Review of the Edwards Aquifer Habitat Conservation Plan: Report 1 (2015)

5

Applied Research Program

As Chapter 3 makes apparent, there is a great deal of knowledge regarding fountain darters and Texas wild rice within the Edwards Aquifer Authority (EAA) and their collaborators, but similar knowledge is lacking for the Comal Springs riffle beetle (CSRB) and most of the other covered species. Critical to the recovery and protection of all aquifer species is knowledge of the species-specific demography and ecology, including knowledge of natural population fluctuations. It is for this reason that the Habitat Conservation Plan (HCP) has an Applied Research Program, the intent of which is to “better understand the ecological dynamics of the Comal (and San Marcos) system(s), particularly under low flow conditions.”

The Applied Research Program has several goals. These are to (1) fill gaps in knowledge about particular listed species, (2) increase understanding of key processes that affect their population dynamics, and (3) provide data and information that can be used to parameterize and validate the ecological models. The overall goal of the program is to generate useful information during Phase 1 to be able to make well-informed decisions about the overall direction of the HCP during Phase 2.

Based on the projects funded to date and the composition of the EAA’s Science Committee, which plays an advisory role in the Applied Research Program, it is evident that the Applied Research Program was created to address primarily ecological questions rather than hydrogeologic questions. This is partly because the EAA already has an Aquifer Science Research Program in place to explore hydrogeologic and hydrologic modeling issues that may arise during implementation of the HCP (although it should be

noted that this program is not funded through the HCP). Accordingly, the Applied Research Program focuses on the listed species and the information necessary to adequately assess and model those species under both normal and critical drought conditions. The membership of the Science Committee, which reviews proposals for the Applied Research Program, is dominated by members with ecological expertise, with only two of the ten members being hydrologists.

Even given the focus on ecological questions, however, the Applied Research Program could be significantly restructured to better identify and then fill gaps in understanding the Edwards Aquifer system. Such restructuring would help to ensure that the limited funds available for the Applied Research Program target priority research needs to support the EAA’s ecological modeling efforts and the success of the HCP more generally.

With that larger restructuring need in mind, the following sections separately consider all of the projects that have been funded to date, organized by organism; new studies that might be part of the Applied Research Program; and the committee’s conclusions about the current Applied Research Program including how it is structured and its recommendations for restructuring. The intent is to steer the program in the direction that will be most useful for furthering basic understanding of ecological processes and modeling.

CURRENT PROJECTS

The following is a brief assessment of the 2013, 2014, and 2015 projects that make up the Applied Research Program, organized by species. Rather than provide an exhaustive description, which can be found in EAA documents, this section is meant to evaluate whether these projects meet an important need, such as filling a knowledge gap or being relevant to either the new ecological models or to the existing habitat suitability analyses. Later in the chapter, new project topics are described that should be considered for inclusion.

In general, the Committee notes that it is difficult to fully evaluate these projects until final reports are available because the information on methods and anticipated analyses in the proposals is very limited. Some of the proposals for the 2014 and 2015 studies had only two to three pages (out of almost 100) on methods, and very few discussed how the data would be analyzed. In contrast, these proposals had long and repetitive statements of investigator qualifications. Furthermore, many of the proposals listed a literature review as a task to be done. Literature reviews are usually not part of an Applied Research project, but rather are done during preparation of the proposal to demonstrate that the proposal authors have a strong knowledge of the background information necessary to develop suitable

hypotheses and propose appropriate methods for testing them. Finally, some proposals contained such statements as: “Specific hypotheses will be prioritized during the full literature review process.” It is very difficult to evaluate proposals when the hypotheses to be tested and the methods are not specified in detail. Without such basic information, it is not clear how one knows the appropriate methods to use, and whether any proposed methods would yield useful results. It should be noted that the final reports received to date are well written, but that does not help for those projects which do not yet have final reports submitted.

Fountain Darter

There are four major research themes related to the fountain darter that directly benefit from the Applied Research Program: better interpretation of the monitoring data, refinement of the effects of flow on darter, increased understanding of habitat use by darter (and potentially suitability functions), and generation of data and information for darter population modeling. We examined five darter-centric studies that have been or are planned as part of the Applied Research Program, as listed in Table 5-1. All of these studies have merit for attempting to address valid scientific questions. Whether these studies have met an important need for the HCP is examined by looking at their relevance to one or more of the research themes.

Study 1 involves a food source of the fountain darter, while Studies 2 and 4 focused on fountain darter movement and predation by two fountain darter predators in vegetated versus non-vegetated habitats. Thus, these three studies could provide useful information on habitat utilization by fountain darters. Study 1 has been completed and established a critical thermal maximum (CTM) of 37.89 °C for the amphipod Hyalella azteca taken directly from the Comal River. Nonetheless, it is likely that the tolerance of this species when confronted with multiple stressors could be considerably less than the CTM. The results would be strengthened by additional information about (1) the effects of temperatures between 28 and 34 °C, (2) how important and limiting Hyalella is as a food source for the fountain darter, and (3) how different spring flows relate to the temperatures tested (both magnitude and duration) under field conditions. It is not clear how the tested temperature would be expected to occur in the field, and then what percent of Hyalella would need to be affected to actually have a reduced food effect (and resulting slowed growth) on fountain darter. The overarching issue for these three projects (#1, 2, and 4) is the need to determine what fountain darters eat by life stage and in different habitats, and how changes in prey availability affect their growth and reproduction.

Study 2 examined movement patterns of fountain darters, with some observations under low flow and poor water quality conditions. The idea

TABLE 5-1 Fountain Darter Applied Research Projects

of using fluorescent tags to infer spatial movement patterns is excellent and useful for general understanding of fountain darter habitat for the ecological model. The analysis of the data could have been improved. For example, how to treat “lost” or non-recovered tags so as to not bias the movement information is always difficult. Also, the effect of low flow was not sufficient to be quantified. A follow-up study on movement should be considered, perhaps using tags that provide near-continuous information on the locations and temperatures experienced by the individually tagged fish.

Study 3 focused on flow (and vegetation) effects on fountain darter fecundity. If the sole justification for Study 3 was to resolve issues related to flow effects on darter, then those arguments should be strengthened. The study provided some basic and useful information on the timing of spawning based on observed gonadosomatic index (GSI) values; however, GSI cannot be directly related to batch frequency and size, which are needed in

the modeling to generate egg production for individuals and the population. Neither the effects of flow nor vegetation type on fecundity were quantified, either because there is truly no linkage or because the effect would be difficult to detect. That is, flow and vegetation may act indirectly on reproduction (e.g., via food and then growth) and it is not clear over what time period an individual’s habitat residency or recent past flows affect the energy devoted to reproduction (GSI) and batch development and release.

The predation study (Study 4) used an interesting progression of lab, pond, and field enclosures to examine predation rates. Oddly, Study 4 included “flow” in the proposal title but not in the proposal methods nor in the final report. Using single and paired predator species with and without vegetation seems promising, if the methodological scaling issues can be solved. Such lab and enclosure studies are notorious for having difficulties with predator–prey interactions because of unrealistic spatial and temporal scales (Carpenter, 1996, 1999; Drenner and Mazumder, 1999). Predation is based, among other factors, on the encounter rates between predators and their prey. Creating protective habitat (vegetation in this case) in small systems and failing to replicate aspects of the environment related to predator behavior and prey avoidance of predators can result in a distorted view of the role of predation. It is not clear that the results of the study (that predators are additive and that vegetation has no effect) will be generalizable.

Information about Study 5 (algal-bryophyte dynamics) comes from a 2015 proposal only, and thus is difficult to evaluate. In theory, this could be an important study for filling a knowledge gap about a suspected problem previously ignored. However, is not clear based on the proposal that the methods can generate useful enough information to justify this study over others. The chain of events provided as the rationale for the study is quite complicated (low flow → algal growth → bryophytes die → macrophytes decay → less darter habitat → negative effects on darter growth or mortality). The first few steps may be elucidated by the study, but the latter are likely to be challenging.

Most of the project proposals include as justification relevance to the fountain darter ecological modeling, and this is highly likely given the involvement of the modelers with the study design. It would be useful for the proposals to further clarify what the outputs of each study will look like, and then how those will be incorporated into the modeling. The link between the study outputs and the modeling will either be for process formulation (e.g., flow effect on fecundity), calibration, validation, or bounding conditions in scenario analyses. In order to make this link, and thereby ensure the studies are well designed for use with the modeling, the details are critical. Vague statements about how “a study measures fecundity and that the model needs fecundity” are inadequate for justification and will inevitably lead to the ineffective use of the study results in the modeling.

The final reports should state how the results will inform the process formulations of growth, reproduction, mortality, and movement of fountain darter, as well as model calibration and validation.

Modifications to these studies should be encouraged as the population model evolves and more details of the model are known. These modifications can also go in the other direction—that is, as study results become available they can influence how a process is represented in the model. For example, it may turn out that turbidity is a second order effect on feeding success, and thus the model does not need to include a turbidity effect on growth. Another example would be the movement information from Study 2 showing movement patterns and distances that require the simple movement algorithm in the model (e.g., move if too crowded or in poor habitat) to be changed in order to be capable of exhibiting the observed movement behaviors.

As recommended in Chapter 3, a full blown conceptual model would help to see where these studies fit into the big picture and determine whether they are of the highest priority. The studies for the fountain darter seem reasonable at a very general level, but are currently a loose collection of studies. They may turn out to be exactly what was needed to inform the ecological model. However, given the Committee’s experience, this is unlikely without a more comprehensive evaluation of the link between the study methods and the modeling needs, some preliminary simulation results, and careful examination of what is critical to the modeling.

Submersed Aquatic Vegetation and Texas Wild Rice

The focus on submersed aquatic vegetation (SAV) in the HCP is a result of its importance as fountain darter habitat. The SAV modeling effort (described in Chapter 3) will include growth, recolonization, and dispersal on a small gridded scale (0.25 m²), relying on various calculations to estimate the extent of these processes. It is anticipated that many of the projects in the Applied Research Program applicable to SAV and Texas wild rice (TWR) (listed in Table 5-2) will inform these modeling efforts.

In 2013 when the first set of studies was conducted, the SAV modeling effort was just beginning, such that the studies, which were preliminary, are not anticipated to have high relevance to the modeling. Nonetheless, some of the studies could provide potentially valuable data and information to the SAV model depending on how detailed it becomes. For example, the SAV model may be able to utilize information from Study #2 on the temperature thresholds for certain SAV to ensure their survival and continued growth, as well as information on their bicarbonate use (revealed in Study #3). The data on the relative growth rates for SAV species tested in Study #2 over a range of temperatures and CO₂ concentrations may also be use-

TABLE 5-2 Submersed Aquatic Vegetation and Texas Wild Rice Applied Research Projects

ful. The results of the field vs. laboratory study were predictable (Murray and Kemp, 2008; Sanford et al., 2008; Carpenter, 1999) and may not be particularly valuable to the SAV modeling effort. Plants that grow under field conditions experience variables not found under laboratory conditions, such as competition among species, grazing, and uncontrollable physical parameters (e.g., temperature, turbidity), making plant growth under the two circumstances generally not comparable.

Only one Applied Research project in 2014 is related to SAV or Texas wild rice, and it was not officially part of the program. This is the project conducted at Baylor University to develop an empirical relationship for converting SAV biomass data to areal coverage data. The results from this study are critical for the SAV modeling because all of the data gathered on the Comal and San Marcos systems are percent cover data, while the likely SAV model will simulate plant biomass. As gathered from a verbal description at the Committee’s second meeting and subsequent email communication, the methods for plant collection and laboratory analysis seem to fit with the goal of the study. Given that plants are collected intact, it would be an added benefit to collect plant length and stem counts. The grid size of 0.1 m² is standard for such measurements; however, it may be necessary to collect more than three samples if there is substantial variability when making the conversion between percent cover and biomass. The seasonal variability in plant biomass may not be captured if a species is only sampled once during the growing period. It should be noted that this study will not include Texas wild rice, probably because biomass sampling was considered to be too destructive. However, a stem count to biomass regression could be made without destroying many plants, thereby allowing for an estimate of plant biomass through assessment of the number of Texas wild rice stems.

After receiving the final report in early December 2014, the Committee had the following additional thoughts. First, the researchers did not use the same method of estimating percent cover as is used in the biomonitoring program of the HCP; that is, two people made a visual assessment of percent cover, unlike the biomonitoring program which uses cameras and GPS. Second, the researchers developed regressions to relate biomass to plant cover that involved determining plant volume, which was estimated by multiplying the height of the plant by the percent cover of the sample. This does not take into account the actual volume displaced by the plant nor the structure of the plant (e.g., branching, linear structure, etc.). Without actual volume measurements, it is unclear how accurate the conversion from biomass to percent cover will be.

Two studies regarding SAV and Texas wild rice will be pursued in 2015. The first is an in situ plant competition study using Ludwigia and two nonnative species (Hygrophila and Hydrilla verticillata). Ludwigia is important for fountain darter habitat, and restoration efforts are under

way to increase its presence in the springs. The study will assess Ludwigia growth under varying competition from exotic SAV species. If the initial stem length and biomass of the planted fragments are measured, then the study could provide data to inform the SAV model (e.g., growth and biomass for Ludwigia). In addition, information from this study could be valuable to increase knowledge of competition among SAV species. The second study is an evaluation of suspended sediment timing and duration and its impacts on Texas wild rice (and other SAV) and macroinvertebrates in the San Marcos system. As mentioned in the section on the fountain darter, this study will begin with a literature review, which is an odd approach since most proposals include a literature review by way of introduction and to establish justification for the proposed work. The proposal is contradictory in that it indicates one task to be developing methods for the study, but it also describes methods for collecting turbidity, invertebrates, SAV, and other sampling procedures in detail. Information from this project could fill a knowledge gap for Texas wild rice (e.g., the effect of sediment on plant survival). Since turbidity is largely produced by recreation, the information obtained from this study could potentially inform the implementation of mitigation and minimization measures targeting Texas wild rice.

Comal Springs Riffle Beetle

The CSRB has been suggested as an indicator species for several other Endangered Species Act (ESA)–listed species, and so additional information on this beetle may prove critical to understanding how it and other populations can be modeled in response to flow rates and sedimentation. The Applied Research projects related to the CSRB were intended to fill some of the knowledge gaps about this species, and several of the projects have potential to provide important ecological information needed for future modeling efforts. However, additional considerations are warranted to better prioritize the projects to produce the most relevant information for modeling CSRB populations and habitat. The projects in the Applied Research Program applicable to CSRB are shown in Table 5-3.

The goal of Study #1 was to use a novel experimental design to create “spring upwelling” mesocosms that could shed light on CSRB survivorship inside of the springs during periods of low flow and flow cessation. The vertical flow regimes created in the mesocosms were intended to mimic periods of drought that have caused Comal Springs discharge to decrease to the point that spring upwellings no longer connect the subterranean and surface habitats that CSRB likely inhabit in the wild. The study suffered from several methodological setbacks that resulted in unexpected mortality of the CSRB, making their use in future Applied Research projects problematic. The main experiments were thus conducted with the surro-

TABLE 5-3 Comal Springs Riffle Beetle Applied Research Projects

gate Heterelmis glabrai, which was found to be substantially affected by flow conditions (BIO-WEST, 2014b). It is still unclear what ecological or behavioral conclusions about CSRB can be drawn from experiments using surrogates, which have been used in other 2014 Applied Research projects (e.g., plastron studies).

Study #2 proposed to better evaluate the limitations of plastron respiration of the CSRB to reduced dissolved oxygen levels and elevated temperatures for use in habitat management and modeling of the CSRB. This project shares the same potential limitations as the extended low-flow study above, since a surrogate beetle species is being used pending approval for using CSRB itself. Additionally, without understanding the life history (e.g., number of generations per year and timing of different life stages

during any given month) of the CSRB, this information will have limited meaning for habitat management. It is also not clear from the proposal if only adults will be studied (much like the biomonitoring) or if both adults and immatures will be evaluated in these laboratory studies. There are important physiological differences between adult and immature beetles that are often species-specific. Further, this project represents an attempt to understand the mechanistic reasons for beetle death due to low oxygen or higher temperatures in controlled laboratory experiments without any understanding of the natural changes in population numbers related to the CSRB life cycle in its actual habitat. Filling the gaps in life history information would provide more relevant information to the HCP for future modeling and management.

Study #3 is a survey of the distribution of CSRB in previously sampled and unsampled springs within the Comal Springs/Landa Lake system, meant to provide important data for estimating the CSRB population. This is a critical study for providing relevant and needed information about CSRB for the future ecological modeling efforts. Although it does not include sampling to provide life history information, the project will test the sampling methodologies and detectability of the CSRB, in addition to identifying potential new habitats where there are populations of this threatened species. This project, which was on hold pending approval to amend the scientific permit for take and only recently began, should continue to be given high priority.

The goal of the 2015 proposed field study (Study #4) is to evaluate the importance of the surface, riparian, and submerged food sources to the ecology of the CSRB at the springs. Coupled with a better understanding of the life history features and habitat distribution of the CSRB (see Chapter 3), the results from this project could be quite informative to future modeling and management of this species.

NEW STUDIES THAT SHOULD BE PART OF THE APPLIED RESEAERCH PROGRAM

Fountain Darter

Several areas should be considered for future applied research on fountain darter. First, additional studies on movement would be beneficial, preferably allowing for Lagrangian tracks to be estimated. Various types of mark–recapture and tracking technologies could be investigated and tested to determine movement ranges and patterns under a range of environmental (e.g., spring flow) conditions. Sampling should involve different sizes of fountain darter during each of the key seasons. Understanding the movement patterns of individuals will provide information on the movement

exchanges among habitat areas, range size, and provide data for model calibration and validation.

A second set of special studies could confront the persistent lack of a relationship found between flow and fountain darter metrics. While we expect such a relationship at the very extremes of low flows, it is critical to refine the relationship at low to moderate flows and also at high flows (scour events). Changing flows can have effects on growth, mortality, and reproduction that can affect multiple life stages and accumulate over time, resulting in important effects at the population level. These relationships need to be delineated based on empirical evidence and, in some cases, quantified. While the planned flow-triggered sampling is a good idea, these measurements could be further supported by studies that use lab and field measurements to ensure responses are recorded over a range of flows. This is challenging because fish integrate the environmental conditions they experience, and measurements of flow are instantaneous.

A third issue is obtaining measurements related to individual fountain darter health that go beyond the densities and lengths of individuals measured in the current biomonitoring. Densities have high variability and are difficult to extrapolate spatially, and lengths alone are a relatively insensitive indicator of fish responses to conditions. There have been many bioindicators proposed that reflect the health of individual fish (Adams, 1990; Hasler et al., 2009; Adams and Ham, 2011; Kim et al., 2012), including variations on the classic condition index (Courtney and Courtney, 2014), non-lethal estimation of tissue composition (Cox and Hartmann, 2005), and determination of the number of samples needed (Gagnon and Hodson, 2012). There may be logistical issues in terms of not being allowed to sacrifice the darters to obtain the measurements, but this is worth exploring as a special study.

The use of habitat area, darter densities, and flow criteria to assess the health of the fountain darter population relies on mostly correlative evidence, and thus has a certain level of uncertainty when used to predict responses to changing flow conditions. While there is great value in this approach, it could be strengthened substantially over time with the addition of active research to determine more mechanistically how individual darters and habitat types interact to affect the former’s growth, mortality, reproduction, and movement.

For all of the Applied Research studies that are designed to support the modeling, a clear description of how the results will inform the modeling should be required. Results should inform how growth, reproduction, mortality, or movement is represented in the model, or they should be used for model-data comparisons (calibration or validation). As the ecological modeling for fountain darter proceeds, close interaction between model development and periodic sensitivity and uncertainty analysis should be

used to help identify critical unknowns and assumptions that would benefit from additional experimental and field data collection.

Submersed Aquatic Vegetation and Texas Wild Rice

The Applied Research projects for SAV should address the needs of the SAV modeling efforts by focusing on supplying data on SAV growth, dispersal, and recolonization for those SAV species that are the best habitat for the fountain darter. New studies that elucidate the interactions between SAV and the fountain darter would be particularly helpful, for example, determining once and for all which SAV species provide the best habitat and why. Are the fish using SAV for protection, to find food, and/or as a nursery area for young? Why do fountain darters prefer bryophytes and filamentous algae, which are not vascular plants, and how can that be incorporated into the SAV model?

For Texas wild rice, studies should focus on the restoration of this plant, in particular in areas that are considered suitable habitat yet are devoid of this plant (as discussed at length in the Chapter 3 recommendations). Applied Research studies could examine many aspects of Texas wild rice restoration, including planting Texas wild rice in suitable areas and monitoring for success, determining the effects of restricting recreation from areas where Texas wild rice is growing under various flow rates, and determining whether low-flow conditions are more detrimental to Texas wild rice than recreation.

Comal Springs Riffle Beetle

As discussed in Chapters 3 and 4, life history, life cycle, and spatial distribution information for CSRB is necessary for better modeling of this species. The main information gap is the lack of life history information on the CSRB, including information on true densities of both immature and adult life stages throughout the year, growth rates of the life stages, how many generations occur each year and are they synchronous, how fast the life cycle proceeds, or how the life cycle and other life history attributes like fecundity might be affected by changing flow or sediment conditions. Such information provides the foundation for developing a life table (stage-specific durations, mortality rates, and reproduction) and eventually a population dynamics model. While generating such information is formidable in the short term, striving to obtain information would eventually allow development of a population model for CSRB, which may be a long-term goal.

From the data presented in the biomonitoring reports, it is not clear if the adults and immature stages always share the same habitat in both

space and time. This is a critical piece of information because the long-term population trends (BIO-WEST, 2014c) that have been reported have only reported adult numbers. In order to acquire this information, it will be important for the HCP to identify how representative the currently sampling method (i.e., cotton lures) is to quantitative densities of both adult and immature stages of the CSRB.

One of the Applied Research studies for 2014 begins to address some of this information, namely Study #3, Estimate Comal Springs Riffle Beetle Population in Comal Springs/Landa Lake. However, this project does not identify life history information important to better understanding how the populations, or portions of them, respond to changing habitat conditions related to flow or sedimentation.

Finally, as discussed in Chapter 4, a better assessment of how well the CSRB acts as an indicator species for the other listed species will be critical for more comprehensive management of all threatened or endangered species that are not currently being monitored.

Phosphorus Sources, Cycling, and Availability

The annual summer green algal blooms in the Upper Spring Run reach of the Comal River indicate that there is an abundance of nutrients in the Comal system. These could be from natural sources or of anthropogenic origin. Anecdotal evidence presented in the algal decay proposal (BIO-WEST Project Team, 2104a) suggests that the blooms tend to accompany low-flow and high-temperature conditions. This indicates a strong likelihood that nutrients, particularly phosphorus, are coming from an internal source, such as sediments.

Many, if not most, productive aquatic systems are characterized as having relatively high nutrient levels in the bottom sediments, which have built up over decades of sedimentation and decomposition of organic matter. These bottom sediments, serving generally as nutrient sinks, also can be important sources of nutrients at certain times. In productive stratified (thermally and chemically) lakes, the sediments and hypolimnetic (bottom) waters are usually devoid of oxygen and are thus conducive to redox-dependent dissolution of inorganic phosphorus complexes, which upon destratification (e.g., fall overturn) can return to the surface waters as a major source of available phosphorus. In productive shallow systems, stratification is less stable, often occurs on a diurnal basis, and involves the chemical stratification at the sediment–water interface. In such cases, anoxia and redox-dependent dissolution of inorganic phosphorus complexes can occur each night, as respiration dominates biological activity. Each morning, when the chemical stratification breaks down, the newly released phosphorus is available to the biota (i.e., algae) in the water column. Such

a system has been described as a phosphorus pump (Hambright and Eckert, 2001) and can lead to relatively high levels of sedimentary phosphorus release in productive systems.

It could prove highly beneficial to the HCP to have a better understanding of the nutrient budgets in the two spring systems, particularly since flow and the potential impact of internal nutrient loading will likely be inversely related. In other words, in addition to the physical impacts of low flow, there could be very important indirect effects of low flow on the overall productivity and food web dynamics of the spring/river ecosystems due to nutrients.

A call for proposals to investigate and document P (and N) dynamics could attract scientists from across the country.

WORKING TOWARD AN ECOSYSTEM FRAMEWORK

The Applied Research projects for 2013 and 2014, as well as those planned for 2015, are generally useful for filling knowledge gaps and improving the planned ecological modeling efforts. However, the current program is directed toward individual species rather than the ecosystem as a whole. As discussed in Chapter 3, a generalized conceptual model of the entire Comal and San Marcos Springs ecosystems would provide a much needed foundation for guiding the Applied Research Program. Whether a single broad-scale model or a series of models at issue-specific scales, a framework encompassing all covered species, their potential interactions and drivers, and all available management actions, would empower the EAA with a common language accessible to stakeholders, scientists, and the general public. Such a framework would also allow efficient prioritization of projects. For example, the primary driver of the Incidental Take Permit and the HCP is spring flow, and yet there is still no clear picture of how spring flow will impact either the indicator species or the covered species as a whole. Indeed, only one of the indicator species, fountain darter, is designated for modeling, while there are no apparent plans for developing models for Texas wild rice and CSRB. It is expected that the relationships between spring flow and population sizes of fountain darter, CSRB, and Texas wild rice, as well as other covered species, will be highly nonlinear and complex, with multiple indirect forcing factors.

ENHANCING REVIEW AND OVERSIGHT IN THE APPLIED RESEARCH PROGRAM

The Applied Research Program is the EAA’s main tool to fill a broad range of knowledge gaps necessary for the successful implementation of the HCP. The scientists and engineers that currently conduct much of

this research are knowledgeable and experienced in the system and they represent the disciplines necessary to support work on species ecology, but they may not fully recognize their limitations or needs outside their area of expertise. The program would benefit by ensuring review, evaluation, and oversight from a broad range of stakeholders and by soliciting researchers from a broader range of disciplines as needs arise. Means of achieving this would be (1) more effective use of an advisory committee, such as the Science Committee, and (2) more open solicitations for projects. The membership of the advisory committee should be reviewed to ensure adequate representation from the stakeholder communities as well as the scientific disciplines necessary to address all aspects of the HCP. The use of this advisory committee early in the process to identify research needs and help write the project solicitations would encourage stakeholder input and ensure that all knowledge gaps limiting achievement of HCP goals could be identified and addressed. Use of currently funded investigators to define critical research areas is good practice, but their suggestions should go to the advisory committee for evaluation of the quality and merit of the research based on their own expertise as well as on reviews from outside researchers/scientists who are not associated with the HCP. That is, there should be a clear and procedural separation between the suggestions of the currently funded investigators and the selection of topics to be targeted in solicitations.

The use of an open solicitation that is widely distributed to universities, other research organizations, and the consulting community could help ensure that the expertise required to conduct the research is also available. The advisory committee, likely the current or expanded Science Committee, should again be engaged to help review and evaluate responses to the solicitation and provide input to the selection of the research projects. In addition to helping ensure that the best projects are identified and conducted, greater stakeholder involvement and engagement through the advisory committee would help ensure greater acceptance of the outcomes.

External peer review should also be employed to strengthen the quality and completeness of the Applied Research Program, particularly for proposals in disciplinary areas not well represented by the current Science Committee. Use of peer review is a critical aspect of developing a science-based HCP that is accepted by the various agencies and stakeholder groups.

A key aspect of fully utilizing peer review is a documentation trail of a request for proposals, material presented to the committee, outside reviewer comments, the committee evaluations, responses to the committee evaluations, and final committee recommendations. This documentation is critical to ensure the benefits of peer review and to ensure a transparent process for stakeholders and the general public. To aid transparency, a standard process should be adopted and followed for peer review of all project proposals

including when peer review will be limited to the Science Committee versus external reviewers.

The HCP states that biological goals and objectives formulated are based on the best “scientific and commercial data available.” This statement appears to indicate that “scientific” data are from the published peer-reviewed literature, while “commercial data” are from non-peer-reviewed reports prepared within the consulting industry. Obviously, both types of data could be of equal quality and value, and management and protection of endangered species probably should not always wait for the peer-review system to run its course. However, peer-review, whether conducted by the Science Committee or external reviewers, offers the best approach for identifying sound, evidence-based research on which the HCP should be based.

RECOMMENDATIONS FOR THE APPLIED RESEARCH PROGRAM

Through long-established collaborative partnerships with BIO-WEST, Zara, Texas State University, U.S. Fish and Wildlife Service, and other researchers, the EAA has a sound foundation for development of a proactive research program that will provide the needed scientific understanding to ensure a successful HCP. The Committee recommends that the EAA consider the following structural modifications to further increase the usefulness and efficiency of the current research program.

Project partners should be tasked with the development of a general conceptual model for the Comal and San Marcos ecosystems. As discussed in Chapter 3, these models should include all covered species, their potential interactions and drivers, and all available management actions, and will serve as important road maps for all future developments within the HCP.

The Applied Research Program would benefit from a more transparent process for prioritizing and funding projects that includes stakeholder involvement, for example through the Science Committee, and peer review.

The Applied Research Program would benefit from greater competition and collaboration with outside scientific experts through open and widely disseminated solicitations for research. Increasing the diversity of thought, understanding, and perspective will serve to strengthen the HCP and increase the likelihood that project goals will be met.

The program should offer some longer-term (e.g., two- to five-year) projects in order to maximize interest and collaboration from the region’s leading researchers. Multiple-year project proposals could be awarded with

the simple limitation that funding in subsequent years is contingent on funding availability, project needs, and project success.

Results from the Applied Research Program, particularly from outside researchers, should be provided in a form that ensures transparency and accessibility to other researchers and to the EAA. One means of doing this is a standard data management structure to which all research projects must adhere.

REFERENCES

Adams, S. M., and K. D. Ham. 2011. Application of biochemical and physiological indicators for assessing recovery of fish populations in a disturbed stream. Environmental Management 47(6):1047-1063.

Adams, S. M. 1990. Biological indicators of stress in fish. Symposium 8. American Fisheries Society, Bethesda, Md.

BIO-WEST. 2014a. Fountain Darter Movement under Low flow Conditions in the Comal Springs/River Ecosystem. Final Report. October 30.

BIO-WEST. 2014b. Effect of low-flow on riffle beetle survival in laboratory conditions. Final Report. November 14.

BIO-WEST. 2014c. Annual Report for the Habitat Conservation Plan Biological Monitoring Program Comal Springs/River Aquatic Ecosystem. March.

BIO-WEST and Baylor University. 2013. Edwards Aquifer Habitat Conservation Plan 2013 Applied Research. Final Version. November.

BIO-WEST Project Team. 2014a. Algae Dynamics and Dissolved Oxygen Depletion Study. Proposal #134-14-HCP.

BIO-WEST Project Team. 2014b. Ludwigia repens Interference Plant Competition Study. Proposal #137-14-HCP.

BIO-WEST Project Team. 2014c. Comal Springs Riffle Beetle Habitat Connectivity Study Proposal #132-14-HCP.

Carpenter, S. R. 1996. Microcosms experiments have limited relevance for community and ecosystem ecology. Ecology 77:677-680.

Carpenter, S. R. 1999. Microcosm experiments have limited relevance for community and ecosystem ecology: reply. Ecology 80:1085-1088.

Courtney, J., and M. Courtney. 2014. Improving Weight-Length Relationships in Fish to Provide More Accurate Bioindicators of Ecosystem Condition. Aquatic Science and Technology 2(2):41-51.

Cox, M. K., and K. J. Hartman. 2005. Nonlethal estimation of proximate composition in fish. Canadian Journal of Fisheries and Aquatic Sciences 62(2):269-275.

Doyle, R., S. Hester, and C. Williams. 2014. Edwards Aquifer Authority 2014 Ecomodeling: Vegetation Percent Cover to Biomass. Report of Research Activities. November 25.

Drenner, R., and A. Mazumder. 1999. Microcosm experiments have limited relevance for community and ecosystem ecology: comment. Ecology 80:1081-1085.

Gagnon, M. M., and P. V. Hodson. 2012. Field studies using fish biomarkers—How many fish are enough? Marine Pollution Bulletin 64(12):2871-2876.

Gibson, R., C. Norris, and P. Diaz. 2013. Determination of Limitations of Comal Springs Riffle Beetle Plastron Use during Low-Flow Study. Proposal #124-13-HCP. August 28.

Hambright, K. D., and W. Eckert. 2001. Sediment-water phosphorus dynamics in newly created Lake Agmon (Agmon-Hula wetlands), Israel. Verhandlungen Internationale Vereinigung für Theoretische und Angewandte Limnologie 27:4001-4004.

Hasler, C. T., L. B. Pon, D. W. Roscoe, B. Mossop, D. A. Patterson, S. G. Hinch, and S. J. Cooke. 2009. Expanding the “toolbox” for studying the biological responses of individual fish to hydropower infrastructure and operating strategies. Environmental Reviews 17:179-197.

Kim, J. H., D. H. Yeom, J. H. Kim, and K. G. An. 2012. New ecological health assessment approaches of an urban stream using molecular and physiological level biomarkers and bioindicators. Animal Cells and Systems 16(4):329-336.

Murray, L., and W. M. Kemp. 2008. Biological factors: Aquatic grasses. Pp. 115-120 In: Experimental ecosystems and scale: Tools for understanding and managing coastal ecosystems. J. Petersen, V. Kennedy, W. Dennison, and W. M. Kemp (eds.). New York: Springer.

Sanford, L., S. Suttles, W. M. Kemp, J. Petersen, and L. Murray. 2008. Physical factors: Materials exchange. Pp. 75-81 In: Experimental ecosystems and scale: Tools for understanding and managing coastal ecosystems. J. Petersen, V. Kennedy, W. Dennison, and W. M. Kemp (eds.). New York: Springer.

Texas State University and BIO-WEST. 2014a. Effects of Low Flow on Fountain Darter Reproductive Effort. Final Report. October.

Texas State University and BIO-WEST. 2014b. Effects of Predation on Fountain Darters Study. Final Report. October.

Texas State University. 2014. Suspended Sediment Impacts on Texas Wild Rice and Other Aquatic Plant Growth Characteristics and Aquatic Macroinvertebrates. October 1.

Zara Environmental, Inc. 2013. Study to Establish Comal Springs Riffle Beetle Baseline Population Distribution and Refine Riffle Beetle Collection Methods. Proposal #125-13-HCP.