"View from Here" Blog

By: Steve Culberson;

Ecologists are quick to identify the importance of usable, scale-relevant data when attempting to characterize and predict biological and ecosystem responses to physical changes in the environment. In particular, collection of ambient environmental data describing relevant habitat conditions (physical, biological; static, and dynamic) is the only way to understand biological condition and organism response to the environment. It’s also imperative that we use correct-scale data and information to inform our ecosystem management decision-making.

The frequent mismatch in the need for, and the availability of, environmental data is no more acute than when trying to discern climate effects (decadal time steps or more) to the well-being of biological species of concern (daily time steps or less) like Delta Smelt. Managing water systems on annual timescales for species that depend upon momentary conditions is perhaps not entirely sound.

Analytical Mismatch in Categorical Terms

Whereas climatic changes are (relatively) slow, an organism must achieve existence in every moment. Ecological models and survivorship forecasts for predicting biological performance frequently takes more resolute data (in time and place) than are normally, or historically, available. Furthermore, how an organism fares tomorrow and next week may have a lot to do with how it is feeling today and this week. A life history accumulates as existence through time.

One way engineers and ecologists keep tabs on the physical state of the San Francisco Estuary and associated watersheds is through documenting Delta Outflow (OUT) as reported in DAYFLOW (California Department of Water Resources). Additionally, it has long-been customary to characterize Estuary Annual Water Year Types according to 5 annual categories (Wet, Above Average, Below Average, Dry, and Critical) as calculated via the Sacramento and/or San Joaquin river indices (California Department of Water Resources), particularly where system management decisions and allocations are needed.

Unfortunately, this method of summarizing water yield from the watersheds is deficient when trying to build causal ecological links between the physical and biological components of the Estuary ecosystems. Many important water management decisions rely on annual, categorical descriptions of water yield (e.g., Delta Outflow, or OUT in DAYFLOW terminology), and yet even a cursory examination of this commonly used metric (Annual Water Year Type) leads me to think we need an alternative metric (or metrics) for describing the physical character of our watersheds if we want to improve our ecosystem of the Estuary and its management. Annual categorization of watershed condition can only do so much to inform the real needs of organisms that survive on a minute-to-minute basis.

There are examples (Mac Nally et al. 2010; Null and Viers 2013; Hammock et al. 2019; Hamilton et al. 2022) where analysis using categorical data is meaningful and useable, of course, but sometimes the use of convenient humanly-meaningful categories is found less than adequate (see discussions in, for example, Latour 2015; PPIC 2022), resulting in low P-values, poor predictive model performance issues, and inability to “prove” causation. It’s my intent in this blog to urge a change in how we approach and use this type of “physical condition leads to ecological outcome” analysis for management into the future. Improvements to our data repositories and computational abilities over the last decade support such a change.

An Example of How Categorical Descriptions for Management Fail Ecologically

Annual Water Year Type is too crude a metric (particularly in timescale) to usefully inform our need for improved understanding of ecosystem function when addressing Estuary water system management. We have available alternatives, and I’ll get to those after illustrating my point about mismatch with a simple example.

Relying on five water year types (categories) to describe our Estuary implies that we believe there are only five states of the Estuarine ecosystem. I don’t think we’ve demonstrably shown this, but for the sake of this argument and this blog I accept this degree of “lumping” for now. Importantly, another risky assumption of lumping water years into these categories asserts that all “within category” year are similar – that is, all “Wet” years are equal, all “Above Normal” years are equal, etc. Alarmingly, existing published ecological models attempting to be managerially-relevant rely on this long-standing historical decision regarding useful ecological Water Year categories. I suggest that this decision to treat all within-category years (“Wet,” for example) as equivalent as an input parameter for ecological models is faulty, and because of the prevalence of alternative, modern computing resources available everywhere, is no longer computationally necessary, as it once was. Why would I say this? How does this cloud our understanding and our subsequent attempts at predicting ecosystem performance based upon annual hydrologic summaries?

A few simple charts can show that this latter “lumping” characterization is problematic (that all “Wet” years are the same, for example, is NOT true), and the organisms we are attempting to manage conditions to support may well depend on the vagaries in conditions that this lumping causes us to overlook. I think this last statement (that of “overlooking nuances in environmental conditions”) is especially important given that many of our native and endangered species have evolved to exploit these ephemeral environmental vagaries. Such a systematic lumping of monitoring information leads us to ignore what is really happening at the individual and species-specific level, even while we explain to those interested that we have “included hydrology” in our ecosystem approaches.

My comments rely on visual inspection of graphical displays of all Water Years as mean daily outflow (OUT) in cubic feet per second (CFS) retrieved from DAYFLOW during July 2022 for the years on record from 1997-2016 (Figure 1). I previously conducted an undocumented exercise using the DAYFLOW record from 1930 to 2004 that supported a publication by Enright and Culberson (2010) that displays similar characteristics to the more modern excerpt of years included herein. This excerpt is used to facilitate ease of graphical display and a more general blog-appropriate discussion.

Three example “Wet” years were chosen to illustrate (Figure 2) my simple point that lumping masks important flow and stage characteristics (and likely many others as well) that can ecologically be quite different in years we describe or label as “equal.” As I mentioned above, I believe this can hinder the accuracy and precision of any ecological models constructed using this characterization and may cause us to reach erroneous conclusions about physical and biological drivers in the Estuary and to confuse what we may discuss as ecological “causation.”

Figure 2a is the mean daily outflow (OUT) for 2006, from the first day of the Water Year (October 1st, 2005) to day 365 of the Water Year (September 30, 2006); Figures 2b and 2c are for 2017 and 2019 Water Years, respectively. All of these years have been classified (categorized) as “Wet” years according to the Water Year Classification Index used by the California Department of Water Resources (accessed July 21, 2022). The Y-axis indicates the value Delta Outflow (OUT) for any particular day of the Water Year. As a reminder, for classification purposes, and as a variable used in many models designed to examine correlation or causation with/by stream flow in the Estuary, all “Wet” water years are deemed equal, ignoring the water flow features we can discuss using these individual outflow profiles.

For example, in 2006 we see an early outflow peak at approximately 95 days into the water year, or at about January 5, 2006, when the flows were more than 350,000 cfs. In contrast, peak flows in 2019 (another “Wet” year) did not occur until about 154 days into the water year (mid-March, 2019) and did not surpass 200,000 cfs.

It is likely that these different volumes and timings of peak flows (and build-ups and fall-offs to and from these flows, etc.) have different effects on the ecosystems of the San Francisco Estuary. There are organisms that time their spawning behaviors according to perceptions of “high flows,” for example. A difference of 100,000 cfs peak flow through the Delta may mean the difference between some floodplains getting inundated for longer periods of time (important to, say, Sacramento Splittail spawning success) or maybe not being inundated at all. It would be interesting to catalog all the differences we can plausibly find among all of these “Wet” years regarding inundation frequency, depth, duration, and water quality as a way to appreciate how all “Wet” water years are indeed not at all the same.

Fixing the Problem

With our ever-increasing need to construct ecological forecasting tools (for climate change reasons if for nothing else), and the now widely available computing resources that allow incorporation of continuously-collected data streams (as opposed to annual categorical data), why do many of our management-directed analytical efforts persist in characterizing hydraulic years as conforming to five pre-determined categories (even as we are already collecting flow data at 15-minute intervals, or more frequently!)? This doesn’t make ecological sense to me – organisms don’t respond to “categories,” they experience actual moment-to-moment conditions, every day – and our ecological understanding suffers when we predicate ecosystem behavior upon artificially-established categories. The problem becomes compounded when we choose management options that treat the entire system as having a single, categorical, “condition.”

I suggest we urge analysts who are interested in how hydrology influences the performance of estuarine biology to move away from older notions of “hydrologic performance,” and focus more fully on actual conditions that are already capably recorded on our data records. There’s no need to summarize data into categories when we have tools that can ingest and incorporate analysis and forecasting using an entire data stream of continuously collected variables. We are capable of this type of analysis these days, and in fact what our ecology is a product of – conditions in the field at every relevant time step – measured in days, hours, or minutes.

Perhaps relooking at the hydrological-ecological condition as part of an “ecological flows” perspective is what really is called for (PPIC 2020; Stein et al., 2021). What would a retrospective analysis reveal if the hydrodynamic conditions of the Estuary were treated more as states of a continuum rather than categories of yield estimations?

Closing Thoughts

At bottom, what I’m really on about is trying to use the best data we can (much of which is already available) and retaining resolution in our data collection and analysis when discussing management options rather than relying on summary-related practices that may have become out-of-date over time. Where we can improve our observational networks within the IEP and throughout the Estuary, we should. Where we can avoid summarizing annual conditions and include real-world measurements of real-ecology states-of-being, we should. Where our management discussions can appreciate the intricacies of ecology in our natural surroundings, they should. The citizens of California deserve this, particularly where it means we transform our analytical methods to reflect improved computational resources, better data management tools, and increasingly-informed conceptual relationships within and among ecosystem components. It’s time for us to think (and manage) ecologically!!

References

• Enright, C., and Culberson, S.D. 2010. Salinity trends, variability, and control in the northern reach of the San Francisco Estuary. San Francisco Estuary and Watershed Science, 7(2).
• Hamilton, S.A., Murphy. D.D., Weiland, P.S. 2022. An evaluation of the effectiveness of Fall Outflow Actions for delta smelt. A Technical Report from the Center for California Water Resources Policy and Management.
• Hammock, B.G., Moose, S.P., Solis, S.S., Goharian, E., and Teh, S.J. 2019. Hydrodynamic Modeling Coupled with Long-term Field Data Provide Evidence for Suppression of Phytoplankton by Invasive Clams and Freshwater Exports in the San Francisco Estuary. Environmental Management (2019) 63:703–717 DOI 10.1007/s00267 019 01159 6
• Latour, R.J. 2016. Explaining Patterns of Pelagic Fish Abundance in the Sacramento-San Joaquin Delta. Estuaries and Coasts (PDF) 39:233-247. DOI 10.1007/s12237 015 9968 9
• Mac Nally, R., Thomson, J.R., Kimmerer, W.J., Feyrer, F., Newman, K.B., Sih, A., Bennett, W.A., Brown, L., Fleishman, E., Culberson, S.D., and Castillo, G. (2010). Analysis of pelagic species decline in the upper San Francisco Estuary using multivariate autoregressive modeling (MAR). Ecological Applications (20)5: 1417-1430
• Null, S. E., and J. H. Viers (2013). In bad waters: Water year classification in nonstationary climates, Water Resources Research, 49, DOI10.1002/wrcr.20097.
• Public Policy Institute of California (2020). Making the Most of Water for the Environment. Report (PDF), August 2020.
• Public Policy Institute of California (2022). Tracking Where Water Goes in a Changing Sacramento–San Joaquin Delta. Policy Brief (PDF), May 2022.
• Stein, E. D., Zimmerman, J., Yarnell, S.M., Stanford, B., Lane, B., Taniguchi-Quan, K.T., Obester, A., Grantham, T.E., Lusardi, R.A., and Sandoval-Solis, S. 2021. The California Environmental Flows Framework: Meeting the Challenges of Developing a Large-Scale Environmental Flows Program. Frontiers in Environmental Science.

As I write this blog post in February 2022, the Program Planning Committee for the 2022 IEP Annual Workshop has finished its job (spread across 6 meetings since late-August 2021) and is looking forward to an interesting and varied Workshop Agenda during March 22-24, 2022. The IEP Program Support Team still has significant logistical planning to complete, but we’re making progress towards what we think will be another informative and engaging IEP Workshop.

Feedback on recent past workshops has been positive and encouraging, but not without critique. As we face a different future for the IEP Workshop in 2023 and beyond, I wanted to address a few items regarding the IEP Workshop format and outlook that might be a change for some who are not involved in the Workshop planning process. One thing that will remain is a focus for the Workshop that serves the IEP community first, and hopefully also satisfies communication and technical needs of others.

Focus and Logistics for the IEP Annual Workshop in 2023 and the future

An emphasis on information produced directly from IEP studies and surveys, including related science and program activities

While there is always a desire for IEP scientists to participate in more widely ranging venues and formal conferences concerning estuarine science more broadly, the IEP Workshop must renew its focus on the needs of its participating public servants. We leave the more formal conference organization (State of the Estuary Conference, Bay-Delta Science Conference, for example) to others who have resources dedicated to executing these conferences. The IEP Workshop provides a place to have more in-depth and less-formal interactions, including trainings and “lightning talk” formats, as examples. We’re looking for a place to share in-progress work, develop communication skills, and encourage collegial interaction to support those less-experienced within our ranks.

Decreasing reliance on registration fees

Quite simply, the popularity of the IEP Workshop has grown beyond our ability to support the 400+ participants that would like to attend each year, especially since we have no appropriate mechanism for conducting revenue-neutral registration while offering the kinds of amenities that conference attendees have come to expect from a more formal conference-like gathering. We have managed to pull off several recent Workshops in the face of increasing difficulties (through heroic efforts of IEP Program Support Team staff), but I’m aware that we have reached the end of this method of underwriting our Workshop. We simply don’t have the resources to continue to meet the needs of an annual gathering of 300-400 in-person attendees given the variability of external circumstances. We will continue to explore options to add remote aspects as part of our commitment to sharing IEP science in a timely manner while maintaining technical relevance.

What does this mean for future IEP Annual Workshops?

Change venue and format to be cost-neutral

The IEP Coordinators Team has committed to supporting the Annual Workshop through registration and communications in a cost-neutral way using available State or Federal facilities. This improves effectiveness of registration, training, tracking, and access to those who are directly affiliated with the IEP. It will mean that maximum size of the Workshop will decrease to approximately 200 people and will no longer include amenities such as food or lodging for out-of-town attendees, although they are readily available nearby. It also means we will not have to rely on a volunteer or paid vendor relationship to conduct registrations-related business and payment. Using vendor-based financing or voluntary donations of services of this kind has resulted in significant use of staff resources and resulted in increased financial liability in the event of problems or cancellations. We would like to further minimize or eliminate the need to use this type of arrangement in the future.

Future IEP Workshops will likely continue to include training modules to help satisfy technical and continuing education needs within the Program and will thereby help justify attendance by IEP member agency employees.

Increase our use of on-line tools for sharing updates on IEP activities

The IEP has increased the use of on-line media (web postings, open data repositories, on-line media access points, open access publications) to continue support for those who have come to rely on the Annual Workshop for updates on IEP activities and Project Work Team reporting. Our commitment to enhancing the scientific peer-reviewed literature, and accessible, informative Agency Technical and Annual Report publications remains, and will take on renewed importance as the Workshop becomes more internally focused. As a result, the IEP Annual Workshop can continue to be of use and interest to IEP scientists and managers for ongoing studies, programmatically focused material, and skills training for IEP employees, while the broader distribution of peer-reviewed science and reporting can be more effectively communicated using available, now-established means of electronic communication.

The technical arrangements of the Workshop Program and the physical venues we use for the Workshop will likely change substantially as we move to holding the Workshop in available public venues such as State/Federal auditoriums, public meeting spaces, or government hearing rooms. Many successful seminars and workshops have been held in these spaces in the past, and we think they will suffice for our re-imagined needs beginning in 2023 and into the future.

How can you get involved in planning the 2023 IEP Annual Workshop?

Participate in planning the workshop program

Volunteer to help with our planning efforts by sending your name and desire to participate to Christine Joab or Steven Culberson. We anticipate holding our first planning meeting sometime this coming summer (August 2022).

Send us your ideas for workshop topics and training

Help us understand what the IEP community is most interested in for training sessions and workshop topics. Send ideas for sessions or themed communications to Christine or Steve and bring them to the Science Management Team or your Project Work Teams for discussion and development.

Sign up to lead a session

Sign up to lead a presentation session, discussion, or training event and help identify speakers and participants. We’re looking to change the way we hold the Workshop while retaining what you have found enjoyable and useful in the past. We don’t know where to focus our efforts unless we hear from you. Please get involved and help the Workshop evolve in the way you would like.

Provide us your feedback

Of course, we’re willing to take feedback during the upcoming IEP Annual Workshop in 2022. If you have ideas, please bring them to us in any of our discussion venues or communicate your desires to your IEP Coordinators for their consideration. We look forward to hearing from you about the future of the IEP Workshop and what you’d like to see!

IEP Biologists sorting trawl survey samples onboard Program vessel. Photo credit: Steven Culberson

Welcome to my new blog! I hope you find it interesting and thought-provoking. This is the first in what I see as a series of short articles ("blogs") that treat issues of interest to the Interagency Ecological Program and the San Francisco Estuary science and technical community. If you have feedback or questions please let me know at iepleadscientist@deltacouncil.ca.gov. Here we go:

The Interagency Ecological Program (IEP) has been monitoring in the San Francisco Estuary for a long time. With the passing of IEP’s 50-year Anniversary in 2020, I’ve been doing some reflecting on where we’ve been, and where we’re headed. There’s lots to say (for future blogs, perhaps?!), and recount, and hope for, but one thing is clear to me as the IEP Lead Scientist -- we must review and revise our data collection programs.

What do I mean when I say “review and revise our data collection programs?” Well, it’s complicated. But I mean four things at least:

1. We have to reconfirm the need for the information we are collecting or change what we do to meet that need;
2. We have to examine the scientific justification for collection and analysis procedures while remaining devoid of programmatic inertia during the examination;
3. We have to be open to new ways of collecting data and producing information especially where overlap or gaps exist in current programs, and;
4. We must communicate better -- data collection achieves little if the implications of these surveys are not effectively delivered to policymakers, and if policymaker concerns are not reflected in our surveys.

Before I expand briefly on these thoughts, I will express great concern I have for pursuing potential Program reforms without appropriate resources, or serious, dedicated technically-oriented investigation – doing these evaluations quickly and without proper preparation, and at least some minimum external review, may lead to unintended consequences. Proper review takes money, brainpower, and time. Existing long-term datasets supported by IEP programs are not to be abandoned lightly, or without mechanisms in place to ensure proper conversion to updated methods. In some cases, failure to continue particular datasets may mean losing the ability to understand ecological change into the future, at just a point in time when unprecedented and rapid changes are occurring in the natural world around us. Abandonment of our past may mean moving blindly into the future. How will you evaluate ecological change without a data history? How will you define change if you don’t have a record of how things used to be? Conversely, are we being thoughtful stewards of the resource we are responsible for tracking and evaluating? Are we serving the public good? Are we effectively describing what we find?

Trawling near Chipps Island. Photo credit: Steven Culberson

At the heart of this reconsideration lies the need to effectively connect conversations agency directors, senior policymakers, and stakeholders have with the conversations of scientists and science program managers. Meaningful refinement cannot occur until we establish useful communication between data collectors and data users – this can’t be just creating effective products; it means we have to create effective interactions too.

Paramount in these discussions is the choice of what monitoring focus the IEP pursues: do we focus on the performance of listed species and the specifications of species performance as identified in Biological Opinions? Do we rather decide that the Estuary and its associated ecosystems are of value, and that we need to monitor the ability of the San Francisco Bay-Delta Estuary to provide ecosystem services that human beings desire?

I doubt we’ll decide the answer to these questions as “either/or,” but until we understand the motivations behind collecting information about the ecological functioning of the Estuary we’ll have difficulty structuring and understanding our monitoring enterprise. Why we need the information is a question that needs answering before we decide how to collect it.

In future blog posts I’ll go more in-depth into these four aspects of our reconsideration in turn, and treat other, related topics too, but for now I’ll close by suggesting the following:

1. We’re pretty adept at monitoring some things, but we could do better at learning from the ecosystem we’re responsible to monitor. I’d suggest more fine-scale monitoring at more carefully selected locations so we can articulate and understand important ecological processes across the broader Estuary. Ecological processes underlie everything we do to derive services from the Bay-Delta – from drinking water to healthy fisheries and habitats.
2. Decision-makers and scientists need to spend more time talking directly to one another. Technically-informed policymaking is poorly done via proxy – at the very least weak delegation of authority results in inefficient program management. Where data collection and interpretation is concerned it’s better to have technically-savvy decision-makers sitting together with Estuary-aware applied scientists than risk miscommunication and mimicking the familiar game of “telephone.”
3. The time is ripe for the IEP to embark on a concerted review process. New Biological Opinions and renewal/reissuance of water rights will depend upon accurate monitoring information in implementation. The Delta Independent Science Board is recommending such direction in its recent draft report on the IEP Science Supporting Management of the Delta (PDF), and the IEP is evaluating options for program element reviews of its long-term monitoring efforts.

I look forward to discussing more of this with you soon in future blogs. It’s time to revitalize our Estuary monitoring efforts -- let’s get to work!

Grizzly Island Bridge over Montezuma Slough in Suisun Marsh. Photo credit: Steven Culberson