7
Synthesis, Modeling, and Evaluation

Writing a science plan to guide the Gulf Ecosystem Monitoring (GEM) program for the next 100 years is no easy task. It is simply not possible to know everything that should be addressed. To be useful over the long term, the plan will need to be flexible. The issues in 10 years, or 20, or 50 may be different from today’s issues. Concerns about the ecosystem may change in the face of the possibility of increased tourism, terrestrial resource harvests (timber), hydroelectric development, and other changes in water usage and land use. Even so, we must qualify that we do not expect the GEM document to address each of these issues. This is where flexibility becomes important. The plan needs a system in place for synthesis of knowledge at specific points in time and evaluation of what has been learned and what needs to be done next to progress in understanding the ecosystem.

SYNTHESIS

An initial synthesis needs to include several components. The first step, a much-needed literature review, has been completed in the “Scientific Background” section in Volume II, Part 3, of the GEM plan (EVOSTC, 2001). Recent information from other geographic areas that contain relevant information can be incorporated when needed for specific topics. The second step, compilation, assessment and analyses of databases, has not been done. This step is critical to accommodate the imperative third step, which is a synthesis of Exxon Valdez oil spill research from 1989 to the present. Though a few programs have completed synthetic views of



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A Century of Ecosystem Science: Planning Long-Term Research in the Gulf of Alaska 7 Synthesis, Modeling, and Evaluation Writing a science plan to guide the Gulf Ecosystem Monitoring (GEM) program for the next 100 years is no easy task. It is simply not possible to know everything that should be addressed. To be useful over the long term, the plan will need to be flexible. The issues in 10 years, or 20, or 50 may be different from today’s issues. Concerns about the ecosystem may change in the face of the possibility of increased tourism, terrestrial resource harvests (timber), hydroelectric development, and other changes in water usage and land use. Even so, we must qualify that we do not expect the GEM document to address each of these issues. This is where flexibility becomes important. The plan needs a system in place for synthesis of knowledge at specific points in time and evaluation of what has been learned and what needs to be done next to progress in understanding the ecosystem. SYNTHESIS An initial synthesis needs to include several components. The first step, a much-needed literature review, has been completed in the “Scientific Background” section in Volume II, Part 3, of the GEM plan (EVOSTC, 2001). Recent information from other geographic areas that contain relevant information can be incorporated when needed for specific topics. The second step, compilation, assessment and analyses of databases, has not been done. This step is critical to accommodate the imperative third step, which is a synthesis of Exxon Valdez oil spill research from 1989 to the present. Though a few programs have completed synthetic views of

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A Century of Ecosystem Science: Planning Long-Term Research in the Gulf of Alaska their results (e.g., Fisheries Oceanography vol. 10, [Suppl. 1]—“A Sound Ecosystem Assessment [SEA] Synthesis”), most have not. Many studies that have been funded over the past 13 years have yet to be published. Annual reports are not publications and certainly do not qualify as syntheses. The knowledge gained about Prince William Sound is extensive because of Exxon Valdez oil spill funding. Retrospective analyses have led to new hypotheses and ideas in many instances, not the least of which is the concept of a “regime shift” (Francis and Hare, 1994; Hollowed and Wooster, 1995; Anderson and Piatt, 1999) and the Pacific Decadal Oscillation (Mantua and Hare, in press). However, there is much more to be gained from past studies that should be used to direct the future of GEM. The completion of the third step will lead to the fourth step: assessment of accomplishment of past goals. The synthesis of data and assessment of what has been learned in the recent studies will provide a starting place from which to hone hypotheses needed to direct GEM research. The generation of new hypotheses will lead to proposals for new work, which in turn will lead to the need for additional synthesis. Synthesis is an iterative process and as such is both the first and last steps. For GEM to continue to be successful, periodic re-synthesis of new data will be needed. A synthesis will assure that there is not a long lag time in publication of results and access to data of other GEM researchers, such as currently experienced under Exxon Valdez oil spill. A periodic synthesis on the scale of the five-year increments will promote comparisons between past and recent conditions. Additionally, scheduled syntheses will ensure evaluation of program direction. One presumption in a long-term program is that technology will change, providing opportunities for collecting new data types or collecting existing data more efficiently. Another presumption is that users will become more sophisticated, and their needs will change as they become accustomed to the data streams that are produced. Many successful programs incorporate periodic program review to assess how the program should change in response to these new collection opportunities and needs. (Weisberg et al., 2000). The synthesis will tell whether the science plan and the structure of the program is working. As GEM is envisioned to be a 100-year plan, we suggest that a time line on a scale longer than five years be included in the GEM plan. We have emphasized that long-term research is the linchpin of this program, and the projected time line should reflect that effort. Within that time line periodic syntheses should figure prominently. Synthesis should be viewed as a key component of the plan and funding for synthesis should be incor-

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A Century of Ecosystem Science: Planning Long-Term Research in the Gulf of Alaska porated. While periodic review is necessary, the long-term research should be modified only when a strong case can be made for improving the program (Weisberg et al., 2000). The synthesis and review should involve a wide range of scientists and community members, as data users are critical to the review process (Weisberg et al., 2000). MODELING Synthesis and modeling are interconnected. For example, one first could create a conceptual model that will tell which quantities need to be measured, collect data, synthesize data, and then create a more quantitative model. Alternatively, one could collect and synthesize data, and then create a statistical model that could be used to collect more data to verify the model. In a third approach, one could perform a synthesis on retrospective data and create a working model, also known as an hypothesis, which would be used to design data collections that are synthesized into more sophisticated models. Note that the models and syntheses may take many forms from conceptual to highly quantitative. Regardless of the order of these steps and the sophistication of the techniques, the components of synthesis and modeling are both critical. The combination of synthesis and modeling are tools for evaluation of past work: testing the appropriateness and accuracy of hypotheses and generation of new hypotheses. This approach will keep the GEM program moving forward by addressing issues that arise from the conceptual foundation and filling gaps identified during the evaluative process. The elements of a successful modeling component are outlined in the GEM monitoring plan. It is worth emphasizing that modeling should be a component in all phases of GEM as a research, synthetic, and diagnostic tool. The strategic elements for a successful ocean-observing program are a combination of in situ observations, remote sensing, and modeling (IOC, 2000). All three elements complement each other to provide a more comprehensive view of the environment. Because of the different spatial and temporal scales of response and variability in the physical environment and living resources of the Gulf of Alaska, models will be needed to merge disparate and discontinuous measurements. A hierarchy of models (statistical, theoretical, empirical) should be employed in the GEM program. The skill of models should be routinely assessed. Some models will require some form of data assimilation using information collected during the monitoring program. The data are inserted into the model to ensure that the model outcome more closely resembles the in situ observations. The GEM program should work toward more realistic and accurate numerical models for the prediction of ecological processes. The unparalleled opportunity of a long-term observation program in the Gulf of

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A Century of Ecosystem Science: Planning Long-Term Research in the Gulf of Alaska Alaska coupled with a concerted effort in modeling will produce exciting new tools for the management of the Gulf of Alaska’s living resources. REVIEW OF THE GEM SCIENCE BACKGROUND SECTION GEM planners have already made a first synthesis by compiling information in the GEM planning document (EVOSTC, 2001). The current “Science Background” section is a good comprehensive review of relevant knowledge. The document establishes a common background that can be used as source material. This should stand as an indication of what is known at this time. This state of knowledge in this work plan does not need to be updated, as the updating will take place routinely through GEM synthesis efforts. This is an excellent background from which synthesis efforts can begin. We applaud the GEM writing committee on the excellent scientific background that they created in Volume II, Part 3. This scientific background contains up-to-date knowledge and is well presented. In most cases there is a referenced, accepted scientific basis for the material presented. The use of figures to demonstrate concepts and points is well done. This document will be useful to inform the Trustees, scientific community, and the public. We recognize, however, that all interested parties will not read the entire document; we suggest that the “Executive Summary” highlights in non-technical language the main scientific points on which GEM is based. Generally the physical oceanography is well presented in Volume II of the GEM document. The major deficiency is the lack of attention to processes that might take place on the mid-shelf. While the shelf is addressed in the document, when the choice of habitats is selected, the document turns rather quickly from the Alaska Coastal Current to the offshore areas of the shelf break, continental slope, and deep ocean basin. The mid-shelf region might be very important to the nutrient fluxes and primary production of the region, because relatively deep nutrients must get into the euphotic zone, and the pathway is unknown. There are some smaller inaccuracies and over-simplifications in the physical oceanography section. For example, the definition of the shelf as being located at depths of less than or equal to 200 m is wrong, given that there are many locations deeper than that, including locations in Prince William Sound. There are also some problems with the discussion of circulation in Prince William Sound. Although this circulation is intimately connected with the circulation of the Gulf of Alaska, the plan emphasizes the circulation of the central Gulf of Alaska over the circulation over the adjacent shelf, and the thrust of this document pushes the studies into the deep Gulf of Alaska.

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A Century of Ecosystem Science: Planning Long-Term Research in the Gulf of Alaska In the GEM plan the discussion of time and special scales is very brief. This topic might well be the weakest part of the GEM program. The processes that affect primary production are going to have space scales on the order of kilometers. Single monitoring stations will not be useful tools. Granted, Ocean Station P and GAK1 measurements have added to our understanding of the system, but these are really “first looks” similar to an initial Mars probe. From ongoing studies, mesoscale physical and biological processes on the shelf are appearing to be important in the Gulf of Alaska. A program to measure on these time and space scales over the entire shelf will be very, very expensive to maintain. In addition, it is important to make measurements in winter, as this might well be the most critical time for the marine populations. Or GEM could break the problem; for example, in meteorology the long period changes are climate-related problems whereas there are daily changes (weather) embedded in these long-term processes. There are similar time and space scales in oceanographic processes, and sampling must be designed to measure all these scales. There is no distinction in the document with regard to the atmosphere. For example, GEM should develop studies to address the seasonal variability embedded in the long-term monitoring program. Three to five years of seasonal measurements will be required to determine the seasonal signal. After those studies scientists should be able to reduce the measurements into a monitoring mode, assuming that an increased understanding will allow more targeted sampling. Unfortunately, there is no example of a system in which this has been done. There are some physical science statements with which we disagree or question. We question the source of the statement about long-term warming of the northeastern Pacific Ocean. This has not been substantiated with data to date. The longest air temperature time-series for the region (Sitka, Alaska) shows no increasing trend since 1828 (Royer, 1993). We question where the iron limitation hypothesis came from. The hypothesis that the primary productivity on the shelf of the northern Gulf of Alaska is not documented. It seems likely that there is enough iron from terrestrial sources to offset any depletion, however, these measurements have not been made. The biological support for the science is good, and we commend the GEM team for this strong compilation of the current state of knowledge. Simultaneously, we would like the GEM plan to recognize the tentative nature of some of the most recent unpublished findings. Be aware that the conclusions may change when studies are completed and prior to publication. GEM should not be dependent on tentative findings. A 100-year plan should be only a broad outline with details to be worked out in work plans. A broad-brush understanding of the area in question at this time in history is necessary for the start of a 100-year plan.

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A Century of Ecosystem Science: Planning Long-Term Research in the Gulf of Alaska It is inappropriate to include detailed research questions in the “Scientific Background” section, such as: “Do diurnal-period shelf waves along the Kodiak shelf influence biological production and the dispersal of planktonic organisms (EVOSTC, 2001, Vol. II, p. 64)?” We suggest that these questions be removed from the document. The objective of this section of the document is to set the stage for the scientific questions and hypotheses to be generated. We cannot fault the questions themselves, because they ask just about everything. They are at once extremely general and too detailed. Including this level of detailed questions in the background of this document leads us as reviewers to believe that all research will be restricted to addressing these specific questions. That would discourage original hypothesis generation and research in the proposal process. In conclusion, we believe that the GEM plan we reviewed provides an excellent scientific background for the Gulf of Alaska region. We want to see a synthesis of data that have been collected under Exxon Valdez oil spill and we want to see periodic re-synthesis and evaluation. We suggest that various types of modeling will be useful tools to aid this synthetic process.