemma for us. Dunne: Have you agreed what those curves will be? Do you say, 'When we get those curves, and then we look at the proposed project through those curves. Of course, there may not be a single independent factor, but there'll be a finite set of factors, and to me, there's not a big difference between those two things. Casillas: Yes. Mostly because there is change over time, the system has been modified, and there's natural variation imposed on that -- all of those have added to the set of response curves that we see. I think the difficulty in trying to connect that, and that's what we said is the issue at this point, is that the lack of information of how salmon actually utilize the information, how we validate their use of the system so we can actually put bona fide parameter, numbers, boundaries about what we see. Until we have that, we can't really get to your answer. Bartell: But it seems that filling in this matrix will be a concrete step in the direction of identifying what some of those curves might look like and how they might relate to a solutions base . Casillas: Right. We do recognize the dilemma at the end of the road. And we're not clear from our perspective how we would talk to the region and tell them what we think when we look at these what we will actually say. Courtney: Maybe I can interject and clarify where I think we're headed in the workshop. I think the important words Ed has here are 'important' and 'single.' I think where you're headed is a finite list of a small number of factors you want to see evaluated, and a recognition that those interact. And they're not entirely independent. And if we can capture those two ideas, and I don't believe I'm mischaracterizing it, I think what you're saying is it's more than just salinity; there are a few other things we want to consider, and we want to see how all those things interact. Dunne: That's somewhat more limited than taking into account the history, all that sort of stuff. That gets intractable real fast. Casillas: Well, that serves as a basis that one would look at. Again, it's the qualifiers we use to describe what's going on, whether it's a small change or a small period of time. How long should we encompass our evaluation? Where are the limits? Where do we stop looking? Those are things that we have to address in this evaluation. We know that we have some information from the late 1800s. We've done some of that evaluation, and there's no reason why we shouldn't use that to further our understanding. It's not that we're trying to create something new out of the blue here. We knew we were developing this. In fact, we did develop it and you saw some of the outputs. So there are some limits. Yes, we recognize that. But we're basing it on information we've already developed. That can help set the boundaries of time you want to consider. How the policymakers will use that information, that will be up to them. Eriksen: You were talking about response curves. I wonder if you can explain what those are. Casillas: When we talked about depth and velocity criteria that we thought were important to salmon in relation to flow, in asking the question how did the system operate in some historical context, how did it operate now, and look at those curves and ask are they the same or are they different? If we say that what's important to salmon is a certain velocity, and we reduce that ability relative to flow, obviously we say there's a reduction in available habitat. As I said, the whole evaluation is a function of genotype, genetic, structure, the inputs in the system, the phenotypic expression of those animals -- how they interact with the environment -- and the availability of the habitat they use. So, if we remove one portion and see that the system is depressed, the question will be -- as Tom [Dunne] has alluded to -- how do we value that? That will be the difficult part. We agree, but at least we can define that and that will be more than what we have so far. And we recognize that that's probably the limit of where we can go at this stage. Bartell: Given that their model covered the entire system, do you mean that you'd like to see output from other locations in addition to the 29 places they looked at? Casillas: The characterization that we have speaks to a focus in the periphery as opposed to the channel. The channel was really what they were trying to characterize, which they adequately stated that that's where the biggest change is going to occur. But from our perspective, that's not where the salmon are so we really want to look more precisely at what's going on in the periphery. Boesch: But I think the model made the case that the kinds of changes that are likely are much less dramatic. Why do you need to refine the periphery? Casillas: We're asking for a justification that it adequately resolves what's going on in the periphery. As you saw, the grid focused on the channel - that was their purpose. The grids were less robust in the periphery so we just need some characterization that the ability to characterize what's going on in the periphery was in fact adequate with what they did. That wasn't presented previously. Dunne: But you wouldn't need a complicated model to reason out defensively that you'd expect the kinds of results they got in the periphery. Physical reasoning should tell you that they change in the periphery would be very small. Casillas: That's right. Dunne: So why do need to go refining that part of the model? Casillas: We have stakeholders we need to respond to, and they're going to say did you do the best you could do in this evaluation? Dunne: So stakeholder satisfaction is important? Instead of lengthening the studies, would it not be possible to have someone just explain to the stakeholders the physical reasonableness of that result? Casillas: They've tried, and they've done that, but stakeholders can be very contentious. I think we want agreement by all parties -- by the agencies -- that in fact the best was done that could be done. Boesch: Who defines the best science -- the stakeholders or the scientists? Casillas: Science, presumably. Dunne: So at some point you have to have a certain amount of trust in the science. There is good reason to believe that at the periphery, far away from the deepening, one should expect very little change. That's what their model says. You don't think that could be said credibly to stakeholders? Bartell: What I think we're seeing is that there's a certain contingent of stakeholders that would only be satisfied if you construct a linked hydrodynamic, salinity, sediment transport model that would re-create the entire history of the evolution of the estuary to be used to characterize the impact of this proposed project. Courtney: I'd like to interject. Part of what we do is get you to the point of facing up to the smell test. What I think I'm hearing from the panel is that it doesn't matter, we could do more modeling and would address your concerns, but we all know already what the results would be and that the effect would be trivial. Am I correct? Dunne: But what about the stakeholders? Courtney: It doesn't matter; that's not our goal. It's NMFS's concern. Our role is are we already at the point in the science to have confidence in what the results will be? And if we are, I think we should say so. And if you don't think it's enough to pass your smell test, we're here to back you up. Casillas: And I'll give you the background for the statement why I think we can do better. [Presentation continues] Curtis: I have a question and a concern. If you're concerned about the modeling, it seems like you want to be sure you're modeling the right thing. I'm not at all convinced that salinity is a dominant factor in determining the success of these young salmonids in the estuary. Are you? Casillas: No. Curtis: I'm not either.. So it concerns me that we're spending a lot of time on the salinity model and we haven't got our eye on the ball. I'm worried about those shallow habitats, too, but rather than doing a dance, that's what we should be talking about. What do you need to define those shallow habitats? Boesch: Well, if you're talking about altering the geomorphology of an estuary, the first-order question is how it would affect the salinity because that gives you indicators of a lot of other things. Curtis: I understand. But is what they have on salinity enough? And accept that it's enough and say so. It's time to start talking about the things that we think are more directly involved with survival, or success, of these fish in the estuary. [Presentation continues] Tortorici: I just wanted to add one thing before we finish. This gets back to the discussion at the beginning of Ed's [Casillas] presentation regarding the stakeholder issue. From our agency's perspective, and I think you can appreciate this, that because these species are threatened and endangered, we have to take a really close look at projects, especially of this magnitude, in order to make a proper policy and regulatory decision. I think sometimes because we talk about these species every day and we say, "Oh, they're threatened and endangered," it sort of flies over our head that the implication is they could go extinct. And so we need to be very careful in terms of the science we used, the perspectives we take, and the interpretation that we make of that information. Quite honestly, our agency is in a fishbowl. Everything we do is scrutinized -- I just can't even begin to tell you -- to the nth degree. And so while on its surface it may be obvious that this change is insignificant and so why can't we just explain it to folks and surely they'll understand it, in this environment in the Pacific Northwest, it just does not work that way. And so we need to be absolutely sure, to the best extent we can, that we've got the best science to make this decision. I say this to you all because we're not trying to nit pick here, and we're not trying to create extra work or problems or irritations for people. We're really trying to convince not only ourselves, but the other federal agencies and the public we serve that we've done the best possible job we can to do the analysis. Dunne: Cathy, that doesn't necessarily mean that running a complex, numerical model on the basis of what I'm sure would be adequate data eventually because we just don't ever do it, that's not necessarily the application for the best science. And it's not the best way to get people who don't understand numerical models to believe you. There's another way of doing science that's all about understanding and conveying that understanding. I can tell you, it's a lot more tractable than arguing about mesh size and how to parameterize... Tortorici: What we're trying to get to is a point where we're comfortable from a scientific perspective that we've got the pieces that we need in place to make the proper decision. I agree with you -- talking about mesh size and all that stuff to the general public is not relevant to them. It's trying to explain that in a biological context about why we're making the decision we are, and translating that into something folks can understand. That's where the rubber really hits the road. But we're trying to get the underpinnings straight in order to make the decision to have the proper explanation from both a scientific and a legal perspective. Courtney: This is a scientific process, the process we're engaged in here. You are presenting your cases, information to six eminent scientists who are going to give you their opinions. You can change the models on some of the things you're talking about, and it won't change the results. I think that's what I've heard. If that's the case, then that's a scientific opinion, which you must respond to. Boesch: Just listening to Ed's presentation and the critique of the salinity model, I agree that the focus on salinity is a response variable which, in terms of affecting the salmon alone, is a very uni-dimensional analysis when, in reality, these organisms are responding to a lot of other variables. However, I think the value of this kind of modeling, and I guess we should reserve judgment fully until we hear about Antonio's model tomorrow, in an estuary is that the distribution of salinity tells you a lot more than just what that salinity is at that point and what effect it might have on the organism. Because it is based fundamentally on the conservation of mass, and so it tells you a lot about the changes in the water masses that are taking place. So assuming that Rob's [McAdory] models are sound, I would think of the list you have up there, for the estuarine portion -- that is the brackish portion, the wide part of the estuary -- I would say based on first principles, in terms of understanding how the physics of these systems work, is that number one the salinity itself would not be substantially altered by the plan in the peripheral areas, and also that the velocities experienced by the tidal cycle would not be greatly altered because otherwise if they were, you would be seeing some pattern changes in salinity, and therefore, temperature as well. The one point you did make that I think would be worthwhile to look at, and I'd be interested to hear Rob's comments, is that the area above the head of the salt wedge, that narrow part of the freshwater tidal estuary, that alteration of the channel might be much more significant in terms of the hydrodynamics of that part of the system. And it could well affect velocities, even in the shallow areas. It could affect water level even. On many of the parameters you listed -- water level, salinity, temperature, and flow -- I would think that you could draw some strong inferences based upon that model about the relatively small degree of change that would be caused in the peripheral areas by channel deepening. So I think you can say things -- more than just about salinity from the model. Courtney: I think there are lots of things Ed raised some of which I think would be useful to go through in perhaps more detail. We're slated to get panel opinion, and I think those would be a good place to start. We've begun to talk about the adequacy of the model vs. the completeness of the model. There's the issue of the peripheral zones vs. the channel. I think we had a very rich series of comments, and I think it would be useful to run through them and maybe seek some comment on those. Would it be useful to look at the list of NMFS's concerns? Baptista: If I may add, Tom, I agree with your questions, 'Can we explain this reasonably to stakeholders?' with one exception. There is something peculiar about Cathlamet Bay, and based on that, I want you to consider whether there's reasonable doubt on whether there needs to be some more investment of time in this particular process. Dunne: If I understand what Rob said, what's different about that bay is that it has a deep hole channel in it that's connected to the channel to be deepened. Baptista: A couple of things are different. That's one of them. But the other is that it's a very sensitive zone relative to the limit of propagation of the ocean influence. So there are two things happening in that bay that are different. There are enough things we have done, quite independent of channel deepening, that are worth thinking about. Goldman: There was one comment about evaluating previous dredging. Do you have that data? Casillas: That was one of my issues that we would like to see. I don't have that. Boesch: Is that available in the EIS? Eriksen: It's not addressed in the current EIS. McAdory: There's getting to be some data sets about the salinity, like the ones Antonio's getting, I'm not familiar with those in detail, but to the extent they exist, these long-time series of salinity, particularly around the surface and edge, where things are important, but anywhere for that matter, it would be an interesting exercise to see if you could find the signal of the dredging activity in that. After doing some multivariate analysis and taking out the tide and the flows and things like that, can you see that signal in there because they do deepen this thing to these amounts every year or so, and there could be a lot of problems with that. Can you find a signal of the dredging anywhere in these salinity measurements that have been taken for years. Can you see a little change, up or down, that have been associated with that action? Courtney: I'd like to attempt to reach some resolutions, or at least get your opinions. I'm not trying to cut off discussion... I've put up what I think is the first of the series of overheads where Ed laid out NMFS' concerns. I'd like to run through those with you and hear your responses. The first one, I think speaks to the need to have broader conditions, more information, a broader range of models. What I heard from Ed is that NMFS doesn't have any fundamental concern about the model structure itself. Is that correct? It's just a question of how it's applied. NMFS feels they'd like to see a broader range of conditions because presumably that would tell them sensitivity to other conditions. We've begun to hear a suggestion from the panelists about what they think about that. If we were to ask the modelers to go away and run annual variations, have a broader range of conditions, what would be the utility of such an exercise? Boesch: I think it would be sort of pointless at high flow. The questions is whether you should experiment at some slightly higher, or the extreme low of, flows. That would constrain the exercise. Goldman: That's my comment that aquatic organisms typically respond to worse conditions and very low conditions in the [San Fransisco] Bay Delta system. And I would think that running the model at the minimum flows that are expected historically, or may occur again despite the dams ameliorating those flows to some degree, if you have a drought, you're going to run out of water. Your flows are going to get lower and the organisms are going to be a lot more stressed by this than they are by running averages. I think extremes are really important for the organism. You can lose a whole year class sometimes by some environmental extreme. Courtney: So what I hear is there is a comment on the fourth of these bullets, which is what are the most biologically relevant changes and you're saying - look at the extremes and that will tell you your worst-case scenario. Goldman: Correct. Boesch: The low-flow extreme. I wouldn't say the high-flow extreme because arguably you couldn't make a good case they would be altered ... the project from high flow... periodically. Bartell: I'm not sure I agree with your initial premise about no problems with the model. At least not according to the document we were given that reviewed the model. I don't mean to put you on the spot Rob, but I'm sure you've seen these comments before, from David Jay et al. Things that need to be addressed include difficulties with the numerical mixing algorithm, potential problems with different bathymetry data, limited horizontal and vertical resolution -- again this goes back to scaling. Not as a point of criticism, just to say that these issues are out there, and I don't know whether they've been addressed or resolved. So the assumption that the model has been generally accepted in terms of its overall structure and operations is not exactly correct. Tortorici: The issue is that what Ed was trying to explain in the construct of how the model was used, fine. McAdory: Not everybody likes my work, but I feel good about it, and the more I look at it the better I feel about it. Baptista: One thing I want to mention is that in my opinion, the work that Charlie [Berger] and Rob [McAdory] did, given the constraints they had in terms of time and resources and so forth, was quite good. Whether that would be the work that they would like for any model to use in terms of a basis for a regional study, that's a different question. Bartell: Don't misunderstand me, I think these guys are among the best in the world. Typically, the people that build and operate the models are the ones that are least satisfied with their performance. They're also the ones who have the best understanding of why they work the way they do and of their strengths and limitations. I was just curious in view of NMFS' concerns about model performance what kind of an effort may be under taken in terms of developing some kind of a consensus between the different modeling approaches. Boesch: So the question remains is the modeling good enough for the objectives. Cathy pointed out, 'Don't think only about salinity objectives.' You have to ask that question, 'Is it good enough?' rather than, 'Is it as good as it can be?' Because that may be something everyone would like to achieve, but it may not be necessary to answer these questions. Courtney: Let me press that point a little further. I think, taking your first point up here Ed, that you've got a qualified yes from the panelists that it probably would be worth looking at some broader questions, but not every condition. In fact, a very specific condition -- that is, low flow. Charles is nodding; I'm looking for you guys to record your opinions here. Dunne: Actually, I'm surprised the Corps didn't smooth their own path and do the low-flow... McAdory: Well, we did. The group thought it was inconceivable that flows would be at 120. They were thinking 134. When I went down to 120, I thought I was in fairy land, but I thought I'm going to cut it by 10 percent and see. So I don't know if that's true or not, but if you take all the dams out, who knows how low it will go. But as long as those dams are there, and they're required to have the flows at a certain level, they felt we would be wasting our time going there. Boesch: Under the current flow regulation regime, what's the frequency that flow would be less than 120? Baptista: I'll show some graphs tomorrow that may help. Casillas: 70 at the Dalles for a month, I think. Berger: But that's modulated by the time it gets to the estuary. McAdory: Modeling a lower flow would be easy. The lower the flow, the easier it is to model because the higher the flow, the more likely you are to have instabilities from those high velocities. Baptista: For a very different type of change, much more substantial than what we are talking about here, I will show tomorrow some results that indicate that changes for the higher range of river discharges may actually be more significant for the river than for the lower range of river discharges. Again, I'm not a biologist. I'm a physicist, interpreting data and putting it in a context that fisheries researchers seem to understand. Bartell: Rob, you keep calling this a screening calculation. What would you do to the model to take it beyond that characterization? McAdory: I'd want to verify it against a large data set. I don't know if there's one thing you could do; the more data you compare it to, the more time you take to run it, and the more detailed it is. Things like that. There does come a point when you feel like to answer whatever questions you have, you're wasting your clients' money. But for the purposes for which it was designed, I feel it adequately answers the questions. I'm not sure I'd do anything to it. We're just trying to understand what the order of magnitude of salinity changes are coming up due to this deepening, and then let a biologist tell whether that's important or not. Bartell: How deep would the channel have to be before you think could lighten up the system in terms of salinity? Berger: By the way, I don't know what the actual depths were run here, but it was more than the three-foot deepening. McAdory. Yeah, it was eight feet because we assumed there was going to be maintenance. I don't know, if you made it deep enough, you might make it very hard for that salinity to get out at all. Berger: At some point, you're getting pretty far away from verification, and you're putting a lot of confidence in whatever turbulence model you've got behind this thing. Well, of course, it gets turned off when you stratify it. If you get away from verification, I think you can get in trouble. McAdory: In this case, if you really look at the places where dredging is proposed and how much different that is from where they are, especially after they do maintenance dredging now, you're talking about an extremely small change to the cross-section of the system to all aspects of the system. I don't think anybody expects large salinity changes in the boundaries for these minor changes, given that everything else is the same. However, we're perfectly willing to be surprised and we do find some surprising results occasionally. For instance, your question instead of making it deeper had been make it a lot wider, then Charlie [Berger] would've given you some another answer from something we learned recently. So, you start off with some idea of where you're going, but you don't always get where you think you're going. So, I think the results are reasonable, and if we're still talking about whether we should invest more in the salinity order of magnitudes, I'm not sure I'd do it a whole lot differently. Courtney: Still looking for resolution, I'd like to pose a question to the fish biologist on the panel. Is there anything you would disagree with with NMFS's concern essentially that the periphery of the estuary is really where we should be most concerned? Quinn: I think it's basically correct. First, I want to step back and say that I appreciate Cathy's comments about their [NMFS'] responsibility because it's a very heavy one they feel, and if they don't carry it, nobody else will. I also think Ed makes a good point that is that it is unreasonable to salinity, how important is that, and we'll write that off. Temperature, how important is that, and we'll write that off. Depth and velocity. Because, in fact, the animals use a habitat space that's defined by a number of those things. To reduce them to simply to one at a time doesn't really do justice to the behavior that the fish have. I think it's a valid point to bear in mind, particularly if there are also interactions with other stressors, pathological or something like that. It seems to me that the important considerations of the whole estuary are probably on the edges, for the life history stages that use the edges. Those populations that are relatively large when they come down seem to, generally speaking, trundle through fairly quickly. Those that come down smaller spend more time at the edges and -- look around, what have we done? We've basically screwed up the edges, whether it's diking and docks. All kinds of things have been hacking away primarily at the edges. Until recently, people weren't even talking about chum salmon because they weren't counted at Bonneville Dam because there were heaps and heaps of them. And probably a lot of their losses have been estuarine losses, and also the kind of low-gradient rivers that flow into those areas. I think those are the right places to look, and it's reasonable to look at interactive kinds of things. It's real hard for me to see salinity per se being an issue, but in the context of other things, maybe it could be. So my feeling is not to minimize it, but to try and get it into a context where it's brought in with other things that will have a connection to growth, survival, migration, which are the main three response variables we're likely to pick up on. Boesch: I guess the key questions you might argue about are the third and fourth bullets. That is, whether the model can tell you some things about the potential for changes in the periphery of all those other variables, or whether those inferences are not justified. Or a justification has not yet been provided. In other words, given the kinds of dynamic changes Rob showed us, what kinds of changes would occur in terms of the altered hydrodynamics of that system to the peripheral environments that could make a difference? How would you come up with a plausible explanation. I'm saying that if you buy the adequacy of the model for predicting salinity changes, I think you have to buy the adequacy of the model for predicting salinity changes in the periphery as well. Because there's no other way to get the salinity there. It's all a connected system. So, in terms of the adequacy of the model, in terms of predicting the peripheral situation vis-à-vis salinity, my confidence hasn't been shaken by the debate. Now whether you can infer from that that salinity isn't changed, therefore, water level, current velocities are not also changed, we can debate that, but I think we can start by drawing some inferences that if the salinity isn't changed, therefore the general patterns of circulation and movement of water aren't changed, so why would water level and current velocities be changed? Eriksen: A lot of it has to do with the scale of the deepening versus the overall cross section of the river. Goldman: Right. You take it down three feet and its -- what -- 60 feet wide? Eriksen: Well, the channel's 600 feet wide, and there will only be a few places where we dig the whole width, usually one side or the other is deeper already. In the estuary, we're four miles wide. Even if you look at flood flows in the estuary, the tides drive water surfaces in the estuary much more than they do upstream. We did do a one-dimensional model for water surface elevations, and we didn't really find any changes until we got upstream of Longview and Klamath. As we got near Portland, we had, I think it was, 12 hundredths to 18 hundredths of a foot reduction in water surface. Again, that is reflective of the scale of the dredging as opposed to the overall scale of the process. Boesch: Having said that... I'm trying to reason aloud... I think the process among the agencies could be better informed by sitting down and specifically identifying those parameters that NMFS is concerned might be changed as a result of the channel deepening. Then examine the evidence, have a discussion, have a debate, and then come to some specific resolution rather than a general view that we don't understand the periphery well enough. Well, what is it about the periphery in terms of those key environmental characteristics that we have less than adequate confidence about? And how can I convince you that that won't be affected, or alternatively, what further analysis can we do to narrow that uncertainty? Courtney: I'd like to point your attention to the third bullet, which is what sort of variation should we look at? High flow, low flow... Should we also try to see that in terms of annual variation? Are there other things we need to consider? Temperature of the water coming down? How would we try to get a handle on looking at several factors at once. There are well-tried techniques of sensitivity analysis which do exactly that. And partition variance in terms of inter-annual, or daily, or seasonal, etc., tidal variation - would that be a useful exercise? And where one of the parameters would be channel deepening or not? That would then give you a context in which to understand how much of the variance would be associated with the channel versus what I've heard from Rob's and Karl's presentations, which is that it's a highly variable system inherently. Dunne: I think the pattern is more responsive to flow and to topography than it is to anything else -your exercise will not tell us anything we don't already know. What we're still not getting our heads around, and I don't know whether it's possible, is that the biologists would say, 'Look, if you could predict patterns of temperature and salinity through that estuary at the following range of flows (and, by the way, the low flow can easily be checked by going to the USGS web site)... Suppose for every month of the year, you've got predictions of temperature, salinity, etc. If you did that, you would know where all the flies are living, etc., and then you could say, 'Here's a kind of time series of flow in the Columbia, including its extremes, and here's how this project changes the volume of habitat, for example. Again, it requires the biologists to say, 'This is what these critters need.' It seems to me you'd get more answers out of direct modeling like that than you would by running a sensitivity analysis. I think we probably know what the answers are most like to be sensitive to, and then when we know that, I don't think we're going to do anything about it. I would say that you want to be concerned about the effect of the channel averaged over some significant amount of time. That would take into account whether you lose a year-class, have a bad energy crisis, or low flow, and so on. We need to simulate a range of discharges that take into account these rare events. You want to do it for the purpose of answering the questions, where do the bugs live, and where can the fish survive, and so on. Not just isolate the sensitivity to a variant. Bartell: We've seen some really good results on a short time scale. If we do this project, is there some mechanism to show how it might impact flows and sediment dynamics that will, in the long run, maybe 50-100 years, contribute to changing the geomorphology of the system to an extent that patterns of salinity do change dramatically, or it does have an impact on the periphery of the system. I don't know how to answer those questions because there are so many other things going on in the system besides the project. Dunne: Again, in the lowered sediment transport regime, with all those dams up there, it's hard to imagine you're going to get.... I raised that issue earlier -- maybe one of the things to model is what the impact on salinity would be if that northern channel shuts off, gradually over time. But it was hard for me to push that very strongly because sediment transport has been significantly reduced than any changes in the bathymetry of the estuary presumably now going on quite slowly relative to how they used to go on. Eriksen: Along those lines, I think Don [Boesch] pointed out, if you don't see a change in salinity, you can infer there's little change in velocity and flow distributions, flow patterns. And if those changes are small, the related changes in sedimentation, water temperature are also going to be small, undetectable. You can infer a lot from the salinity model and that's why we concentrated on it. We did look at water surfaces upstream with a different model, and there again, we're looking at a two-tenths of a foot change in water surface. It's about one-quarter mile wide, 500 square feet, or something, out of 100,000. So there's your range and sedimentation is not that accurate. To go and invest in a sediment transport model that you think is going to give you answers to that change. You can model the system if you're concerned about the system and you're looking to see how it operates from a sediment standpoint, but to go back and model that system and model that change from a one percent change of hydraulics, it's just not going to happen. Courtney: I'd like to characterize some of the things I think I've heard the panel say. You seem to be saying that you agree that it's more than just salinity. We want to know how does it translate into salmon habitat attributes. And when we know that, we can give you more information about what's the appropriate level of modeling that might be useful. I'd like to give each member of the panel the opportunity to record their opinions and thoughts on the modeling. Goldman: No level of statistical sophistication in modeling can compensate for having missed the most important variable. I think it's terribly important as we get into the fisheries part to try to figure out what's important to the salmonids-- particularly to the chinooks in the long-residence time in the estuary. I feel sorry for the NMFS people in the sense that they're faced with a declining fishery, and if the fishery continues to decline with this dredging approved, the public might conclude that the dredging was responsible, when in fact it's the dams and all the other perturbations to the population. So they're in a real difficult position. The other problem is that I found in the 40 years I've worked at Tahoe is that the smartest thing we've done is kept it simple for the public. 'Keep Tahoe Blue.' Everyone understands that and it works. In a sense, I think as we market whatever the decision of this overall group is about dredging or non-dredging, they have to make it palatable and understandable to the public. The other point that I made earlier is that aquatic systems are subject to extremes. The low oxygen is what kills off the fish. It may occur only once every four years in a hyper-eutrophic situation. But most of the situations that really make a difference to the aquatic organisms are the whole food chain. So we have to think about extremes. We have to think about the lowest possible flows that might be created by the drought and the power shortage in terms of coming to a resolution of this. Day 2 Antonio Baptista Alternative Approach for Modeling view: ESPT_figs.PDF Goldman: This was a very impressive presentation. But I'm struck by the fact that you're modeling is really driven by sampling hardware, what you can measure remotely, continuously record... Baptista: The modeling is not drive by that. The quality of the modeling is controlled by that. We look at the data to have a sense of how well we are doing. But when the data go off, we continue to model. Goldman: Okay. And it would be so useful if you were able to add just one parameter of real biological importance, like chlorophyll. I don't know if you know about the ROS units, Remote Operating Sampling units. Are your units intact and you go and download them. Baptista: Actually telemetry, so it's real time. Goldman: So you could actually include another sensor. Baptista: We can include any sensor that we can stick in the water. The problem with biological sensors is fouling issues. A lot of our maintenance in the field comes from fouling. Goldman: I'm well aware of that. The ROS units you can actually park in zones where fouling is less of a problem because they run up and down the wire. But it seems to me that this would just increase the power and usefulness if you could include a biological parameter like chlorophyll for instance, or like turbidity, which is still another physical parameter but which has a lot of biological implications like salinity. Baptista: We actually have had some sensors in the system. We are putting some now in Cathlamet Bay, which is an area where the fouling should be a smaller problem. Goldman: The other thing is that if you have duplicate endware, you can just change these, but it does mean that somebody's got to go out once a week... Baptista. I didn't mention this, but I have a field station in Astoria, and I have permanent stuff there. So they are in the water 3 out of 5 days a week or maybe more. Now every time you have to go and send a diver to change an instrument, it's expensive. So we have to try to balance what's feasible. Boesch: Antonio, the visualizations were striking. I got the impression looking at them, maybe a misimpression, that the ocean dynamics that affect the plume shape somehow have an implication of translating back to dynamics in the estuary.If that's the case, what kind of limitations would that provide to the kinds of models that Rob talked about? Baptista: The indications are not negligible, but it depends on the specifics of the boundary conditions. I think I would've done the same as Rob. He imposed a salinity of 33 part per thousand, which is quite reasonable. And he imposed one tidal level in the ocean boundary. Those are things that you can play with and try to minimize the lack of the bigger system. I believe that the bigger system needs to be there for CORIE; I don't actually believe that for a three-month study, or whatever the length of the study was, that you can afford to put those things in there. There would be a difference in the results -- change of salt, etc. DePinto: When you say there's a difference in the results, I agree there would be a difference in the absolute concentration, but would there be a difference in the change pre- and post-channel deepening? Baptista: That's a key point. My sense is that there are other things in the modeling approach that would probably affect the change before that comes into play. For instance, wetting and drying would be one of those and perhaps the six levels that we're using will affect that before you come to the point where the ocean conditions affect the change. Boesch: You emphasized that it isn't necessarily the low flow that we should be concerned about because the models that you ran from the 1979 and 1890 differences in terms of response of the different flow regimes showed that the habitat opportunities under low flow conditions in the estuary really haven't changed that much. Considering even with rather types of dramatic types of morphological changes compared to the one we're thinking about now. So that if you buy that, additional morphological changes are unlikely to affect the habitat opportunities under low-flow conditions. It was only in the case of Cathlamet Bay and upstream with higher flow conditions that habitat opportunity was affected over the century. The other thing I noticed with respect to the discussion we had yesterday about what is the low-flow condition that should be tested. Rob's [McAdory] point is 120 is as low as anyone could imagine. But your 2001 data are about that. So, on a kind of a time scale, that is weeks to months, that is going to be meaningful to the estuary. The impression I'm given, based upon those two observations -- both the first one that historically low-flow habitat opportunities have not been altered very much, and secondly that the low flows sort of averaged over the period of weeks to months during this year, which is a very low-flow period, were not lower than the 120 cfs. It seems to me pointless to do exercises at flows lower than 120. Baptista: I don't disagree with that, but it depends on what you're trying to do. Curtis: I think one difference though is that right now the reservoirs are down about 30 or 40 feet from where they would be on a normal year because they've been spilling a lot for hydro. I'm not a hydrologist, but I think we're going to have a lot lower flows this year than 120 when we get to the end of the summer. McAdory: What you really want to look at is August-September. Baptista: The other thing is what is the critical period in which you are trying to understand salmon survival. If the species you're looking at is primarily is a summer species, then that type of flow is what you should be thinking about. Quinn: With respect to the depth criteria that they had, what's the general effect of variation in river discharge? At higher discharges, there is a smaller time period with the appropriate criteria. Because if I read the graph correctly, at higher discharges you have a smaller number of hours with the appropriate velocity criteria in the places where there was either no effect or downward. Is that correct for the depth as well? Baptista: Yes. However, the reason I always try to deflect from that is that I don't believe that the bathymetry representation in Cathlamet Bay that was used in these studies was appropriate. Quinn: I don't mean specifically Cathlamet Bay, but in general. Baptista: The trend is similar. The difference that is striking is that the habitat opportunity doesn't go down from pre-development to now in those graphs - actually it goes the other way. Quinn: I'm not actually worrying about pre-development; I'm just thinking about year-to-year with more or less what we have now. Baptista: You still separate zones. The same way you separate with velocity. Quinn: If you have a higher river discharge from one year to the next with the current channel and islands and so forth, does the time window of that depth criteria shrink, stay the same, or grow? Velocity, you've already said, goes down. Baptista: I'll have to look back at the graphs, which I can do. Quinn: I can intuitively visualize that. I'm just asking what the answer is. Otherwise, I'm left to conclude that the more water going down the river the worse things are. It's a darn good thing we built all the dams to save the fish from the river [laughter] Baptista: The reason I'm hesitating with my answer is that I don't believe in the depth-criteria results, given the uncertainties in the bathymetry. So in a complex system like this, I try to shy away from a model result I don't believe in. Quinn: Okay. You see what I'm getting at though. It's a huge magnitude of river discharge. I'm just trying to gauge the sense of the effects if they're positive, negative, or neutral against which we can gauge the effects to be associated with something projected. Boesch: The other way to think of that though, Tom, is in response to yesterday's discussion with Rob and Karl, in that, based on the model at least in the simple context of the change in the cross-sectional area in that part of the estuary on the basis of channel deepening, that the water level is not affected by channel deepening so that it's hard to imagine how the area time of depth inundation will be changed by the result of that. Quinn: Okay. But if you're trying to model the effects on the fish, you have a certain background that's imposed by year-to-year variation in discharge as well as tide and so forth. Where does all of this fit in. Goldman: Well, one thing I think that's quite obvious is that high flows have positive and negative effects. For one thing, you flush the food out of the estuary fairly rapidly. Phytoplankton doesn't have time to produce and divide and feed zooplankton and young salmon. At the same time, low flows can have negative effects from possibly low oxygen concentrations, concentration of predators with the prey. So moderation in all things -- maybe average flows are probably the best. DePinto: One thing I think we need to remember in this whole discussion is that this analysis of habitat opportunity that was done here was done with a two-dimensional model. So the only criteria they could look at was velocity or depth. The issue of opportunity vs. flow conditions for salinity might be very different, and you can only do that by applying a three-dimensional model. McAdory: Also the depth-average velocities in a stratified system are problematic because you could have large velocities going opposite directions in the water column, yet they average to zero, so it has its limitations. Baptista: It's true that the depth-average model... The only useful of this exercise was to start thinking about how to interpret this process. So this is the behavior for habitat opportunity based on the depth criteria. And you still separate the zones, but you have a much flatter behavior -- in some cases, it's a reverse behavior. This is the riverine zone. Those are Cathlamet Bay and Gray's Bay. Those are the two ocean bays -- Young's Bay and Baker Bay. So there's a fundamental different change in behavior, how it relates to river discharge. Bartell: Would it not be possible to go back and analyze the results of Rob's [McAdory] model in much the same way that you're doing this, using the same regional definition to look at plan and without-plan comparisons, and then certainly the argument falls back as to the credibility of those model predictions? Alternatively, you could do the same with your model. Baptista: Yes, but you require a range of discharges, of controlling forcings, to do it. You can't do it just based on low-river discharges. Bartell: Well, granted. But at least they can look at the two data points they have -- 134 and 120... Baptista: That's too close in one of the ends of this spectrum. Remember this goes from the 100's to the 600's/500's. McAdory: When you increase the flows, you increase the stratification. But, you move the whole thing downstream to where it's not relevant, it's less relevant to a place where the low... They're two balancing things there... If you get 600cfs, I'd bet you could drink the water at Astoria... Baptista: By looking at these types of things, you can compare a reference situation against whatever changed. That's true for pre-development vs. modern, and it's true to some extent for base vs. plan. Whether you can see a significant difference or not that's something to be looked at. But yes, absolutely. Berger: If you want to look at base vs. plan, then you could look at something like this, but you need to know what criteria you're looking at. I say this as a caution: numerical models are not reality. Baptista: Yes, it's important to keep in mind that these things are models. They are a basis for you to think about the system. That's it. Don't push it any further because we can't give it to you. Bartell: Yes, but coming back... The channel deepening would fundamentally alter the governing equations of determining how your system performs. And so whether or not you believe that 30cm is actually 30cm per second, you can still look at the habitat opportunity with or without the plan. And then argue what's the necessary level of resolution and calibration and evaluation I need to decide whether or not I believe that and use that information in the decision-making process. Baptista: And that's in effect what you guys [McAdory/Berger] have done with salinity. Right? You have a base and you have a change. BREAK Casillas: Do I think we need more spatial resolution than was done? The answer is yes. And more emphasis on the periphery, as we said. And, as Antonio showed, if the simple divisions that he made that were based on the CREDDP study point to that the estuary responds differently to various forcings, and so at least that seems to be a starting point to make those divisions. We had talked in our discussions that maybe if there's another set of even further divisions that we want to make -- we haven't looked at that yet -- but that's something we may want to consider. If the time frame allows this, I don't know. McAdory: With regard to the periphery, in my opinion, there's a small effect on salinity. Whether or not that has any effect on the organisms, someone else will have to determine. I think the spatial resolution was fine. I had nothing to do with the biological interpretations of the model. Eriksen: I support Rob as far as being satisfied with the study we did. I think one thing Antonio's analysis showed is that the only area of the estuary that really showed any significant change to any physical changes that have happened since 1880, was the Cathlamet Bay area. The lower bays and the central estuary didn't show velocity, or depth-wise, and real changes over that 120-year period. So I don't think there would be much point in putting a lot of effort into those areas and refine them any more than we have to measure the effect of a three-foot deepening on the existing conditions. If there are some questions about Cathlamet Bay, that maybe is an area where we could pick up a little more detail on the model. But I can't see going beyond that. Boesch: Would interpreting the velocity data that were generated by Rob's [McAdory] model be adequate to address the