Species Status Assessment Report for Morro Shoulderband Snail

Species Status Assessment Report Morro Shoulderband Snail (Helminthoglypta walkeriana) and Chorro Shoulderband Snail (Helminthoglypta morroensis)

Morro Shoulderband Snail Chorro Shoulderband Snail SWCA Consultants Dan Dugan, EcoVision Partners

Ventura Fish and Wildlife Office U.S. Fish and Wildlife Service Pacific Southwest Region 8

FEBRUARY 2019 Version 1.1

The Ventura Fish and Wildlife Office prepared this report with guidance and assistance from Bjorn Erickson, Recovery Division, Region 8.

Valuable input to our analysis was provided by Lisa Andreano, Kate Ballantyne, Travis Belt, Vince Cicero, Katie Drexhage, Barbie Dugan, Dan Dugan, Barrett Holland, Dwayne Oberhoff, Pete Sarafian, Robert Sloan, Jeff Tupen, and Mike Walgren during a “snail summit’ held on November 16, 2017 in Los Osos, California. Peer review of the draft SSA report was provided by Kate Ballantyne, Travis Belt, Dan Dugan, Robert Sloan, and Jeff Tupen. We appreciate their input as it resulted in a more robust assessment and final report.

Version 1.1 The SSA has been updated with a more accurate list of threats identified at the time the species was listed in 1998, as well as a list of threats that have been ameliorated since that time.

Suggested reference:

U.S. Fish and Wildlife Service. 2018. Species status assessment report for the Morro Shoulderband Snail (Helminthoglypta walkeriana) and the Chorro Shoulderband Snail (Helminthoglypta morroensis), Version 1.0. June 2018. Ventura, California

Species Status Assessment Report Morro Shoulderband Snail (Helminthoglypta walkeriana) and Chorro Shoulderband Snail (Helminthoglypta morroensis)

Prepared by

U.S. Fish and Wildlife Service

EXECUTIVE SUMMARY This species status assessment report provides the results of comprehensive reviews conducted for the Morro shoulderband snail (Helminthoglypta walkeriana) (Hemphill 1911) and the Chorro shoulderband snail (H. morroensis) (Hemphill 1911). It provides a thorough account of both species’ overall viability. The Morro shoulderband snail (MSS) and Chorro shoulderband snail (CSS) are terrestrial species endemic to San Luis Obispo County in the central coastal region of California. The MSS has the narrower distribution of the two species, being largely restricted to the Baywood Fine Sand soil series in and around the communities of Los Osos and Morro Bay. The distribution for CSS encompasses a wider area as it is found on a much greater diversity of soil substrates (e.g., clays, silty loams) extending from the coastal community of Cayucos through the Los Osos Valley to the community of Edna, east of the City of San Luis Obispo. In 1994, the Service listed both MSS and CSS as the banded dune snail under the species name Helminthoglypta walkeriana, which contained to two subspecific entities: H. walkeriana and H. w. morroensis. Taxonomic revisions subsequent to the listing elevated these subspecific taxa to full species: Helminthoglypta walkeriana and H. morroensis (Roth and Tupen 2004: entire). After 2004, H. walkeriana and H. morroensis were associated with the common names Morro shoulderband snail (MSS) and Chorro shoulderband snail (CSS), respectively. For purposes of this assessment, we use the name banded dune snail for individuals identified prior to the publication of the taxonomic treatment in 2004 that elevated these subspecific taxa to their current separate species status. At the time of listing, we thought Helminthoglypta walkeriana morroensis (currently, Chorro shoulderband snail, CSS) was extinct and speculated that there may have been as few as several hundred individuals of H. walkeriana (currently, Morro shoulderband snail, MSS) extant. Within a few years of listing, CSS was rediscovered near the northern limit of Morro Bay. Since the time of listing, living CSS individuals have been documented at other locations from northern Morro Bay south and inland through the City of San Luis Obispo and we now know MSS numbers far exceed what was thought at that time. Threats influencing the viability of Morro shoulderband snail populations at the time of listing were urban development, off-road vehicle activity, nonnative vegetation (referred to as invasive species in this proposed rule), parasitoids, and competition from brown garden snails, all of which were exacerbated by effects associated with small population size and drought conditions (59 FR 64613). Since the time of listing, we have determined that some of these threats are no

longer affecting the species, particularly off-road vehicle activity, brown garden snails, parasitoids, and controlled burns (Service 2006, pp. 11–15). Currently, the most common threats to both species are those associated with land use practices that eliminate, reduce, fragment, and/or modify habitat used by the species. We expect that climate change will likely exacerbate the severity of these threats. Both MSS and CSS need resilient populations distributed across their respective distributions to maintain viability into the future. For both species to maintain viability, populations or some portion thereof must be resilient to the normal range of environmental variation. Factors influencing the ability of MSS and CSS to withstand stochastic events within the normal range of environmental variation include abundance and distribution of individuals, habitat quality and configuration (including presence of a seasonal hydrological microclimate to facilitate feeding and reproduction) and the likelihood that suitable habitat will persist into the future. Maintaining representation of healthy populations across the diversity of MSS and CSS habitats or ecological gradients is expected to conserve the relevant diversity associated with species persistence across these habitat types and maintain their limited distributions to reduce risk associated with catastrophic events. A diversity of groups conduct conservation actions for MSS within the species’ distribution. Although most lands within its distribution are not formally or legally protected via open space or conservation easements, many are under some form of protection as part of a State Park, State of California ecological reserve, or parcels set aside specifically to conserve and enhance natural resource values. For example, the County’s Broderson and Midtown parcels are both protected though deed restrictions that preclude development other than those that would enhance resource values. Both are managed in accordance with a habitat management plan that was approved by the California Coastal Commission in 2012 (Ballantyne pers. comm. 2018). The Service is not aware of specific conservation actions for CSS; however, areas conserved as open space by the City and/or County of San Luis Obispo as well as those acquired and/or managed by the Land Conservancy of San Luis Obispo benefit the species through habitat preservation. For both species, we assessed the level of resiliency, redundancy, and representation currently and into the future by ranking the condition of each population area and assessing these rankings across the geographic distribution and ecological settings of the species. Rankings are an assessment of population abundance and the relative condition of occupied habitat based on published reports and the knowledge and expertise of Service staff. To forecast the likely future state of MSS and CSS, we evaluated a range of plausible scenarios projected over 30 years, each including the likelihood of prolonged or more intensive drought and wildfire frequency and/or intensity associated with continued climate change as a baseline. For MSS, we evaluated three future scenarios: 1) current conditions with no additional conservation measures (status quo), 2) current conditions with limited additional conservation measures, and 3) current conditions with major additional conservation measures. For CSS, we assessed two future scenarios: 1) current conditions with no additional conservation measures (status quo) and 2) current conditions with intensified agricultural use. Overall, the results of our analyses indicate that the viability of MSS has likely improved since time of listing due to the existence of substantially more individuals than thought at time of listing and conservation efforts (predominantly in the form of land acquisition). The species still

2 has the potential to decline in the future depending on the potential for development and level of continued conservation efforts. Our analyses indicate that the viability of CSS is likely similar to that at time of listing (given that it was not extinct) despite not being regulated since 2004. Because of this, its condition is projected to remain the same or decrease slightly, depending largely on future land uses in San Luis Obispo County.

Table of Contents

EXECUTIVE SUMMARY 1

CHAPTER 1. INTRODUCTION 7

CHAPTER 2 – LIFE HISTORY AND BIOLOGY 9 Taxonomy 9 Genetic Diversity 10 Morphology 10 Reproductive Biology 11 Growth and Longevity 11 Activity Patterns 12 Feeding 13 Habitat Associations 14

CHAPTER 3 – POPULATION AND SPECIES NEEDS 15

Historical Range and Distribution 15

Recovery Plan 16

Species Needs 19 Resiliency 19 Representation 19 Redundancy 20

CHAPTER 4 – CURRENT CONDITION 22

Threats 22

Conservation Actions 24

Current Range and Distribution 25

Current Condition 37 Morro Shoulderband Snail 37 Chorro Shoulderband Snail 42

CHAPTER 5 – FUTURE CONDITION 47

Morro Shoulderband Snail 47 Future Scenario 1: Current conditions for 30 years with no additional conservation efforts (status quo) 47

Future Scenario 2: Current conditions for 30 years with limited additional conservation efforts 50 Future Scenario 3: Current conditions for 30 years with major additional conservation efforts 53

Chorro Shoulderband Snail 56 Future Scenario 1: Current conditions for 30 years with no additional conservation efforts (status quo) 56 Future Scenario 2: Intensification of agricultural uses over current conditions for 30 years 59

CHAPTER 6 – SYNTHESIS 63

Morro Shoulderband Snail 63

Chorro Shoulderband Snail 65

LITERATURE CITED 68

APPENDIX A 73

Recovery Criteria Identified for Morro Shoulderband Snail (= Helminthoglypta walkeriana) 73 Downlisting 73 Delisting 75

LIST OF FIGURES Figure 1. Species Status Assessment Framework Figure 2. Geographic distribution of MSS and CSS (Roth and Tupen 2004: 4). Figure 3. Conservation Planning Areas for Morro Bay Species from the Recovery Plan that includes MSS (adapted from Service 1998: 39) Figure 4. MSS Distribution and Population Areas (outlined and labeled in white) Figure 5. Relative Abundance for MSS in Downtown Los Osos Population Area 2012-2014 (= Areas A-D) (SWCA Consultants) Figure 6. Relative CSS Abundance from 2017 Surveys (EcoVision Partners 2017: 26) Figure 7. CSS Distribution and Ten Population Areas (outlined and labeled in white) Figure 8: Various age classes of live MSS from beneath a nonnative iceplant patch, Midtown Site, Los Oso (County of San Luis Obispo 2015) Figure 9. Current Resiliency of MSS Population Areas Figure 10. CSS Population Areas: Current Resiliency

Figure 11. MSS Populations Areas: Future Scenario 1 (for 30 years with no additional conservation efforts) Figure 12. MSS Population Areas: Future Scenario 2 (30 years, limited additional conservation efforts) Figure 13. MSS Population Areas: Future Scenario 3 (30 years with major additional conservation efforts) Figure 14. CSS Population Areas: Future Scenario 1 (30 years with no additional conservation efforts) Figure 15. CSS Population Areas: Future Scenario 2 (30 years, intensified agriculture) Figure A1. CPAs from the 1998 Recovery Plan and current resiliency condition of Morro shoulderband snail SSA population areas.

LIST OF TABLES Table 1. MSS characteristics used to create condition categories in Table 2 Table 2. Current resiliency of MSS population areas Table 3. CSS characteristics used to create condition categories in Table 4 Table 4. Current Resiliency of CSS population areas Table 5. Resiliency of MSS population areas under current conditions for 30 years with no additional conservation efforts (status quo) Table 6. Resiliency of MSS population areas under current conditions for 30 years with limited additional conservation efforts Table 7. Resiliency of MSS population areas under current conditions for 30 years with major additional conservation efforts Table 8. Resiliency of CSS under current conditions for 30 years with no additional conservation efforts Table 9. Resiliency of CSS regions with intensification of agricultural uses over 30 years Table 10. Summary of MSS Resiliency: Current and Future Condition by Population Area Table 11. Summary of CSS Resiliency: Current and Future Condition by Population Area

CHAPTER 1. INTRODUCTION This report summarizes the results of a species status assessment (SSA) for Helminthoglypta walkeriana (Morro shoulderband snail; hereafter MSS) and H. morroensis (Chorro shoulderband snail; hereafter CSS). The SSA for these species does not result in a decision by the Service on whether a status change for either species should occur but, instead, provides a review of the available information strictly related to the biological status of both species. The Service will make any decision regarding any status change after reviewing this document and all relevant laws, regulations, and policies. We will publish any proposed decision in the Federal Register, with opportunities for public input. Using the SSA framework (Figure 1), we considered what each species needs to maintain viability by characterizing the status of the species in terms of its resiliency, representation, and redundancy (Service 2016, entire; Smith et al. 2018, entire). For the purpose of this SSA, we generally define viability as the ability of species to sustain populations in the wild over time.

Figure 2. Species Status Assessment Framework

• Resiliency describes the ability of populations to withstand stochastic events (i.e., those that arise from random factors). For example, we can measure resiliency based on metrics of population health, birth versus death rates, or population size. Highly resilient populations are better able to withstand random disturbances such as drought or the effects of anthropogenic activities. • Representation describes the ability of a species to adapt to changing environmental conditions. We measure representation by the breadth of genetic or environmental diversity within and among populations. Representation gauges the probability that a species is capable of adapting to environmental changes. The more representation (or diversity) a species has, the more it is likely 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 across the geographical range.

• Redundancy describes the ability of a species to withstand catastrophic events. Measured by the number of populations, their resiliency, and their distribution (and connectivity), redundancy gauges the probability that the species has a margin of safety to withstand or bounce back from catastrophic events involving many populations. To evaluate the biological status of MSS and CSS, both currently and into the future, we assessed a range of conditions to allow us to consider the species’ resiliency, redundancy, and representation (the 3Rs). This SSA report provides a thorough assessment of biology and natural history and assesses demographic risks, stressors, and limiting factors in the context of determining the viability and risks of extinction for the species. The SSA report discusses (1) individual needs for both MSS and CSS (Chapter 2); (2) population and species needs for both species (Chapter 3); (3) current condition for both species (Chapter 4); (4) future condition scenarios for both species (Chapter 5); and (5) a description of the viability in terms of resiliency, redundancy, and representation (Chapter 6). It represents a compilation of the best available scientific and commercial information and a description of past, present, and likely future risk factors to MSS and CSS.

CHAPTER 2 – LIFE HISTORY AND BIOLOGY In this chapter we provide basic life history and biological information for both MSS and CSS, inclusive of taxonomic history, genetics, morphological description, and known life history traits. We report those aspects of the life history of MSS and CSS important to our analysis for each taxon. For further information about either taxon, please refer to Roth and Tupen (2004: entire) and our 5-Year status review (Service 2006: entire). In general, we know very little about the specific life history of either MSS or CSS. Using information compiled for other Helminthoglypta species (van der Laan 1975a: entire; 1975b: entire; 1980: entire), we infer information and apply to both species for purposes of this SSA where appropriate.

Taxonomy Species identification within the genus Helminthoglypta considers several characteristics, including shell morphology, analysis of radula and soft tissue (i.e., the reproductive system), ecological associations, and geographic ranges (Walgren 2003a: 4). Taxonomic determinations can also use genetic analysis (Roth and Tupen 2004: 2, Goodward et al. 2017: 113-114). Both MSS and CSS, referred to collectively as the banded dune snail, belong to the land snail genus, Helminthoglypta (Ancey 1887), which contains three subgenera that comprise more than 100 species and subspecies. Taxonomic revisions are ongoing with a trend toward increased species diversity (Miller 1985: 94-98; Roth and Tupen 2004: 1). Helminthoglypta is a large genus primarily found throughout California but also ranging north into southern Oregon and south into Baja California, Mexico inclusive of its offshore islands. In California, members of the genus occupy topographic ranges west of the Sierra Nevada, through the Central Valley, south to the Mojave Desert, and along the California coast, including the Channel Islands. The banded dune snail was first described as Helix walkeriana by Hemphill (1911: entire) based on collections made in San Luis Obispo County near “Morro, California.” Hemphill also described a subspecific taxon of Helix walkeriana, variety morroensis, from near “San Luis Obispo City” based on sculptural features of the shell (Roth and Tupen 2004: 2). Both forms of the species were reassigned to the genus Helminthoglypta from the genus Helix in 1930 (Roth and Tupen 2004: 2). At the time of listing (Service 1994: entire), the banded dune snail included Helminthoglypta walkeriana and a more inland subspecific taxon referred to as H. w. “morroensis.” Since the time of listing, the status of these two taxa has been re-examined (Roth and Tupen 2004: entire; Tupen and Roth 2005: 9-10; Walgren 2003a: 4). Roth (1985: 2) acknowledged that the taxonomic status of the banded dune snail remained “unsettled” and recognized both subspecific taxa as subspecies. Walgren later stated that both subspecific taxa were valid subspecies “…based on unique shell morphology, ecology, and geographically isolated ranges” (Walgren 2004b: 98). He also recommended that “…further research should focus on…soft tissue anatomy and DNA to address the taxonomic status of [the] various types”. Roth and Tupen (2004: 6) analyzed variations in the shell forms and soft tissue anatomy (genitalia) of the two taxa. They determined that variations in shell shape, shell sculpture, and soft tissue anatomy between the two taxa were consistent with reproductive isolation. Based on these data, Roth and Tupen elevated both subspecific taxa to full species status resulting in the following combinations: Helminthoglypta walkeriana (MSS) and H. morroensis (CSS) (Roth and Tupen 2004: entire).

While there remain some differences in opinion regarding the taxonomic rank assigned to these entities (as full species or subspecific taxon), there is a clear consensus that both snail taxa are valid biological entities of at least the subspecies rank. We believe that Roth and Tupen’s 2004 work sufficiently supports their conclusion and is consistent with the majority of species descriptions for other terrestrial snails (Hemphill 1911: 102; Pilsbry 1939: 128; Roth 1973: entire; Bequaert and Miller 1973: entire). As such, the Service accepted this new specific nomenclature and issued a position paper in 2004 stating that we would regulate only Helminthoglypta walkeriana (MSS) under the Endangered Species Act (ESA) of 1973 (Service in litt. 2004). Although not formally adopted through a notice in the Federal Register, we regard both taxa to be full species and are evaluating each of them in this SSA accordingly.

Genetic Diversity There have been no genetic studies conducted at any taxonomic level for either MSS or CSS.

Morphology Since the original description (Hemphill 1911: 102) as Helix walkeriana, identification of both MSS and CSS uses morphology and distinctive sculptural shell features. Like other species in the genus Helminthoglypta, the shells of both are heliciform, umbilicate, and reddish brown to chestnut in color. They have a single characteristic, narrow, dark spiral band on the “shoulder” with thin light yellowish margins above and below (Hemphill 1911: 102; Roth 1985: 5). Shell characteristics form the basis of all historic descriptions of MSS and CSS, with no reference to or descriptions of the soft anatomy (Roth and Tupen 2004: 2). Shell morphology remains the most widely applied approach within the genus Helminthoglypta to this day (Tupen pers. comm. 2018). Analysis of soft anatomy, specifically the reproductive system, provides an important means of identifying groups within Helminthoglypta (Walgren 2003: 3, 102). The first description of soft anatomy for MSS and CSS was in Roth and Tupen (2004: 13-14, 20) and along with their analysis of shell morphology, geographic distribution, and habitat associations, resulted in the recognition of two distinct species supported by other researchers. In their comparison of collected individuals, Roth and Tupen (2004: 16) reported skin color (darker in CSS), mantle pigmentation (more extensive in CSS), and penial morphology as the most notable anatomical differences between the two taxa. The shells of MSS are umbilicate, globose, reddish brown to chestnut in color, thin, and slightly translucent (Roth 1985: 5). The shell has five to six whorls and a single, narrow (2 to 2.5 mm [0.08 to 0.1 in.]), dark spiral band on the “shoulder” with thin light yellowish margins above and below. Sculptural features of the shell include incised spiral grooves, spiral and transverse striae that give the surface a checkerboard-like look and papillae at the intersections of some of the striae (Walgren 2003a: 93). Adult shell dimensions range from 18 to 29 mm (0.7 to 1.1 in.) in diameter and from 14 to 25 mm (0.6 to 1.0 in.) in height (Roth 1985: 5). The shells of CSS are more depressed (lesser shell height/shell width ratio) than the shells of MSS and have a larger, less occluded umbilicus (Tupen and Roth 2005: 10). The sculpture of the shell is profusely granular or intensely papillose, with weak to absent incised spiral grooves on the body whorl. Incised spiral grooves, a key sculptural feature of the shell/body whorl of MSS,

are generally overridden by intense papillation on the shell of CSS (Roth 1973: 151; Walgren 2003a: 10). In addition to the extreme papillation, Roth (1973: 151) indicated decreased whorl number for CSS and Walgren (2003a: 93) suggested an overall smaller size at maturation. Roth and Tupen (2004; Figure 2) show no significant difference in size between MSS and CSS or among populations of CSS. Based upon this research, Tupen (2018 pers. comm.) postulates that observed size differences are likely more a site-specific phenotypic response to some environmental factor(s). Walgren (2003a: 88) developed a preliminary dichotomous key for the banded dune snail in the Chorro and Los Osos valleys, including something described as an “intermediate” form of the species. The range of the proposed intermediate form extends eastward from Los Osos and the eastern fringe of the Morro Bay Estuary through the Los Osos Valley to San Luis Obispo and includes three outlier populations (Walgren 2003a: 60). The shell morphology of the intermediate form is described as having “intermediate degrees of papillation, incised spiral grooves, diagonal lines, umbilicus occlusion, whorl number, and size at sexual maturity” Walgren (2003a: 90). The 2017 surveys for CSS documented the presence of a Helminthoglypta taxa with shell morphology and sculptural features that are distinct from CSS found in the southern region of the survey area (EcoVision Partners 2017: 31).

Reproductive Biology There have been no studies or documentation of the reproductive biology for MSS or CSS; however, many aspects of reproduction and reproductive behavior of these two species may be similar to other related Helminthoglypta species. Like most terrestrial gastropods, species in the genus Helminthoglypta are hermaphroditic and lay eggs (USDA 1999: 3). Studies in Sonoma County, California, of the related coastal species H. arrosa indicate most copulation and egg laying occurs during the rainy season and only during the months of October and November (van der Laan 1980: 49, 52; Roth 1985: 13). Adult snails emerge from aestivation within 24 hours after the first soaking rain in October and begin mating both at night and on overcast and rainy days (van der Laan 1980: 49, 52; USDA 1999: 3). Mating occurs only at ambient temperatures of 50° F to 59° F (10° to 15° C ), although H. arrosa was active in temperatures as low as 39° F (4° C) (van der Laan 1980: 50, 52). Helminthoglypta arrosa eggs are deposited in shallow holes in the soil below the leaf litter and are reported to average 2.2 mm (0.09 in.) in diameter with a mean number of eggs per egg mass of 75.6 (range 45-171) (van der Laan 1980: 50; USDA 1999: 3). Most eggs were fertile and hatched sooner and more successfully at higher temperatures (94 percent hatched at 60° F [15.5° C]) (van der Laan 1980: 51). The modal length of time between copulation and hatching of eggs was six months, with young snails reported to hatch in March and April (van der Laan 1980: 51-52; USDA 1999: 3). Helminthoglypta may reproduce multiple times after becoming reproductively mature (Jordan and Black 2015: 8).

Growth and Longevity Roth (1985: 13) described growth in Helminthoglypta as determinate with reproductive maturity, as indicated by the outward flare of the apertural lip, occurring shortly after the attainment of maximum size. van der Laan (Roth 1985: 13) indicated maturity is reached in 3 to 3.75 years for H. arrosa living in coastal scrub in Sonoma County, California and estimated longevity at 6 to 11

10 years. Roth (1985: 13) indicated that maturation and longevity patterns for the banded dune snail could be similar. As with reproduction, most growth among Helminthoglypta species occurs during the rainy season when moisture conditions are suitable for feeding activity (van der Laan 1980: 49, 52; Roth 1985: 13). High moisture/water availability is required for snail activity and facilitates feeding in the coastal Helminthoglypta species studied by van der Laan (1980: 52). The generally more xeric conditions experienced by inland forms of the banded dune snail (i.e., CSS) may result in longer aestivation durations than coastal species, with corresponding reductions in foraging opportunities and seasonal growth.

Activity Patterns Many species of Helminthoglypta occur in Mediterranean climate regions of California and have adapted to changing environmental conditions by having a two-part life cycle. While feeding, reproduction, and most individual growth occurs during the rainy season (Roth 1985: 13), the majority of the year can be spent in aestivation to survive the drier portions of the year (Belt pers. comm. 2018). Refugia used for the aestivation phase of the life cycle for both MSS and CSS appear to be opportunistic in nature. They can include native and nonnative plant species; accumulations of litter and grass; dense clumps of native and nonnative grasses, young patches of iceplant (Carpobrotus spp.), cactus (Opuntia spp.); and anthropogenic features and debris (stockpiled construction materials, wood, cement, plastic) (Roth and Tupen 2004: 17; SWCA 2013-2017: entire; D. Dugan, pers. comm. 2018). As previously stated, most activity among species of Helminthoglypta living in California occurs during the rainy season (Roth 1985: 13). In coastal San Luis Obispo County, the period of greatest activity generally extends from October through April but can vary each year depending on the frequency and duration of seasonal rainfall and heavy fog/dew. During this period, individuals may be particularly active during the evening, night, and early morning hours when humidity is higher. Helminthoglypta species are also active during overcast and rainy days (van der Laan 1980: 49, 52; USDA 1999: 3; Tupen, pers. comm. 2018). Both MSS and CSS likely emerge from aestivation during and following periods of rainfall in search of food resources and for mating and egg-laying activities. Individuals of both species have also been observed to emerge from aestivation prior to wet conditions when barometric pressure drops before a storm. This emergence typically occurs when individuals are in a “lighter stage of aestivation” (i.e., not in summer), which appears to occur in the weeks between storm events in early winter and later spring (Belt pers. comm. 2018). Terrestrial snails become inactive during prolonged dry periods and enter a state of aestivation where individuals produce an epiphragm (a seal of dried mucus) across the shell aperture to greatly reduce water/weight loss (van der Laan 1975b: 361). Helminthoglypta frequently aestivate sealed to the lower outer branches of shrubs (van der Laan 1975b: 365; Roth 1985: 13). Attachment to a substrate may provide additional protection from desiccation by forming a more complete seal of the aperture (van der Laan 1975b: 365). There is a possible decreased vulnerability to predation during dormancy when the attachment point is 20-30 cm (7.9-11.8 in.) above the ground surface (van der Laan 1975b: 365). Helminthoglypta arrosa was found to have the ability to survive 170 days or more in aestivation under experimental laboratory conditions and lose as much as 40 percent of their body weight (van der Laan 1975b: 361). In response to

increasingly desiccating conditions, snails withdraw further into their shells and may secrete multiple epiphragms, (van der Laan 1975b: 363, 367). Smaller snails tended to experience higher mortality rates during aestivation, possibly due to their thinner shells and higher surface to volume ratios (van der Laan 1975b: 364). Helminthoglypta come out of aestivation after rain events that thoroughly wet the environment and may regain as much as 50 percent of their body weight back within 24 hours (van der Laan 1975b: 364). Terrestrial gastropods do not move much, usually only to find food or reproduce. Olfaction is the primary sensory behavior used to find and move toward a food item (on the scale of centimeters to meters), although the terrestrial flamed tigersnail (Anguispira alternata) from the eastern United States appears capable of switching foraging behavior when snails encountered a physical barrier to movement (Atkinson 2003 in NatureServe Explorer). Like other terrestrial snails, we expect MSS and CSS to have a patchy distribution coincident with the presence of suitable refugia and food sources.

Feeding No studies or documented observations exist on the feeding behaviors of the banded dune snail. The dissected radula of the banded dune snail had the typical morphology found in herbivorous land snails (Hill 1974: 8). Hill (1974: 8) provided a tentative conclusion that the banded dune snail was a detritus feeder due to some individuals observed feeding on decaying plant material but he later concluded that the species primary food source was “more probably the fungal mycelia growing on the decaying plant material.” Walgren and Andreano (2013: 165) hypothesized that banded dune snail is likely a detritus feeder (Walgren and Andreano 2013: 165). In terms of mature dune scrub stands that produced twiggy litter low in food values, Roth (1985: 16) indicated preferences similar to H. arrosa. van der Laan (1975a: 358) suggested that snails and slugs occupying late successional plant communities select disturbed areas more often for feeding and tend towards saprophagy (i.e., feeding on dead or decaying organic material) more than herbivory. The banded dune snail is not a garden pest and is considered essentially harmless in this respect (Chambers 1997 in Service 2001: 9234). We infer the food requirements for MSS and CSS from studies of closely related Helminthoglypta species that occupy similar habitats because we expect them to have similar diets (van der Laan 1975a: 356). During his study of the feeding preferences of H. arrosa, van der Laan (1975a: 358) found that the species was an herbivore and reducer of dead plant material and strongly preferred dead plant material over living material. Helminthoglypta arrosa accepted certain forb species and a bracket fungus provided during the study but rejected all grasses, certain forbs, an alga, and all other macroscopic fungi and that early successional plants, especially annuals and biennials, were generally more palatable than plants in a later successional state (i.e., taller) (van der Laan 1975a: 358). Study results showed no significant differences between snail size and the kind of food selected (van der Laan 1975a: 355, 358). Helminthoglypta arrosa accepted two plant species with chemical deterrents but rejected all plants with known high concentrations of toxins (van der Laan 1975a: 358). The snails both accepted and rejected plants with hard exteriors and spines (van der Laan 1975a: 358). The frequency of palatable plant species appears to be inversely proportional to the maturity of the community (van der Laan 1975a: 358).

Habitat Associations Morro Shoulderband Snail In the final rule designating critical habitat for the banded dune snail (Service 2001: 9235-9236), we identified those primary constituent elements (PCEs) essential to support primary biological needs of foraging, sheltering, reproduction, and dispersal for the coastal form of Helminthoglypta walkeriana (i.e., MSS) only. These elements included sand or sandy soils for reproduction; a slope not greater than 10 percent to facilitate movement of individuals; and the presence of native coastal dune scrub vegetation (Service 2001: 9236). Not identified in the final rule was what we now recognize as the seasonal need for hydrological conditions to support feeding and breeding activities. Like other Helminthoglyptid species, MSS likely emerge from aestivation during and following periods of rainfall in search of food resources and for mating and egg- laying activities. The 12-month findings for the Mohave shoulderband snail (H. greggi), notes that the species is dependent on local precipitation and subsequent increases in humidity within its rock outcrop habitats. Although water represents the primary limiting resource in desert environments, other climatic and physical factors—such as temperature, topography, and food availability, or a combination of these factors—can influence the ecology of desert snails (Service 2017: 57563-57564). We expect these factors also influence MSS, although do not know their degree of influence. We also recognize that drier habitats are necessary to serve as aestivation refugia for MSS during a large portion of their life cycle (Belt pers. comm. 2018). Chorro Shoulderband Snail There are no PCEs for CSS as this taxon was not included in the designation of critical habitat of the banded dune snail (Service 2001; entire). Historic information on the habitat associations of CSS is brief and lacking in detail. Walgren (2003a: 65) described habitat for this species as vegetation and/or plant community associations including “sand verbena-beach bursage, coyote brush, coast live oak woodland, nodding needlegrass, European beachgrass, California annual grassland, iceplant, and dune lupine-goldenbush series communities.” Roth and Tupen (2004: 6) reported the primary plant associates for CSS include sweet fennel (Foeniculum vulgare), coyotebush (Baccharis pilularis), poison hemlock (Conium maculatum), and native bunch grasses of the genus Stipa. Chorro shoulderband snails are also commonly associated with stands of mission fig cactus (Opuntia ficus-indica) where it occurs in and around the City of San Luis Obispo (EcoVision Partners 2017: 27; Tenera 2003: 6-8). EcoVision Partners (2017: 3) reported CSS within the leaf litter of coyotebush and California sagebrush. Individuals also occur in the interface of rock outcrops and grasslands, rock piles, and individual rocks (Ballantyne pers. comm. 2018; Sloan pers. comm. 2018; EcoVision 2018: 3). Similar to MSS, CSS require suitable seasonal hydrological conditions for feeding and breeding activities. It appears that the use of refugia is diverse and opportunistic. Like MSS, CSS likely emerge from aestivation during and following periods of rainfall in search of food resources and for mating and egg-laying activities. Precipitation and humidity requirements for CSS are very likely similar to those of MSS, although CSS occur in more xeric habitats further removed from the direct coastal influence experienced by MSS.

CHAPTER 3 – POPULATION AND SPECIES NEEDS Herein we consider the historical distribution and species needs for viability for MSS and CSS. We first review the historical information on the range and distribution of the species. We then review the conceptual needs of the species, including population resiliency, redundancy, and representation to support viability and reduce the likelihood of extinction.

Historical Range and Distribution The final 1994 listing rule states that the banded dune snail “formerly occupied primarily coastal dune scrub habitat along approximately 8 km (5 mi) of dunes extending onto the Morro sand spit, at Baywood Park, San Luis Obispo, sites between Morro Bay and Cayucos, and probably along Morro Bay in the vicinity of Cuesta-by-the-Sea.” Additionally, it notes individuals from San Luis Obispo (type locality for “morroensis”) and 4.8 km (3 mi) south of Cayucos (Roth 1973: 153). At the time of listing, we thought the banded dune snail was restricted to sandy soils of coastal dune and coastal sage scrub communities near Morro Bay. Roth (1985: 16) speculates that Helminthoglypta walkeriana was probably uncommon as early as the 1930s and considered it to be rare in 1985 based upon surveys identifying only six live individuals (what would be MSS today) and numerous empty shells. Based on this, he inferred that there might have been only several hundred individuals in the remaining population (Roth 1985: 12). At the time of listing, we thought Helminthoglypta walkeriana “morroensis” (what would be CSS today) was extinct; however, in 1997, a population of snails with form “morroensis” shell morphology was identified at North Point Natural Area near the northern limit of Morro Bay (Roth and Tupen 2004: 3, Figure 1; Tupen, pers. comm. 2018). Since that time, living CSS have been found at other locations from north of Morro Bay inland through the City of San Luis Obispo (Walgren 2003a: Tenera 2003a: 14; Tenera 2003b: 6-8; EcoAnalysts 2004: entire; EcoVision Partners 2017: 23). As noted previously, the Service discontinued regulation of CSS in 2004 and, as such, we did not receive further information on the species until completion of the 2017 EcoVision Partners surveys (EcoVision Partners 2017: entire). At the time of their recognition as two separate species in 2004, MSS and CSS distributions did not appear to overlap (Roth and Tupen 2004: 4). Roth and Tupen (2004: 17) noted that if sympatric populations were to exist, the area where the two distributions approach each other (i.e., the Turri Road region of Los Osos and northern Morro Bay would be the likely location of sympatry. Sympatric occurrence is known from three locations in the Los Osos area: Turri Road near Warden Creek, northeast of the community of Los Osos (Tenera in litt 2006: 3); an artificially constructed peninsula south of the Morro Bay State Park Marina (CDPR 2007: Appendix B); and a borrow pit on the former Morro Bay Power Plant property in Morro Bay (Dugan pers. comm. 2018). Passive transport of MSS to each of these sites may explain one or more of the co-occurrences. The Warden Creek site is located adjacent to the former Los Osos landfill, construction of the Marina peninsula used imported materials, and the site on the power plant used imported materials (Dugan pers. comm. 2018).

Figure 2. Geographic distribution of MSS and CSS (Roth and Tupen 2004: 4).

NPNA = North Point Natural Area; MSSB = Morro Strand State Beach; SBCR = San Bernardo Creek Road MBSS = Morro Bay Sand Spit; Elfin/LO 1 = Elfin Forest Natural Preserve; LO 2 = Los Osos; CSLO = Camp San Luis Obispo; Bishop = Bishop Peak Natural Area

Recovery Plan The Service completed a recovery plan for five species from western San Luis Obispo County in 1998, with MSS included as one of these species (Service 1998: 10-14, 40). Recovery units were not identified for included species; rather four Conservation Planning Areas (CPAs) were identified to encompass those locations the Service believed were of greatest importance to secure the recovery of the three listed Morro Bay species: MSS, Indian Knob mountainbalm (Eriodictyon altissimum), and Morro manzanita (Arctostaphylos morroensis). A focal criterion

for the general delineation of the CPAs and two additional areas was that each contained native habitats supporting one or more of these three species (Figure 4). The recovery objective for MSS is delisting. Appendix A provides the objectives/criteria for delisting and downlisting, as well as Recovery Plan tasks identified to help achieve them. How these tasks relate to the resiliency, redundancy, and representation (the 3 Rs) for MSS is discussed, as well as the progress for achieving identified tasks. The Recovery Plan does not address CSS.

Figure 3. Conservation Planning Areas for Morro Bay Species from the Recovery Plan that includes MSS (adapted from Service 1998: 39)

Species Needs As discussed in Chapter 1, 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 the 3Rs.

Resiliency Resiliency is the ability to sustain populations, or occurrences in the case of both MSS and CSS, in the face of stochastic demographic and environmental variation. Environmental variation includes normal year-to-year variation in rainfall and temperatures, as well as unseasonal weather events. To be resilient, a species must have occurrences capable of sustaining themselves through good and bad years. Additionally, the degree of connectivity among populations and occurrences affects resiliency by providing opportunities for rescue/recolonization in the face of extirpation. Morro Shoulderband Snail For MSS to remain healthy and maintain viability, its populations or some portion thereof must be resilient to the normal range of environmental variation. If a population area (geographically- related set of occurrences) occurrence is small and isolated with reduced reproductive capacity, then it may not be able to withstand a series of low-rain years or further habitat loss, and the population may become extirpated. Local extirpations could preclude recovery of the species. Factors influencing the ability of MSS to withstand stochastic events include the abundance and distribution of individuals, habitat quality and configuration (including presence of a hydrological microclimate to facilitate feeding and reproduction), and the likelihood that suitable habitat will persist into the future. Chorro Shoulderband Snail The same anticipated needs identified for MSS are also relevant to maintain resiliency for CSS. Factors influencing the ability of CSS to withstand stochastic events include their abundance; habitat quality defined as presence of habitat that provides necessary sheltering, feeding, and breeding conditions in a relatively contiguous landscape; and the likelihood that this habitat will persist into the future.

Representation Representation is the range of variation within a species. This range, referred to as adaptive diversity, is the source of a species’ adaptive capabilities. Maintaining adaptive diversity includes both the genetic diversity and ecological diversity of a species. By maintaining these two sources of adaptive diversity across a species’ range, we expect preservation of the species’ responsiveness and adaptability over time. Genetic diversity is the number and frequency of unique alleles within and among populations. Ecological diversity is the physiological, ecological, and behavioral variation exhibited by a species across its range. Morro Shoulderband Snail Population areas of MSS need genetic and ecological diversity to remain viable. By maintaining the amount and breadth of these forms of diversity, we expect preservation of the species’

adaptability. As we do not have information on the genetic diversity within the species, we assume that maintenance of healthy population areas across the diversity of MSS habitat types or ecological gradients throughout its distribution will likely conserve the relevant genetic diversity associated with species persistence across these habitats. The presence of Baywood Fine Sand soils appears to be the single unifying habitat characteristic wherever MSS are found. While the native plant community that the species is most often associated with is coastal dune/sage scrub, individuals occur, albeit to a much lesser extent, in ecotonal areas with oak woodland and central maritime chaparral (Walgren and Andreano pers. comm. 2018). Currently, the greatest numbers of individuals seem to occur in disturbed and ruderal habitats (Service files, SWCA 2018:5). We do not know why but speculate that these areas may provide better sheltering/refugia opportunities and palatable, early-successional annual and biennial plants species as a food source than may be found in older, native habitats. Chorro Shoulderband Snail Adaptive diversity is also necessary for CSS to maintain viability. By maintaining the amount and breadth of genetic and ecological sources of adaptive diversity, we expect preservation of the species’ responsiveness and adaptability. Species that span environmental gradients (spatially and temporally heterogeneous environments) are expected to harbor the most phenotypic and genetic variation (Lankau et al. 2011: 320). Thus, preserving the breadth of diversity of a species requires maintaining populations across historical latitudinal, longitudinal, and elevation gradients, as well as climatic gradients. As with MSS, we do not have information on the genetic diversity for CSS but again assume that maintenance of healthy population areas across the north-south and east-west gradients within the distribution is likely to conserve the relevant genetic diversity and associated adaptive capacity for the species.

Redundancy Species-level redundancy is the ability of a species to withstand catastrophic events. Redundancy protects a species against the unpredictable and highly consequential events for which adaptation is unlikely. In short, it is about spreading the risk. To achieve redundancy, the species needs to have multiple populations or occurrences widely distributed across the species’ geographic range. This reduces the likelihood that all populations or occurrences would be affected by any single event simultaneously. Given sufficient redundancy, single or multiple catastrophic events are unlikely to cause the extinction of a species. It follows then that the greater redundancy a species has, the more viable it will be. Morro Shoulderband Snail The Morro shoulderband snail is a local, endemic species occurring only within an estimated 6,520 acres (2,638 hectares) located in and around the community of Los Osos and City of Morro Bay (see Figure 2). This inherently limited distribution makes the species at risk of extirpation from catastrophic events. We believe that Morro shoulderband snails need multiple resilient connected population areas distributed throughout its limited distribution area to provide for redundancy. Catastrophic events that are most likely to affect MSS include prolonged, more frequent, or more intense drought events; range-wide wildfire; and/or localized flood events. Chorro Shoulderband Snail

The distribution of CSS is also localized. Its range is estimated to be approximately 70,650 acres (28,590 hectares located predominantly inland and east of the estimated distribution of MSS (see Figure 2), We believe that CSS also need multiple connected resilient population areas distributed throughout the distribution to provide for redundancy. Those catastrophic events considered most likely to affect CSS include prolonged, more frequent, and/or more intense drought events; wildfires; localized flood events; changes in the intensity of agricultural practices, and/or new or increased predation.

CHAPTER 4 – CURRENT CONDITION The following sections describe the known current conditions for both MSS and CSS and include a discussion of threats, conservation actions, and range and distribution.

Threats Threats influencing the viability of Morro shoulderband snail populations at the time of listing were urban development, off-road vehicle activity, nonnative vegetation (referred to as invasive species in this proposed rule), parasitoids, and competition from brown garden snails, all of which were exacerbated by effects associated with small population size and drought conditions (59 FR 64613). Since the time of listing, we have determined that some of these threats are no longer affecting the species, particularly off-road vehicle activity, brown garden snails, parasitoids, and controlled burns (Service 2006, pp. 11–15). Currently, a number of threats to MSS and CSS are present within their respective distributions, many of which are common to both species. The most common threat to both is the implementation of land use practices that eliminate, reduce, fragment, and/or modify habitat used by the species. We expect that climate change will likely exacerbate the severity of threats. We discuss identified likely threats to the species below. Development. Human development consists of converting the landscape into residential, commercial, industrial, and recreational features, with associated infrastructure such as roads. Converting the landscape into development not only removes individuals of MSS and CSS, but also removes their habitat, thereby reducing the space available for the species to inhabit and functionally lowering carrying capacity. In addition, development results in indirect effects by fragmenting the habitat and creating edge effects, such as increased vulnerability to desiccation, fire, and predation. The effects of development on MSS and CSS are predicated upon myriad factors (e.g., how the City and County of San Luis Obispo revise and implement their respective general plans, the economy, water availability). Agriculture. Agriculture, especially change from grazing lands to more intensive uses (e.g., avocado orchards, row crops, or vineyards) is primarily a threat to CSS. The following discussion focuses on this species unless otherwise specified. Observed agricultural uses in the species range include row crops, vineyards, hay fields, and orchards (EcoVision Partners 2017: 28). Local jurisdictions do not typically regulate agricultural uses in those areas zoned for agriculture. The large-scale mechanical disturbance of soils and vegetation associated with the planting, maintenance, and harvest of crops eliminates habitat and likely results in injury and mortality to individual snails within these areas. Individuals remaining in these areas occupy fragmented, often low value, habitat along drainage swales, fence lines, roadside rights-of-way, and un-tillable features. Lands under cultivation occur on relatively level soils throughout the range of CSS but agricultural activity appears most intensive along the floor of Los Osos Valley and the Edna region south of the City of San Luis Obispo. Vegetation Management. Mowing for weed/hazard abatement occurs regularly along public roads within the distribution for both CSS and MSS. Mowing and habitat alteration for hazard abatement is a common threat to MSS on properties and along roads, especially in the central portion of its distribution in and around the community of Los Osos. The mowing of grasses and shrubs alters habitat characteristics and very likely results in direct and indirect injury or mortality to snails within both affected and adjacent areas. In addition to direct mechanical injury

or mortality, mowing is likely to impact both MSS and CSS populations already stressed by adjacent agricultural or urban uses through increased vulnerability to desiccation and predation, particularly if mowing occurs during the dry season when snails are aestivating (EcoVision Partners 2017: 29). The County of San Luis Obispo implements measure to reduce impacts to MSS when conducting requested mowing activities on lands under their jurisdiction and notes that surveys do not often identify individuals in area that have been regularly mowed (Ballantyne pers. comm. 2018). Predation. Little information is available from direct observation about MSS and CSS predators. The listing rule notes predation as a possible threat. Several sources have indicated possible mortality from sarcophagid fly pupae (Hill 1974:11-12; Roth 1985: 16) and noted that fly puparia are present in the shells of MSS (Tupen and others at snail summit 2017). Current thought is that these flies lay their eggs on newly deceased snails instead of parasitizing living individuals and, therefore, do not affect either species (Service, 2006; Tupen and others at snail summit 2017; Walgren and Andreano pers. comm. 2018). It is expected that the introduced predatory decollate snail would likely prey on MSS and/or CSS if it became established into areas within each species’ range, as it preys on other snails and has been shown to attack and consume native southern California Helminthoglypta species during laboratory studies (Barker and Efford 2004: 307). The decollate snail has been used as a biological control for the brown garden snail among southern California citrus growers. An abundance of brown garden snail shells and shells from an unknown Helminthoglypta species were found at the survey location with at least 12 decollate snail shells near a citrus grove in the southern portion of the 2017 CSS survey area (EcoVision Partners 2017: Appendix B, survey site 48). The legal status of the decollate snail as a “detrimental animal” in California has resulted in the prohibition of its importation, transportation, and possession of in all but 12 counties (Tupen and Roth 2001: 401). The listing rule for banded dune snail noted that rodent predation could affect the species. Results of the 2017 CSS survey noted rodent predation as a threat at 13 percent (8/60) of the survey locations (EcoVision Partners 2017: Attachment B) with a cache of at least 20 Big Sur shoulderband snail (H. umbilicata) shells observed at one site (EcoVision Partners 2017: Attachment B, site survey 1). Furthermore, information provided in studies of other Helminthoglyptid species indicates predators of MSS and CSS likely include a variety of vertebrate and invertebrate species. Predators of H. arrosa include deer mice (Peromyscus maniculatus), garter snakes (Thamnophis sirtalis), northern alligator lizard (Elgaria coerulea), and a carabid ground beetle (Scaphinotus ventricosus) (van der Laan 1975b: 367). Additionally, Heagy (1980 in Roth 1985: 5) indicated the scarcity of banded dune snails in her study area could have been due to predation by deer mice, alligator lizards, or beetles, or competition from other snail species. Roth (1985: 8) reported that one newly deceased banded dune snail shell found in March 1985 near the southern tip of Morro Bay was probably a rodent kill. Finally, numerous avian species are reported as potential opportunistic snail predators including the American kestrel (Falco sparverius), California quail (Callipepla californica), common raven (Corvus corax), greater roadrunner (Geococcyx californianus), loggerhead shrike (Lanius lucovicianus), European starling (Sturnus vulgaris), and rock wren (Salpinctes obsoletus) (Center for Biological Diversity 2014: 23). Other avian species such as crows and jays (Family Corvidae), thrashers (Toxostoma spp.), and northern mockingbirds (Mimus polyglottos) are likely opportunistic snail predators as well.

Climate Change. The summers of 2016 and 2017 were each the warmest in California since record keeping began in the late 1800’s (NOAA National Centers for Environmental Information 2018). Considering data up to 2015, Brown et al. (2016: entire) reported that most of the warming occurred in the past 35 years with 15 of the 16 warmest years occurring since 2001. In particular, California is becoming hotter and drier. The 3-year period from 2012 to 2014 was the hottest and driest in California in the 100-year timeframe considered (Mann and Gleick 2015: 3858), and it was the most severe drought in California in the past 1,200 years (Griffin and Anchukaitis 2014: 9017). This trend appears likely to continue (Thorne et al. 2017: entire). Climate change is likely to affect many terrestrial gastropod populations in California, including MSS and CSS. Species with small geographic ranges are particularly vulnerable to extinction by climate change (Allan et al. 2005: p. 284). The increased frequency of protracted drought events is likely to result in higher mortality during prolonged periods of seasonal aestivation, particularly among smaller individuals in the population (van der Laan 1975b: 364). Higher levels of egg mortality from desiccation are expected. Warmer temperatures and greatly reduced wet season precipitation during prolonged multi-year drought events also increase stress on vegetation (Coates et al. 2015: 14277) and may limit time for feeding and breeding in MSS and CSS. Coastal sage scrub communities had the highest seasonal variability in terms of the relative amount of ground covered by green vegetation during the drought years of 2013-2014 (Coates et al. 2015: 14283). Coastal sage scrub plant species also had the highest land surface temperature values of the communities analyzed, likely resulting from lower vegetation cover, lower evapotranspiration, and south-facing slopes typical of coastal sage scrub communities (Coates et al. 2015: 14284). These effects of prolonged drought reduce the value and quality of sheltering habitat as well as food availability within the primary plant community association for MSS and CSS. Combined with threats described above, the negative effects of climate change on growth and reproduction are likely to result in decreased population abundance and increased vulnerability to local extirpation.

Conservation Actions Morro Shoulderband Snail As previously noted, a diversity of groups carry out conservation actions for MSS within the species’ distribution and many areas are under some form of protection as part of a State Park, State of California ecological reserve, or parcels set aside specifically to conserve and enhance natural resource values (e.g., under deed-restriction). Both the Morro Coast Audubon Society and Small Wilderness Area Preservation conduct activities to improve habitat quality for MSS and other coastal dune scrub species on lands conserved and protected under their ownership and/or management (Sweet Springs Nature Preserve and Elfin Forest, respectively). These actions focus primarily on the removal of exotic plant species (perennial veldt grass, iceplant), restoration of coastal dune scrub, and erosion control. The California Department of Parks and Recreation also conducts similar activities on their lands (i.e., Montaña de Oro and Morro Bay State Parks and Morro Strand State Beach). The County of San Luis Obispo owns two large parcels in Los Osos, Broderson and Mid-Town, that support coastal dune scrub and, to a lesser extent, central maritime chaparral. Management actions on both parcels focus on the restoration and enhancement of habitat for MSS (KMA 2017: entire, County of San Luis Obispo 2017: entire). The Land Conservancy of San Luis

Obispo County recently purchased approximately 14 acres adjacent to Morro Coast Audubon Society Sweet Springs Preserve. They plan to enhance habitat quality for coastal dune scrub species, including MSS, before transferring these lands to Morro Coast Audubon Society ownership and management (Theobald pers. comm. 2017). Most of the lands above are included in CPAs identified in the recovery plan that addresses MSS (Service 1998: 39-40). The Elfin Forest Reserve occurs in the Northeast Los Osos CPA and contains habitat occupied by MSS. Portions of Montaña de Oro State Park occur in the Morro Spit, West Pecho, and South Los Osos CPAs and contain significant tracts of coastal dune scrub and central maritime chaparral. Portions of Morro Bay State Park are within the Northeast Los Osos CPA 4, as well as identified as part of a potential restoration corridor. The Los Osos Oaks Preserve is an important habitat area as its oak woodland is ecotonal with coastal dune scrub. The County’s Broderson and Midtown sites are within the South Los Osos CPA. Chorro Shoulderband Snail We are not aware of any conservation actions being implemented specifically for CSS; however, areas conserved as open space by the City and/or County of San Luis Obispo, as well as those acquired and/or managed by the Land Conservancy of San Luis Obispo, benefit the species through habitat preservation.

Current Range and Distribution Morro Shoulderband Snail Hill (1974; 6, Figure 2) and others projected a very limited distribution for Helminthoglypta walkeriana (as the coastal form of the banded dune snail). Its range was thought to extend only a short distance inland along the southeastern shore of Morro Bay to Shark Inlet, southward to near Islay Creek, and northward on the Morro Bay sand spit at the western edge of the community of Los Osos. In the listing rule, the Service expanded this to include the coastal dune and coastal sage scrub communities underlain by sandy soils near Morro Bay (e.g., Los Osos) (Service 1994: 64615). We currently estimate the distribution for MSS to be approximately 6,520 acres (2,638 hectares) located in and around the community of Los Osos/Baywood Park and City of Morro Bay (Figure 5). Currently, we know that thousands of MSS exist in this area (SWCA 2018: 7). Using known species occurrence and estimated abundance along with the presence of Baywood Fine Sand soils and small areas of Dune Land soils, we delineated six geographic units (hereafter, population areas) for the purpose of this analysis. The Baywood Fine Sand soil series consists of deep, excessively well drained soils on stabilized sand dunes near the coast (USDA 1984: 19, 20). Limited areas of Dune Land, a similar soil series, are included where contiguous with Baywood Fine Sand soils along the immediate coast. The Dune Land soil series is composed of well-drained soils somewhat stabilized by the presence of beach grasses and/or coastal dune scrub plant species (USDA 1984: 41). We based the boundaries of the population areas primarily on readily identifiable anthropogenic features (e.g., roads, development). Native plant communities at lower elevations within the range of MSS consist predominantly of coastal dune/sage scrub, with the upper slopes characterized by central maritime chaparral. In localized areas, coast live oak woodland is present. Throughout the estimated distribution of MSS, most native plant communities are in a disturbed condition. In some areas, these communities are dominated or have been replaced by the nonnative, invasive perennial veldt

25 grass (Ehrharta calycina) grassland or ruderal plant species. Morro shoulderband snails are not often found in the understory of stands of Eucalyptus species present within its distribution (Walgren and Andreano 2012: 167); nor is the species found under stands of pine forest within Morro Bay State Park, despite the underlying presence of Baywood Fine Sand soils (Walgren and Andreano, pers. comm. 2018).

Figure 4. MSS Distribution and Population Areas (outlined and labeled in white)

Descriptions for the six population areas depicted in Figure 4 follow below: North Morro Bay: This population area is approximately 200 acres (81 hectares), much of which is protected as part of Morro Strand State Beach. Coastal dune scrub underlain by Dune Land soils is the most common native habitat for MSS and is present throughout most of the area. Neither critical habitat (Service 2001: 9245) nor a CPA for the species (Service 1998: 39) is present in this population area. The species occurs in this area; however, information on distribution and abundance is limited to anecdotal observations made by State Parks biologists (Walgren and Andreano pers. comm. 2018) and information contained in Roth and Tupen (2004: 4). Sand Spit: This population area is approximately 1,775 acres (717 hectares) and consists almost entirely of native habitats. A portion of Montaña de Oro State Park, California Department of Fish and Wildlife (CDFW) Morro Dunes Ecological Reserve, and City of Morro Bay open space/recreation (MBI 2017: figure 11.1) are protected lands found within this area. Native habitat suitable for occupation by MSS includes coastal dune scrub and, to a much lesser extent, central maritime chaparral, underlain by Dune Land and Baywood Fine Sand soils. Critical habitat unit 1 (Service 2001: 9236-9237) and CPA 1 (Morro Spit) are found within this population area (Service 1998: 39) as is a portion of CPA 2 (West Pecho). Morro shoulderband snails occur in its large tracts of coastal scrub habitat. Information for MSS is largely from informal, anecdotal observations made by State Parks biologists although portions were included in a survey effort of State Park lands conducted by State Park biologists in 2001-2002 (Walgren and Andreano pers. comm. 2018, Walgren in litt. 2003). Roth and Tupen (2004: 4) also provide location data regarding presence in this population area). In the final rule for MSS critical habitat, we conclude that lands within this population area are essential to maintain genetic diversity of MSS. Maintenance of suitable habitat conditions through proper management in this area would provide for continued connectivity and dispersal between populations, thereby ensuring genetic diversity over the long-term (Service 2001: 9236-9237). Morro Bay: This population area is approximately 1,070 acres (433 hectares) entirely underlain by Baywood Fine Sand soil, the majority of which has been in residential and commercial uses as part of the City of Morro Bay for many years. It includes a golf course and campground portions of Morro Bay State Park and urban uses within the City of Morro Bay. We consider only a very small portion in the east and southeastern portion of this area protected as part of native habitat on and surrounding Black Hill in Morro Bay State Park. Coastal scrub underlain by Baywood Fine Sand soils is the dominant native habitat in this area; stands of nonnative blue gum (Eucalyptus globulus) and Monterey cypress (Cupressus macrocarpa) occur in and around the golf course and campground. Soils underlying Black Hill proper are markedly different from Baywood Fine Sand soils surrounding it, excluding it from the population area. No critical habitat for MSS is present in this area (Service 2001: 9245) nor is it within in a CPA identified in the recovery plan (Service 1998: 39). We know that individuals are present within a small portion of this population area (Dugan pers. comm. 2018), information on the distribution and abundance very limited and largely anecdotal or from Roth and Tupen (2004: 4). East Los Osos: This population area is approximately 620 acres (251 hectares) represented by a combination of public and private lands predominantly zoned for large parcel (e.g., an acre or greater) development or agriculture. Protected areas include eastern portions of Morro Bay State Park and a small adjacent parcel owned by the Bureau of Land Management. Native habitat suitable for MSS is present as coastal scrub underlain by Baywood Fine Sand soils. Portions of

critical habitat unit 3 and CPA 4 (Northeast Los Osos) are present in the northern portion of this area (Service 2001, p. 9245; Service 1998, p 39; Figure 4). Morro shoulderband snails occur throughout this population area; however, the nature of information on species presence and abundance relies predominantly on the results of surveys conducted in association with proposed development, information found in Roth and Tupen (2004: 4), and incidental observations made by State Parks biologists. State Parks biologists conducted surveys for MSS in limited portions of this area in 2001-2002 (Walgren in litt. 2003, Walgren and Andreano pers. comm. 2018). Language in the critical habitat rule states that lands in this population area are essential to maintain the genetic variability of the species and the full range of ecological settings within which the snail is found. We also observe that favorable habitat conditions necessary for the expansion and persistence of the core population were present at that time (Service 2001: 9237). Downtown Los Osos: This population area is approximately 1,430 acres (578 hectares) and consists largely of smaller, private parcels zoned for residential development and commercial uses, all of which are underlain by Baywood Fine Sand soils that was once vegetated with coastal scrub. Much of this area is now single-family residential developments and the commercial and public services uses that serve them. Only a small percentage of habitat in this population area is conserved as part of the Elfin Forest Preserve in the northernmost portion and the Morro Coast Audubon’s Sweet Springs Preserve. An area in central Los Osos, referred to as the Midtown parcel, was restored to coastal dune scrub as a condition of the Los Osos Wastewater Project coastal development permit but its ultimate fate remains uncertain. While deed-restricted to preclude development not associated with habitat restoration/enhancement, this parcel is proposed to remain zoned as recreation/public facilities (County of San Luis Obispo 2015: Los Osos Area Update Proposed Changes map). Due to past hazard abatement and other activities, perennial veldt grass now dominates many of the undeveloped in-fill parcels that once supported coastal scrub. This population area does not contain critical habitat for MSS (Service 2001, p. 9245) nor is it within in a CPA for the species (Service 1998, p. 39; Figure 4). Morro shoulderband snail individuals occur throughout this population area, often in highly disturbed habitat (SWCA 2017: 5). Our knowledge of the distribution and, to a limited extent, abundance of MSS in this area is much greater than for any population areas based on data collected during pre-construction monitoring surveys for the construction and operation of the Los Osos Wastewater Project between 2012 – 2014 (SWCA 2018: 5; Figure 5). While much of this population area is developed, there remain over 500 vacant parcels scattered throughout (Service LOHCP files). Many of these parcels, connected by trails and dirt roads, likely serve as dispersal routes and refugia for MSS (Service files; Walgren and Andreano pers. comm. 2018) as more than 2,000 individuals were identified throughout this area during monitoring surveys conducted between 2012-2016 for the Los Osos Wastewater Project (SWCA 2018: 5). South Los Osos: This population area is approximately 1,425 acres (577 hectares), much of which is considered protected. It includes the Bayview Unit of CDFW’s Morro Dunes Ecological Reserve, portions of Montaña de Oro State Park, and approximately 72 acres of deed-restricted, conserved lands owned and managed for its natural resource values by the County of San Luis Obispo (and commonly referred to as the ‘Broderson Parcel”). The entirety of critical habitat unit 2 and most of CPA 3 are within this population area. Much of this area is residential; but large parcels of native habitat remain. Habitat in this population area suitable for MSS includes coastal scrub and, to a lesser extent, central maritime chaparral where it is ecotonal with the scrub community. Most of the information on species presence and abundance is from the results of surveys conducted in association with proposed development. State Parks biologists also note 29

observations on their lands and portions were surveyed in 2001-2002 (Walgren in litt. 2003) as well as part of monitoring conducted in association with the Los Osos Wastewater Project (SWCA 2017: 5). Lands encompassed within this population area are included in critical habitat because “they contain a core population of MSS that could be expanded and threats to the species reduced with appropriate management” (Service 2001: 9237) as they are adjacent to or contiguous with seemingly suitable native habitats.

Figure 5. Relative Abundance for MSS in Downtown Los Osos Population Area 2012-2014 (= Areas A-D) (SWCA Consultants)

Chorro Shoulderband Snail The distribution of CSS consists of approximately 70,650 acres (approximately 28,590 hectares) located predominantly inland and to the north and east of the estimated distribution of MSS (Figure 6). Unlike MSS, CSS are not restricted to sandy soil substrates but are found on a diversity of general soil types described in Roth and Tupen (2004: 17), including alluvial clay soils,

serpentine rock outcrops, talus slopes, and weathered serpentine derived clays. Walgren (2003b: 64) found the typical soil association for the then interior form of the banded dune snail (currently CSS) to be dark clay soils but added that the species has also been observed in active dune sand near clay soils. The results of the 2017 surveys confirmed these generalized soil associations and provided greater specificity, particularly the USDA soil series (clay or clay loams) and their slope/steepness (EcoVision Partners 2017: 32). Study results found a greater abundance of CSS on moderately steep to steeply sloping soils (15 to 75 percent and 50 to 75 percent) as well as strongly sloping soils (9 to 15 percent slopes); however, individuals were not encountered on steep slopes with actively migrating, loose, or unconsolidated soils. The observed presence in steeper areas may be due to other factors such as the type of adjacent land uses and the generally higher levels of habitat disturbance associated with less steep or level survey sites. Associated plant communities where CSS occur include oak woodland, chaparral, coastal sage scrub, and grassland. California sagebrush, coyote brush, and black sage are often present. Much of the Chorro Valley, the hillsides east of the coast, the Cayucos, Toro, and Morro Creek valleys, and areas within Los Osos Valley are used as rangeland for cattle (EcoVision 2017: 29). As previously noted, the level of survey effort completed throughout the known distribution of CSS is extremely limited, with no surveys conducted for this species between 2004 and 2016. Current information on species presence is based on the EcoVision Partners 2017 surveys and those surveys conducted prior to July 2004 (e.g., Walgren 2003a: entire; Padre 2004: 3-4; Service Files; EcoVision Partners 2017: entire; Sloan pers. comm. 2018). For the EcoVision Partners survey effort, a comprehensive survey of all areas where CSS might occur was not possible due to restricted legal access but also to time and financial constraints. During the 2017 survey, EcoVision Partners identified live individuals, shells, or shell fragments on 17 different soil series, which were predominantly clay or clay loams soils (14 soil types from 6 series) (EcoVision Partners 2017: 27). They also estimated relative abundances using categories of very low, low, medium, high, and very high (EcoVision Partners: Figure 6). Due to the high diversity of soil series present and larger overall species distribution (see Figure 2), we used level 12 USGS watersheds (https://water.usgs.gov/GIS/huc.html) to delineate 10 population areas for analysis purposes (Figure 7).

Figure 6. Relative CSS Abundance from 2017 Surveys (EcoVision Partners 2017: 26)

Figure 7. CSS Distribution and Ten Population Areas (outlined and labeled in white)

Descriptions for the six population areas depicted in Figure 7 follow below: Cayucos Creek: This region is approximately 740 acres (299 hectares) and represents the north and westernmost location where CSS occur. With the exception of Cayucos State Beach, owned and managed by the California Department of Parks and Recreation, we do not consider any lands in this region protected. Most of the region is in private ownership either as part of the developed community of Cayucos or as ranchlands used for active agriculture or grazing. Vegetation is predominantly grasslands with scattered patches of oak woodland and coastal sage scrub. Dominant soils include clays and loamy clays of the Cropley clay, Diablo and Cibo, and Los Osos-Diablo complex series. Rock outcrops are also present (USDA Web Soil Survey 2017). Information on distribution for CSS is very limited and based largely on anecdotal observations made by State Parks biologists (Walgren and Andreano, pers. comm. 2018; Roth and Tupen 2004: 4). Surveys in 2017 identified shells that may be within this population area (or very close) (EcoVision Partners 2017; 23). Old Creek: This area is approximately 1,570 acres (635 hectares) in size and includes Whale Rock Reservoir and its immediate surrounding watershed. The reservoir and its watershed (~1,400 acres [566 hectares]) are open space under the ownership and management of the City of San Luis Obispo. This area is fenced and allows only passive uses (e.g., hiking, fishing, bird watching). As such, it is, at least in the near-term, protected. Vegetation not part of reservoir operations and water distribution functions is predominantly nonnative grassland; however, small stands of oak woodland, chaparral and coastal sage scrub are present. Dominant soils include clays and clay rock outcrops of the Cropley, Diablo, Cibo, and Diablo-Lodo complex series (USDA Web Soil Survey 2017). Chorro shoulderband snails have been documented in this area; however, information on distribution is very limited and based largely on past anecdotal observations and the results of the 2016-2017 survey effort (Roth and Tupen 2004: 4; EcoVision Partners 2017: 23). Abundance data are limited to the two occurrences from the 2017 survey effort; relative abundance was very low (1-2 individuals) for each (see Figure 7). Willow Creek – Frontal Pacific Ocean: This area is approximately 4,050 acres (1,639 hectares in size and is found to the north and south of the Toro Creek area. Very little, if any, of this area is under formal protection. Residential development and urban uses in the community of Cayucos and northern City of Morro Bay occur in the westernmost portions of this area. Remaining acreage is in private ownership and consists predominantly of grassland, with patches of oak woodland, chaparral and coastal sage scrub. Limited riparian is present along Willow Creek. Dominant soils are clays and clay rock outcrops of the Cropley, Diablo, Cibo, Diablo-Lodo complex, and Los Osos-Diablo complex series (USDA Web Soil Survey 2017). Chorro shoulderband snails have been documented in this area; however, information on distribution is very limited and based largely on past anecdotal observations and the results of the 2016-2017 survey effort (EcoVision Partners 2017: 23). Abundance data are limited to the three occurrences from the 2017 survey effort where the relative abundance was medium (7-15 individuals) at two locations and high (16-25) at a single location (see Figure 7). Toro Creek: This area is approximately 3,780 acres (1,529 hectares) in size. None of the lands in this area are considered protected as most of the area is in private ownership as large-parcel ranchlands zoned for agriculture (e.g., grazing). Vegetation is predominantly grasslands with scattered patches of oak woodland, chaparral, and coastal sage scrub. Riparian habitat is present along Toro Creek. Dominant soils are clays, clay rock outcrops, and clay loams of the Cropley, Diablo, Cibo, and Los Osos-Diablo complex series (USDA Web Soil Survey 2017). An adult

shell was identified in this population area by Dwayne Oberhoff in 2015 (Dugan pers. comm. 2018) and Tupen (pers. comm. 2018) recalls individuals in the area as well. As such, we believe the population area is occupied by CSS; however, have no information on their distribution or abundance. Morro Creek: This area is approximately 6,335 acres (2,563 hectares) in size and located to the north and south of State Highway 41 that runs between the Cities of Morro Bay and Atascadero. Similar to the Toro Creek population area, we are not aware that any of these lands are under formal protection. Most are in private ownership as large-parcel ranchlands zoned for agriculture (e.g., grazing, avocado orchards). Vegetation is predominantly grasslands with scattered patches of oak woodland and coastal sage scrub. Riparian woodland occurs along Moro Creek. Dominant soils are clays, clay loams, and silty clay loams of the Cropley, Diablo, Cibo, Diablo-Lodo complex, Lodo, and Lopez series. Rock outcrops are also present (USDA Web Soil Survey 2017). Chorro shoulderband snails have been documented in this area; however, information on distribution is very limited and based largely on past anecdotal observations and the results of the 2016-2017 survey effort (EcoVision Partners 2017: 23). Abundance data are limited to one occurrence with a low (3-6 individuals) relative abundance (see Figure 7). Chorro Creek: At 21,835 acres (8,837 hectares), this is the largest of the population area polygons within the estimated distribution of CSS. Developed areas within this area include the California Men’s Colony, Dairy Creek Golf Course, Cuesta College, and Camp San Luis Obispo (California Army National Guard). With the exception of Chorro Creek Ecological Reserve (CCER) and portions of Chorro Creek Regional Park and the San Luis Obispo Wildlife Area, we believe that much of this area is unprotected. The majority of this area is large-parcel ranchlands zoned for agriculture (e.g., grazing, avocado orchards) in private ownership or part of Camp San Luis Obispo. Vegetation is predominantly grassland with scattered patches of oak woodland, chaparral, and coastal sage scrub. Several creeks (e.g., Chorro, San Bernardo, San Luisito, Stenner, Dairy, Pennington) traverse this area, some of which support riparian habitat. A diversity of soils are mapped for this area; however, still consist predominantly of clays, clay loams, and silty clay loams, with interspersed rock outcrops similar to the other units (USDA Web Soil Survey 2017). Chorro shoulderband snails have been documented in this area as part of surveys conducted at Camp San Luis Obispo prior to 2004 (e.g., Walgren in litt. 2002; Morro Group 2004). Information on distribution within this population area is largely limited to anecdotal observations; however, the species likely occurs on CCER as it has been detected in grasslands within the right-of- way for Highway 1 near CCER (CDFW in litt. 2018) and as part of the 2016-2017 survey effort (EcoVision Partners 2017: 23). Abundance data are limited to the seven occurrences identified in the 2017 survey effort: two occurrences with a relative abundance of very low (1-2 individuals), one occurrence at low (3-6 individuals), one at medium (7-15 individuals), and three at high (16-25 individuals) (see Figure 7). Morro Bay: This area is approximately 900 acres (364 hectares) in size and protected as part of Morro Bay State Park owned and managed by CDPR. Vegetation is predominantly grassland with scattered patches of oak woodland, chaparral, and coastal sage scrub. Dominant soils are clays, clay loams, and loams of the Cropley, Diablo, Cibo, Diablo-Lodo complex, Lodo, and Lopez series. Rock outcrops are also present (USDA Web Soil Survey 2017). Information on distribution for CSS is very limited and based largely on anecdotal observations made by State Parks biologists and includes one of the few observations of sympatry between MSS and CSS individuals (Walgren and Andreano, pers. comm. 2018). Chorro shoulderband snails were not

found in this area during the 2017 survey effort (EcoVision 2017: 23) (see Figure 7); therefore, abundance data are lacking. Los Osos Creek: This area is approximately 6,655 acres (2,693 hectares) in size and predominantly situated in the Los Osos Valley. The majority of this area is in private ownership as large-parcels zoned for agriculture (e.g., grazing, row crops) and, therefore, not considered protected. Vegetation is predominantly grassland with scattered patches of oak woodland, chaparral, and coastal sage scrub and riparian woodland along Los Osos Creek. As seen in the Chorro Creek units, a diversity of soil series are present although still made up predominantly of clays, clay loams, and silty clay loams, with interspersed rock outcrops (USDA Web Soil Survey 2017). Chorro shoulderband snails have been documented in this area, but information on distribution is very limited and based largely on past anecdotal observations and results of the 2016-2017 survey effort (EcoVision Partners 2017: 23). Abundance data are limited. The County observed CSS shells in association with drainage areas on the Giacommazi and Andre parcels in Los Osos Valley near the site of the current wastewater facility (Ballantyne pers. comm. 2018); 8 acres of the former site is deed-restricted to protect habitat values. Two occurrences were also identified in the 2017 EcoVision Partners survey effort: one with a relative abundance of very low (1-2 individuals) and the other of low (3-6 individuals) (see Figure 7). Upper San Luis Obispo Creek: This area is 8,795 acres (3,632 hectares) in size, some of which is protected from development activities as City of San Luis Obispo open space. Much of the central portion of the City of San Luis Obispo is within in this area as is the campus and outlying lands of California Polytechnic State University, San Luis Obispo. Vegetation in the undeveloped parts of this area is predominantly a combination of grassland, oak woodland, chaparral, and coastal sage scrub. Several unnamed intermittent creeks are present within this area. As with the previous two units, a diversity of intertwined soils series are present, though the dominant forms are clays, clay loams, and silty clay loams, with interspersed rock outcrops (USDA Web Soil Survey 2017). Chorro shoulderband snails are known from this area from surveys conducted at Bishop Peak (Tenera 2003a: 14, A4), California Polytechnic State University SLO (Walgren in litt. 2002), and development projects prior to 2004 (Tenera 2003b: 6-8). Information on distribution is limited and based largely on past anecdotal observations and results of the 2016-2017 survey effort (EcoVision Partners 2017: 23). Abundance data are limited to the four occurrences found during the 2017 survey effort: three occurrences with a relative abundance at very low (1-2 individuals) and the fourth estimated at low (3-6 individuals) (see Figure 7). Lower San Luis Obispo Creek: At approximately 15,815 acres (6,400 hectares), this area is the second largest within the distribution of CSS and contains lands protected as open space (e.g., Laguna Lake, Ferrini Ranch, Irish Hills Natural Reserve). Prefumo and San Luis Obispo Creeks, as well as numerous other unnamed intermittent drainages, are present in this area. Vegetation in the undeveloped parts of this area is predominantly a combination of grassland, oak woodland, chaparral, and coastal sage scrub. As with several previous units, a diversity of intertwined soils series are present; however, are still dominated by clays, clay loams, and silty clay loams, with interspersed rock outcrops (USDA Web Soil Survey 2017). Chorro shoulderband snails are known to occur in this area from surveys conducted on Bishop Peak (City of San Luis Obispo 2004: 4, 16, Figure 6, 22 ), the Unocal (now Chevron) Tank Farm (EcoAnalysts 2004: entire), and the 2016-2017 survey effort (EcoVision Partners 2017: 23); however, information on distribution is otherwise limited. Abundance data are limited to the six occurrences found during

the 2017 survey effort, three of which had a relative abundance of very low (1-2 individuals), two of which were low (3-6 individuals), and one was very high (>25 individuals) (see Figure 7).

Current Condition

Morro Shoulderband Snail Resiliency Factors influencing the ability of MSS to withstand stochastic events include abundance, habitat quality defined as presence of suitable habitat in a relatively intact landscape, and the likelihood that this habitat will persist into the future. Abundance and Distribution of Individuals: The level of survey effort throughout each of the six population areas that comprise the distribution of MSS is limited and variable. For this reason, it does not provide us with comparable quantitative estimates for abundance. For the most part, only limited surveys have been conducted in the six population areas, largely for the purpose of determining species presence relative to the need for take authorization. Portions of the North Morro Bay, Sand Spit, Morro Bay, East Los Osos, and South Los Osos population areas are within State Parks ownership but no comprehensive surveys or monitoring are conducted. Based on information from State Parks biologists, we know that State Park lands are occupied by MSS, but data on the level of species occupation or how those individuals may be faring is lacking (Walgren and Andreano pers. com. 2018). There have been no comprehensive surveys for MSS conducted on Morro Dunes Ecological Reserve, which occurs in the South Los Osos population area; however, CDFW assumes the reserve contains a robust population of the species (CDFW in litt. 2018). While we know the species is present on Morro Dunes Ecological Reserve (Service files; Stafford in litt. 2018), there is no evidence that the population is robust or that large numbers of individuals are present. Survey data gathered between 2012 and 2017 in habitat of similar quality and species composition seem to indicated greater MSS numbers in disturbed habitats than in native habitats (SWCA 2018: 5). Figure 8 depicts the age classes of MSS found beneath iceplant on the previously graded Midtown site. The Downtown and South Los Osos population areas have been subject to a greater level of survey effort associated with required monitoring for the installation of infrastructure to connect the community of Los Osos with its wastewater system. Between 2012 and 2017, over 2,200 individuals were found in these two population areas, with over 80 percent occurring in the Downtown Los Osos area (SWCA 2018: 5).

Figure 8: Various age classes of live MSS from beneath a nonnative iceplant patch, Midtown Site, Los Oso (County of San Luis Obispo 2015)

Habitat Quality and Configuration: Previously, we discussed those PCEs identified as part of the designation of critical habitat for MSS (Service 2001, entire). These elements are essential to the conservation of the species. An element not included in the critical habitat designation but now recognized as essential is sufficient seasonal moisture necessary to sustain an environment that supports feeding and reproductive activities. In our designation of critical habitat, we note the potential for improvement of habitat in the critical habitat units through restoration or improved management (e.g., removal of nonnative plant species) (Service 2001: 9236). Based on data collected as part of the Los Osos Wastewater Project monitoring efforts, we know that individuals can persist (and reproduce) in nonnative and ruderal habitats if a suitable microclimate is present (SWCA 2018: 5; Figure 8) and vegetation disturbance is not frequent. The quality of habitat does not appear to be as simple as the presence of coastal dune/sage scrub plant species underlain by Baywood Fine Sand soils. Habitat Persistence: Long-term resiliency of a population is dependent on whether or not suitable habitat is likely to persist in the long-term. Habitat loss and degradation are threats that affect both individual and population persistence. Individuals/populations in habitat not protected and managed to reduce or eliminate threats are at risk of mortality or extirpation. Currently, there is not active management against threats for most of those lands within the estimated distribution of MSS. To summarize the overall current condition of MSS resiliency in each of the six population areas, we identified each population area as being one of three categories (high, moderate, and low) based on abundance, habitat quality, and habitat protection using the schema in Table 1. For each characteristic of resiliency, a condition category of high scored 3, medium scored 2, and low scored 1. In determining the summary category, we weighted each factor equally, dividing by the total number of factors. We rounded intermediate scores to the nearest whole number. We

38 qualitatively define an overall high resiliency score as the individuals within the population area having a high probability of persistence, an overall moderate resiliency score as the individuals within the population area having a medium probability of persistence, and an overall low resiliency score as the individuals within the population area having a low probability of persistence.

Table 1. MSS characteristics used to create condition categories in Table 2 Condition Protected Abundance Habitat Quality category Habitat

Largely intact and MSS commonly observed High connected; all PCEs 51-100% over time; reliably present currently present

Somewhat degraded; more MSS often observed over Moderate than one PCE currently 21-50% time; known to be present present MSS rarely observed or Highly degraded and Low known to be present in low fragmented; only one PCE 0-20% numbers over time. currently present

As shown in Table 2 below, two population areas currently exhibit an overall high resiliency, four areas have moderate resiliency, and one area demonstrates low resiliency (Figure 9).

Table 2. Current resiliency of MSS population areas

Population Abundance Habitat Quality Protected Habitat Overall

North Morro Bay Moderate High Moderate Moderate

Sand Spit Moderate High High High

Morro Bay Low Low Low Low

East Los Osos Moderate Moderate Low Moderate

Downtown Los High Low Low Moderate Osos

South Los Osos Moderate High High High

Figure 9. Current Resiliency of MSS Population Areas

Representation Representation is demonstrated by the presence of MSS individuals throughout its limited distribution. All population areas are extant; however, resiliency across those areas varies. The most resilient areas, South Los Osos and Sandspit, occur in the southern portion of the distribution and is contiguous with large tracts of habitat protected within Montaña de Oro State Park. Resiliencies in the moderate range are found in the northernmost and central portions of the distribution and include North Morro Bay, East Los Osos, and Downtown Los Osos. We consider the last of the Downtown Los Osos population areas to have moderate resiliency solely based on the documented abundance of individual snails (see Figure 5). The Morro Bay population area demonstrates a low resiliency; however, loss of this population area would not likely affect species representation because numbers of individuals are likely very low and it is generally isolated from the other five population areas, providing little in terms of adaptive capacity for the species. Loss of the more central, moderate resiliency population areas would likely have a much greater impact on representation. Redundancy Historically, based on the mapping for Baywood Fine Sand soils, it is likely that MSS population areas were once contiguous throughout the species’ distribution. Currently, community development is what primarily separates population areas. We know MSS are extant at some level throughout the distribution identified by Roth and Tupen (2004: Figure 1) and depicted on Figure 5. The distribution of the species’ unifying habitat characteristic, Baywood Fine Sand substrate, has not changed and is still present even within developed areas. Resiliency of the population areas within the MSS distribution has changed over time due to loss, degradation, and/or fragmentation of native habitat. Prolonged and/or more intensive droughts, increased wildfire frequency and/or intensity, and localized flooding are events that could affect MSS at the catastrophic scale. Against a backdrop of climate change expected to exacerbate these events, population areas with low or moderate resiliency are at greater risk of local extirpation if such a catastrophic event were to occur, which would reduce the overall redundancy of the species. Current Condition Summary The resiliency of the MSS population areas within its distribution has changed over time due to loss, degradation, and/or fragmentation of native habitat. Currently, only two population areas demonstrate a level of resiliency considered high, with three (half) of the population areas in the northern and central-most portions of the species’ distribution demonstrating moderate resiliency. The remaining population area in the north-central portion of the distribution has an estimated resiliency of low, largely based on the uncertainty about species presence/abundance within it. The loss of this low resiliency population area would not likely affect species representation across the remaining portion of range numbers of individuals are likely very low and it is generally isolated from the other five population areas. For redundancy, we consider those population areas with low or moderate resiliency to be at a greater risk of local extirpation if a catastrophic event were to occur, which has the potential to jeopardize species persistence. Key Uncertainties Our MSS analysis includes the following uncertainties:

• Are the population areas, which are composed of many occurrences and likely many populations, delineated in Figure 5 biologically appropriate units for viability analysis? • Should abundance, habitat quality, and habitat protection be equally weighted and, if so, are these useful metrics to describe the probability of persistence of MSS in each population area? • Are the available survey data an appropriate proxy for abundance across the range? • Can the breadth of adaptive diversity within the species be measured by assessing its presence in delineated population areas?

Chorro Shoulderband Snail Resiliency Factors influencing the ability of CSS to withstand stochastic events include abundance, habitat quality defined as presence of suitable habitat in a relatively intact landscape, and the likelihood that this habitat will persist into the future. Abundance and Distribution: The level of survey effort throughout the distribution of CSS is extremely limited. As noted, formal surveys were not conducted between 2004 and 2016. Information on species presence until 2017 is largely from presence-absence surveys conducted prior to July 2004 and incidental observations thereafter. In 2017, EcoVision Partners conducted surveys at 60 sites within west-central San Luis Obispo County. The survey methodology was adapted from survey protocols for terrestrial mollusks used for the Northwest Forest Plan (Dunk, Zielinksi, and Preisler 2004: entire), Methods consisted of two 20-minute habitat searches: a Feature Search and an Area Search. The Feature Search involved an intensive survey of a particular habitat feature thought to provide the most likely habitat for terrestrial mollusks on the site. An Area Search followed and entailed a more wide-ranging search of various possible habitat features in the surrounding area. Survey site selection was constrained in many areas by lack of access to potential habitat features on private property. Survey locations included 18 historic CSS occurrences, 29 new sites within the species distribution depicted in Roth and Tupen (2004: 4), and 13 new sites in likely suitable habitat outside of the Roth and Tupen (2004: 4) projected range. Live CSS and/or shells/shell fragments were present at 26 of the survey locations, including 14 of the historic sites and 12 new locations (EcoVision Partners 2017: 20, Figure 4). Use of a consistent, time-constrained search effort between all sites provided a general indication of the relative abundance of CSS at the surveyed sites. Demonstration of abundance used a range of very low (1-2 observations) to very high (>25 observations) (EcoVision 2017: 26. Relative abundance was highest at sites within public open space areas and military reservations and lower at sites within roadside rights-of-way. Habitat Quality: In the 2017 survey effort, those areas where species presence was indicated by live snails, shells, or shell fragments included the following habitat features: rock outcrops (8), ruderal roadsides (8), grasslands (4), drainage swales (3), stands of coastal scrub (1), seep areas (1), and patches of iceplant (1). Plant communities within these habitat features were coastal scrub (16), serpentine endemic (4), annual grassland (3), annual and perennial grassland (2), and beach bluff (1). Plant species associates within these communities, specifically the plant species in which CSS presence was detected, included coyotebush, California sagebrush, fennel

(Foeniculum vulgare), Mission fig, morning glory (Calystegia spp.), sawtooth goldenbush (Hazardia squarrosa), iceplant, and alkali heath (Frankenia salina). Within annual/perennial grassland communities, CSS do not appear to be associated with any particular plant species or occur uniformly throughout habitat areas; rather they tend to occur in association with features such as rock outcrops within the overall habitat area (Dugan, pers. comm. 2018). Habitat Persistence: Long-term resiliency of a population is dependent on whether or not suitable habitat is likely to persist into the future. Habitat loss/degradation and lack of management can affect population persistence. When habitat is unprotected and/or managed, individuals or populations present are at a moderate and continuous risk of mortality (individuals) or extirpation (populations). As an unregulated species, this risk is greater for CSS. Examples of protected lands within the distribution of CSS include nature preserves, ecological reserves, open space areas, and lands owned and managed by a land conservancy. As with MSS, to summarize the overall current conditions for CSS resiliency in each of the ten population areas, we identified each population area as being one of three categories (high, moderate, and low) using the schema in Table 3, based on relative abundance from the results of the 2017 study (EcoVision Partners 2017; 26), habitat quality, and habitat protection. Again, a high condition category for each resiliency characteristic scored 3, medium scored 2, and low scored 1. In determining the summary category, we weighted each factor equally, dividing by the total number of factors where a condition was provided and did not include unknowns in the denominator. We rounded intermediate scores to the nearest whole number. We qualitatively define an overall high resiliency score as the individuals within the population area having a high probability of persistence, an overall moderate resiliency score as the individuals within the population area having a medium probability of persistence, and an overall low resiliency score as the individuals within the population area having a low probability of persistence.

Table 3. CSS characteristics used to create condition categories in Table 4

Condition Protected Relative Abundance Habitat Quality category Habitat

At least 1 site* ranked Intact areas of suitable habitat High 51-100% High or Very High contiguous with other areas of same At least 1 site* ranked Habitat degraded by anthropogenic Moderate Moderate or 2 or more features/fragmentation but native 21-50% sites ranked Low species and suitable habitat extant

Less than 2 sites* ranked Habitat much degraded; few native Low Low or any sites ranked species or areas of contiguous 0-20% Very Low suitable habitat

Unknown Unknown Unknown Unknown *survey location from 2017 EcoVision Partners report

Table 4 and Figure 10 below reveal for CSS nine areas at moderate resiliency and one area at low resiliency.

Table 4. Current Resiliency of CSS population areas

CSS Population Relative Habitat quality Protected habitat Overall Area Abundance

Cayucos Creek Unknown Moderate Low Moderate

Old Creek Low Moderate High Moderate

Willow Creek High Moderate Low Moderate Toro Creek Unknown High Low Moderate Morro Creek Low High Low Moderate Chorro Creek High High Low Moderate

Morro Bay Unknown Moderate High High Los Osos Creek Low High Low Moderate Upper San Luis Moderate Moderate Low Moderate Obispo Creek Lower San Luis High Moderate Low Moderate Obispo Creek

Figure 10. CSS Population Areas: Current Resiliency

Representation While abundance information is not available for the Cayucos Creek and Morro Bay population areas, individuals are present at some level in these areas such that the species is considered represented in all population areas within its historic distribution. Nine out of ten population areas exhibit a moderate score. Redundancy The population areas for CSS are substantial in area, contain suitable habitat, and occupied such that we do not anticipate the effects of catastrophic events, such as prolonged and/or more intensive drought, increased wildfire frequency and/or intensity, and/or localized flooding, to reduce redundancy for the species. Current Condition Summary The resiliency analysis of CSS population areas reveals a single population area at high resiliency and nine areas at moderate resiliency. While abundance information is not available for the Cayucos Creek, Toro Creek and Morro Bay population areas, individuals are present at some level in these areas such that the species is considered represented in all population areas within its historic distribution. The population areas for CSS are substantial in size, contain substantial amounts of seemingly suitable habitat, and likely occupied such that we do not anticipate the effects of catastrophic events to jeopardize species persistence. Key Uncertainties Our CSS analysis includes the following uncertainties: • Are the population areas delineated in Figure 6, which are composed of many occurrences and likely many populations, biologically appropriate units for viability analysis? • Should abundance, habitat quality, and habitat protection be equally weighted and, if so, are they useful to describe the probability of persistence of MSS in each population area? • Is ignoring “unknowns” in our resiliency schema appropriate? • Are available survey data an appropriate proxy for abundance across the range? • Can we measure the breadth of adaptive diversity within the species by assessing its presence in delineated population areas?

CHAPTER 5 – FUTURE CONDITION We have considered what MSS and CSS need for viability and the current condition of those needs. We now consider what the species’ future conditions are likely to be using future scenarios. We developed these scenarios to capture a range of plausible conditions. Then, continuing with the concepts of resiliency, redundancy, and representation, we estimate the potential range of future viability of each species under each scenario. While the recovery plan states a persistence time frame of 50 years (Service 1998: 40), we selected a timeframe of 30 years due to Scenario 2, which envisions full implementation of a regional conservation strategy expected to take 25 years to complete. We then applied this same timeframe to the scenarios for CSS.

Morro Shoulderband Snail

Future Scenario 1: Current conditions for 30 years with no additional conservation efforts (status quo) In this future scenario, we presume the current conditions for MSS continue for 30 years with no additional conservation efforts; that is, the current conditions continue into the future and include an increasing likelihood of prolonged or more intensive drought, wildfire frequency and/or intensity, and localized flooding associated with continued climate change. This future scenario anticipates no additional conservation efforts (e.g., land acquisition, increased level of management) would be implemented for the species. Resiliency Long-term resiliency of a population is dependent on whether suitable habitat is likely to persist in the long-term. Habitat loss and degradation are threats that affect both individual and population persistence. In this scenario, we assume that no population areas will receive additional conservation actions or protection. Therefore, we assume that overall, habitat quality will decrease throughout the species’ distribution in the next 30 years because of continued development that will likely result in increased habitat fragmentation and an increase in the presence of nonnative species. Where habitat quality is high, it is expected to become moderate; where habitat quality is moderate, it is expected to become low. If habitat quality is already low, it will remain low. We also assume that abundance will decrease where habitat quality was already low. We calculated overall resiliency scores again using the same methodology as for the current condition. Condition categories that changed from current to any future scenario are in shown in bold in the table below. Under this scenario, the overall condition of four population areas will decrease. East Los Osos and Downtown Los Osos will go from currently being in moderate condition to being in low condition in the future as the habitat quality in East Los Osos declines and the abundance in Downtown Los Osos declines. Sandspit and South Los Osos population areas change from high resiliency to moderate resiliency with a decrease in habitat quality from high to moderate (Table 5, Figure 11).

Table 5. Resiliency of MSS population areas under current conditions for 30 years with no additional conservation efforts (status quo)

Population Area Abundance Habitat Quality Protected Habitat Overall

North Morro Bay Moderate Moderate Moderate Moderate Sand Spit Moderate Moderate High Moderate

Morro Bay Low Low1.33 Low Low

East Los Osos Moderate Low Low Low Downtown Los Moderate Low Low Low Osos

South Los Osos Moderate Moderate High Moderate

Figure 11. MSS Populations Areas: Future Scenario 1 (for 30 years with no additional conservation efforts)

Representation We expect representation, as presence of MSS individuals, to continue in all six of the population areas in its overall distribution; however, resiliency would decrease from moderate to low in two population areas (Downtown Los Osos and East Los Osos) and from high to moderate in two population areas (Sandspit and South Los Osos). Three population areas would now be in an overall condition of low and individuals in half of the range could be at risk of extirpation. If this were to happen, the representation and adaptive capacity of the species could be substantially reduced. Redundancy Having more population areas in the low resiliency category, defined as individuals within the population area having a low probability of persistence, puts overall species redundancy at risk. This suggests that more population areas are at high risk of extirpation decreasing the overall species ability to withstand catastrophic events. Into the future, the effects of prolonged or more intensive drought, increased wildfire frequency and/or intensity, and localized flooding associated with persistent climate change will continue. With low resiliency in 50 percent of the population areas, individuals in half of the range may be at risk of extirpation, which would reduce overall redundancy and decrease the ability of the species to withstand future catastrophic events.

Future Scenario 2: Current conditions for 30 years with limited additional conservation efforts In this future scenario, we presume the current conditions for MSS continue for 30 years, including the likelihood of prolonged or more intensive drought, wildfire frequency and/or intensity, and localized flooding associated with anticipated continuing climate change, along with conservation measures implemented only in a limited portion of the species’ distribution. In this scenario, the limited nature of the conservation actions is related to our expectation that almost all would occur in one population area (South Los Osos) as part of the County’s implementation of the Los Osos Habitat Conservation Plan (LOHCP), a regional plan currently in development that proposes MSS as a covered species. In this plan, approximately 70 percent of the conservation program would consist of enhanced habitat management in the Bayview Unit of CDFW’s Morro Dunes Ecological Reserve (MDER), the majority of which is located in the South Los Osos population area. The remaining 30 percent of the conservation program (habitat restoration and habitat acquisition/protection) could occur in portions of MDER; however, would most likely focus on smaller parcels on non-State Park lands in the Sand Spit and East Los Osos population areas. Implementation of the LOHCP would disproportionately affect MSS in the Downtown Los Osos population area, as this is where most of the development would occur. It is also where most of the documented individuals occur. As this area is the single one for which we have reliable data on species numbers, loss of a substantial number of individuals could disproportionately affect overall population numbers. The LOHCP is currently in the final draft stage and the requested permit term is 25 years. As such, there is uncertainty regarding the timing of implementation for conservation actions. Absent additional conservation actions within the other population areas except South Los Osos, habitat quality would continue to decline, similar to what we expect in the first scenario. The South Los Osos population area is anticipated to see an increase in abundance commensurate with the conservation actions effected as part of LOHCP implementation.

Under this scenario, the overall condition of three population areas will decrease over the current condition. East Los Osos and Downtown Los Osos will go from currently being in moderate condition to being in low condition in the future as the habitat quality declines in East Los Osos and the abundance declines in Downtown Los Osos due to increased development and a continued low level of protection. Resiliency in the Sandspit population area will decrease from high to moderate due to decline in habitat quality. Abundance in the South Los Osos population area would increase; resiliency would remain high (Table 6; Figure 12).

Table 6. Resiliency of MSS population areas under current conditions for 30 years with limited additional conservation efforts Protected Population Abundance Habitat Quality Overall Habitat

North Morro Bay Moderate Moderate Moderate Moderate

Sand Spit Moderate Moderate High Moderate

Morro Bay Low Low Low Low

East Los Osos Moderate Low Low Low

Downtown Los Moderate Low Low Low Osos

South Los Osos High High High High

Figure 12. MSS Population Areas: Future Scenario 2 (30 years, limited additional conservation efforts)

Representation Representation of MSS would continue throughout its overall distribution; however, under this scenario, resiliency would decrease from moderate to low in two population areas, resulting in half of the population areas in the low category. Individuals in half of the range could then be at risk of extirpation. If this were to happen, representation and adaptive capacity of the species could be substantially reduced. Redundancy Having more population areas in the low resiliency category, defined as individuals within the population area having a low probability of persistence, puts overall species redundancy at risk because it suggests that more population areas are at high risk of extirpation decreasing the overall species ability to withstand catastrophic events. Into the future, the effects of prolonged or more intensive drought, increased wildfire frequency and/or intensity, and localized flooding associated with persistent climate change will continue. With low resiliency of three (50 percent) populations, individuals in half of the range may be at risk of extirpation, which would reduce overall redundancy and decrease the ability of the species to withstand future catastrophic events.

Future Scenario 3: Current conditions for 30 years with major additional conservation efforts In this future scenario, we expect the current conditions for MSS to continue for 30 years including the likelihood of prolonged or more intensive drought, wildfire frequency and/or intensity, and localized flooding associated with anticipated continued climate change, but with additional conservation measures throughout the species’ distribution. This scenario envisions full implementation of the LOHCP conservation program as well as active management (e.g., invasive plant species removal, habitat restoration) for MSS within currently protected but generally unmanaged lands throughout the distribution of the species, as well as limited habitat protection through acquisition and subsequent management. With full implementation of the LOCHP, we expect MSS abundance to decrease in downtown Los Osos as more of the area develops and the South Los Osos population area would experience an increase in abundance associated with the conservation actions in the HCP. California State Parks owns, manages, and operates Montaña de Oro State Park, Morro Bay State Park, and Morro Strand State Beach. Due to staffing and funding shortfalls, they are currently not able to manage much of their lands except in a general sense. This has meant there have not been scale habitat restoration actions. If increased and consistent funding were to become available to State Parks, focused conservation actions for MSS in specific portions of Montaña de Oro and Morro Bay State Parks, as well as Morro Strand State Beach, could be implemented. These actions would likely increase native habitat quality in those population areas included in these park units (e.g., South Los Osos and Sand Spit, East Los Osos, and North Morro Bay, respectively). Where habitat quality was already high in these population areas, we expect that abundance will increase under this scenario. Under this scenario, the overall condition of Downtown Los Osos would decrease and the overall condition North Morro Bay would increase. (Table 7, Figure 13).

Table 7. Resiliency of MSS population areas under current conditions for 30 years with major additional conservation efforts

Population Area Abundance Habitat Quality Protected Habitat Overall

North Morro Bay High High Moderate High Sand Spit High High High High Morro Bay Low Low Low Low

East Los Osos Moderate High Low Moderate Downtown Los Moderate Low Low Low Osos

South Los Osos High High High High

Figure 13. MSS Population Areas: Future Scenario 3 (30 years with major additional conservation efforts)

Representation In this scenario, representation of MSS would continue in all of the population areas in the distribution of the species. With the exception of Downtown Los Osos and Morro Bay, we expect improved habitat conditions from the conservation actions taken on protected lands within the remaining population areas in addition to implementation of the LOHCP conservation strategy (e.g., enhanced management, restoration, habitat protections). Having three population areas in the high resiliency category suggests that the overall representation and adaptive capacity of the species is more likely to continue into the future. Redundancy Having more population areas in higher resiliency categories, defined as individuals within the population area having a higher probability of persistence, increases species redundancy because it suggests that population areas are at lower risk of extirpation increasing the overall species ability to withstand catastrophic events. Into the future, the effects of prolonged or more intensive drought, increased wildfire frequency and/or intensity, and localized flooding associated with persistent climate change will continue. Having three population areas in the high resiliency category could increase the ability of the species to withstand future catastrophic events.

Chorro Shoulderband Snail Given that there is currently no regulation of CSS, the plausible future scenarios for this species are different than for MSS. The first plausible future scenario is that current conditions continue into the future for 30 years including the likelihood of prolonged or more intensive drought, wildfire frequency and/or intensity, and localized flooding associated with anticipated continued climate change. The second plausible future scenario involves an intensification of agricultural uses on agriculturally-zoned lands with the same effects of anticipated climate change. Neither scenario anticipates the implementation of any additional conservation efforts for the species.

Future Scenario 1: Current conditions for 30 years with no additional conservation efforts (status quo) In this future scenario, we presume the current conditions for CSS continues for 30 years, with no additional conservation efforts; that is, the current conditions continue into the future for 30 years, including the likelihood of prolonged or more intensive drought, wildfire frequency and/or intensity, and localized flooding associated with anticipated continued climate change. There would be no additional conservation efforts. Because habitat within the distribution of the species has not been set aside and protected specifically for CSS, we expect future habitat conservation to occur in a fashion similar to how it has over the past 30 years (i.e., in accordance with implementation of City of San Luis Obispo and County of San Luis Obispo general plans). The Land Conservancy of San Luis Obispo is an organization that has facilitated acquisition and management of conservation lands within the range of the species and we expect them to continue to do so in a similar fashion into the future. Several of the existing preserves and open space lands set aside are within the City of San Luis Obispo. We expect additional habitat protection to occur in the two southernmost population

areas, Lower San Luis Obispo Creek and Upper San Luis Obispo Creek, on lands zoned as conservation/open space or as mitigation for development in areas zoned for residential and other uses. Additionally, in contrast to MSS that are most often found in plant communities found on generally flat or gently sloping terrain, CSS occur in more varied topographies and are most often associated with features (e.g., rock outcrops, crevices, boulders, fence posts) within the surrounding plant community than throughout the community itself. These areas are not typically disturbed as part of site development and so could serve as refugia for the species. In addition, because habitat within the distribution of the species has not been set aside and managed specifically for CSS, we do not expect habitat quality for CSS to change for the better or worse due to continued lack of protection in the future. As seen in Table 8 below, this scenario would likely result in little change to the species overall resiliency (Figure 13).

Table 8. Resiliency of CSS under current conditions for 30 years with no additional conservation efforts

Relative Habitat Protected Population Overall Abundance quality habitat

Cayucos Creek Unknown Moderate Low Moderate

Old Creek Low Moderate High Moderate

Willow Creek High Moderate Low Moderate

Toro Creek Unknown High Low Moderate

Morro Creek Low High Low Moderate

Chorro Creek High High Low Moderate

Morro Bay Unknown Moderate High High

Los Osos Creek Low High Low Moderate

Upper San Luis Moderate Moderate Moderate Moderate Obispo Creek Lower San Luis High Moderate Moderate Moderate Obispo Creek

Figure 14. CSS Population Areas: Future Scenario 1 (30 years with no additional conservation efforts)

Representation While abundance information is not available for the Cayucos Creek, Toro Creek and Morro Bay population areas, we expect individuals to be remain present at some level in these areas such that the species is considered represented in all population areas within its historic distribution. Nine of the 10 population areas exhibit moderate resiliencies, which is the same as the current condition. Redundancy The population areas for CSS are substantial in size, contain substantial seemingly suitable habitat, and occupied such that we do not anticipate the effects of catastrophic events, such as prolonged and/or more intensive drought, increased wildfire frequency and/or intensity, and/or localized flooding, to reduce redundancy for the species.

Future Scenario 2: Intensification of agricultural uses over current conditions for 30 years In this scenario we expect agricultural activities to intensify (e.g., conversion of grazing lands to row crops, avocado orchards, cannabis cultivation, vineyards) in the next 30 years across those areas which are zoned for agriculture. As in CSS future scenario 1, we expect future habitat conservation to occur in a fashion similar to how it has over the past 30 years in accordance with implementation of City of San Luis Obispo and County of San Luis Obispo general plans, such that habitat protection will increase in the Upper and Lower San Luis Obispo Creek population areas. Currently, much of the central and northern portions of the overall CSS distribution is grazing lands although row crops can be found in the valley areas (e.g., in the Los Osos Creek and Upper San Luis Obispo Creek areas) and avocado orchards are present in the Willow Creek area. The County of San Luis Obispo has seen an intensification of agricultural uses in the last 30 years, much of it related to the wine industry, which results in the conversion of open grazing land to vineyards. Much of this has occurred in the North County, outside of the range for CSS, but also in areas south of the City of San Luis Obispo in and around the Edna Valley, which has its own wine appellation. Typically, topographic features such as rock outcrops remain in place. If occupied, these areas would likely function as refugia for CSS however, individuals would be isolated on these features away from any potential dispersal areas and vulnerable to the effects of agricultural activities such as pesticide use. A change in form of agriculture is not typically a discretionary action and, therefore, not subject to environmental review. Even in those instances where there could be a discretionary action associated with the new type of agricultural use (e.g., wine-tasting room), as CSS is not regulated, impacts to the species would not be evaluated. We do not know how much agricultural land within the distribution of CSS is likely to change from grazing to a more intensified use, but it is relatively certain that change will occur in most of the population areas zoned for agriculture in the next 30 years. We therefore assume that habitat quality will decrease in five of the ten population areas due to the intensification of agriculture over the next 30 years. Lands in Cayucos Creek, Willow Creek, Morro Creek, Chorro Creek, and Los Osos Creek are generally zoned for agriculture and we therefore expect that overall habitat quality will decrease for CSS in those population areas under this scenario.

As seen in Table 9 below, this scenario would likely result in three changes to the species overall resiliency, as most areas retain moderate resiliency. We expect Cayucos Creek, Morro Creek and Los Osos Creek to exhibit a reduced resiliency going from moderate to low resiliency under this scenario (Figure 14).

Table 9. Resiliency of CSS regions with intensification of agricultural uses over 30 years Relative Habitat Population Protected habitat Overall Abundance quality

Cayucos Creek Unknown Low Low Low

Old Creek Low Moderate High Moderate

Willow Creek High Low Low Moderate

Toro Creek Unknown High Low Moderate

Morro Creek Low Moderate Low Low

Chorro Creek High Moderate Low Moderate

Morro Bay Unknown Moderate High High

Los Osos Creek Low Moderate Low Low Upper San Luis Moderate Moderate Moderate Moderate Obispo Creek Lower San Luis High Moderate Moderate Moderate Obispo Creek

Figure 15. CSS Population Areas: Future Scenario 2 (30 years, intensified agriculture)

Representation We expect there would still be species representation in all population areas, although we would expect the population areas with low resiliency (Cayucos Creek, Morro Creek, and Los Osos Creek) to be subject to a greater risk of localized extirpation, which could put the species representation in these areas at risk. Redundancy The distribution of the species is not likely to change in 30 years, although CSS numbers may decrease in response to reduced habitat quality. The low resiliency scores for Cayucos Creek, Morro Creek, and Los Osos Creek under this scenario reflect unknown and low abundance and low level of protected habitat in Cayucos Creek and a decrease in habitat quality due to agricultural intensification in Morro Creek and Los Osos Creek. Even considering reduced potential resiliencies, the population areas for CSS are substantial in size, contain substantial amounts of seemingly suitable habitat, and occupied such that we do not anticipate the effects of catastrophic events, such as prolonged and/or more intensive drought, increased wildfire frequency and/or intensity, and/or localized flooding, to reduce redundancy for the species.

CHAPTER 6 – SYNTHESIS

This chapter provides a synthesis of the results of our current and future analyses and discusses the consequences for future viability of MSS and CSS. We assessed the viability of both species by evaluating the ability of the species to maintain a sufficient number and distribution of healthy populations to withstand environmental stochasticity (resiliency), changes in its environment (representation), and catastrophes (redundancy). The final 1994 listing rule states that the banded dune snail “formerly occupied primarily coastal dune scrub habitat along approximately 8 km (5 mi) of dunes extending onto the Morro sand spit, at Baywood Park, San Luis Obispo, sites between Morro Bay and Cayucos, and probably along Morro Bay in the vicinity of Cuesta-by-the-Sea.” Populations are separated now primarily by development. Surveys by Roth in 1985 resulted in the discovery of only six live individuals (MSS) although empty shells were numerous. He speculated that at that time there might have been as few as several hundred individuals in the remaining population. At the time of listing, we thought CSS was extinct. Since time of listing, CSS occur at various levels of occupancy throughout their historic range, which extends from North Morro Bay south and inland to the City of San Luis Obispo. Most of these observations are incidental as there were no focused surveys for this species after until the EcoVision Partners surveys in 2017. Threats influencing the viability of Morro shoulderband snail populations at the time of listing were urban development, off-road vehicle activity, nonnative vegetation (referred to as invasive species in this proposed rule), parasitoids, and competition from brown garden snails, all of which were exacerbated by effects associated with small population size and drought conditions (59 FR 64613). Since the time of listing, we have determined that some of these threats are no longer affecting the species, particularly off-road vehicle activity, brown garden snails, parasitoids, and controlled burns (Service 2006, pp. 11–15). Currently, the most common threat to both species is the implementation of land use practices that eliminate, reduce, fragment, and/or modify habitat used by the species. Climate change likely exacerbates the severity of threats.

Overall, our analyses indicate that the current viability of MSS has likely improved to some degree since time of listing due to the existence of substantially more individuals than previously thought and conservation efforts (predominantly in the form of land acquisition). The species still has the potential to decline in the future depending on the potential for development and level of continued conservation efforts. Our analyses indicate that the current viability of CSS is likely similar to that at time of listing (given that the species was not extinct and is not regulated) and its viability is projected to stay the same or decrease slightly, depending on future land use change in San Luis Obispo County. We discuss the magnitude and the implications of potential changes in resiliency, representation, and redundancy for each species below.

Morro Shoulderband Snail

Resiliency

Resiliency is the ability to sustain populations in the face of environmental variation and transient perturbations. For MSS to remain healthy and maintain viability, its populations or some portion thereof need to be resilient to the normal range of environmental variation. We evaluated factors influencing the ability of MSS to withstand stochastic events by population area, including abundance (as available) and distribution of individuals, habitat quality and configuration, and the likelihood that suitable habitat will persist into the future. We then calculated an overall current condition for each population area using these factors and forecasted the condition of these factors into the future for 30 years under three different future scenarios (Table 10). The future scenarios attempt to encompass the range of plausible possibilities for each population area over the next 30 years. First, we forecasted the condition of each population area under the status quo, with continued climate change effects and no additional conservation efforts for the species (Status Quo). Second, we forecasted the condition of each population area if the LOHCP, a regional plan currently in development that proposes MSS as a covered species, were to be implemented as this would result in additional conservation actions in one population area and continued climate change effects (Limited Conservation). Finally, we forecasted full implementation of the LOHCP conservation program, active management for MSS within currently protected but generally unmanaged lands throughout the distribution of the species, and additional habitat protection through acquisition and subsequent management (Major Conservation).

Table 10. Summary of MSS Resiliency: Current and Future Condition by Population Area Future Future Future MSS Population Current Scenario: Scenario: Scenario: Area Condition Limited Major Status Quo Conservation Conservation North Morro Moderate Moderate Moderate High Bay Sand Spit High Moderate Moderate High Morro Bay Low Low Low Low East Los Osos Moderate Low Low Moderate Downtown Los Moderate Low Low Low Osos South Los Osos High Moderate High High

Representation Representation is the ability to adapt to changing environmental conditions; it is the species evolutionary capacity or flexibility. We assume that maintaining representation of healthy populations across the diversity of MSS habitat types or ecological gradients within its distribution will likely conserve the relevant genetic diversity and adaptive capacity associated with persisting across these habitat types.

Currently, species presence in all population areas demonstrates representation. The low resiliency population areas occur in the center of the species distribution, suggesting that individuals in the Morro Bay population area are at greater risk of extirpation and thus loss of representation. In the future, with the status quo, we project two additional population areas towards the center and east of the range to be in the low category suggesting that the entire central portion of the range would be at risk of extirpation without major conservation, leaving representation of the species only in the periphery of its range.

Redundancy Redundancy is the ability of a species to withstand catastrophic events. Redundancy protects a species against the unpredictable and highly consequential events for which adaptation is unlikely. Morro shoulderband snails need multiple resilient population areas distributed throughout its extremely limited distribution to provide for redundancy. Historically, based on the mapping for Baywood Fine Sand soils, it likely that MSS population areas were once contiguous throughout the species’ distribution. Community development primarily separates these population areas. Low resiliency, disconnected population areas, currently and in the future, suggest that the species is vulnerable to loss of redundancy in some areas due to stochastic events and thus the species would be more susceptible to catastrophic events. An increase in the number of low resiliency population areas in two of the three future scenarios suggests that redundancy could be compromised in the future unless major conservation actions are undertaken. Prolonged and/or more intensive droughts, increased wildfire frequency and/or intensity, and localized flooding are events that could affect MSS at the catastrophic scale. Against a backdrop of climate change expected to exacerbate these events, reduced redundancy could put the species at risk if a catastrophic event were to occur.

Chorro Shoulderband Snail

Resiliency Resiliency is the ability to sustain populations in the face of environmental variation and transient perturbations. For CSS to remain healthy and maintain viability, its populations or some portion thereof need to be resilient to the normal range of environmental variation. We evaluated factors influencing the ability of CSS to withstand stochastic events by population area; including abundance and distribution of individuals, habitat quality and configuration, and the likelihood that suitable habitat will persist into the future. The level of survey effort throughout the distribution of CSS is extremely limited. Between 2004 and 2017, there were no focused surveys. Information on species presence until 2017 relies largely on presence-absence surveys conducted prior to July 2004 and incidental observations thereafter. In 2017, surveys were conducted in limited areas but throughout its distribution. Survey site selection was constrained in many areas by lack of access to potential habitat on private property. We used these data about the factors influencing the resiliency of CSS to calculate an overall current condition for each population areas and forecasted the condition of these factors into the future for 30 years under two different future scenarios (Table 11).

The future scenarios attempt to encompass the range of plausible possibilities for each population area over the next 30 years. First, we forecasted the condition of each population area under the status quo, with continued climate change effects and habitat conservation proceeding in a fashion similar to how it has over the past 30 years in accordance with implementation of City of San Luis Obispo and County of San Luis Obispo general plans (Status Quo). Second, we forecasted the condition of each population area under status quo, but with the additional effects of intensification of agriculture in those areas zoned for agricultural uses (Ag Intensification).

Table 11. Summary of CSS Resiliency: Current and Future Condition by Population Area

Future Scenario Future Scenario CSS Population Area Current Condition Status Quo Ag Intensification

Cayucos Creek Moderate Moderate Low

Old Creek Moderate Moderate Moderate

Willow Creek Moderate Moderate Moderate

Toro Creek Moderate Moderate Moderate Morro Creek Moderate Moderate Low

Chorro Creek Moderate Moderate Moderate

Morro Bay High High High Los Osos Creek Moderate Moderate Low Upper San Luis Moderate Moderate Moderate Obispo Creek Lower San Luis Moderate Moderate Moderate Obispo Creek

Representation Representation is the ability to adapt to changing environmental conditions; it is the species evolutionary capacity or flexibility. Maintaining representation of healthy populations across the north-south and east-west gradients within the distribution of CSS is likely to conserve the relevant genetic diversity and associated adaptive capacity for the species. Currently, we believe all population areas are extant, which demonstrates representation. Currently, nine out of 10 population areas exhibit moderate resiliencies, and one exhibits high resiliency. Into the future under the status quo, no loss of species representation is expected. If habitat conversion increases due to agricultural intensification, three of the 10 population areas scattered throughout the range could be at risk of extirpation, but representation would likely remain across the rest of the range.

LITERATURE CITED

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EcoVision Partners. 2017. Chorro shoulderband snail (Helminthoglypta morroensis): An assessment of range & habitat associations. Report prepared for the U.S. Fish and Wildlife Service. September. Fisher, T.W., R.E. Orth, and S.C. Swanson. 1980. Snail against snail. California Agriculture Nov.-Dec. 3pp. Griffin D, and K.J. Anchukaitis. 2014. How unusual is the 2012–2014 California drought? Geophysical Research Letters 41:9017–9023. Goodward, D. M., L. H. Gilbertson, P. F. Rugman-Jones, and M. L. Riggs. 2017. A Contribution to the Phylogeography and Anatomy of Helminthoglyptid Land Snails (Pulmonata: Helminthoglyptidae) from the Deserts of Southern California. Bull. Southern California Acad. Sci. 116(2), 2017, pp. 110–136. Heagy, D. 1980. A distribution study of the endangered banded dune snail (Helminthoglypta walkeriana) in Roth, B. Status survey of the banded dune snail, Helminthoglypta walkeriana. Final report. Fish and Wildlife Service, Sacramento Endangered Species Office, California. Hemphill, H. 1911. Descriptions of some varieties of shells with short notes on the geographical range and means of distribution of land shells. Transactions of the San Diego Society of Natural History (1): 99-108. Hill, D.L. 1974. Helminthoglypta walkeriana: a rare and endangered land mollusk. California Polytechnic State University, San Luis Obispo, California. Unpublished senior thesis. Jordan, S. F. and S. H. Black. 2015. Weasma, T. R. (1998) and N. Duncan (2004). Conservation Assessment for Helminthoglypta hertleini, Oregon Shoulderband. USDA Forest Service Region 6 and USDI Bureau of Land Management. [KMA] Kevin Merk Associates, LLC. 2017. Los Osos Wastewater Project: Broderson site restoration and enhancement project, Annual monitoring report – year 3. Prepared for the County of San Luis Obispo, Public Works Department. December. Lankau, R. et al. 2011. Incorporating evolutionary principles into environmental management and policy. Evolutionary Applications 4(2):315-325 Miller, W.B. 1985. A new subgenus of Helminthoglypta (Gastropoda: Pulmonata: Helminthoglyptidae). The Veliger, 28(1), 94–98. Mann M.E., and P.H. Gleick. 2015. Climate change and California drought in the 21st century. Proceedings of the National Academy of Sciences 112:3858–3859. NatureServe Explorer. Banded Dune Snail (Anguispiri kochi): Comprehensive Species Report. http://explorer.natureserve.org/servlet/NatureServe?searchName=Anguispira+kochi+ NOAA National Centers for Environmental Information. 2018. Climate at a glance: U.S. time series, average temperature. Available (Feb. 2018): https/www.ncdc.noaa.gov/cag/time- series/us. Pilsbry, H. A. 1939. Land Mollusca of North America north of Mexico vol. I part 1. Acad. Nat. Sci. Philadelphia. pp. 1–574.

Roth, B. 1973. The systematic position of Helminthoglypta traskii fieldi Pilsbry, 1930 (Gastropoda: Stylommatophora). Bulletin of the Sothern California Academy of Sciences 72(3): 148-155. Roth, B. 1985. Status survey of the banded dune snail Helminthoglypta waIkeriana. Prepared for the U.S. Fish and Wildlife Service, Sacramento Endangered Species Office, Sacramento, California. Roth, B. and J. Tupen, 2004. Revision of the Systematic Status of Helminthoglypta walkeriana morroensis (Hemphill, 1911) (Gastropoda; Pulmonata). Zootaxa, 616:1-23. Sloan, R. 2018. Biologist. Peer review comments on draft Morro shoulderband snail and Chorro shoulderband snail SSA report. May 18. Smith D.R. et al. 2018. Development of a species status assessment process for decisions under the U.S. Endangered Species Act, Journal of Fish and Wildlife Management 9(1): entire; el944-687X . doi:10.3996/052017-JFWM-041 Stafford, B. 2018. Senior Environmental Scientist, California Department of Fish and Wildlife, Region 4. Personal communication with Julie Vanderwier, Fish and Wildlife Biologist regarding results of limited surveys for Morro shoulderband snails at Morro Dunes Ecologist Reserve. April. SWCA Environmental Consultants. 2013. 2012 annual construction monitoring report for the Los Osos wastewater project, San Luis Obispo, California. Prepared for the County of San Luis Obispo, Department of Public Works. January. SWCA Environmental Consultants. 2014. 2013 annual construction monitoring report for the Los Osos wastewater project, San Luis Obispo, California. Prepared for the County of San Luis Obispo, Department of Public Works. January. SWCA Environmental Consultants. 2015. 2014 annual construction monitoring report for the Los Osos wastewater project, San Luis Obispo, California. Prepared for the County of San Luis Obispo, Department of Public Works. January. SWCA Environmental Consultants. 2016. 2015 annual construction monitoring report for the Los Osos wastewater project, San Luis Obispo, California. Prepared for the County of San Luis Obispo, Department of Public Works. January. SWCA Environmental Consultants. 2017. 2016 annual construction monitoring report for the Los Osos wastewater project, San Luis Obispo, California. Prepared for the County of San Luis Obispo, Department of Public Works. January. SWCA Environmental Consultants. 2018. 2017 annual construction monitoring report for the Los Osos wastewater project, San Luis Obispo, California. Prepared for the County of San Luis Obispo, Department of Public Works. January. Tenera Environmental. 2003a. Wildlife Resources of the Bishop Peak Natural Reserve. Prepared for the City of San Luis Obispo. July. Tenera Environmental. 2003b. Bowden Ranch Estates: Morro Shoulderband Snail (Helminthoglypta walkeriana) Survey Report. Prepared for Oasis Partners and Bowden Ranch Estates JV.

Theobald, D. 2017. Stewardship Manager, Land Conservancy of San Luis Obispo. Personal communication with Service biologist Julie Vanderwier regarding new acquisition in Los Osos. September 22. Thorne, J.H. et al. 2017. The impact of climate change uncertainty on California’s vegetation and adaptation management. Ecosphere 8(12): 1-14. Tupen J. and B. Roth, 2001. Further Spread of the Introduced Decollate Snail Rumina decollata (Gastropoda: Pulmonata: Subulinidae) in California, USA. The Veliger, volume 44, number 4, pages 400-404. Tupen J. and B. Roth, 2005. New study confirms restricted status of endangered California land snail. Tentacle. 13: 9-10. Tupen, J. 2018. Senior Biologist, ECORP Consulting. Peer review comments on draft Morro shoulderband snail and Chorro shoulderband snail SSA report. May 17. van der Laan, K. L. 1975a. Feeding preferences in a population of the land snail Helminthoglypta arrosa (Binney) (Pulmonata: Helicidae). The Veliger, volume 17, number 4, pages 354-359, April 1. van der Laan, K. L. 1975b. Aestivation in the land snail Helminthoglypta arrosa (Binney) (Pulmonata: Helicidae). The Veliger, volume 17, number 4, pages 360-368. van der Laan, K. L. 1980. Terrestrial pulmonate reproduction: seasonal and annual variation and environmental factors in Helminthoglypta arrosa (Binney) (Pulmonata: Helicidae). The Veliger, volume 23, number 1, pages 48-54, July 1. [USDA] U.S. Department of Agriculture, Soil Conservation Service. 1984. Soil Survey of San Luis Obispo County, California; Coastal Part. September [USDA] U.S, Department of Agriculture. 1999. Management Recommendations for Survey and Manage Terrestrial Mollusks. Version 2.0. Region 6, Portland, OR. 305 pp. [Service] U.S. Fish and Wildlife Service. 1994. Endangered and threatened wildlife and plants; Endangered and threatened status for five plants and the Morro Shoulderband Snail from western San Luis Obispo County, California. Federal Register, Vol. 59:240, 64613-64623 [Service] U.S. Fish and Wildlife Service. 1998. Recovery plan for the Morro shoulderband snail and four plants from western San Luis Obispo County, California. Portland, Oregon. [Service] U.S. Fish and Wildlife Service. 2001. February 7, 2001. Designation of Critical Habitat for the Morro shoulderband snail (66 Federal Register 9233) [Service] U.S. Fish and Wildlife Service. 2004. In Litt. Letter to Stakeholders and Interested Parties regarding the regulatory status of the Morro shoulderband snail. U. S. Department of the Interior, Fish and Wildlife Service, Ventura Field Office, Ventura, California. June 7.. [Service] U.S. Fish and Wildlife Service. 2006. Banded Dune Snail (Helminthoglypta walkeriana) [=Morro shoulderband snail (Helminthoglypta walkeriana) and Chorro shoulderband snail (Helminthoglypta morroensis)] Five Year Review; September 11. [Service] U.S. Fish and Wildlife Service. 2016. USFWS Species Status Assessment Framework: an integrated analytical framework for conservation. Version 3.4 dated August 2016

Walgren, M. 2003a. The current status of the Morro Shoulderband snail (Helminthoglypta walkeriana), California Polytechnic State University, San Luis Obispo, California. Unpublished MS Thesis. Walgren, M.J. and L.E. Andreano. 2012. Pulmonate gastropod species composition inside and outside eucalyptus forests. California Fish and Game 98(3): 164-170 Walgren, M.J. and L.E. Andreano. 2018. Staff Environmental Scientists, California Department of Parks and Recreation (State Parks). . Personal communication with Service biologist Julie Vanderwier regarding new acquisition in Los Osos. January 2.

APPENDIX A Recovery Plan for the Morro Shoulderband Snail and Four Plants from Western San Luis Obispo County, California (Service 1998)

Recovery Criteria Identified for Morro Shoulderband Snail (= Helminthoglypta walkeriana) • Downlisting: Downlisting from endangered to threatened can be considered when sufficient populations and suitable occupied habitats from all four Conservation Planning Areas (CPAs) are secured and protected. These areas should be intact and relatively unfragmented by urban development. Snail populations must be large enough to minimize the short-term (next 50 years) risk of extinction on any of the four CPAs, based on results of tasks 3.2.1.1, 3.2.1.2, and 3.2.1.3 and on at least preliminary results from task 4.1. The identification and survey of potential habitat within the snail's historic range to see if undiscovered populations exist is necessary to consider downlisting. Should surveys locate additional populations, especially north of Morro Bay, recovery criteria will need to evaluated and revised.

o 3Rs: Resiliency (populations/occurrence persistence in each CPA); Representation (distribution of populations/occurrences across CPAs); Redundancy (multiple populations/occurrences across CPAs) . Evaluation: All of CPA 1 and portions of CPAs 2-4 are secure under various ownerships/management. These include the County of San Luis Obispo (County), California State Parks (State Parks), California Department of Fish and Wildlife (CDFW), Land Conservancy of San Luis Obispo County (LCSLO), Morro Coast Audubon Society (MCAS), and the Small Wilderness Area Program (SWAP). Lack of funding precludes adequate threats management on most of these lands. Most of Morro Spit CPA 1 and West Pecho CPA 2 were determined to have moderate resiliency in our current condition analysis. The remaining part of West Pecho CPA 2 exhibits high resiliency as does South Los Osos CPA 3 and Area A. Northeast Los Osos CPA 4 exhibits low resiliency as does Area B, an important area that remains currently unsecured. See Figure A1 below.

Figure A1. CPAs from the 1998 Recovery Plan and current resiliency condition of Morro shoulderband snail SSA population areas.

o Task 3.2.1.1: Determine if brown garden snail is a competitive threat to Morro shoulderband snail . Evaluation: Since the time of listing in 1994, there has been no additional information indicating that the brown garden snail (Cornu aspersum [formerly Helix aspersa]) represents a competitive threat. As data indicate that MSS feed primarily on dead plant materials and the brown garden snail consumes live plant materials, competition between these species is likely minimal in this respect.

o Task 3.2.1.2: Study habitat use and life history needs of the Morro shoulderband snail . Evaluation: While few scientific studies have been conducted regarding habitat use and life history needs for MSS, monitoring and habitat restoration activities conducted in association with the construction of a sewer system in the community of Los Osos have generated substantial new information on the diversity of habitats in which the species can occur. We have also obtained new information based upon anecdotal observations or surveys conducted in association with proposed development in the Los Osos area.

o Task 3.2.1.3: Identify Morro shoulderband snail parasites and determine if parasitism rates are threatening populations . Evaluation: Parasitism was a factor considered at the time of listing; however, current information and thinking indicates that it is not likely a current threat to the species.

o Task 4.1: Monitor populations to ascertain trends . Evaluation: There has been no systematic monitoring conducted to provide data that would allow for trend analysis. • Delisting: Delisting can be considered when habitats from all CPAs and any newly located populations are successfully managed to maintain the desired community structure and secured from threats of development, invasion of non-native plants, structural changes due to senescence of dune vegetation, recreational use, pesticides (including slug and snail baits), parasites, and competition or predation from non-native snail species. Results of recovery tasks must continue to a low medium-to-long term risk of extinction from any of the four CPAs.

o Task 2.1.1.1: Develop and implement strategies to control or eliminate illegal OHV use . Evaluation: Previous threats to habitat resulting from illegal OHV activities are largely controlled; however, illegal trail development and use by hikers,

mountain bikers, and equestrians negatively affects habitat for MSS by increasing erosion, reducing native plant cover, and facilitating further invasion by nonnative plant species. o Task 2.1.1.2: Develop and implement strategies to control non-native plant species . Evaluation: In MSS habitat, State Parks staff annually prioritize treatment areas on a case-by-case basis, as funding is available. When funding is available, they implement actions to control invasive species in Montaña de Oro State Park, Morro Strand State Beach, Morro Bay State Park, and Los Osos Oaks Preserve. Identified invasive species prioritized for removal include Ehrharta calycina, Conicosia pugioniformis, Emex spinosa, Cortaderia species, and Eucalyptus species because they are the most invasive and conspicuous in the landscape. Lack of funding precludes most State of California resource agencies (e.g., State Parks and CDFW) from implementing invasive species control programs on lands where these species are present. The MCAS hosts regular work parties to target removal of invasive nonnative plant species and has a dedicated volunteer work force who remove Ehrharta calycina and Eucalyptus globulus seedlings at their Sweet Springs Preserve (outside of the CPAs) under the direction of a Recovery Action Plan. The Los Osos/ Morro Bay Chapter of SWAP does the same for the Elfin Forest Reserve in CPA 4. o Task 2.1.1.3.1: Develop and implement prescribed burn plan . Evaluation: State Parks staff have proposed to implement prescribed burn activities in conjunction with CALFIRE to improve the quality of coastal dune scrub and central maritime chaparral and their constituent species within their park units. Limited activities have occurred in the past, some resulting in mortality of resident MSS. State Parks now works with the Service as part of their prescribed burn planning efforts. If properly applied in small areas to create a mosaic of varying stand ages for coastal dune scrub and central maritime chaparral, such burns could improve the quality of these habitats for MSS. o Task 2.1.1.3.2: Develop and implement strategy for wildfire suppression . Evaluation: Complete fire suppression within the range of MSS may be a threat to its persistence by altering the age structure of the plant communities. CALFIRE has developed and is implementing a fuels reduction program as part of their community wildfire protection plan (CWPP) within the wildland- urban interface around the community of Los Osos. The Service has participated in this effort for areas where MSS are known or likely to occur. While intended to protect the community from the effects of a catastrophic fire that originates in the wildland area, a species benefit is also the protection of native habitat areas against the type of intense fire that could originate in the urban area and spread uncontrolled into the wildland areas. Given the climatological and topographic characteristics in the Los Osos area, this may be the more likely scenario. If such a fire were to occur, it could result in

extirpation of local populations. The draft community-wide habitat conservation plan for the community of Los Osos would address take of MSS associated with full implementation of the CWPP. o Task 2.1.2: Prevent potential introduction of non-native predatory snails . Evaluation: We are not aware of any formal local programs to prevent the introduction of nonnative predatory or other snails within the range of MSS. The introduced predatory decollate snail (Rumina decollate) is described as a possible predator of the native co-occurring Big Sur shoulderband (H. umbilicata) and introduced brown garden snail at a site in coastal San Luis Obispo County. It preys on other snails and, during lab studies, will attack and consume native southern California species of Helminthoglypta. Its use by southern California citrus growers as a biological control for the introduced brown garden snail could facilitate predation on MSS if introduced into areas within the latter’s range. Documentation of the species at Diablo Canyon Nuclear Power Plant in San Luis Obispo County in 2001 caused great concern due to its proximity to where MSS occur. During surveys conducted for Chorro shoulderband snail (H. morroensis) in 2017, decollate snail shells were observed at one location near a citrus grove near the town of Edna in the southernmost part of the City of San Luis Obispo with an abundance of European garden snail shells and a number of shells from the unknown Helminthoglypta species. It is unknown whether this occurrence of decollate snail is the second documented occurrence in San Luis Obispo County or if other occurrences exist. The legal status of the decollate snail as a “detrimental animal” in California prohibits its importation, transportation, and possession in most counties. While we do not consider the decollate or other predatory snail species to be an imminent threat, monitoring for the presence of such species to determine if there are occurrences in or near the range of MSS should be conducted. Eradication of any identified nonnative predatory snail species individuals should be part of monitoring for native snail species. o Task 2.1.3: Discourage pesticide applications . Evaluation: The Service generally discourages the use of pesticides (inclusive of herbicides) in habitat for MSS unless approved pursuant to a condition contained in a biological opinion/incidental take permit and in accordance with standard industry practices. We have no control over the use of pesticides on private lands. To achieve success in the control or eradication of some invasive plant species in Los Osos (e.g., Ehrharta calycina, Emex spinosa) selective herbicide use is necessary to control infestations not effectively removed by hand. o Task 4.2: Evaluate effectiveness of methods used to reduce threats . Evaluation: In addition to the benefit of land acquisition to remove the threat of development, the County has been evaluating methods to remove nonnative plant species as part of their habitat restoration efforts. We are not aware of 77

any ongoing evaluations regarding the efficacy of methods used to reduce other threats to MSS. o Task 5.1: Inform and consult with local lead agencies . Evaluation: The Service works with local lead agencies and other entities (e.g., the County, CALFIRE, Los Osos Community Services District, State Parks, LCSLO, MCAS) to ensure that MSS are considered during all of their discretionary permit processes or other activities and encourages and supports their participation in efforts to conserve the species. o Task 6.1: Re-evaluate recovery criteria . Evaluation: Recovery criteria have not yet been re-evaluated based on substantial new information regarding habitat suitability and threats obtained since the time of listing, completion of the recovery plan, and/or designation of critical habitat.