Huachuca Springsnail SSA Report June 2016

Species Status Assessment Report for the Huachuca Springsnail

Version 1.0 June 2016

U.S. Fish and Wildlife Service Region 2 Albuquerque, NM

Arizona Ecological Services Field Office Phoenix, AZ

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Huachuca Springsnail SSA Report June 2016

Species Status Assessment Report for the Huachuca springsnail. June 23, 2016 U.S. Fish and Wildlife Service, Region 2, Albuquerque, NM

This document has been prepared for the purposes of peer and partner review. It is not intended to solicit comments from the public at large.

This document was prepared by Nichole Engelmann with assistance from Mike Martinez, Susan Oetker, and Stacey Stanford.

Suggested reference:

U.S. Fish and Wildlife Service. 2016. Species status assessment report for the Huachuca springsnail. Albuquerque, NM, 73 pp..

Species Status Assessment Report For

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Huachuca Springsnail SSA Report June 2016

Huachuca springsnail (Pyrgulopsis thompsoni)

Prepared by the Arizona Ecological Services Field Office

U.S. Fish and Wildlife Service

EXECUTIVE SUMMARY

This species status assessment reports the results of the comprehensive biological status review by the U.S. Fish and Wildlife Service (Service) for the Huachuca springsnail (Pyrgulopsis thompsoni) and provides a thorough account of the species’ overall viability and, therefore, extinction risk. The Huachuca springsnail is a small aquatic snail endemic to Santa Cruz and Cochise Counties in southeastern Arizona and adjacent portions of northern Sonora, Mexico, with an estimated 29 historical spring ecosystem sites (23 on Federal land, four on private land, two in Mexico) of which 23 are confirmed as occupied sites. To evaluate the biological status of the Huachuca springsnail both currently and into the future, we assessed a range of conditions to allow us to consider the species’ resiliency, redundancy, and representation (together, the 3Rs). The Huachuca springsnail needs multiple resilient populations widely distributed across its range to maintain its persistence into the future and to avoid extinction. A number of factors influence whether Huachuca springsnail populations will grow to maximize habitat occupancy, which increases the resiliency of a population to stochastic events. These factors include (1) sufficient spring flow (water quantity), (2) sufficient water quality, which we define as being free of pollutants and within the natural parameters for springsnails (dissolved oxygen, temperature etc.), (3) free-flowing spring ecosystems, which we define as a spring or seep that is not impounded or obstructed in a way to reduce water quality or water turn-over, (4) sufficient substrate (pebble, gravel, cobble, and woody debris) and aquatic vegetation (aquatic macrophytes, algae, and periphyton) quantity within the springs, and (5) the absence or minimal presence of invasive species like crayfish and mudsnail. If a sufficient number of spring ecosystems provide reliable flow, coupled with appropriate water quality, substrates, suitable water quality, and lack of invasive species that would predate on or compete with the springsnail, then we anticipate springsnails will survive and potentially thrive in abundance. As we consider the future viability of the species, a larger number of populations with high resiliency distributed across the known range of the species would provide higher overall species viability. Populations of Huachuca springsnail have been documented from sites in Cochise and Santa Cruz counties of Arizona, and Sonora Mexico. Extant populations of Huachuca springsnail are estimated to currently occur in at least 23 sites, verified through survey efforts done from 2004 to present. Historically there were an estimated 29 sites; specimens were not collected or tested genetically at all of these sites at the time springsnails were found in them to know if the species truly occurred at all 29 locations. Therefore there is still some uncertainty in the total number of historical populations. Maintaining the extant populations of Huachuca springsnail provides redundancy, and the species is currently represented across most of the historical range with three known haplotypes (1, 2, and 9) at eleven sites, and an unknown haplotype at three sites

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Huachuca Springsnail SSA Report June 2016

(Table ES-1). A haplotype is a combination of closely linked DNA sequences on one chromosome that are often inherited together, and are used to map genetic structure in a population. We assessed the Huachuca springsnail’s levels of resiliency, redundancy, and representation currently and into the future under three scenarios (Table ES-2), and we then ranked the conditions of each population (Table ES-3, Table ES-4). Rankings are based on qualitative assessments which we then assigned numerical rankings (Table 3.2 and 3.3). Assessments of the relative conditions of spring ecosystems are based on the knowledge and expertise of biologists from the Service, Arizona Game and Fish Department, and other technical experts and resource professionals. Table ES-5 is a combination of the previous tables in describing how each scenario could relate to the resiliency, redundancy and representation of the species.

Table ES-1. A study in 2015 sampled 14 sites and determined the haplotypes for 11 of these. These 11 sites denote the most current information available for the representation of genetic diversity of the species. The remaining nine sites that are considered extant have not been sampled.

Category Number of Sites Site ID

Haplotype 1 & 2 3 BC01, MC01, SC02

RC01, GC01, Haplotype 9 6 GC02, HC02, CS01, SC01,

Haplotype 1, 2, 9 2 Scotia02, Scotia03

Unknown 3 GC03, GC04, GC05 Haplotype

Total 14

The two most significant stressors to the Huachuca springsnail are the loss of spring discharge, and modification of the spring ecosystems that individuals and populations need to complete their entire life history. The primary causes of historical habitat loss within the range of the Huachuca springsnail are related to anthropogenic modification of spring ecosystems, and/or changes in water quality. Any action that removes suitable habitat can contribute to the potential decline or extirpation of local populations. The primary source of potential future habitat loss is through severe wildfire and grazing. Nonnative snails (competitors) or crayfish (predators) could also invade the springs and affect Huachuca springsnail populations, although it is difficult to reliably predict if, or when, this may occur. The viability of the Huachuca springsnail depends on maintaining multiple resilient populations over time. There is uncertainty regarding if, or when, springs occupied by Huachuca springsnails may experience a reduction or elimination of spring flow, and/or be modified by other factors in the future. This uncertainty is due to not knowing which springs are reliant on groundwater, and which are reliant on snow melt and precipitation runoff, and the uncertainty on when climate change will impact water availability for both sources. Modification uncertainty arises from modifications coming from stochastic events that cannot be predicted, or potential

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Huachuca Springsnail SSA Report June 2016 management actions that are currently not planned. There have also been stochastic events that have either reduced the abundance of springsnails from previously abundant sites and seemingly reintroduced springsnails to sites which had previously lacked presence results. Given the uncertainty of when either the removal or reintroduction could occur given the stochastic nature of either, we have assessed what the Huachuca springsnail may have in terms of resiliency, redundancy, and representation under three future plausible scenarios using a scenario matrix (Table ES-2). We determined that scenarios 1B, 2B, and 3B are the most likely to occur.

Table ES-2. The scenario matrix using the two most significant factors affecting the Huachuca springsnails viability into the future. See Appendix A for further information about the scenarios.

Factors Factor Scenario Scenario Spring Discharge Free Flowing/Modification No measurable change in flow rate; ≥80% of ≤10% springs modified in 1 A occupied springs way to minimize habitat stable flow Measurable change in >10%, ≤20% of occupied flow rate; flow still or historical springs 2 present at moderate B modified that reduce level in ≥80% of habitat occupied springs All or most occupied >20% of occupied or springs ≥80% have 3 C historical sites modified to extreme reduction, reduce habitat and low level of flow

• 1B: No measurable change in spring flow; springs that are occupied or could be occupied by the Huachuca springsnail experience limited modification. • 2B: A measurable change in spring flow but still enough flow to remove most fine substrates in majority of springs; springs that are occupied or could be occupied by the Huachuca springsnail experience limited modification. • 3B: Springs experience extreme reduction in flow; and springs that are occupied or could be occupied by the Huachuca springsnail experience limited modification, but with limited flow these modifications are magnified in effect. We used the available information to forecast the likely future condition of the Huachuca springsnail. Our goal was to describe the viability of the species in a manner that addresses the needs of the species in terms of resiliency, redundancy, and representation. We considered a range of potential scenarios that forecast important influences on the status of the species, and our results describe this range of possible conditions in terms of how many and where the Huachuca springsnail populations are likely to persist into the future. The scenarios 1B, 2B, and 3B were the ones we considered most likely. We present results from 2B and 3B due to scenario 1B being a continuation of current condition and therefore unlikely due to the environment being projected to change under climate models. All three scenarios include some modification due to the likelihood that wildfire, cattle grazing, and/or anthropogenic modification are expected to

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occur at a low level over the next 50 years. For our analysis, sites were ranked as high, medium, or low quality depending on the habitat parameter scores. The analysis of future conditions for scenario 2B was completed using the structure in Table ES-3:

Table ES-3. Since modifications could not be assessed based on habitat parameters, future conditions under scenarios were determined based on spring flow because models indicate there will be a reduction in water availability due to climate change.

Scenario 2B Scenario 3B Current Future Current Future

≥14, Flow ≥14, Flow Medium High Quality Score=5 Score=5 Quality High High ≤14, Flow Medium ≤14, Flow (Scores 11-17, (Scores 11-17, Low Quality Score=3 Quality Score=3 Median 14) Median 14) Likely Flow Score=1 Low Quality Flow Score=1 Extirpated ≥8, Flow Medium ≥8, Flow Low Quality Score=3 Quality Score=3 Medium ≤8, Flow Medium (Scores ≤8, Flow (Scores 5-11, Low Quality Low Quality Score=3 5-11, Median 8) Score=3 Median 8) Likely Flow Score=1 Low Quality Flow Score=1 Extirpated

Low Likely Low Likely →→→→→ →→→→→ (Scores ≤5) Extirpated (Scores ≤5) Extirpated

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Huachuca Springsnail SSA Report June 2016

Table ES-4. Condition of Huachuca springsnail populations, now (2016) and in 50 years considering both primary factors under scenarios 2B and 3B. Current condition determined from qualitative measures. Colors pertain to the habitat quality: Purple = High Quality, Blue = Medium Quality, and Pink = Low Quality. Sites we expect to become extirpated are shown with a strikethrough.

Spring Spring Current Future Future Current Future Future Population Population Conditio Conditio Conditio Conditio Conditio Conditio (Binomial (Binomial n n 2B n 3B n n 2B n 3B Name) Name) BC01 High High Medium HC01 High Low Low BT01 Low Low Low HC02 High Low Low CS01 High High Medium MC01 Medium Low Low ML01 Low Low Low MC02 Medium Low Low RC01 High Medium Low MC03 High Medium Low CW01 High High Medium MC04 Medium Low Low MS01 High High Medium SC01 High Medium Low SS01 High Medium Low SC02 High Medium Low NS01 Medium Low Low Scotia01 High Medium Low CH01 Medium Low Low Scotia02 High Medium Low GCO1 High High Medium Scotia03 Medium Low Low GC02 High High Medium CF01 NA NA NA GC03 Medium Medium Low OC01 NA NA NA GC04 Medium Medium Low GC05 Medium Medium Low GC06 Medium Medium Low

* BS: Bear Springs. BT: Blacktail Spring. CS: Cave Spring. ML: Tombstone Reservoir. RC: Ramsey Canyon. CW: Cottonwood Spring. MS: Monkey Spring. SS: Sheehy Spring. NS: Neighbor Spring. CH: Canelo Hills. GC: Garden Canyon. HC: Huachuca Canyon. MC: McClure Canyon. SC: Sawmill Canyon. Scotia: Scotia Canyon. CF: Cienega los Fresnos. OC: Ojo Caliente. Persistence of springsnails (genus Pyrgulopsis), is strongly tied to spring flows, which are affected by groundwater depletion, reduction in snowpack melt, and precipitation. A formalized conservation approach (i.e. CCA if finalized) could ameliorate direct impacts to springsnail habitat but there is not currently one in place. A CCA is not likely to have an influence over climate-based stressors on future water availability. While management actions cannot affect the rate of spring flow, they could affect how resilient the populations are to those fluctuations. Meaning that apart from conservation actions for ground water pumping, management can have little effect on the amount of water available to support spring flows. Therefore management actions should be focused on ensuring that sufficient habitat persists to allow the populations to be resilient to water availability fluctuations.

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Huachuca Springsnail SSA Report June 2016

Table ES-5: This table represents the overall species status summary including the 3Rs that are examined in the SSA, Resiliency, Redundancy, and Representation, with the three scenarios that were determined to be the most likely.

3Rs Needs Current Condition Future Condition (Viability) Resiliency: Population • Adequate spring discharge • 29 known current and historical Projections based on scenarios: (Large populations able to • Sufficient water quality sites. • 1B: Greater than 80% of populations are likely to remain withstand stochastic • Free-flowing spring • 1 site is extirpated, 2 sites in Mexico extant into the future events) ecosystem/unmodified and 2 sites on private land have • 2B: Most populations are expected to experience some level habitat unknown status, and 10 sites had of decline in resiliency, Site conditions under scenario 2B • Appropriate substrate and inconclusive CPUE by AGFD include: aquatic vegetation • 15 sites assessed at high quality o 6 high quality sites • 10 sites assessed at medium quality o 11 medium quality sites • 4 sites assessed at low quality, this o 8 low quality sites includes the 1 extirpated site and the o 2 sites likely extirpated 2 sites in Mexico which have no o 2 sites unknown available information. • 3B: All populations are expected to experience a large decline in resiliency with lower scoring sites likely to be extirpated. Site conditions under scenario 3B include: o 0 high quality sites o 6 medium quality sites o 11 low quality sites o 10 sites likely extirpated o 2 sites unknown Redundancy Multiple populations • 1 site determined to be extirpated Projections based on scenarios: (Number and distribution throughout the range of the from modification of habitat • 1B: Greater than 80% of populations are likely to remain of populations to species • Remaining sites are varying distances extant into the future withstand catastrophic from each other. • 2B: Six sites remain high quality events) • 3B: 10 sites would likely be extirpated from lack of flow; six sites are likely to retain medium quality. Representation • Genetic variation exists • 1 site known to be extirpated. Projections based on scenarios: (genetic and ecological between populations (three • 1 haplotype (haplotype 5) no longer • 1B: Greater than 80% of populations are likely to remain diversity to maintain known haplotypes) found extant into the future, maintaining current genetic variation adaptive potential) • No known ecological • Remaining sites having varying • 2B: 18 sites are likely to retain representation across the variation proportions of the three known range. haplotypes (haplotypes 1,2, and 9) • 3B: Genetic variation and representation limited across the range. 10 sites likely extirpated from lack of flow (includes 2 sites with known haplotypes); 11 sites reduced to low quality (includes 5 sites with known haplotypes). 8

Huachuca Springsnail SSA Report June 2016

Table of Contents EXECUTIVE SUMMARY ...... 3 CHAPTER 1: INTRODUCTION ...... 11 Definitions of the 3Rs ...... 12 The format for this SSA Report includes: ...... 12 CHAPTER 2: INDIVIDUAL NEEDS ...... 13 2.1. Biology and Life History ...... 13 2.1.1. Taxonomy and Genetics ...... 13 2.1.2. Morphological Description ...... 14 2.1.3. Reproduction ...... 15 2.1.4. Survival, Growth, and Longevity ...... 15 2.1.5. Dispersal ...... 16 2.2. Habitat ...... 16 2.3. Feeding Habits ...... 19 2.4. Summary of Individual Needs ...... 20 CHAPTER 3: POPULATION NEEDS AND CURRENT CONDITION ...... 21 3.1. Range and Distribution ...... 21 3.2. Needs of the Huachuca Springsnail ...... 29 3.2.1. Population Resiliency ...... 29 3.2.2. Species Redundancy ...... 33 3.2.3. Species Representation ...... 34 3.3. Current Conditions ...... 37 3.4. Summary of Needs and Review of Current Condition ...... 41 CHAPTER 4: FACTORS INFLUENCING VIABILITY ...... 43 4.1. Reduction of spring discharge...... 43 4.2. Springhead Modification ...... 45 4.3. Conversion from Lotic to Lentic Systems ...... 46 4.4. Aquatic Vegetation Removal ...... 46 4.5. Water Contamination ...... 47 4.6. Predation ...... 47 4.7. New Zealand Mudsnail ...... 48

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Huachuca Springsnail SSA Report June 2016

4.8. Management Actions and Conservation Measures ...... 48 4.9. Summary ...... 50 CHAPTER 5: SPECIES VIABILITY ...... 52 5.1. Introduction ...... 52 5.2. Resiliency ...... 53 5.3. Redundancy...... 59 5.4. Representation ...... 62 5.5. Species Assessment Summary ...... 63 LITERATURE CITED ...... 65 APPENDIX A ...... 72

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Huachuca Springsnail SSA Report June 2016

CHAPTER 1: INTRODUCTION The Huachuca springsnail (Pyrgulopsis thompsoni) is a small hydrobiid (member of the Hydrobiidae family) snail that occurs in springs and seeps in the Huachuca Mountains and nearby valleys in Arizona and Mexico. Members of the family Hydrobiidae are strictly aquatic and often occur in abundance within suitable spring habitats. The Huachuca springsnail has been a candidate for listing (as currently defined) under the Endangered Species Act of 1973, as amended (Act), since 1996 (Service 1996, entire). The Species Status Assessment framework (Service 2015, entire) is intended to be an in-depth review of the species’ biology and risks, an evaluation of its biological status, and an assessment of the resources and conditions needed to maintain long-term viability. The intent is for the resulting Species Status Assessment Report (SSA Report) to be easily updated as new information becomes available and to support all functions of the U.S. Fish and Wildlife Service’s (Service) Endangered Species Program from Candidate Assessment to Listing to Consultations to Recovery. As such, the SSA Report will be a living document upon which other documents, such as listing rules, recovery plans, and 5-year reviews, would be based if the species warrants listing under the Act. This SSA Report is a summary of the information assembled and reviewed by the Service and incorporates the information and data available. Importantly, the SSA Report does not result in a decision by the Service on whether this taxon should be proposed for listing as a threatened or endangered species under the Act. Instead, this SSA Report provides a review of the available information strictly related to the biological status of the Huachuca springsnail. The listing decision will be made by the Service after reviewing this document and all relevant laws, regulations, and policies, and the results of a proposed decision will be announced in the Federal Register, with appropriate opportunities for public input. For the purpose of this assessment, we generally define viability as the ability of the species to sustain populations in natural spring ecosystems over time, in this case, 50 years. We chose 50 years because it is within the range of the available hydrological and climate change model forecast (see IPCC 2014). Figure 1.1 Species Status Additionally, because of the short generation time of the Assessment Framework Huachuca springsnail (approximately one year), 50 years encompasses approximately 30-40 generations, which is a relatively high number of generations over which to observe effects to the species. Using the SSA framework (Figure 1.1), we consider what the species needs to maintain viability by characterizing the status of the species in terms of its resiliency, redundancy, and representation (3Rs) (Wolf et al. 2015, entire). To evaluate the biological status of the Huachuca springsnail both currently and into the future, we assessed a range of conditions to allow us to consider the species’ 3Rs. This SSA Report provides a thorough assessment of biology and natural history, and assesses demographic risks and limiting factors in the context of determining the viability and risks of extinction for the species.

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Huachuca Springsnail SSA Report June 2016

Definitions of the 3Rs The following are working definitions of the 3Rs that will be used throughout this document. They are derived from the SSA framework (Service 2015, entire):

• Resiliency is having sufficiently large populations for the species to withstand stochastic events (arising from random factors). We can measure resiliency based on metrics of population health; for example, birth versus death rates and population size. Resilient populations are better able to withstand disturbances such as random fluctuations in birth rates (demographic stochasticity), variations in rainfall (environmental stochasticity), or the effects of anthropogenic activities. • Redundancy is having a sufficient number of populations for the species to withstand catastrophic events (such as a rare destructive natural event or episode involving many populations). Redundancy is about spreading the risk and can be measured through the duplication and distribution of populations across the range of the species. The greater the number of populations a species has distributed over a larger landscape, the better it can withstand catastrophic events. • Representation is having the breadth of genetic makeup of the species to adapt to changing environmental conditions. Representation can be measured through the genetic diversity within and among populations and the ecological diversity (also called environmental variation or environmental diversity) of populations across the species’ range. The more representation, or diversity, a species has, the more it is capable of adapting to changes (natural or human caused) in its environment. In the absence of species-specific genetic and ecological diversity information, we evaluate representation based on the extent and variability of habitat characteristics within the geographical range The format for this SSA Report includes:

• The resource needs of individuals and populations (Chapter 2); • The Huachuca springsnail’s historical distribution and a framework for what the species needs in terms of the distribution of resilient populations across its range for species viability (Chapter 3); • A review of the likely causes of the current and future condition of the species and determining which of these risk factors affect the species’ viability and to what degree (Chapter 4); • Compilation of the above for a description of the species’ viability in terms of resiliency, redundancy, and representation (Chapter 5). This document is a compilation of the available information and data and is a description of past, present, and likely future risk factors to the Huachuca springsnail.

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Huachuca Springsnail SSA Report June 2016

CHAPTER 2: INDIVIDUAL NEEDS BIOLOGY AND BIOGEOGRAPHY In this chapter, we provide basic biological information about the Huachuca springsnail, including its physical environment, taxonomic history and relationships, morphological description, and reproductive and other life history traits. We follow with an outline of the resource needs of individuals and populations. Here we report those aspects of the life history of the Huachuca springsnail that are important to our analysis. Some assumptions are made about life history from closely related congeners (organisms belonging to the same taxonomic genus) including the Page springsnail (Pyrgulopsis morrisoni), a species that is also endemic to Arizona. Although this was deemed reasonable, we recognize it contains inherent uncertainties1.

2.1. Biology and Life History 2.1.1. Taxonomy and Genetics The Huachuca springsnail is a member of the family Hydrobiidae. It is one of approximately 170 known species of Hydrobiid snails in the United States. It was originally identified by Landye (1973, p. 25), and Bequart and Miller (1973, pp. 213-214) in the genus Fontelicella from specimens collected at Peterson Ranch Spring (a.k.a. Sylvania Spring or Scotia Canyon Spring), and Monkey Spring, in Santa Cruz and Cochise Counties, Arizona. Landye (1981, p. 28) treated populations from Canelo Hills Cienega, Monkey Spring, and Sheehy Spring as three separate Fontelicella species. These populations were later synonymized (categorized as the same species) and the species was fully described by Hershler and Landye (1988, pp. 41-43) as Pyrgulopsis thompsoni from specimens examined from Cottonwood Spring, Monkey Spring, Canelo Hills Cienega, Sheehy Spring, and Peterson Ranch Spring, Santa Cruz County, Arizona; and from Ojo Caliente, Sonora, Mexico. We have carefully reviewed the available taxonomic information and conclude that P. thompsoni is a valid taxon. The currently accepted classification is: Class: Gastropoda Subclass: Rissooidea Family: Hydrobiidae Genus: Pyrgulopsis Species: Pyrgulopsis thompsoni Although taxonomic research indicates significant genetic divergence within this species, we consider all currently identified sites to be Huachuca springsnail. Genetic research on the Huachuca springsnail was first conducted in 2004, during which nine populations were studied genetically (Hurt and Hedrick 2004, entire).

1 Assumptions from the Page springsnail were made due to the species having the most recent species-specific information for a springsnail in the Southwest. Assumptions include a lifespan between 9-15 months, reproduction from mid-late July to November, faster development in warmer water, sensitivity to copper, and that they are egg- laying. Assumptions also include juvenile development being assisted by calcium and mineral salt content, high fecundity in good habitat, and likely resistance to genetic bottlenecking. Uncertainties for these assumptions are related to the Huachuca springsnail being a different species (but same genus and family). Species specific information is needed for the Huachuca springsnail to minimize these assumptions and uncertainties.

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Huachuca Springsnail SSA Report June 2016

Of these nine populations four areas that represented these divergences were identified (Hurt and Hedrick 2004, p. 411; Hurt 2004, p. 1184; Myers 2012, p. 7). These areas are geographically separated, with some sites being isolated and genetically unique to be its own area under this evaluation (Hurt and Hedrick 2004, p. 411; Hurt 2004, p. 1184). At a minimum, these studies seem to suggest genetic differentiation within the larger complex referred to as Huachuca springsnail. Further work regarding the genetics of Huachuca springsnail populations was conducted in 2015 when the Arizona Game and Fish Department (AGFD) worked with Fort Huachuca (Fort) under a Department of Defense Legacy Resource Program (2015 Legacy Study; Piorkowski and Diamond 2015). In this study, snails were collected from eleven sites and genetically analyzed. Their findings point to four haplotypes, two of which are more closely related (haplotypes 1 and 2), one (haplotype 9) which is more removed, and one that is unknown (Piorkowski and Diamond 2015, p. 22). A previously identified haplotype (haplotype 5) also appeared to be absent from the landscape (Hurt 2004, p. 1184). Most sites sampled during the 2015 Legacy Study were found to be homogenetic with either just haplotypes 1 and 2 or just haplotype 9. Two sites however, contained all three haplotypes (1, 2, and 9) indicating a recent but rate dispersal event (Piorkowski and Diamond 2015, p. 30). It is of interest that all three haplotypes can co-exist for a period of time in the same area. Again, until further studies are done to determine the extent of differences between haplotypes 1 and 2, how differentiated haplotype 9 is, the unknown haplotype, and what the haplotypes are represented for sites outside of the Fort, we consider all currently identified sites to be Huachuca springsnail. 2.1.2. Morphological Description The Huachuca springsnail is considered a moderate to large-sized springsnail with a shell height of 1.7 to 3.2 millimeters (0.07 to 0.13 inches) (Hershler and Landye 1988, pp. 41-43) (Figure 2.1). The shell is moderately convex (curved or rounded outwards) with slightly shouldered whorls (each one of the complete rotations of the shell spiral). The inner lip of the shell is thin. The aperture (the opening of the shell) is fused to the body whorl, and contains an operculum (plate that closes the opening of the shell when snail is retracted). The umbilicus (the depression on the underside of the shell) is chink-like or open. Species identification must be verified by characteristics of reproductive organs or molecular analysis (Hershler et al. 2014, p. 2). For a more detailed description and thorough review of the morphological characteristics of Arizona hydrobiid snails, see Hershler and Ponder (1998) and Hershler (1994).

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Huachuca Springsnail SSA Report June 2016

Figure 2.1. Photos of Huachuca springsnails under a dissection microscope (left) (Nicole Chinnici, Northeast Wildlife DNA Laboratory), and close up of a field specimen (right) (Martin D. Piorkowski, AGFD). 2.1.3. Reproduction In hydrobiids, the sexes are morphologically separate with females typically noticeably larger than males. Empirical and definitive observations of Huachuca springsnail reproduction are not available. So while there is general insight into ecological conditions suitable for reproduction, species-specific information is limited and any significant inter-specific variations of ecological requirements are unknown. In general Pyrgulopsis species are dioecious (individuals with different sexes), where females are oviparous (egg-laying) (Hershler et al. 2014, p. 2) and reproduction appears to occur throughout the year in warm water and seasonally in colder environments (Mladenka and Minshall 2001, p. 209). Environmental cues often have an influence on the reproductive seasonality of aquatic organisms, and they may play a role for the Huachuca springsnail. Such environmental cues for the Huachuca springsnail are not known, but could include factors such as photoperiod, water temperature, water quality, or food availability. Given their similar climates (arid Southwest), we infer from the Page springsnail that the Huachuca springsnail may have a peak reproductive period from mid-August through September, based on observations of newly emerged snails, from mid-August through September, with a gradual reduction of new juveniles beginning in mid-October and continuing through the end of November (Pearson et al. 2014, p. 65). Based on laboratory observations of the Page springsnail, females lay one egg approximately every eight to 10 days (Pearson et al. 2014, p. 66). We are uncertain whether the Huachuca springsnail follows a similar trend. 2.1.4. Survival, Growth, and Longevity Similar to reproductive life-history, information on the survival, growth, and longevity have not been studied at the species-specific level for the Huachuca springsnail. General insights related to Hydrobiids indicated that lifespan is about one year, and adults can overwinter by burrowing in sediments (Lysne et al. 2007, p. 649, 650; Pearson et al. 2014, p. 64; Lysne and Koetsier 2006, p. 235). The lifespan of most aquatic gastropods is usually nine to 15 months (Pennak 1989, p. 552), and the survival of one species in the genus Pyrgulopsis in the laboratory was

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Huachuca Springsnail SSA Report June 2016 nearly 13 months (Lysne et al. 2007, p. 3), therefore an average lifespan of 1 year is a reasonable estimate for the Huachuca springsnail. It is not known if Huachuca springsnails exhibit burrowing behavior, but if they do, this may allow Huachuca springsnails to survive at ephemeral sites like other springsnails and aquatic snails have been observed to do (Pearson et al. 2014, p. 64; Lysne and Koetsier 2006, p. 235). It is not known how long a springsnail may survive in an ephemeral spring (Expert Group 2016). The larval stage for many Hydrobiids is completed in an egg capsule and upon hatching tiny snails crawl out into their adult habitat (Brusca and Brusca 1990, p. 759; Hershler and Sada 2002, p. 256). It is not known if the Huachuca springsnail lays single eggs or a capsule, but the larval stage would be completed within either. Pearson et al. (2014, p. 66-67) observed the development rate of Page springsnail in a laboratory setting, noting that growth was rapid during the first two weeks but reduced as snails approached adult size. Wells et al. (2012, p. 73) also observed in a laboratory setting that it took six to seven weeks for a Page springsnail to reach full maturity. Given the similarities of environment between the Page and Huachuca springsnail (dry arid climate, variable precipitation), we assume that the Huachuca springsnail develops at a similar rate. The temperature of an environment can significantly affect an organism’s energy allocation, with warmer temperatures having a positive correlation to metabolic rate of poikilothermic organisms (organism whose internal temperature varies considerably) (Hammill et al. 2004). There can also be a direct relationship between temperature and an organism’s mating behavior, reproduction, development, and general survival for some species, meaning that if temperature increases those behaviors and survival rates increase, and if temperature decreases then those behaviors and survival rates decrease. This relationship has been demonstrated in the giant ramshorn snail (Marisa cornuarietis) (Funkhouser 2014, p. 5; Wilson et al. 2007, p. 2137). However, for the Phantom Cave springsnail (Pyrgulopsis texana) temperature did not have an effect on reproduction or growth (Funkhouser 2014, p. 16). It is unknown if the Huachuca springsnail’s life history exhibits a relationship to water temperature, what would qualify as warm and cool springs within their range, and what the threshold for warm temperatures is before adverse effects take place. 2.1.5. Dispersal Given their size, Huachuca springsnail mobility is limited and significant dispersal events likely do not occur. However aquatic snails have been known to disperse by becoming attached to the feathers of migratory birds (Roscoe 1955, p. 66; Dundee et al. 1967, pp. 89-90), and stochastic events such as floods may assist with reintroductions and dispersal (Piorkowski and Diamond 2015, p. 27). Given the information available, we conclude that such dispersal events can occur, but that they are very rare and should not be relied upon for any site colonization or significant genetic flow.

2.2. Habitat

In the arid Southwest, snails of the family Hydrobiidae are largely relicts of the wetter Pleistocene Epoch (2.6 million – 11,000 years ago) and are typically distributed across the landscape as geographically isolated populations exhibiting a high degree of endemism (found only in a particular area or region) (Bequart and Miller 1973, p. 214; Taylor 1987, pp. 5-6; Shepard 1993, p. 354; Hershler and Sada 2002, p. 255). Springsnails are gill-breathing and have 16

Huachuca Springsnail SSA Report June 2016

an entirely benthic (occurring on the bottom of the water body) life cycle (Hershler et al. 2014, p. 2). Therefore Hydrobiid snails occur in springs, seeps, spring runs, cienegas, and a variety of diverse aquatic systems, but particularly spring ecosystems that produce running water. Substrate for most Pyrgulopsis springsnails is typically firm and characterized by cobble, gravel, woody debris, and aquatic vegetation; they are rarely found on or in soft sediment. These substrate types provide suitable surfaces for grazing and egg-laying (Taylor 1987, p. 5; Hershler 1998, p. 14), as well as a suitable environment for the production of periphyton and algae, the primary food source of springsnails. The Huachuca springsnail, being endemic to Santa Cruz and Cochise counties in southeastern Arizona and adjacent portions of northern Sonora, Mexico, is most commonly found in rheocrene ecosystems (water emerging from the ground as a flowing stream). However, some sites are spring-fed aquatic climax communities commonly described as cienegas (marshes) (Hendrickson and Minckley 1985, pp. 133-134). The habitat of the Huachuca springsnail regardless if it is a rheocrene or cienega ecosystem is characterized by various aquatic and emergent plant species that occur within plains grassland, oak and pine-oak woodlands, and coniferous forest vegetation communities within the Huachuca Mountains and the San Rafael Valley. The 2015 Legacy Study (Pirokowski and Diamond 2015, p. 27) showed that there was no statistically significant relationship between percent vegetation and/or substrate composition and the distribution of the Huachuca springsnails. This suggests that the Huachuca springsnail exhibits a different habitat use pattern than some other springsnails. Nevertheless, the species is typically found in the shallower areas of springs, and often in gravelly seeps at the spring source. Within these spring environments, we assume that the following habitat relationships extend to the Huachuca springsnail. Proximity to spring vents, where water emerges from the ground, plays a key role in the life history of springsnails. Many springsnail species exhibit decreased abundance farther away from spring vents, presumably due to their need for stable water chemistry and flow regime provided by spring waters (Hershler 1984, p. 68; Hershler 1998, p. 11; Hershler and Sada 2002, p. 256; and Martinez and Thome 2006, p. 14). Several habitat parameters of springs, such as dissolved carbon dioxide, dissolved oxygen, temperature, conductivity, and water depth, have also been shown to influence the distribution and abundance of Pyrgulopsis snails (O’Brien and Blinn 1999, pp. 231-232; Mladenka and Minshall 2001, pp. 209-211; Malcom et al. 2005, p. 75; Martinez and Thome 2006. pp. 12-15; Lysne et al. 2007, p. 650; Martinez and Myers 2008, pp. 191-192). Dissolved salt may also be an important factor, because it is essential for shell formation (Pennak 1989, p. 552). This is supported by ongoing research at the Phoenix Zoo which indicates that calcium plays an important role in juvenile development, and copper appears to adversely affect recruitment of Page springsnail (Wells et al. 2012, p. 72), though the mechanism is not known. A study by Tsai et al. (2007, pp. 215-216) found that Huachuca springsnails were present in springs with water temperatures averaging 18.4±2.1 °C (65.1+3.8 °F), with dissolved oxygen levels of 5.44±0.86 mg/L (5.44±0.86 ppm) dissolved oxygen, and water that had turbidity levels of 261.68±42.4 mg/L (261.68±42.4 ppm) total dissolved solids. However, only those springs that had springsnails present were sampled and therefore results might be biased (Piorkowski and Diamond 2015, p. 27). The 2015 Legacy Study, while it didn’t examine dissolved oxygen, found that water chemistry was not as indicative of Huachuca springsnail presence as previously 17

Huachuca Springsnail SSA Report June 2016

thought, and that the Huachuca springsnail might have a potentially wide range of tolerances (Piorkowski and Diamond 2015, p. 27). This same study did continue to support the hypothesis that distance from spring vents is important, as no snails were present greater than 12 m (39.4 ft.) from a spring vent (Piorkowski and Diamond 2015, p. 16) (Figure 2.2.1). Lastly the 2015 Legacy Study and a previous study by Hershler et al. (2014) also emphasized that habitat characterized by minimal competition and predation by invasive species has positive effects on springsnail populations (Hershler et al. 2014, p. 5; Piorkowski and Diamond 2015, p. 17) (Figure 2.2.2.).

Pass 1 Pass 2 Average R² = 0.4514 R² = 0.3741 R² = 0.3759 100 7

90

6

80

70 5

60 4 50 3 40

30 2

Number springsnails of Number 20 1 10 Average number of springsnails of number Average 0 0 0.0 1.5 3.0 4.5 6.0 7.5 9.0 10.5 12.0 13.5 Distance from spring origin (m)

Figure 2.2.1. Comparison of springsnail numbers by distance from the spring origin using the Tile protocol. Trendlines and associated R2 values indicate the level of relatedness the trendline has with the data and are as follows: solid = Pass 1; dashed = Pass 2; dotted = Average. (Piorkowski and Diamond 2015, p. 16).

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Springsnail Detection No Springsnail Detection

100

80

60

40 Percent Percent of sample sites 20

0 Ramshorn Physids Crayfish Amphipods Fish Frogs Caddisflies Aquatic Odonata Beetles spp.

Figure 2.2.2. Percentage of sites with other detected aquatic and semi-aquatic species and the proportion of sample sites with Huachuca springsnail detection on and immediately adjacent to Fort Huachuca, Arizona 2014 (Piorkowski and Diamond 2015, p. 17). Based on our current knowledge of springsnails, and assuming that Huachuca springsnails have similar habitat-relationships, important habitat elements appear to include: (1) sufficient spring flow (water quantity), (2) sufficient water quality, which we define as being free of pollutants and within the natural parameters for springsnails (dissolved oxygen, temperature etc.), (3) free- flowing spring ecosystems, which we define as a spring or seep that is not impounded or obstructed in a way to reduce water quality or water turn-over, (4) sufficient substrate (pebble, gravel, cobble, and woody debris) and aquatic vegetation (aquatic macrophytes, algae, and periphyton) quantity within the springs, and (5) the absence or minimal presence of invasive species like crayfish and mudsnail.

2.3. Feeding Habits

Like most freshwater gastropods, the Huachuca springsnail is believed to be an opportunistic herbivore (feeding off of plant material) or detritivore (feeding off of dead material, especially plants) that consumes periphyton by scraping hard surfaces with a radula, or tongue (see Mladenka 1992, pp. 46, 81; Hershler and Sada 2002, p. 256; Lysne et al. 2007, p. 649). Springsnails in the family Hydrobiidae are known to feed primarily on periphyton, which is a complex mixture of algae, detritus, bacteria, and other microbes that live upon submerged surfaces in aquatic environments (Mladenka 1992, pp. 46, 81; Hershler and Sada 2002, p. 256; Lysne et al. 2007, p. 649). Production of periphyton and algae in a natural spring system is likely tied to water quality, nutrient availability, and exposure to sunlight.

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2.4. Summary of Individual Needs

Until further species specific information is available, the following summarizes our understanding of individual Huachuca springsnail needs in the main life stages of springsnails (Table 2.4.1).

Table 2.4.1. The Huachuca springsnail’s main life history stages and their resource needs at each stage.

Life Stage Resource Need Reference • Sufficient water flow • Pearson et al. 2014, pp. 65-67 • Suitable substrate for egg • Brusca and Brusca 1990, p. 759 Eggs adhesion/protection • Wells et al. 2012, p. 72 • Calcium in water for development • Sufficient water flow to • Hershler and Sada 2002, p. 256 prevent desiccation • Hershler 1994, p. 68 • Periphyton for food • Hershler 1998, p. 14 • Suitable substrate and • Hershler et al. 2014, p.5 vegetation within 12 m • O’Brian and Blinn 1999, p. 231 (39 ft) of springhead • Pennak 1989, p. 552 Juveniles • Minimal presence of • Wells et al. 2012, p. 72 (6-7 weeks) invasive competitors and predators • Adequate water quality (dissolved oxygen and lack of contaminants) • Calcium in water for development • Sufficient water flow to • Hershler and Sada 2002, p. 256 prevent desiccation • Hershler 1994, p. 68 • Periphyton for food • Hershler 1998, p. 14 • Substrate and vegetation • Hershler et al. 2014, p.5 within 12 m (39 ft) of • O’Brian and Blinn 1999, p. 231 springhead • Pennak 1989, p. 552 • Minimal presence of • Funkhouser 2014, p. 4,5 Adults invasive competitors and (1 yr. lifespan) predators • Adequate water quality (dissolved oxygen and lack of contaminants) • Stable temperature. (temperature likely to influence metabolic rates, mating, and size)

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CHAPTER 3: POPULATION NEEDS AND CURRENT CONDITION

In this chapter we consider the Huachuca springsnail’s historical distribution and what the species needs in terms of the distribution of resilient populations across its range for continued viability. We first review the historical information on the range and distribution of the species. We next review the conceptual needs of the species, including population resiliency, redundancy, and representation to maintain viability and reduce the likelihood of extinction. Finally we consider the current conditions of Huachuca springsnail populations. For the purpose of this assessment we define sites as representing currently occupied or historically occupied spring ecosystems. Populations are defined either as stand-alone sites or those sites grouped into analysis units (AUs) which were designated to include the spring sites that shared a drainage or water source.

3.1. Range and Distribution

The original description of the species by Hershler and Landye (1988, p. 41) included specimens from five sites in Santa Cruz County, Arizona (Cottonwood Spring, Monkey Spring, Canelo Hills Cienega, Sheehy Spring, and Peterson Ranch Spring), and from one site in Sonora, Mexico (Ojo Caliente). By 2003, the AGFD had expanded the range to include 13 sites: Monkey Canyon, Sonoita Creek, Santa Cruz River, Canelo Hills Cienega, Scotia Canyon, Garden Canyon, McClure Canyon, Sawmill Canyon, Huachuca Canyon, Blacktail Canyon, Ramsey Canyon, Cienega Creek, and Redfield Canyon (AGFD 2003, p. 2). Subsequent review of these sites by Myers (2012, entire) and AGFD in 2016 have removed the following sites as not likely historical localities for Huachuca springsnails: Sonoita Creek, Cienega Creek, and Redfield Canyon (AGFD 2015, p. 2; Sorensen 2016c, entire). Only Varela-Romero et al. (1992, p. 1) reported the species from Cienega Los Fresnos in Sonora, Mexico. A recent synthesis of this information indicates the species has been reported from approximately 29 sites. Of these, at least 16 occur on the Fort, seven in the Coronado National Forest (CNF), four on private land in Arizona, and two in Sonora, Mexico (Myers 2012, pp. 2, 27-30; Myers 2010, pp. 1-2; Piorkowski and Mulligan 2012, p. 14; Piorkowski and Diamond 2015, p. 39) (see Figures 3.1.1 and 3.1.2 below). The discrepancy in the number of sites presented by various authors likely reflects confusion over names and locations of springs, because some springs have multiple names and vague location descriptions. It is also important to state that these 29 historically listed sites were originally reported as Huachuca springsnail sites because of their location within the Huachuca Mountain range or a nearby the mountain range. Genetic analysis of springsnails at these sites was not completed to verify the species at that time, and Key Assumption: In this SSA efforts to continue the comprehensive genetic analysis Report, we assume sites that that AGFD did in 2015 (Piorkowski and Diamond 2015, have had positive surveys since pp. 74-85) is ongoing. We define sites as the following: 2004 are currently occupied. currently occupied sites are those that had positive Sites with known occurrence presence from 2004 onwards, and historically occupied records only prior to 2004 are are those that were mentioned prior to 2004 but with no considered historical. positive presence since.

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Figure 3.1.1. General locations for all known (historical and current) Huachuca springsnail sites within the United States and Mexico.

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Figure 3.1.2. General locations for all known Huachuca springsnail sites within the United States, including those on Fort Huachuca, Coronado National Forest, and private land. Based on the information that is known, there have been stochastic events, such as flooding events, that have both removed springsnails from previously occupied sites (Huachuca Canyon and Blacktail Springs respectively) and likely reintroduced springsnails to sites which had null presence results (Piorkowski and Diamond 2015, p. 27). Therefore identifying sites that could be extirpated or reestablished is difficult because the lack of presence of snails and the reintroduction of snails appear to have a plastic quality. Information regarding spring modification by the City of Tombstone indicates that the site known as Tombstone Reservoir (ML01) is now extirpated due to water depletion (Expert Group 2016). This modification occurred from the City having water rights to at least one spring in Miller Canyon (Tombstone Reservoir site), and developing the spring under a Special Use Permit and an Operating Plan with the CNF (Expert Group 2016; J. Kraft 2016). We do not know if other sites in Miller Canyon are under this permit and if they could be similarly developed, and whether any other losses of springs on the Fort or CNF have occurred and resulted in the loss of any population of Huachuca springsnail. Field sampling to ascertain if a site was occupied by Huachuca springsnails has been done by Hurt (2004, p. 1181), Tsai et al. (2007, p. 214), and Piorkowski and Mulligan (2012, entire) at

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Huachuca Springsnail SSA Report June 2016 various sites throughout the range. The most recent comprehensive survey however was done in July, August and September of 2014 by the AGFD for the 2015 Legacy Study. During this survey, 22 sites were surveyed on the Fort and CNF (Piorkowski and Diamond, 2015, p. 14). These sites were selected for study based on sites identified in various final reports and established databases (Piorkowski and Mulligan, 2012; Myers 2012; Hendrickson and Minckley 1985; and the U.S. Geological Survey databases). Each site was surveyed using a timed survey methodology. The findings confirmed that 15 of the 22 sites (71%) were occupied by Huachuca springsnails (Piorkowski and Diamond 2015, p. 14). An additional site on the CNF, Neighbor Spring (NS01), was confirmed to have Huachuca springsnails in 2016 (J. Sorensen, 2016a). Based on the sites from Hurt (2004), Tsai et al. (2007), the 2015 Legacy Study, and the 2016 survey, there are currently 23 genetically verified occupied sites. To facilitate our analysis given the wide range of sites, we grouped sites sharing the same water source or were within the same drainage into analysis unites. Not all sites could be grouped however given the species’ range, and not all sites have current descriptions. The following Table 3.1 has site and unit descriptions which are taken from Piorkowski and Mulligan (2012), Myers (2012), and Piorkowski and Diamond (2015).

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Huachuca Springsnail SSA Report June 2016 Table 3.1. Description of standalone sites and the analysis units in regards to the site binomial names, land ownership, and brief descriptions of the habitat based on available information. Site/Analysis Unit Site Binomial Land Site/Analysis Unit Description Name ID Ownership

Bear Springs BC01 Forest Service Currently occupied. This is a single spring source characterized primarily by cobble and pebble, with surrounding vegetation being leaf litter and watercress (Nasturtium officinale). No spring modification was noted, and springsnails were present at this site in 2015.

Blacktail Spring BT01 Fort Huachuca This site was historically occupied with positive occupancy being documented in 1992. In 2012 and 2015 no potential habitat or springsnails were detected.

Cave Spring CS01 Fort Huachuca This site is currently occupied. It is along a tributary of Miller Canyon, and is found at the foot of a large rock face. The spring’s substrate is primarily silt and sand with some cobble. Surrounding vegetation includes columbine (Aquilegia sp.) and watercress. The spring is noted to have had historical modifications, but both habitat and springsnails were detected in 2015.

Tombstone Reservoir ML01 Forest Service This site is considered historically occupied. In 2012 this site, located along Miller Canyon Road, contained suitable habitat of pebble and silt substrate with some cobble, and surrounding vegetation of algae (Chlorella sp.). In 2015, no habitat or springsnails were found. It is believed that the City of Tombstone modified the spring for water usage, and the site is now considered extirpated

Ramsey Canyon RC01 Forest Service This site is currently occupied. It contains substrate that is primarily cobble with equal proportions of boulder and pebble. Surrounding vegetation includes rushes and sedges (Carex sp.). This site has not been modified, and both habitat and springsnails were present in 2015.

Cottonwood Spring CW01 Private This site is considered currently occupied. It is on private land, and is described as a spring coming from a hillside, the spring itself has low but consistent flow over hard, boulder substrate. The spring run proceeds for 75 feet before it is diverted into a pipe. This spring run is predominantly silt with some sand and gravel. Vegetation around the springhead is cottonwood (Populus sp.) and 25

Huachuca Springsnail SSA Report June 2016

willow (Salix sp.), and the spring run is dominated by sedges and grasses (Poaceae sp.).

Monkey Spring MS01 Private This site is considered currently occupied. The spring is on private land, and is described as a natural free flowing spring with silt and gravel substrate before the spring run drops into a concrete ditch. There is little vegetation due to the presence of the ditch, but flow is good. The water rights could be a part of mitigation measures for the proposed Rosemont Mine and subsequently protected.

Sheehy Spring SS01 Private This site is considered currently occupied. This spring is on private land, and is described as an unmodified, free flowing marsh area in the upper area and series of pools and runs in the lower area. The substrate is combination soft substrates in the upper areas and of gravel and silt in the lower areas, with surrounding vegetation including watercress, leaf litter, and other aquatic plants. This site is included in a Draft Habitat Conservation Plan (HCP) for the San Rafael Ranch due to Huachuca springsnails being found during site monitoring.

Neighbor Spring NS01 Forest Service This site is considered currently occupied. This spring is in the Coronado National Forest, and is described as containing silt and leaf litter substrate, with bulrush (Scirpus sp.), sedges and grasses (Poaceae) as surrounding vegetation. Water flow had low velocity and low volume.

Canelo Hills Cienega CH01 The Nature This spring is considered currently occupied. The spring is managed by The Conservancy/ Nature Conservancy on private land. The site surveyed was described as being Private Land unmodified with the spring being dominated by orange algae, pockets of water were found in the near vicinity with springsnails. The substrate was predominantly silt and leaf litter with minor amounts of gravel and cobble. Surrounding vegetation was predominantly grass.

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Garden Canyon AU GC01 GC02 Fort Huachuca Five of the six springs in this unit are considered occupied. The unit is GC03 GC04 comprised of six separate spring heads. Sites in this unit are primarily rock and GC05 GC06 pebble, with some silt, and surrounding vegetation including rush, watercress, sedges (Carex sp.) and moss. All six sites in Garden Canyon have potential habitat, all but GC06 had springsnails present, and all sites had been historically modified.

Huachuca Canyon AU HC01 HC02 Fort Huachuca All sites in this unit are considered occupied. This unit is comprised of two distinct spring heads. Both sites in this canyon contain substrates that are primarily pebble and silt with some cobble. Surrounding vegetation includes sedges and watercress. Both sites had historical springhead modification and available habitat.

McClure Canyon AU MC01 MC02 Fort Huachuca Three of the four sites are considered occupied, site MC04 needs more MC03 MC04 information. This unit is comprised of four distinct and separate spring heads (different water sources) but which are within the same drainage and in close proximity to each other, all have been historically modified. Sites are primarily cobble and pebble with some silt and with vegetation including leaf litter and sedges.

Sawmill Canyon AU SC01 SC02 Fort Huachuca Both sites in this unit are considered occupied. The unit is comprised of two distinct populations that share the same water source. This unit is considered unique due to both sites being in close proximity and sharing the same spring connected through a pipe as a water source, but with a distinct difference in haplotype representation (haplotype 1 and 2 at one site, haplotype 9 at the other). Both sites are primarily cobble and silt substrate with surrounding vegetation of columbine and sedges. The SC02 site had an unknown species of vegetation as well, and is characterized by a galvanized steel culvert pipe. Free- flowing water is present at the SC02 site due to a historical modification (pipe) from SC01.

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Scotia Canyon AU Scotia01 Forest Service All sites in this unit are considered occupied. The unit is comprised of three Scotia02 distinct and separate spring heads. The three sites in this unit progress from Scotia03 substrate being primarily silt with equal parts boulder and cobble (Scotia01), to being primarily pebble and silt (Scotia02), and finally being primarily silt (Scotia03). Vegetation also ranges from watercress, sedges and goldenrod (Solidago sp.), to algae. Both Scotia01 and Scotia02 had been historically modified. The Scotia02 site has an impounded spring-fed pond that is fenced to exclude livestock. The area has a high density of groundcover vegetation.

Mexico AU CF01 OC01 Unknown Occupancy data is unknown, therefore we consider this unit to be historically occupied. The unit is comprised of two distinct and separate springheads. Information on both sites is currently unavailable. The CF01 site could have springsnails given its proximity to the species’ general range, but the OC01 site given its distance from the general range is unlikely to contain Huachuca springsnails.

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Overall, land ownership is a mix of Federal, State and private land. Nearly all surveyed sites in the 2015 Legacy Study are on the Fort.

3.2. Needs of the Huachuca Springsnail

We define viability as the ability of the species to sustain populations in the wild over time. Using the SSA framework, we describe the species’ viability by characterizing the status of the species in terms of its resiliency, redundancy, and representation (the 3Rs). Using the current condition time frame of 15 years, the future condition time frame of 50 years and the current and projected levels of the 3Rs, we thereby describe the species’ level of viability over time. 3.2.1. Population Resiliency

For the Huachuca springsnail to maintain viability, its populations, or a significant portion of its populations, must be highly resilient. We assume that good habitat quality correlates to a population that would be highly resilient. Stochastic events that have the potential to affect the Huachuca springsnail populations and habitat include weather events such as heavy rains within short periods of time that create scouring flood conditions and droughts or low precipitation conditions over a year-long period that could cause habitat modification, anthropogenic spring habitat modification, shifts in water quality and quantity, and changes in spring microhabitat including the presence of crayfish (Orconectes virilis) and other invasive species (Figure 2.2.2). The Huachuca springsnail populations that are highly resilient will continue to occupy habitats of sufficient size to sustain self-sufficient populations. Given the difficulty of gathering population demographics without using invasive techniques we have limited information for populations. Timed presence-absence estimates (catch per unit effort, CPUE) show a large variation in CPUE estimates among sites, ranging from 0 to 851 springsnails detected within a 10-minute survey period. High CPUE counts indicate that the species can be locally abundant (Piorkowski and Diamond 2015, p. 14). The fecundity of the Huachuca springsnail is not known at the species specific level, but we assume that it is high from studies on other congeners, including the Page springsnail. Higher site densities of Huachuca springsnails are probable if there is sufficient suitable habitat and a population abundant enough that finding a mate does not cause a snail to expend an exorbitant amount of energy (Service 2015, p. 15; Expert Group 2016). As a relic of the Pleistocene Epoch the Pyrgulopsis genus is also assumed to be relatively resilient to disturbance and localized reductions in abundance given its persistence over geologic time. This resilience has been attributed to high reproductive and recruitment rates within populations and a resistance to the adverse effects of genetic bottlenecking following population dips (Martinez and Sorensen 2007, p. 31; Service 2015, p. 16). These attributes are also assumed for the Huachuca springsnail. Furthermore, the perennial spring ecosystems that springsnails inhabit provide protection from desiccation, predation and temperature extremes for each life stage of the springsnails. Maximum habitat occupancy is determined by a number of factors. As discussed below, these include: (1) sufficient spring flow (water quantity), (2) free-flowing spring ecosystems, which we define as a spring or seep that is not impounded or obstructed in a way to reduce water quality or

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water turn-over, (3) sufficient water quality, which we define as being free of pollutants and within the natural parameters for springsnails (dissolved oxygen, temperature etc.), (4) sufficient substrate (pebble, gravel, cobble, and woody debris) and aquatic vegetation (aquatic macrophytes, algae, and periphyton) quantity within the springs, and (5) the absence or minimal presence of invasive species like crayfish and mudsnail (Figure 3.2.1). If spring ecosystems provide reliable flow, appropriate water depth, substrates, suitable water quality and minimal predator/competitor presence then we anticipate that springsnails in these sites will survive, thrive in abundance, and result in an increase of population resilience. Each of these factors is discussed below and shown in Table 3.1. Habitat factors were determined to be of high, medium, or low quality based on input by biologists from AGFD, the Service, CNF, and the Fort. To be able to assess the quality of the habitat overall these qualitative categories were assigned numerical scores, as described below. Adequate spring discharge (water quantity) The Huachuca springsnail requires spring environments that have sufficient flow volume to complete their life history. Sufficient flow is necessary to remove fine grain sediments, allowing for the growth of periphyton on hard substrates and providing suitable egg-laying sites. Springs are ‘recharged’ from two possible sources to support discharge, the first being groundwater and the second being precipitation and snowpack melt. Springs inhabited by springsnails above the Mountain Front Recharge (MFR) Zone are sustained by snowpack melt and precipitation, which will likely fluctuate with climate change projections (Corell et al. 1996, pp. 18-19). The MFR Zone is the area where mountain runoff from snowpack and precipitation infiltrates into the groundwater (Wahi et al. 2008, p. 1). Any springs inhabited by Huachuca springsnail below this MFR Zone are sustained by groundwater discharged from regional aquifers, and this groundwater discharge must occur in perpetuity for the springs to persist (Corell et al. 1996, p. 18-19). If groundwater discharge is curtailed or eliminated, and snowpack and precipitation levels decrease substantially, Huachuca springsnail populations could lose resiliency or be extirpated due to desiccation as a result of springs not having sufficient discharge. We considered spring discharge level to be functioning at a high level (score of 3) if water is flowing at a rate and depth sufficient to remove most fine-grained sediments, at a moderate level (score of 2) if water is flowing at rate and depth that removes some fine-grained sediments, and at a low level (score of 1) if water is flowing at a rate and depth that is inadequate to remove fine-grained sediments. All scores assume the spring is flowing consistently and not intermittently. We weighted the score by +2 if the spring is considered to be functioning at a high level, and a +1 was given for those springs considered to be functioning at medium level. Free-flowing spring ecosystems and appropriate habitat quality Second to spring discharge, the most important feature in maintaining habitat for the Huachuca springsnail is the presence and permanence of free-flowing spring water, or absence of modification that inhibits flow. This is crucial for the species because a conversion from a flowing system to a ponded system decreases oxygenation of the water, cycling of nutrients, and removal of fine grain sediments. All of which determine the amount of periphyton, and available substrate for egg-laying and adhesion. Factors that can modify springheads include erosion due

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to flooding, improper cattle grazing, human foot traffic both permitted (hiking) and not permitted (immigration), vehicle traffic, and wildfires. We considered springs to be highly free-flowing (score of 3) if flow was not impounded or obstructed in a way to reduce water quality or water turnover, moderately free-flowing if a spring is partially impounded or obstructed in a way to reduce water quality or turnover (score of 2), and not free-flowing (score of 1) if a spring was entirely impounded or obstructed to reduce water quality or turnover. Sufficient water quality Water quality parameters such as temperature, dissolved oxygen, and salt and nutrient concentrations must be sufficient to sustain Huachuca springsnail populations. There should also be a lack of chemical contamination. Water quality, from the information we have, is predominantly determined by the spring or seep system having sufficient flow (e.g. lacking modification that inhibits flow). Hydrobiid snails are sensitive to water quality and each species is usually found within relatively narrow habitat parameters (Sada 2008, p. 59). However, these are conflicting conclusions between the Tsai et al. (2007) study and the Pirokowski and Diamond (2015) study in regards to the sensitivity of the Huachuca springsnail to water quality. The findings of Tsai et al. (2007) indicate that the Huachuca springsnail has relatively narrow habitat parameters (Tsai et al. 2007, pp. 215-216), while the 2015 Legacy Study concludes that the Huachuca springsnail exhibits a wider range of tolerances to habitat conditions than other springsnails (Piorkowski and Diamond 2015, p. 27). Until further information is available to support the conclusions of the 2015 Legacy Study we assume that Huachuca springsnails are reliant on the unique water quality parameters of the springs they occupy. These water quality parameters have been studied for the Page springsnail, with results indicating Page springsnails are found more often and in greater densities in shallower water characterized by relatively lower levels of dissolved oxygen and conductivity (Martinez and Thome 2006, pp. 8, 11-13). Densities of Page springsnail were highest in spring areas with dissolved oxygen levels between 5.78-8.69 mg/L (5.78-8.69 ppm) and conductivity levels between 128-368 µS/cm (0.0128-0.0368 S/m) (Martinez and Thome 2006, pp. 8, 11-13). It is likely that similar parameter ranges apply to the Huachuca springsnail, but more information is need to determine if these parameters help explain why abundance is higher in some sites vs. other sites. We considered water quality to be functioning at a high level (score of 3) if water conditions appear to provide appropriate conditions for springsnail occupation, at a moderate level (score of 2) if water conditions appear to provide marginal conditions for springsnail occupation and at a low level (score of 1) if water conditions appear unable to support springsnail occupation. Sufficient substrate and aquatic vegetation quantity Suitable substrates for most springsnails are typically firm, characterized by cobble, gravel, sand, woody debris, and aquatic vegetation such as watercress, duckweed (Lemna minor), water parsnip (Berula erecta), water pennywort (Hydrocotyl venicillata), water speedwell (Veronica anagalli aquatica), and dock (Rumex verticillatus). The combination of substrate and vegetation increase productivity by providing suitable egg-laying sites and providing food resources (Martinez and Thome 2006, pp. 8, 11-13). Though the 2015 Legacy Study showed there is no statistically significant relationship between percent vegetation and/or substrate composition and

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the distribution of Huachuca springsnails, until more information is provided to support these findings, we continue to assume that substrate characteristics influence the density and productivity of springsnails. We considered substrate and vegetation to be functioning at a high level (score of 3) if they are dominated by hard substrates such as cobble, gravel, pebble, and vegetation suitable for springsnail occupation; at a moderate level (score of 2) if they contain a portion of hard substrates and suitable vegetation; and at a low level (score of 1) if they lack hard substrates and suitable vegetation. Absence or minimal density of invasive predators and/or competitors Population dynamics in general are influenced by the balance between predators and competitors. As invasive species become more prominent across ecosystems, the endemic nature of springsnails is susceptible to adverse effects. These adverse effects include decreased abundance, increase in competition for food and substrate resources, and/or increase in predation. Two gastropods, the New Zealand mudsnail (Potamppyrgus antipodarum) and the red-rimmed melania (Melanoides tuberculatus) have recently been documented across large areas of the western United States (Hershler et al. 2014, p. 5). We considered a spring run length of 12 m (39.4 ft.) from the springhead to be functioning at a high level (score of 3) if there are no documented crayfish and/or invasive mudsnails; at a moderate level (score of 2) if the spring run contains minimal density of crayfish and/or mudsnails; and at a low level (score of 1) if there is a high proportion of crayfish and/or mudsnails. We consider all the factors above, apart from the presence/absence of competitors and predators, to be directly related and dependent on the flow a spring. If there is no spring flow, water quality is not applicable, flow rate is likely to determine if a spring is free flowing or stagnant, and the volume and velocity of spring flow determines the types of substrate p. These relationships are shown below in Figure 3.2.1.

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Habitat Qualities Effects on springsnails Population

Condition

Water quality Spring flow discharge Overall habitat availability Free-flowing spring

Quality of Population size vegetation and

substrates

Absence of Huachuca springsnail competitors and population condition predators

Figure 3.2.1. Factors influencing the current conditions of the Huachuca springsnail. 3.2.2. Species Redundancy

Like all other flora and fauna, the Huachuca springsnail requires multiple resilient populations that contain the genetic representation throughout its range to provide for redundancy. Redundancy is increased when there are more populations, and there is a wide distribution across the range. Greater redundancy reduces the risk that a species range will be negatively affected by a catastrophic natural or anthropogenic event at a given point in time. A species with high redundancy across its historical range is less susceptible to extinction and therefore more likely to be viable into the future than a species confined to a small portion of its range (Carroll et al. 2010, entire; Redford et al. 2011, entire). Most Huachuca springsnail populations are essentially isolated from one another geographically due to not being connected by a water source (unless a flood event should occur), and/or separated by a mountain range or valley. Due to their isolation, once extirpated, sites are unlikely to be recolonized without active management, although stochastic events could potentially revitalize populations through peak flow in a drainage or ‘hitchhiking’ on a bird or other animal. An example of recolonization has been observed in Huachuca Canyon, where snails had not been documented since 2003 but were found again in 2014 by AGFD (Piorkowski and Diamond 2015, p. 27). Again, we are only able to assess the redundancy of the categories of genetic information, or representations which were made available through the 2015 Legacy Study, and further genetic analysis of other sites is ongoing. Of the 15 sites that had positive occupancy in the 2015 Legacy Study, 11 were genetically sampled. The results of these are in (Table 3.2.1).

Table 3.2.1. Haplotypes representing some of the Huachuca springsnail range based on the categories for representation from the 2015 Legacy Report. We have no information for other sites that we presume to be occupied.

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Number of Category Sites Site ID

Haplotype 1 & 2 3 BC01, MC01, SC02

Haplotype 9 6 RC01, GC01, GC02, HC02, CS01, SC01,

Haplotype 1, 2, 9 2 Scotia02, Scotia03 Unknown 3 Haplotype GC03, GC04, GC05

Total 14

The presence of multiple occupied springs would provide refugia within the historical range from catastrophic events such as ground water reduction for springs below the MFR Zone or by stream runoff decreasing in certain drainages, by providing redundancy required by the species to withstand localized losses and changes to habitat. Springs sustained by snowpack cannot be managed by groundwater use planning, due to reliance on climate, therefore making active management of groundwater use and lower elevation springs of high importance. More information is needed to determine which springs are reliant on groundwater and which are reliant on snowpack and precipitation. 3.2.3. Species Representation

For this assessment, representation is defined as having the breadth for genetic makeup for the species to adapt to changing environmental conditions. The more representation, or diversity, a species has, the more it is capable of adapting to changes (natural or human caused) in its environment. Genetic work on the Huachuca springsnail has been limited to verifying whether springsnail specimens collected are within the species clade (Hurt 2004, entire; Tsai et al. 2007, entire), and only more recently done to determine the location of haplotypes. For any sites considered historical, it is likely that the species has lost some representation because we consider those sites no longer occupied. For sites that are considered occupied but that were not sampled in the 2015 Legacy Study, more information is needed to determine their genetic structure. The 2015 Legacy Study investigated the genetics of the populations sampled on the Fort and some surrounding areas (Piorkowski and Diamond 2015, p. 20-21). The findings from this study indicate that the Huachuca springsnail has genetic diversity represented with four haplotypes (1, 2, 9 and an unknown). There had been a haplotype 5 that had been found at some sites (Hurt 2004, p. 1184), but the 11 sites sampled in the 2015 Legacy Study did not detect this haplotype. Until further studies are done we assume that the unknown haplotype is within the Huachuca springsnail species. The three known haplotypes appear to be able to occupy the same spring habitat (Scotia Canyon), but all other sites were composed of only haplotype 9, haplotypes 1 and 2, or the unknown haplotype (Figure 3.2.2). Exchange of genetic material, and the co-habitation

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of haplotypes, is probably a rare occurrence and is likely limited to instances of flood events where a springsnail might move to another site further down the drainage or when springsnails might “hitchhike” on migratory birds. Therefore, maintaining representation in the form of genetic or ecological diversity may be important to the capacity of the Huachuca springsnail to adapt to future environmental change. It should be noted that while springsnail populations can exhibit genetic drift and bottlenecking (Johnson 2005, pp. 2307-2308), they are likely predisposed and adapted to this phenomenon by virtue of their natural history of persisting in springs through geological time. For the sites where the Huachuca springsnail is found, we consider four categories to represent the species; those areas that contain haplotypes 1 and 2; areas that contain haplotype 9; areas that contain the unknown haplotype; and areas that contain haplotypes 1, 2 and 9 (no sites contain these three haplotypes and the unknown haplotype). Further information is needed for the sites not sampled for genetics in the 2015 Legacy Study to determine what haplotypes are represented on those sites.

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Figure 3.2.2. Location of each Huachuca springsnail haplotype (haplotype 1 and 2, yellow; haplotype 9, blue; and unknown haplotype, pink) found on and immediately adjacent to Fort Huachuca from the 14 sample sites. The size of the chart is relative to the Catch per Unit Effort (CPUE) metric defined by number of springsnails per 10 minute survey as an index of springsnail density. Springsnails were not detected at sites BC01, HC01, ML01, so these sites are not depicted. (Image from Piorkowski and Diamond 2015, p. 23).

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3.3. Current Conditions

Available information indicates that the current range of the Huachuca springsnail includes at least 23 of the 29 springs considered to be the historical range of the species. These springs are located in approximately 10 drainages within the Huachuca Mountains, potentially three sites in or near the Huachuca Mountains, and two sites in Mexico. A substantial portion of the spring habitat throughout its current estimated range is managed by the Department of Defense (16 sites), specifically the Fort, and is currently relatively intact and well managed. Other sites within the United States are managed by the CNF (7 sites) and private landowners (4 sites). Intact habitats contribute to redundancy by providing suitable habitat for the 23 known occupied populations throughout the range of the species, and potentially for the other 6 populations (BT01, GC06, MC04, and the two sites in Mexico, ML01 is considered extirpated), though more information is needed to determine or affirm their occupancy. The spring sources on the Fort and surrounding land have limited access to the public, limited livestock access, and no agricultural use. However the majority of sites, 17 of 23 (74%), on Federal land have been modified in some fashion in the past (springhead boxes likely from the 1930’s, covers, etc.). Of the 17 modified sites, springsnails were detected at 13 in 2015 (Piorkowski and Diamond 2015, p. 39). There is one documented extirpation at the Tombstone Reservoir site (ML01), which was modified by the City of Tombstone. And although nonnative fish and crayfish are widespread in aquatic systems across Arizona, we have limited information indicating they can co-occur with Huachuca springsnail. Crayfish are known to occur in Garden Canyon and Blacktail Canyon (Fernandez and Rosen 1996, p. 23; S. Stone, 2012), specifically individuals have been found in GC06 and BT01, and crayfish parts (claw, shell etc. of deceased crayfish) found in GC04. The protections afforded to the spring ecosystems by the Fort, and the management considerations taken by the CNF described in section 4.8, have resulted in the spring ecosystems remaining relatively intact, which has provided areas for the Huachuca springsnail to persist. The framework used to analyze the current conditions of Huachuca springsnail populations is found in Table 3.1. The current status of both stand-alone sites and analysis units, which encompass more than one site, using the framework is provided in Table 3.2. and Table 3.3. Furthermore, Figure 3.3.1 shows the distribution and habitat quality ranking from this framework of the sites on the Fort and CNF.

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Table 3.1. The analysis framework including descriptive qualities of each factor used to assign numerical values of 1, 2, or 3 for each factor condition. The presence of sufficient flow was weighted for High and Medium quality sites since this factor was determined to be the most critical for the survival of the species.

Condition of Factor Population High Medium Low Resiliency Factor 3 2 1

Sufficient water to allow flow Not likely enough water to flow Sufficient water to flow at a rate at a rate and depth to at a rate and depth adequate Adequate spring and depth to remove some fine- remove most fine-grained to remove fine-grained discharge grained sediments sediments sediments

+ 2 + 1 + 0 Free-flowing spring Flows without anthropogenic Flow entirely blocked or nearly Flows with partial barriers ecosystems barriers so

Water provides appropriate Water provides marginal Water unable, or nearly Sufficient water conditions for springsnail conditions for springsnail unable, to support springsnail quality occupation occupation occupation Dominated by hard Appropriate substrates such as cobble, Contain a portion of hard Mostly lacks hard substrates substrate and gravel, pebble, and aquatic substrates and suitable vegetation and suitable vegetation aquatic vegetation vegetation Absence or minimal No documented crayfish Low proportion of crayfish and/or High proportion of crayfish density of invasive and/or invasive mudsnails invasive mudsnails within 12 m of and/or invasive mudsnails predators and/or within 12 m of springhead springhead within 12 m of springhead competitors >11, ≤ 17 >5 , ≤11 ≤5, NA Cumulative Score High Quality Medium Quality Low Quality

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Table 3.2. Current estimated conditions of the Huachuca springsnail “stand alone” populations (both current and historical), represented quantitatively. If sites had CPUE results this is also noted but is not included in the Cumulative Score. A factor score of 0 for flow indicates that the site was dry during the site visit. The Cumulative Score is a sum of the factor scores. A higher Cumulative Score indicates a higher relative condition of that site and/or unit. The matrix to determine these scores relied on the expertise of biologists from the Service, AGFD, and review of the Myers (2012) and Piorkowski and Mulligan (2012) reports. Numerical scores were assigned based on these qualitative assessments. Purple = High Quality, Blue = Medium Quality, Pink = Low Quality, and Pink = likely extirpated

Presence of Likelihood Free- Substrate CPUE Sufficient invasive Binomial to have flowing and Estimates Cumulative water predators Haplotype Name sufficient spring aquatic AGFD Score quality and/or flow ecosystem vegetation 2012-2015 competitors BC01 5 3 3 3 3 851 17 1 & 2 BT01 0 0 3 0 0 0 3 CS01 5 3 2 2 3 23.5 15 9 ML01 0 0 0 0 0 0 0 RC01 3 3 3 3 3 8 15 9 CW01 3 3 3 3 3 NA 15 MS01 5 3 3 2 3 NA 16 SS01 3 3 3 3 2 NA 14 NS01 1 1 2 1 2 0.1 7 CH01 1 2 3 2 2 NA 10

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Table 3.3. Current conditions of the Huachuca springsnail for the analysis unit populations (some units contain historical sites). The data is given quantitatively. These numerical rankings are derived from qualitative evaluations of the factors. If sites had a CPUE results, this is also noted but is not included in the Cumulative Score. The Cumulative Score is a sum of the summed factor scores. A higher Cumulative Score indicates a higher relative condition of that unit. The matrix to determine these scores relied on the expertise of biologists from the Service, AGFD, and review of the Myers (2012), and Piorkowski and Mulligan (2012) reports. Numerical scores were assigned based on these qualitative assessments. *indicates those sites where all three haplotypes were found. Purple = High Quality, Blue = Medium Quality, and Pink = Low Quality.

Likelihood to Sufficient Free-flowing Substrate and Presence of CPUE Estimates Cumulative Binomial Name have sufficient water spring aquatic predators and/or AGFD 2012- Haplotype Score flow quality ecosystem vegetation competitors 2015 GCO1 5 3 3 3 3 1.9 17 9 GC02 5 3 3 2 3 25.3 16 9 GC03 3 2 2 1 3 86.5 11 unknown Garden GC04 3 2 2 2 2 3.4 11 unknown Canyon AU GC05 3 2 2 1 3 0.1 11 unknown GC06 3 1 2 3 1 NA 10 Summed Score 76

HC01 1 3 3 2 3 NA 12 Huachuca HC02 1 3 2 3 3 1.1 12 9 Canyon AU Summed Score 24

MC01 1 2 2 2 3 1 10 MC02 1 2 2 2 3 NA 10 McClure MC03 3 2 2 3 3 0.1 13 1 & 2 Canyon AU MC04 NA NA 3 NA 3 NA 6 Summed Score 38

SC01 3 3 3 2 3 72.5 14 9 Sawmill SC02 3 3 2 3 3 56.9 14 1 & 2 AU Summed Score 28

Scotia01 3 3 3 2 3 NA 14 Scotia02* 3 3 3 2 3 9.4 14 1, 2, 9 Scotia AU Scotia03* 1 2 3 1 3 3 10 1, 2, 9 Summed Score 38

CF01 NA NA NA NA NA NA NA Mexico AU OC01 NA NA NA NA NA NA NA Summed Score NA

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Figure 3.3.1. Locations and habitat quality ranking for all known sites containing Huachuca springsnails within the United States Rankings are the same as seen in Tables 3.2 and 3.3.

3.4. Summary of Needs and Review of Current Condition

The needs of the Huachuca springsnail, both individuals and populations are listed below. Individuals - Sufficient spring flow - Relatively shallow water with sufficient water quality parameters (temperature, dissolved oxygen, nutrients/salts), and free of pollutants - Free-flowing spring ecosystems, which we define as a spring or seep that is not impounded or obstructed in a way to reduce water quality or water turn-over - Course, firm substrates (i.e. pebble, gravel, cobble, and woody debris). - Food base comprised of aquatic macrophytes, algae, and periphyton - Few or no nonnative predatory species

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Populations - Stable or possible increasing trends in relative abundance - Intact free-flowing spring ecosystems - Sufficient abundance to ensure appropriate encounter rates - Sufficient groundwater and snowpack/precipitation to support spring discharge in the occupied drainage. Species - Sufficient number of populations that represent the available genetic diversity In terms of a summary for the Huachuca springsnail’s current conditions, based on the information we have, all but two of the standalone sites are in moderate to high condition. For the standalone sites, those that had the highest quality habitat include BC01, CS01, and MS01. This determination is in part due to the high CPUE counts at these sites. For the analysis units, the high quality units include the Sawmill AU, Garden Canyon AU, McClure Canyon AU, and the Scotia Canyon AU. The Sawmill AU and Garden Canyon AU are seen as high quality sites due to both having high CPUE counts and the Sawmill AU representing all known genetic haplotypes, making it both a unique and genetically representative site. The Scotia Canyon AU also represents all known genetic haplotypes, but the CPUE counts are lower and offer less overall redundancy than the Garden Canyon AU. We considered representation using the 2015 Legacy Study’s haplotype analysis which genetically analyzed 11 sites. From the four categories of haplotypes found, haplotype 9 was the most redundant with occurrence in six populations. Only three sites represented haplotypes 1 and 2, and only the Scotia02 and Scotia03 sites represented all three haplotypes. Sites that had high habitat scores do not appear dependent on high flow rates even with the weighting of that factor, and that high habitat scores do not appear to directly relate to high CPUE counts as one may intuitively conclude. We recognize that other factors beyond what we are able to evaluate in this SSA Report could be impacting abundance. Lastly, as evident from both current condition tables, we lack some key information on the presence of competitors and predators, as well as specific habitat assessments.

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CHAPTER 4: FACTORS INFLUENCING VIABILITY

In this chapter, we evaluate the past, current, and future factors that are affecting what the Huachuca springsnail needs for long term viability. We analyze pathways for each factor, and each of the factors are examined for its historical, current, and potential future effects on the species. The current and expected distribution and abundance also determine the viability and vulnerability of the species to extinction. The factors influencing the Huachuca springsnail are described below briefly, more information on the factors can be found in Appendix B. The two primary factors affecting the future viability of Huachuca springsnails are the loss of spring discharge and alteration of spring habitat. Since the majority of springs that are occupied by the springsnail are on the Fort and the CNF, there are some existing protections in place related to the general land use plans of each agency. An effective CCA between the Fort, the neighboring CNF, and the AGFD could assure the effectiveness of these protections, particularly if further efforts are made to reduce risks to the species into the future. Based on our evaluation, we have determined that the effects of declining groundwater, precipitation changes, and likely snowpack decline on spring flow are the factors with the greatest amount of uncertainty regarding the future viability of the species across all sites. Other factors are of concern, but may be more site or unit specific. All are discussed below, and further information can be found in the Cause and Effects Tables in Appendix B.

4.1. Reduction of spring discharge

The Huachuca springsnail’s range within the United States occurs in two groundwater basins. The Upper San Pedro Ground Water Basin (SPB) includes the San Pedro River, the Fort, CNF and the City of Sierra Vista. The San Rafael Groundwater Basin (SRB) includes the Santa Cruz River and the CNF. Water in the SPB flows down from the mountains towards Sierra Vista where a ‘cone of depression’ in the aquifer currently exists due to groundwater pumping (ADWR 2009, p. 492). And the SRB flows from the Huachuca mountains to the Santa Cruz River where it continues to flow south (ADWR 2009, p. 461). Recharge of these basins and regional aquifers are dependent on winter snowpack, spring snowmelt, and seasonal precipitation stream runoff, and this recharge is critical to the long term maintenance of spring discharge (Corell et al. 1996, p. 19; ADWR 2009, entire). The SPB is also being recharged by efforts of the Fort through water conservation and storm water capture mitigation measures. Both are anticipated to have long term positive effects, but are not expected to be seen for 20 years (Army 2013, G-10). Groundwater depletion has been implicated in the decline of other freshwater mollusks (Landye 1973, p. 1; Landye 1981, p. 1; Service 2005, pp. 46303-46333), and is considered a risk to the Huachuca springsnails due to potential impacts to spring flow. The water conservation measure mentioned above reduces the water withdrawals on the Fort, and the Storm Water Capture increases the recharge amount to approximately 106 acre-feet of water per year from detention basins. These mitigation measures were described in a programmatic Biological Assessment authored by the Fort (Army 2013, D-5, G-10). While these mitigation measures will assist with long term maintenance of the SPB, and while the Fort determined that groundwater usage for continuing operations into the future would have no effect on the Huachuca springsnail (Army

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2006, p. 189), there is still the increasing frequency and intensity of ecosystem disturbances like drought that is attributable to climate change are increasing (IPCC 2014, p. 51). Climate change during the 21st century is projected to reduce renewable surface water and groundwater resources in most dry subtropical regions (IPCC 2014, p. 69). Seager et al. (2007, pp. 1181–1184) analyzed 19 different computer models with differing variables to estimate the future climatology of the southwestern United States and northern Mexico in response to predictions of changing climatic patterns. One predicted a trend toward a wetter climate within the Southwest, but all others predicted a drying trend (Seager et al. 2007, p. 1181). A total of 49 projections were created using the 19 models; all but three of the projections predicted a shift to increasing dryness in the Southwest as early as 2021–2040 (Seager et al. 2007, p. 1181). The current prognosis for climate change impacts on the Sonoran Desert of the southwestern United States includes fewer frost days; warmer temperatures; greater water demand by plants, animals, and people; and an increased frequency of extreme weather events (heat waves, droughts, and floods) (Weiss and Overpeck 2005, p. 2074; Archer and Predick 2008, p. 24). How climate change will affect summer precipitation is less certain, because precipitation predictions are based on continental-scale general circulation models that do not yet account for land use and land cover change effects on climate or regional phenomena, such as those that control monsoonal rainfall in the Southwest (Weiss and Overpeck 2005, p. 2075; Archer and Predick 2008, pp. 23–24). Groundwater extraction around the City of Sierra Vista has already contributed to a measurable depletion and depression in the local water table, although some measures are now in place to reduce this effect. Groundwater models developed by the U.S. Geological Survey in 2011 do not provide the level of specificity necessary to predict the exact nature of the relationship between groundwater levels, San Pedro and Santa Cruz River base flow levels, and spring flow discharge should the springs be reliant on groundwater (Tillman et al. 2011, entire). Given the flow patterns of the aquifers, we presume that declines in ground water levels in the valley sub-basins will likely translate to some decline in spring flow in the springs below the MFR Zone, which has varying elevations depending on the area. The springs above this zone are reliant on precipitation and snowpack melt, and should experience more stable flow overall. It is important to note that our information regarding the geology of the area does indicate that the Huachuca Mountains are composed of consolidated rock and the springs found there are more likely to depend on precipitation and snow melt for spring flow than on groundwater in the basin-fill adjacent to the mountains (Army 2006, p. 73). However we need further hydrologic information and therefore will continue to include groundwater usage as a factor affecting both current and future conditions. Water usage has already resulted in extirpation of the Miller Canyon/Tombstone Reservoir (ML01) population and is a potential risk to other sites in Miller Canyon where the City of Tombstone carried out spring modifications (at ML01). We anticipate the effects of groundwater decline on future levels of spring discharge will be the primary factor influencing the future conditions of any springs below the MFR Zone that Huachuca springsnails occupy, and that snowpack melt and precipitation changes will be the primary factor affecting springs above the MFR Zone. The continued presence of spring flow is the primary factor likely to influence the survival of the Huachuca springsnail.

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4.2. Springhead Modification

Human activity has historically contributed to widespread modification of the species’ habitats resulting in the loss of natural springhead integrity and, in some instances, the elimination of the aquatic environment (17 of the 22 sites surveyed in the Legacy Study 2015 were modified). Covering the springhead (at Scotia02, MC02, and MC03) may reduce natural organic matter input, aquatic vegetation, and algal growth (Figure 4.1).

Figure 4.1. Modified springhead at the Scotia02 site (Peterson Ranch Tank), seen with fencing and corrugated metal covering. Photo taken by M. Martinez in 2006. Diversion of water also reduces springsnail habitat. Channelizing and/or modifying spring runs reduces or eliminates spring habitat (as seen with the ML01 site). Of the 22 springs surveyed by AGFD in 2015, 17 springs where the species occurs currently or historically have been subjected to some level of modification (Piorkowski and Diamond 2015, p. 39). Anthropogenic springhead modification is a factor that might impact some extant populations in the future. Future modifications on the Fort are not likely due to the Fort’s management plan and conservation efforts (Army 2001, p. 50, 145; Army 2006, p. 239). However, on private land and on the CNF potential modifications could occur from construction of spring head boxes or installation of pipes (as seen with the ML01site), or from trampling by livestock. Trampling by livestock has not been documented for the Huachuca springsnail, but other springsnail species, such as the Chupadera springsnail (Pyrgulopsis chupaderae) in Socorro County, New Mexico, was extirpated from a site due to significant habitat degradation from trampling and manure deposits (USFWS 2012, p. 41089). The CNF intends to limit habitat modifications due to livestock with exclosure fencing and grazing rotation schedules that will maintain an area in good condition (USFS 2013, p. 53, 57, 88). Effects from livestock are likely to be site-specific; for example Peterson Springs (Scotia02, a high quality site) is excluded from grazing, but Upper Peterson (Scotia03, a medium quality site) does not include an exclosure. The Sheehy Spring site (SS01, a high quality site) does not contain an exclosure, but a grazing rotation is planned under the Draft San Rafael Ranch HCP that is being finalized to further minimize effects of livestock use at the site. 45

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We also consider severe wildfire to be a modifying factor due to its ability to remove aquatic and surrounding vegetation, resulting in erosion that can cause inundation of springs, and degrade water quality. Modification due to wildfire is moderately likely to occur regardless of land ownership. Hershler and Williams (1996, p. 1) suggested that efforts to maintain springsnail populations should focus on the maintenance of natural spring head integrity, which will improve water quality and conserve a broad array of spring-dependent organisms.

4.3. Conversion from Lotic to Lentic Systems

To various degrees, a free-flowing system (lotic) can become ponded (lentic), which may or may not be less conductive to occupation by the Huachuca springsnail. Modifying a springhead, carrying out other activities near or in a spring channel, and stochastic natural events can all result in a conversion from a lotic to lentic system to varying degrees. Changes to spring ecosystems resulting in pooling have occurred at the Peterson Ranch Spring (Scotia02), which remains occupied. Sorensen described it as being “an impounded pond that is spring fed and fenced in to exclude livestock” (Sorensen 2016b). Pooling can alter springsnail habitat by changing water depth, velocity, substrate composition, vegetation, and water chemistry, which can cause population reduction or extirpation. It is important to note however, that pooling does not necessarily lead to extirpation. Based on the Page springsnail’s habitat, we assume, though with uncertainty, that the Huachuca springsnail would exhibit similar tendencies towards lower densities in pooled systems versus natural free-flowing environments (Service 2015, pp. 22-23). We assume any further conversions to lentic systems would be due to stochastic events like flooding and not actions that would purposefully alter the environment (construct a springhead box etc.).

4.4. Aquatic Vegetation Removal

Removal of aquatic vegetation to increase spring flow or as a part of a vegetation management plan is considered a threat to the Huachuca springsnail populations. While information does not indicate that removal of aquatic vegetation within occupied habitat has occurred, is occurring, or will occur, this factor is described here because submerged aquatic vegetation is important to springsnail persistence because it provides springsnails with food, cover from potential predators, and a substrate to adhere to complete life history actions. Physical removal of emergent and submerged native vegetation (including algae) and organic debris can reduce the quality of spring habitats, potentially resulting in lowered population numbers. Vegetation removal could result in direct fatality of Huachuca springsnails from crushing and desiccation, and indirect mortality through habitat modification and temporary water quality changes. Overall however, aquatic vegetation removal occurs rarely in the species range, if at all, and is not expected to occur in the future to an extent to be detrimental to the species.

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4.5. Water Contamination

Although hydrobiid snails as a group are found in a wide variety of aquatic habitats, each species is usually found within relatively narrow habitat parameters (Sada 2008, p. 59). As such, hydrobiid snails may be sensitive to the specific water quality parameters that exist within their endemic habitats. Proximity to spring vents, where water emerges from the ground, plays a key role in the life history of springsnails. As previously discussed, many springsnail species exhibit decreased abundance farther away from spring vents, presumably due to their need for stable water chemistry; and several habitat parameters of springs, such as substrate, dissolved carbon dioxide, dissolved oxygen, temperature, conductivity, and water depth, correlate with the distribution and abundance of Pyrgulopsis sp.. Water contamination is identified as a risk because of the potential use of fire retardant to manage wildfires. Historically the Huachuca Mountains experienced low-intensity fires in four to 10 year intervals (Army 2006, A-24). However, beginning in the late 19th century, these frequent ground fires ceased to occur due to intensive livestock grazing that removed fine fuels coupled with effective fire suppression in the mid to late 20th century that prevented frequent, widespread ground fires (Swetnam and Baisan 1996, pp. 20-25). Absence of ground fires allowed a buildup of woody fuels that precipitated infrequent but intense crown fires (Danzer et al. 1997, pp. 30-33) which can result in the need for fire retardant use. Contamination from aerial fire retardant is a potential risk to the species. Contamination of aquatic sites, and entire units, could potentially occur via direct application or runoff from treated uplands. Our information indicates that the Ryan Fire in 2002 burned near the Canelo Hills site (CH01) and although retardant slurry was applied to the buildings on the property, it is unknown how the fire itself affected the site and if the application of the retardant had an effect. At the time of the Ryan Fire, ferrocyanide, was a component of slurry (Myers 2016). Ferrocyanide degrades in the sunlight to become cyanide, which can be toxic to some aquatic organisms. While the chemical compounds in these previous formulations have been adjusted and phased out due to field toxicity (Calfee and Little 2003, pp. 1529-1533), we still consider exposure to ammonia based retardants a concern due to springsnails sensitivity to water quality.

4.6. Predation

There are many predators of freshwater gastropods species. Of the known predators to springsnails the nonnative crayfish and the mosquitofish (Gambusia affinis) have both been found in springs and/or canyons of springsnail sites. The spread of the non-native northern crayfish (Hershler et al. 2014, p. 5) is of concern because a laboratory aquaria experiment that mimicked stream conditions found that crayfish consumed snails in the family Physidae (which occupy similar habitats as springsnails) and their eggs within one week of introduction (Fernandez and Rosen 1996, pp. 24–25). Crayfish are well distributed and abundant throughout Arizona and currently occur in both Garden and Blacktail Canyons (Fernandez and Rosen 1996, p. 23; S. Stone 2012), with individuals specifically being found in two Huachuca springsnail sites (GC06 and BT01), and crayfish parts (claw, shell, etc. of deceased crayfish) found in another (GC04). Mosquitofish have also been found in the Sheehy Spring (SS01) site (AGFD 2016a). Crayfish and other predators may negatively affect efforts to maintain extant

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populations of Huachuca springsnails and future efforts to re-establish others. Due to its long- term biogeographic isolation, the Huachuca springsnail may not be evolutionarily adapted to cope with these and other nonnative predators. However, the long-term impact of predators on Huachuca springsnails has not been studied and is presumed to be a minor factor influencing the current status, but could be a significant factor to influencing the species’ current status, but could be a factor that influences future resiliency.

4.7. New Zealand Mudsnail

The nonnative New Zealand mudsnail is an invasive freshwater snail of the family Hydrobiidae that is known to compete with and slow the growth of native freshwater snails, including springsnails (Lysne and Koetsier 2008, pp. 103, 105; Lysne et al. 2007, p. 647-653). The slowing of growth occurs because the New Zealand mudsnail outcompetes hydrobiid snails for food and shelter resources. A study by Riley et al. in 2008 showed that growth of springsnails was significantly reduced by the presence of the New Zealand mudsnails (Riley et al. 2008, p. 517; Hershler et al. 2014, p. 5). The mudsnail can be easily transported and unintentionally introduced into aquatic environments via birds, hikers, researchers, and resource managers. There are currently no documented Huachuca springsnail springs (historically or currently occupied) that are occupied by the mudsnail but if they are introduced into a spring system occupied by the Huachuca springsnail, the effect could cause localized extirpations.

4.8. Management Actions and Conservation Measures

In 2010, the Army finalized the updated Fort Huachuca Integrated Natural Resources Management Plan (INRMP) that provides guidance on land use, military training operations, and conservation of wildlife and their habitat on the Fort (Army 2010, entire). The INRMP provides for the continued inventory of remote springs, monitoring of known occupied sites as needed, general protection of springs, and development of a conservation agreement (Army 2010, pp. 113; Army 2001, p. 111, 145). As discussed above, a risk to Huachuca springsnail on the Fort is severe wildfire, and the use of fire retardant. The 2010 INRMP contains several continuing goals and objectives from the 2001 INRMP related to fire management. These include the collection of fire history data, fire mapping, fuel hazard reduction, and prescribed fire to reduce the risk of stand-replacing fire (Army 2010, pp. 115, 116; Army 2001, pp. 114, 120-121). To this point, actions implemented near springsnail habitats are: 1) silt fencing along Garden Canyon, between the road shoulder and creek banks; and 2) thinning of shrubs and small trees along the road through Garden Canyon up to the junction with Sawmill Canyon (1890 m (~6,200 ft.) elevation) to slow the spread and lower the intensity of the Monument Fire in 2011 (Stone 2012, p. 1). We have no additional information regarding the status of these goals and objectives as they relate to site-specific conditions at springsnail sites on the Fort. The best available information indicates that high fuel loads are still present and could contribute to severe wildfire. The 2006 final Biological Assessment and subsequent Biological Opinion for the Ongoing and Future Military Operations and Activities at Fort Huachuca concluded that continued operations at the Fort may affect and were likely to adversely affect the Huachuca springsnail; however, because the Huachuca springsnail was a candidate at the time, it was not included in our formal consultation. The Fort’s determination was based on the potential for human-caused wildfires,

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and disturbance by the public in areas where springs are close to picnic areas or hiking trails. No effects were anticipated from habitat loss, erosion, and groundwater withdrawals, or direct fatalities due to the Fort’s activities (Army 2006, p. 189). Conservation measures that related to the springsnail and spring ecosystems included water conservation measures, groundwater mitigation, annual monitoring of the species, prohibiting off road travel, protecting springs occupied by the endangered Huachuca water umbel (Lilaeopsis schaffneriana var. recurva) (which shares habitat with the Huachuca springsnail in some localities) during fire events, implementing prescribed burns and fuels reduction activities, restricting and signing areas to limit recreational use, and protecting habitat as needed (Army 2006, pp. 255-280, 291). Further protections of sites should occur with a revision of the CNF’s Travel Management Plan, which will involve the decommissioning of roads, grazing restrictions and rotations, and consideration of modifications made to the Miller Canyon/Tombstone Reservoir site (ML01) under a Special Uses Permit that was between the City of Tombstone and the CNF (Expert Group 2016; J. Kraft 2016). A draft Land and Resource Management Plan has been released by the CNF that describes fire and fuels reductions, invasive species management, and grazing management (USFS 2013, pp. 58, 66, 88). In addition, a draft HCP for the San Rafael Ranch that would manage grazing in a pasture that includes Sheehy Spring (SS01) is in the process of being finalized, which will help maintain the species representation across the landscape. In regards to the risk of invasive competitors and predators, the Fort and the CNF could undertake management actions similar to AGFD’s actions to control the spread of the mudsnail and alleviate the risk from springs (Army 2010, p. 117). The AGFD’s Invertebrate Program implements Hazard Analysis-Critical Control Point Plans (HACCP) to minimize the risks of incidentally moving undesirable organisms between waterways, including strict equipment use and cleaning protocols for field sampling of springsnail sites. HACCP planning is an international standard for reducing or eliminating the spread of unwanted species during specific processes or practices or in materials or products based on the Standard Guide for Conducting HACCP Evaluations (HACCP 2016). Additionally, AGFD has identified measures related to nonnative species control in their 10-year Nongame and Endangered Wildlife Conservation Plan and work conducted under state wildlife grants. These measures include protocols to prevent the spread of disease and nonnatives, such as crayfish and mudsnails, within the State of Arizona and at its borders (AGFD 2012a, entire; AGFD 2012b, entire). Since the range of the Huachuca springsnail is included in the Huachuca FireScape Plan and the Fort Huachuca Fire Management Plan, the risks from misapplication of fire retardant are minimized since pilots are provided information about springs and water drainages to avoid (USFS 2009, entire). The Fort has also funded and is currently implementing a high elevation fuels management plan (Army 2013, pp. 47, 89). Fuels reductions around spring and wetland areas are also planned under the CNF’s Resource Management Plan (USFS 2013, p. 58). The CNF also follows best management practices for any land management actions they undertake. The CNF has also proposed to reconstruct, or return to natural condition, three previously modified springs every 10 years (USFS 2013, p. 57). If such a proposal becomes a planned activity, this would provide conservation benefits, but at this time we are uncertain that such an activity will be implemented. Between the above land owners, there is an interagency effort to develop a CCA for the Huachuca springsnail. The Fort and the CNF have expressed an interest in entering into a CCA with the Service and AGFD. AGFD has lead for development of a draft CCA, which was

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reviewed by the partners and officially submitted to the Service’s Region 2 Office in March 2016. Some of the specific conservation measures identified in the draft CCA include monitoring spring flow, reestablishing spring flow, monitoring springsnail populations, and following fire retardant application guidelines (AGFD 2016b). Lastly, the Phoenix Zoo has expressed interest and capability of holding and rearing Huachuca springsnails in captivity and assisting in determining some life history traits (Expert Group 2016). A captive population would also qualify as a refugia population.

4.9. Summary

The most significant stressor to the Huachuca springsnail is the risk of declining spring discharge, and therefore the loss of spring ecosystems that individuals and populations need to complete their life history. The primary cause of historical habitat loss within the range has been anthropogenic modification of spring ecosystems. Any action that generally removes suitable habitat can contribute to the potential decline or extirpation of local populations. Since a majority of historically and currently occupied springs occur on Federal lands (the Fort and CNF) and receive some protection through current management, we do not anticipate further modifications to springheads and spring ecosystems. Additionally, although nonnative snails and crayfish could be unintentionally introduced to springs, the implementation of HACCP plans minimizes the potential for spread of both the New Zealand mudsnail and crayfish. As such, the primary source of potential future habitat loss is groundwater depletion and decreased snowpack that could result in reduced or eliminated spring flow. Groundwater withdrawals will continue to affect base flow in the Upper San Pedro and San Rafael Basins where the Huachuca springsnail is found. There is uncertainty regarding when, where, or how much it will affect the springs harboring the species at lower elevations however, as there is no available data to quantify the site-specific relationships of those spring systems to the based flow in these basins. Climate change will affect the amount of precipitation and snowpack in the upper elevations that is the primary source of recharge to both of these basins and support flow in upper elevation springs. These stressors and how they impact the factors are shown in Figure 4.2.

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Figure 4.2. Schematic showing the relationship between the “sources” and “influences” to the habitat metrics that are used in the framework which influence the species resiliency across the landscape. 51

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CHAPTER 5: SPECIES VIABILITY

We have considered what the Huachuca springsnail needs for viability and the current condition of those needs (Chapters 2 and 3), and we reviewed the factors that are driving the historical, current, and future conditions of the species (Chapter 4). We now consider what the species’ future conditions are likely to be.

5.1. Introduction

The Huachuca springsnail historically was known, or assumed to occupy, up to 29 springs. Since this determination, 23 sites have had positive occupancy data (CPUE, Tables 3.2, and 3.3). Information from three private land sites and the two potential sites in Mexico is not currently available. The known extant populations have primarily moderate to high habitat quality, and one population has low quality due to the spring naturally drying (Blacktail Spring, BT01), and one is considered extirpated due to habitat modification (Miller Canyon/Tombstone Reservoir, ML01). While future impacts from further habitat modifications are not expected to the majority of springs with extant populations, the risk of drought causing lowered precipitation and snowpack melt and associated reduction in spring flow remains a concern. The 19 long-term climate models reported in the Seager et al. 2007’s study predicted a drying trend within the Southwest and included predictions of fewer frost days; warmer temperatures; greater water demand by plants, animals, and people; and an increased frequency of extreme weather events (heat waves, droughts, and floods) (Weiss and Overpeck 2005, p. 2074; Archer and Predick 2008, p. 24). These projections support the potential that wildfires may be a modifying factor of spring ecosystem into the future. For the purposes of this analysis, these 19 climate models reported by Seager et al. (2007) have uncertainty regarding when, where, and to what extent climate change will occur. We are reasonably certain that climate change will result in more variable snowpack and precipitation (IPCC 2014, p. 69; Seager et al. 2007, pp. 1181–1184), but we are less certain how and when it will affect spring flow rates. Taking into account this inherent uncertainty of the extent and when the effects to the species will occur, we developed the following scenarios. The viability of the Huachuca springsnail depends on maintaining multiple resilient populations over time. A resilient population improves the species’ representation and redundancy throughout its range. Given the uncertainty regarding if or when springs occupied by the Huachuca springsnail could experience a reduction or elimination of spring flow, and how many springs may be modified in the future, we have forecasted what the Huachuca springsnail may have in terms of the 3Rs under three plausible future (over the next 50 years) scenarios. These scenarios are derived from the scenario matrix (Table 5.1.) and further described in Appendix A.

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Table 5.1. Both the spring discharge factor and modification factor are independent; therefore each factor has three potential scenarios for the next 50 years. Combinations of scenarios (total of nine) were assessed based on the information available for plausible future scenarios.

Factors Factor Scenario Scenario Spring Discharge Free Flowing/Modification No measurable change in flow rate; ≥80% of ≤10% springs modified in 1 A occupied springs way to minimize habitat stable flow Measurable change in >10%, ≤20% of occupied flow rate; flow still or historical springs 2 present at moderate B modified that reduce level in ≥80% of habitat occupied springs All or most occupied >20% of occupied or springs ≥80% have 3 C historical sites modified to extreme reduction, reduce habitat and low level of flow

Based on the information we have, the following scenarios were determined to be the most likely. 1B: No measurable decrease in spring flow; springs that are occupied or could be occupied by the Huachuca springsnail experience limited modification. 2B: A measurable change in spring flow but still enough flow to remove most fine substrates in majority of springs; springs that are occupied or could be occupied by the Huachuca springsnail experience limited modification. 3B: Springs experience extreme reduction in flow; and springs that are occupied or could be occupied by the Huachuca springsnail experience limited modification, but with limited flow these modifications are magnified in effect.

5.2. Resiliency

In general, Huachuca springsnails are adapted to the endemic nature of spring ecosystems. While we can discern relative population sizes at sites through CPUE counts, we do not have site specific population estimates. We assume with that Huachuca springsnail populations follows a similar pattern to Page springsnails and that with appropriate habitat and sufficient flow, a short term (~one year) reduction in the population at a spring would not be expected to result in extirpation, and the population would likely rebound quickly. Resiliency of Huachuca springsnail populations is likely to be affected by two primary factors: 1) spring flow decline, be that from groundwater pumping or snowpack/precipitation stochasticity;

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and 2) springhead modification from anthropogenic factors, grazing, or severe wildfire events which includes both severe wildfires going through site(s) and fire retardant use. The influence of invasive predators and competitors, although present in some sites, is not considered a primary factor. Spring flow decline could result from groundwater decline and snowpack and precipitation runoff being less consistent and in variable amounts. We are currently uncertain of the proportion of springs, if any, which rely on groundwater given the sites on the Fort and the CNF are in the Huachuca Mountains which are considered consolidated rock. Should sites be dependent on groundwater, there is a cone of depression within the San Pedro Basin aquifer near the City of Sierra Vista which could impact spring outflow in the future as groundwater pumping continues. The Fort is recharging the aquifer with their water conservation measures which reduces the water withdrawals on the Fort; and the Storm Water Capture Program which increases the recharge amount to approximately 106 acre-feet of water per year from detention basins (Army 2013, D-5, G-10). Climate change will likely be the primary influencing factor on springs dependent on snowpack and precipitation, and this factor is not easily managed or easy to projected. The Fort is managing the spring sites within its jurisdiction by placing boulders to inhibit vehicle disturbance of sites in Garden Canyon and implementing a fuels management and groundwater recharge program to minimize potential risks of anthropogenic and wildfire modification as well as water availability (Army 2006, p. 196; Army 2013, D-5, G-10). The CNF is managing the spring sites in their area to minimize effects of livestock modification by fencing some spring areas to exclude livestock, and rotating cattle through an area during a limited time window. The CNF also has programs to help reduce fire fuels, and manage invasive species (USFS 2009, entire; USFS 2013, pp. 53, 58, 66). The Sheehy Spring site (SS01) is located on private land on the San Rafael Ranch and management of livestock in that pasture is included in a draft HCP to promote habitat conservation. Management actions to reduce these primary factors that affect the Huachuca springsnails resilience for the other privately held sites, and the sites in Mexico, are unknown. Given these management actions by the Fort and the CNF and by the San Rafael Ranch, we conclude that any future modification of spring habitat would most likely occur due to wildfires and some impacts from grazing, but that these modifications would not affect greater than 20% of occupied or available habitat for 50 years into the future (scenario B). However we are uncertain of, and unable to forecast, the extent or location of spring flow reductions. We therefore discuss how population resiliency would vary under each of the three potential scenarios: 1B: No measurable decrease in spring flow; ≥80% of occupied springs have stable flow If groundwater does not impact populations at sites that are above the MFR Zone, or if groundwater pumping is mitigated and spring flow that relies on groundwater does not have a measurable loss over the next 50 years, most extant Huachuca springsnails are expected to maintain their current levels of resiliency. Habitat improvement actions will continue under the general land use plans discussed above, and potentially through the CCA once it is finalized. It is possible that those sites that scored higher in the moderate percentile could improve to be classified as a high quality site.

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If stochastic events occur, such as flooding and/or severe wildfires, that reduce or eliminate populations on land managed by the Fort and/or the CNF, management and rehabilitation actions are expected to be undertaken to attempt to remediate the effects. Actions could include erosion control, habitat creation or restoration, and/or population reintroduction from other viable sites. Once habitat is restored, it is likely that populations would rebound due to improved spring flow. Under this scenario, populations would likely retain or improve their overall condition which was shown in Tables 3.2 and 3.3. We expect that high scoring sites (n=15) correlates to sites that have a high likelihood of persistence through the next 50 years. Sites that were in the moderate scoring bracket (n=10), are considered to be moderately resilient but also likely to persist into the future. Sites that were scored low (n=2, one likely extirpated) are likely to have low resilience, but with appropriate management actions as described in the INRMP, Ongoing and Future Military Operations and Activities BA, and the CNF LRMP (Army 2001, Army 2006, Army 2010, USFS 2013), these sites could be improved to more likely persist into the future. More information is needed on the sites that have no information to determine their resilience and likelihood of persistence into the future (n=2). 2B: A measurable decrease in spring flow but still enough flow to remove most fine substrates in a majority (≥80%) of occupied springs or suitable springs. If, over the next 50 years, the water source that influence spring outflow, be it groundwater or snowpack/precipitation, declines in a measurable but not dramatic way, then populations could experience reduced spring flow and become less resilient. Since springsnails are so dependent on spring flow and the habitat it provides, a population will lose resiliency as habitat quality declines. Depending on the water source, some or most populations could be impacted, and we presume that if an analysis unit is impacted; all sites within that unit will be impacted. The methodology for determining the future condition under this scenario is shown in Table 5.2.1. Under this scenario, the six sites which had high to moderate scores but low flow scores (HC01, HC02, MC01, MC02, Scotia03, NS01 and CH01) are likely to be reduced to low resilience or extirpated. The remaining 17 sites are likely to experience some changes but would otherwise maintain moderate to high resilience given their current habitat scores (Table 5.2.2).

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Table 5.2.1. High scoring sites (scores between 11 and 17) that fall at or below the median of 14 and with a flow score of 3 would become a medium ranked site, unless flow scores were a 1 in which case that site would likely be low ranking. If a high scoring site fell at the median but had a 5 score for flow, it remained high scoring. Any medium scoring sites (scores between 5 and 11) that fell at or below the median of 8 became low ranking sites, if however a site was about the median but had a low flow score, it too was determined probable to become low scoring. Any low scoring sites under this scenario would be extirpated

Scenario 2B

Current Future

≥14, Flow High Score=5 Quality High ≤14, Flow Medium (Scores 11-17, Score=3 Quality Median 14) Flow Low Score=1 Quality

≥8, Flow Medium Score=3 Quality Medium ≤8, Flow Low (Scores 5-11, Score=3 Quality Median 8) Flow Low Score=1 Quality

Low Likely →→→→→ (Scores ≤5) Extirpated

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Table 5.2.2. The projections of the Huachuca springsnail populations in the next 50 years under Scenario 2B (measurable flow reduction). Rankings for future conditions were determined based on where the current status score was in relation to that category’s median. Scores below 14 became medium quality sites (unless the site had a flow score of 5), and scores below 8 became low quality sites. Low scoring sites are likely to become extirpated. Low flow scoring sites, even if they were high scoring, we project would be low scoring or extirpated. Sites we expect to become extirpated are shown with a strikethrough. Purple = High Quality, Blue = Medium Quality, and Pink = Low Quality.

Spring Future Spring Future Haplotype Haplotype Population Condition Population Condition BC01 High 1 & 2 GC01 High 9

BT01 Low GC02 High 9 CS01 High 9 GC03 Medium ML01 Low GC04 Medium RC01 Medium 9 GC05 Medium GC06 Medium CW01 High MS01 High HC01 Low SS01 Medium HC02 Low 9 NS01 Low MC01 Low

CH01 Low MC02 Low MC03 Medium 1 & 2 MC04 Low SC01 Medium 9 SC02 Medium 1 & 2

Scotia01 Medium Scotia02 Medium 1, 2, 9 Scotia03 Low 1, 2, 9 CF01 NA OC01 NA

3B: Flow of springs has extreme reduction in ≥80% of occupied springs or suitable springs. A loss of flow in this scenario would equate to flow that is unable to remove fine sediments from the spring or the complete drying of the spring. A reduction of this magnitude would result in the loss or near loss of populations. Such events would have deleterious effects for the extant populations that would likely be extirpated. For this scenario we project only high ranking sites that were above the median of 14 and with high sufficient flow scores were likely to maintain moderate ranking. Under this scenario only six sites fit our analysis with being likely to retain moderate resilience scores given their high flow scoring (Score of 5 for flow: BC01, CS01, CW01, MS01, GC01, GC02). The methodology for determining the future conditions under this scenario are in Table 5.2.3. The sites noted under Scenario 2B (NS01, HC01, HC02, MC01, MC02, Scotia03 and

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CH01) would likely be extirpated because they had low flow scores, site MC04 could be extirpated but flow information is not known, and the current score falls below the median of the medium ranked sites, and all other sites would be reduced to low resilience (Table 5.2.4).

Table 5.2.3. Only the sites that had a score of 5 for flow remained above low quality. All other sites were determined to be either likely extirpated or low quality dependent on the level of flow are the site.

Scenario 3B

Current Future

≥14, Flow Medium Score=5 Quality High ≤14, Flow Low (Scores 11-17, Score=3 Quality Median 14) Flow Likely Score=1 Extirpated ≥8, Flow Low Score=3 Quality Medium ≤8, Flow Low (Scores 5-11, Score=3 Quality Median 8) Flow Likely Score=1 Extirpated Low Likely →→→→→ (Scores ≤5) Extirpated

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Table 5.2.4. The projections of the Huachuca springsnail populations in the next 50 years under Scenario 3B (extreme flow reduction). Rankings for future conditions were determined based on where the current status score was in relation to that category’s median. Only scores above the high quality median score of 14 and with flow scores at 5 we believe are likely to persist. All other sites are likely to become low scoring or extirpated. Sites we expect to become extirpated are shown with a strikethrough. Blue = Medium Quality, and Pink = Low Quality.

Spring Future Spring Future Haplotype Haplotype Population Condition Population Condition BC01 Medium 1 & 2 GC01 Medium 9 BT01 Low GC02 Medium 9

CS01 Medium 9 GC03 Low

ML01 GC04 Low Low GC05 Low RC01 Low 9 GC06 CW01 Medium Low MS01 Medium HC01 Low SS01 Low HC02 Low 9 NS01 Low MC01 Low CH01 Low MC02 Low MC03 Low 1 & 2 MC04 Low

SC01 Low 9

SC02 Low 1 & 2

Scotia01 Low Scotia02 Low 1, 2, 9 Scotia03 Low 1, 2, 9 CF01 NA OC01 NA

5.3. Redundancy

For this analysis redundancy is defined as having a number of populations of the species that can withstand catastrophic events. A catastrophic event is defined here as a rare destructive event or episode that involves many populations. The most likely catastrophic events for the Huachuca springsnail includes the loss of spring flow to occupied habitats, and landscape level severe wildfires to which the species is not adapted. Drought, increased groundwater pumping, and more variable amounts of precipitation and snowpack melt could lead to general spring flow decline or loss. The Huachuca springsnail is an endemic organism with a generally localized range of the Huachuca Mountains. Therefore, it is not possible for the species to exhibit redundancy over a large geographic area which would provide substantially widespread protections from flow declines. Redundancy is evaluated under the same potential scenarios as follows:

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1B: No measurable decrease in spring flow; ≥80% of occupied springs have stable flow. Under this scenario, spring flow would not measurably decline in response to either groundwater pumping and/or climate change impacts to precipitation and snowpack. We would expect most, if not all, Huachuca springsnail populations to persist, therefore providing adequate levels of redundancy. While more information is needed regarding some sites, and with the exception of the sites that may be impacted by the City of Tombstone’s springhead modification, we are unaware of site-specific planned activities at this time. We understand that fire fuel loads are high on the Fort and the CNF, but with plans in place to reduce fuel loads without impacting the spring sites, we do not believe these activities will lead to modifications. A catastrophic fire cannot be reliably predicted, and such an event could occur under this scenario if it happens prior to the fuel loads being reduced. 2B: A measurable decrease in spring flow but still enough flow to remove most fine substrates in majority (≥80%) of occupied springs or suitable springs. Under this scenario, we assume that all extant populations of Huachuca springsnail and springs where occupancy could occur would exhibit some drop in resiliency. High scoring sites would drop in value and potentially become moderate scoring sites, and some moderate scoring sites could drop to low scoring sites. A drop in spring flow in this scenario would likely put sites HC01, HC02, MC01, MC02, Scotia03 and CH01 in danger of extirpation, and NS01 would become “likely to be extirpated.” Apart from these sites, the remaining 18 sites would retain their moderate to high resiliency and persist into the future, providing a moderate level of redundancy. 3B: Flow of springs has extreme reduction in ≥80% of occupied springs or suitable springs. Under this scenario, most population’s conditions would drop to low, and redundancy is expected to be greatly reduced as populations across the range either greatly reduce in number or are extirpated. Six populations (BC01, CS01, CW01, MS01, GC01, and GC02) would retain moderate resiliency since they scored the highest possible flow rate score. Habitat loss under this scenario is likely to vary depending on the hydrology of the system and the source of water for the springs. These variations could change the rate of habitat loss at the springheads, but habitat loss is expected to occur across the range. We looked at the range of the sites under these rankings and scenarios with the sites that we have UTMs for (Figure 5.1, and Figure 5.2.).

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Figure 5.1. The range of the Huachuca springsnail sites under Scenario 2B with the current UTM coordinates provided by the AGFD from Fort Huachuca and the Coronado National Forest. The color of sites indicates the projected quality of the habitat, which we believe is a good indicator of presence of springsnails and persistence.

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Figure 5.2. The range of the Huachuca springsnail sites under Scenario 3B with the current UTM coordinates provided by the AGFD from Fort Huachuca and the Coronado National Forest. The color of sites indicates the projected quality of the habitat, which we believe is a good indicator of presence of springsnails and persistence.

5.4. Representation

Representation is having the genetic and ecological diversity within the species to be able to adapt to changing environmental conditions. From previous studies there were four haplotypes (1, 2, 5 and 9), with haplotype 1 and 2 being common, and haplotype 9 being less common. The 2015 Legacy Study however found that the once common haplotype 5 was absent from all sampled locations, and that haplotype 9 was more common. They also found an unknown haplotype which requires more information. More genetic studies are needed for the other occupied sites. Maintaining a good diversity of haplotypes, and retaining the populations of Huachuca springsnails current range is prudent to ensuring adequate representation. Especially unique sites like Scotia 02 and Scotia 03 and SC01 and SC02 where haplotypes 1, 2 and 9 co- occur or occur within close proximity. Doing so will maintain the species’ cumulative potential of genetic and life history attributes which would buffer the species’ response to any

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environmental changes over time. We have evaluated representation under the same three potential scenarios: 1B: No measurable decrease in spring flow; ≥80% of occupied springs have stable flow. Under this scenario, spring flows would remain consistent and maintain the same scores as the current conditions throughout the Huachuca springsnails range over the next 50 years. With no habitat changes, populations and haplotype representation would be maintained at current levels. 2B: A measurable decrease in spring flow but still enough flow to remove most fine substrates in majority (≥80%) of occupied springs or suitable springs. Under this scenario, all extant populations and springs where occupancy could occur would exhibit some drop in resiliency over the next 50 years. Springs that currently have high resiliency would likely drop in value and potentially become moderate resilient scoring sites; and currently moderately resilient populations could drop to low resiliency. Springsnails at sites with low flow scores (HC01, HC02, MC01, MC02, Scotia03, CH01 and NS01) would be extirpated with a consequential loss of representation for the species, especially at Scotia03 which contains all three haplotypes. The other 18 sites across the range are expected to persist, and would continue to represent the species across a substantial portion of the species overall range. 3B: Flow of springs has extreme reduction in ≥80% of occupied springs or suitable springs. Under this scenario, most population’s conditions would drop to low, and representation would be greatly reduced as populations across the range either greatly decline in condition or are extirpated. Six populations (BC01, CS01, CW01, MS01, GC01, and GC02) would retain moderate resiliency since they scored the highest possible flow rate score (5). At some of these sites there would be a substantial loss in represented haplotypes and only the Blacktail Spring (BC01) would represent haplotypes 1 and 2. We are unable to predict which specific populations would persist, but under this scenario the species would likely lose a large amount of representation across the species range.

5.5. Species Assessment Summary

We used the best available information to project the likely future conditions of the Huachuca springsnail. Our goal was to describe the viability of the species in a manner that will address the needs of the species in terms of the 3Rs. We considered the possible future conditions of the species, and we considered the range of potential scenarios that included important influences on the status of the species. Our results covered the range of possible, and probable, conditions in terms of how many and where Huachuca springsnail populations are likely to persist into the future. We conclude that areas of high quality habitat have a high likelihood of supporting a springsnail population that will have persistence into the future with reasonable certainty, medium quality habitat will support a population that will also likely persist into the future, and low quality habitat is not likely to support a population into the future without additional management actions. It is likely that modification of springheads, be it from anthropogenic factors, livestock grazing, or wildfire influences, will occur in the future. But given that land use plans are in place on the 63

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Fort and the CNF, these modifications are not likely to affect a majority of springs (USFS 2013, p. 57). In consideration of climate change, it is reasonable that spring flow will change, but we are uncertain on the actual source of water for each spring or analysis unit (groundwater vs. snowpack/precipitation) to understand the magnitude of risk and if the factor could be managed. We assume that both groundwater and precipitation are crucial for spring recharge regardless of the site location. If populations lose resiliency due to a decline in spring flow, their persistence will likely depend on habitat enhancements and/or reintroductions of refugia populations. Having a captive population would be a highly beneficial action because those individuals could be used in such reintroduction efforts. Under Scenario 1B we expect that the Huachuca springsnail viability would closely correlate with the resiliency, redundancy, and representation it exhibits under the current conditions. Based on our evaluation of the available information, we anticipate each highly and moderately scored population to have an 85% likelihood of persisting. Should conservation actions be implemented such as invasive species control and continuation of water conservation measures, then we also anticipate an increase in the resiliency of the low scoring sites to occur. Attaining more information for the sites that have no information is important since this could improve our understanding of the species representation and redundancy across the landscape. Under Scenario 2B,we project that over the next 50 years 17 populations of Huachuca springsnails would exhibit moderate to high condition scores, eight will exhibit low condition scores with a likelihood of being extirpated (their current condition is already low scoring for flow rate), and two sites are very likely extirpated. No projections could be made for the two sites in Mexico which have unknown information. It is expected that the population with moderate to high condition scores will persist with adequate levels of resiliency because suitable habitat will be available. Although redundancy will likely be reduced, members of the genus Pyrgulopsis are often characterized by a few isolated populations that continue to persist, perhaps because the genus is evolutionarily adapted to geographic isolation over geologic time. Under this scenario, we expect that in 50 years Huachuca springsnail viability would be characterized by at least 16 sites exhibiting high to medium levels of resiliency, and 8 sites with low resiliency. Under Scenario 3B, we expect the Huachuca springsnail viability to be greatly decreased due to catastrophic losses of resiliency, redundancy, and representation. All but six springs are expected to become low scoring, if not extirpated.

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LITERATURE CITED

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Arizona Game and Fish Department. 2012b. Arizona’s State Wildlife Action Plan: 2012-2022. Arizona Game and Fish Department, Phoenix, Arizona. Entire.

Arizona Game and Fish Department. 2015. Unpublished abstract compiled and edited by the Heritage Data Management System (Pyrgulopsis thompsoni). 7 pp.

Arizona Game and Fish Department. 2016a. Email correspondence regarding invasive species. Invertebrate Wildlife Program Manager, Arizona Game and Fish Department, Arizona (March 2, 2016). Arizona Game and Fish Department. 2016b. Draft Candidate Conservation Agreement for the Huachuca springsnail (Pyrgulopsis thompsoni) between the U.S. Fish and Wildlife Service and cooperating agencies of the Huachuca Springsnail Working Group. March 4, 2016. 63 pp.

Archer, S. R. and K.I. Predick. 2008. Climate change and ecosystems of the southwestern United States. Rangelands 30(3): 23-28. Bequart, J.C. and W.B. Miller. 1973. The mollusks of the arid Southwest. The University of Arizona Press, Tucson, Arizona. 213-214 pp. Brusca, R.C. and G.J. Brusca. 1990. Invertebrates. Sinaur Associates, Inc. Sunderland, Massachusetts. 922 pp. Calfee, R.D. and E.E. Little. 2003. Effects of ultraviolet-B radiation on the toxicity of the fire- fighting chemicals. Environmental Toxicology and Chemistry 22(7):1525-1531. Carroll, C., J.A. Vucetich, M.P. Nelson, D.J. Rohlf, and M.K. Phillips. 2010. Geography and recovery under the U.S. Endangered Species Act. Conservation Biology 24: 395-403. Corell, S.W., F. Corkhill, D. Lovvik, and F. Putman. 1996. A Groundwater Flow Model of the Sierra Vista Subwatershed of the Upper San Pedro Basin-Southeastern Arizona. Arizona Department of Water Resources. 143 pp.

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Danzer, S.R., C.H. Baisan, and T.W. Swetnam. 1997. The influence of fire and land-use history on stand dynamics in the Huachuca Mountains of southeastern Arizona. Appendix D in Robinett, D., R.A. Abolt, and R. Anderson, Fort Huachuca Fire Management Plan. Report to Fort Huachuca, Arizona. Entire. Dundee, D.S., P.H. Phillips, and J.D. Newsom. 1967. Snails on migratory birds. The Nautilus 80(3):89-91. Expert Group. 2016. Conference call with AGFD, CNF, Fort Huachuca, Phoenix Zoo, and T. Myers. Assorted departments, Arizona. (January 15, 2016). Fernandez, P.J. and P.C. Rosen 1996. Effects of the introduced crayfish Orconectes virilis on native aquatic herpetofauna in Arizona. Final Report, IIPAM Project No. 194054. Heritage Program, Arizona Game and Fish Department, Phoenix, Arizona. Frest, T.J. 1993. Letter to Robert Hershler, Smithsonian Institution. 1 p. Funkhouser, C. 2014. Captive propagation techniques for an endangered species of freshwater snail from a West Texas spring. Master’s Thesis, Texas Tech University. 88 pp. Gerhart, R.A. and H.B. Blasius. 2012. Electronic mail communication from Richard Gerhart, Coronado National Forest, and Heidi Blasius, Bureau of Land Management, to Mike Martinez, Fish and Wildlife Service, Regarding Huachuca springsnail and management plans. March 13 and 14, 2012. 3 pp. Hazard Analysis Critical Control Point (HACCP). 2016. ASTM E2590-15, Standard Guide for Conducting Hazard Analysis-Critical Control Point (HACCP) Evaluations, ASTM International, West Conshohocken, PA, 2015. Accessed on April 22, 2016 http://www.astm.org/Standards/E2590.htm Hammill, E., R.S. Wilson, and I.A. Johnston. 2004. Sustained swimming performance and muscle structure are altered by thermal acclimation in male mosquitofish. Journal of Thermal Biology 29(4-5): 251–257. Hendrickson, D.A., W.L. Minckley. 1984. Cienegas-Vanishing Climax Communities of the American Southwest. Desert Plants 6(3): 129-175. Hershler, R. 1984. The Hydrobiid Snails (Gastropoda: Rissoacea) of the Cuatro Cienegas Basin: Systematic Relationships and Ecology of a Unique Fauna. Journal of the Arizona- Nevada Academy of Science 19(1): 61-76. Hershler, R. 1994. A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae). Smithsonian Contributions to Zoology, Number 554. Smithsonian Institution Press. Washington D.C. 52 pp. Hershler, R. 1998. A systematic review of the Hydrobiid Snails (Gastropoda: Rissooidea) of the Great Basin, Western United States. Part I. Genus Pyrgulopsis. The Veliger. 41(1):1- 132.

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Hershler, R. and J.J. Landye. 1988. Arizona Hydrobiidae (Prosobranchia: Rissoacea). Smithsonian Contributions to Zoology. No. 459. 63 pp. Hershler, R., and W.F. Ponder. 1998. A review of morphological characters of hydrobioid snails. Smithsonian Institution Press. Entire. Hershler, R. and D.W. Sada. 2002. Biogeography of Great Basin aquatic snails of the genus Pyrgulopsis. Pages 255-276, In R. Hershler, D.B. Madsen, and D.R. Curry (Eds.). Great Basin Aquatic Systems History. Smithsonian Institution Press, Washington, D.C. Hershler, R. and J.E. Williams. 1996. Conservation strategies for springsnails in the Great Basin: the challenge and the opportunities. Proceedings of the Desert Fishes Council, 1995 Symposium. XXVII. 1 p. Hershler, R., H.P. Liu, J. Howard. 2014. Springsnails: A New Conservation Focus in Western North America. BioScience. 1-8. Hurt, C. 2004. Genetic divergence, population structure and historical demography of rare springsnails (Pyrgulopsis) in the lower Colorado River basin. Molecular Ecology vol. 13 (5): 1173-1187. Hurt, C. and P. Hedrick. 2004. Conservation genetics in aquatic species: General approaches and case studies in fishes and springsnails of arid lands. Overview Article. Aquatic Sciences 66: 402–413. Intergovernmental Panel on Climate Change (IPCC). 2014. Summary for policymakers. Pages 1-32 in: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Johnson, S.G. 2005. Age, phylogeography and population structure of the microendemic banded spring snail, Mexipyrgus churinceanus. Molecular Ecology (2005) 14, 2299- 2311. Kraft, J. 2016. Email communication. Forest Biologist, Coronado National Forest, Arizona (February 25, 2016). Landye, J.J. 1973. Status of inland aquatic and semi-aquatic mollusks of the American Southwest. USDI Fish and Wildlife Service (Bureau of Sport Fisheries and Wildlife), Washington, D.C. 60 pp. Landye, J.J. 1981. Current status of endangered, threatened, and/or rare mollusks of New Mexico and Arizona. USDI Fish and Wildlife Service (Bureau of Sport Fisheries and Wildlife), Albuquerque, New Mexico. 35 pp. Landye, J.J. 1999. Letter to Jim Rorabaugh, U.S. Fish and Wildlife Service. January 25, 1999. 2 pp.

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Lysne, S., and P. Koetsier 2006. Growth rate and thermal tolerance of two endangered Snake River snails. Western North American Naturalist 66(2): 230-238. Lysne, S.J. and P. Koetsier. 2008. Comparison of desert valvata snail growth at three densities of the invasive New Zealand mudsnail. Western North American Naturalist 68(1):103- 106. Lysne, S.J., L.A. Riley, and W.H. Clark. 2007. The life history, ecology, and distribution of the Jackson Lake springsnail (Pyrgulopsis robusta Walker 1908). Journal of Freshwater Ecology 22(4): 647-653. Malcom, J.W., W.R. Radke, and B.K. Lang. 2005. Habitat associations of the San Bernardino springsnail, Pyrgulopsis bernardina (Hydrobiidae). Journal of Freshwater Ecology 20(1):71-77. Martinez, M.A. and T.L. Myers. 2008. Associations between aquatic habitat variables and Pyrgulopsis trivialis presence/absence. Journal of Freshwater Ecology Vol. 23(2):189- 194. Martinez, M.A. and J.A. Sorensen. 2007. Effect of sampling without replacement on isolated populations of endemic aquatic invertebrates in central Arizona. The Journal of the Arizona-Nevada Academy of Science. 39(1):28-32. Martinez, M.A. and D.M. Thome. 2006. Habitat Usage by the Page springsnail, Pyrgulopsis morrisoni (Gastropoda: Hydrobiidae) from Central Arizona. The Veliger 48(1):8-16. Mladenka, G.C. 1992. The ecological life history of the Bruneau Hot Springs Snail (Pyrgulopsis bruneauensis). Stream Ecology Center, Department of Biological Sciences, Idaho State University. Entire. Mladenka, G.C. and G.W. Minshall. 2001. Variation in the life history and abundance of three populations of Bruneau Hot Springsnails Pyrgulopsis bruneauensis. Western North American Naturalist 61(2):204-212. Myers, T.L. 2016. Email correspondence regarding Canelo Hills site visit. Biologist, Arizona (March 5, 2016). Myers, T.L. 2010. Summary of sites at which known or suspected Pygulopsis thompsoni have been collected or reported. Prepared 07 May 2010 by Terry L. Myers. 2 pp. Myers, T.L. 2012. Summary and evaluation of distributional records and reports of Huachuca springsnails, with comments on additional information needs. Report prepared for Arizona Game and Fish Department. May 17, 2012. 30 pp. O’Brien C. and D.W. Blinn. 1999. The endemic spring snail Pyrgulopsis montezumensis in a high CO2 environment: importance of extreme chemical habitats as refugia. Freshwater Biology 42:225-234.

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Pearson, D., S. Wells, T. Sprankle, J. Sorensen, and M. Martinez. 2014. Reproductive Seasonality and Development Characteristics of the Page Springsnail (Pyrgulopsis morrisoni). Journal of the Arizona-Nevada Academy of Science 45(2):64-69. Pennak, R.W. 1989. Freshwater invertebrates of the United States: Protozoa to Mollusca. John Wiley and Sons, Inc., New York. 628 pp. Piorkowski, M. and J. Diamond. 2015. Springsnails on Department of Defense Installations in the Desert Southwest: Identification, Status and Distribution of At-Risk Springsnail Communities. Draft Report. Arizona Game and Fish Department, Wildlife Contracts Branch, Phoenix, Arizona, USA. 92 pp. Piorkowski, M. and G. Mulligan. 2012. Huachuca springsnail (Pyrgulopsis thompsoni) summary: an investigative presence/absence survey. Arizona Game and Fish Department, Phoenix, Arizona. 29 pp. Redford, K.H., G. Amoto, J. Baillie, P. Beldomenico, E.L. Bennett, N. Clum, R. Cook, G. Fonseca, S. Hedges, F. Launay, S. Lieberman, G.M. Mace, A. Murayama, A. Putnam, J.G. Robinson, H. Rosenbaum, E.W. Sanderson, S.N. Stuart, P. Thomas, and J. Thorbjarnarson. 2011. What does it mean to successfully conserve a (vertebrate) species? Bioscience 61:39–48. Riley, L.A., M.F. Dybdahl, and R.O. Hall Jr. 2008. Invasive species impact: asymmetric interactions between invasive and endemic freshwater snails. Journal of the North American Benthological Society 27(3):509-520. Roscoe, E.J. 1955. Aquatic snails found attached to feathers of White-faced Glossy Ibis. The Wilson Bulletin 67(1):66. Sada, D.W. 2008. Synecology of a springsnail (Caenogastropoda: Hydrobiidae) assemblage in a western U.S. thermal spring province. The Veliger 50:59-71. Seager, R., M. Ting, I. Held, Y. Kushnir, J. Liu, G. Vecchi, H. Huang, N. Harnik, A. Leetma, N. Lau, C. Li, J. Velez, and N. Naik. 2007. Model projections of an imminent transition to a more arid climate in Southwestern North America. Science 316:1181-1184. Shepard, W.D. 1993. Desert springs - both rare and endangered. Aquatic Conservation: Marine and Freshwater Ecosystems 3:351-359. Sorensen, J. 2016a. Email correspondence regarding Neighbor Spring genetics. Invertebrate Wildlife Program Manager, Arizona Game and Fish Department, Arizona (January 4, 2016). Sorensen, J. 2016b. Meeting with Draft Current Conditions Handout (6 pp). Invertebrate Wildlife Program Manager, Arizona Game and Fish Department, Arizona (January 14, 2016). Sorensen, J. 2016c. Email correspondence regarding survey results of Cienega Creek Narrows and Canelo Hills Cienega, February 2016. Invertebrate Wildlife Program Manager, Arizona Game and Fish Department, Arizona (February 16, 2016).

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Stone, H.S. 2012. Electronic mail communication from Sheridan Stone, Fort Huachuca, to Mike Martinez, U.S. Fish and Wildlife Service, regarding Huachuca springsnail INRMP language. March 14, 2012. 3 pp. Swetnam, T.W. and C.H. Baisan. 1996. Fire histories of montane forests in the Madrean Borderlands. Pages 15-36 in P.F. Folliott et al. (Tech. Coord.), Effects of fire on Madrean Province ecosystems. USDA Forest Service, General Technical Report, RM- GTR-289. 277 pp. Taylor, D.W. 1987. Fresh-water mollusks from New Mexico and vicinity. New Mexico Bureau of Mines and Minerals 116:1-50. Tillman, F.D, Cordova, J.T., Leake, S.A., Thomas, B.E., and Callegary, J.B. 2011. Water availability and use pilot; methods development for a regional assessment of groundwater availability, Southwest alluvial basins, Arizona: U.S. Geological Survey Scientific Investigations Report 2011-5071, p. 118 and online appendix. Tsai, Y.J., K. Maloney, and A.E. Arnold. 2007. Biotic and abiotic factors influencing the distribution of the Huachuca springsnail (Pyrgulopsis thompsoni). Journal of Freshwater Ecology 22:213-218. U.S. Army (Army). 2001. Integrated Natural Resources Management Plan. U.S. Army Intelligence Center and Fort Huachuca, Arizona. Prepared by Universe Technologies Inc. Approved October 11, 2001. 282 pp. U.S. Army Garrison Fort Huachuca (Army). 2006. Programmatic Biological Assessment for Ongoing and Future Military Operations and Activities at Fort Huachuca, Arizona, Dec 2006. Environmental and Natural Resources Division. U.S. Army (Army). 2010. Integrated Natural Resources Management Plan. U.S. Army Intelligence Center and Fort Huachuca, Arizona. Prepared by the Environmental and Natural Resource Division of Public Works U.S. Army Garrison. 332 pp. U.S. Army Garrison Fort Huachuca (Army). 2013. Programmatic Biological Assessment for Ongoing and Future Military Operations and Activities at Fort Huachuca; Appendices. Arizona, Dec 2013. Environmental and Natural Resources Division. Entire. U.S. Fish and Wildlife Service (Service). 1995. Draft Conservation Agreement for Pyrgulopsis thompsoni, Huachuca springsnail. Arizona Ecological Services Field Office. 6 pp. U.S. Fish and Wildlife Service (Service). 1996. Endangered and threatened wildlife and plants; review of plant and animal taxa that are candidates for listing as endangered or threatened species. Federal Register 61:7596-7613. U.S. Fish and Wildlife Service (Service). 2005. Endangered and threatened wildlife and plants; listing Roswell springsnail, Koster’s springsnail, Noel’s amphipod, and Pecos assiminea as endangered with critical habitat; final rule. Federal Register 70:46303-46333.

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U.S. Fish and Wildlife Service (Service). 2012. Endangered and threatened wildlife and plants; determination of endangered status for the Chupadera springsnail and designation of critical habitat. Federal Register 77:41088-41106. U.S. Fish and Wildlife Service (Service). 2015. Species status assessment report for the Page springsnail. Albuquerque, NM. 52 pp. U.S. Forest Service (USFS). 2009. Huachuca Firescape Project, Sierra Vista Ranger District. Coronado National Forest. 12 pp. U.S. Forest Service (USFS). 2013. Draft Land and Resource Management Plan. Coronado National Forest. 279 pp. U.S. Geological Survey (USGS). 1995. Geographic names information system. (http://geonames.usgs.gov), Reston, Virginia. Entire database. Varela-Romero, A., C. Galindo-Duarte, E. Saucedo-Monarque, L.S. Anderson, P. Warren, S. Stefferud, J. Stefferud, S. Rutman, T. Tibbits, and J. Malusa. 1992. Re-Discovery of Gila intermedia and G. purpurea in the North of Sonora, Mexico. Proceedings of the Desert Fishes Council. XXII. 1992. 1 p. Wahi, A., J. Hogan, B. Ekwurzel, M. Baillie, C. Eastoe. 2008. Geochemical Quantification of Semiarid Mountain Recharge. Groundwater. 12 pp. Weiss, J.L. and J.T. Overpeck. 2005. Is the Sonoran Desert losing its cool? Global Change Biology 11(12):2065-2077. Wells, S., D. Pearson, T. Sprankle, J. Sorensen, M. Martinez. 2012. Ex-Situ Husbandry and Environmental Parameters Resulting in Reproduction of the Page Springsnail, Pyrgulopsis morrisoni: Implications for Conservation. Journal of the Arizona-Nevada Academy of Science 44(1):69-77 Wilson, R.S., C.H. Condon, and I.A. Johnston. 2007. Consequences of thermal acclimation for the mating behavior and swimming performance of female mosquitofish. Philosophical Transactions of the Royal Society B: Biological Sciences, 362(1487):2131-2139. Wolf, S., B. Hartl, C. Carroll, M.C. Neel, D.N. Greenwald. 2015. Beyond PVA: Why Recovery under the Endangered Species Act is more than Population Viability. BioSciences, 65(2): 200-207.

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APPENDIX A

Potential Threat Scenarios for the Huachuca springsnail

The two primary factors that were determined to likely have the greatest influence on the resiliency and persistence of the Huachuca springsnail were sufficient flow and springs being unmodified. These two factors are predominantly independent from each other as some modified springheads have sufficient flow while other modified springheads do not. Therefore each factor had three scenarios, resulting in nine potential future scenarios. We determined that many of these scenarios were not realistic, and others not likely to occur given the combination. The descriptions of the scenarios and the rationale for their likelihood are given below. The scenarios in bold (Table A-2) are the ones we determined to be the most likely in the foreseeable future of 50 years.

Table A-1: The scenario matrix of future conditions. Combinations of the two factors result in a total of nine combinations

Factors Factor Scenario Scenario Spring Discharge Free Flowing/Modification

No measurable change in flow rate; ≥80% of ≤10% springs modified in 1 A occupied springs way to minimize habitat stable flow

Measurable change in >10%, ≤20% of occupied flow rate; flow still or historical springs 2 present at moderate B modified that reduce level in ≥80% of habitat occupied springs

All or most occupied >20% of occupied or springs ≥80% have 3 C historical sites modified to extreme reduction, reduce habitat and low level of flow

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Table A-2: The nine potential scenarios based on the combination of scenarios for the two primary factors.

Scenario Translation Best case scenario but unlikely. Climate change likely to cause decreases in flows, modifications of springs are likely either through anthropogenic 1A means or stochastic events. The combination of these factors make this scenario unreasonable. Likely if precipitation/snowpack remains relatively stable and no water 1B diversions occur, and conservation actions by the Fort continue Unlikely. Climate change likely to cause decreases in flows, modifications of springs are likely but management and conservation actions already in 1C place or planned will likely prevent this level of extreme modification. Modifications at this scale would also cause extremely reduced flow.

Unlikely. Assumes that climate change is the most prevalent effect. Could 2A only occur if no further modification of habitat occurs and habitat is restored where possible (Miller Canyon). Likely. This could include more stochastic precipitation, no increase in 2B groundwater withdrawals and continued water conservation measures by the Fort, and possible modification of some sites. Unlikely. Management and conservation actions already in place or 2C planned will not allow this degree of modification. Modifications at this scale would also likely cause extremely reduced flow.

Unlikely. Assumes that climate change is the most prevalent factor, but 3A some modification of habitat will be likely under this scenario due to dry conditions. Likely if climate change causes accelerated effects. Groundwater recharge declines but groundwater withdrawals continue. Modification of springs 3B from wildfire, grazing, or some anthropogenic effect is reasonable at this level. Worst case scenario and unlikely. Management and conservation actions 3C already in place or planned will not allow this degree of modification. Modifications at this scale would also likely cause extremely reduced flow.

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