Black Creek Crayfish (Procambarus Pictus) Species Status Assessment

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Black Creek Crayfish (Procambarus pictus) Species Status Assessment

Version 1.0

Photo by Christopher Anderson

July 2020 U.S. Fish and Wildlife Service South Atlantic, Gulf & Mississippi Basin Regions Atlanta, GA ACKNOWLEDGEMENTS

This document was prepared by Kathryn N. Smith-Hicks (Texas A&M Natural Resources Institute), Heath Rauschenberger (U.S. Fish and Wildlife Service [Service]), Lourdes Mena (Service), David Cook (Florida Fish and Wildlife Conservation Commission [FWC]), and Erin Rivenbark (Service). Other species expertise, guidance, and document reviews were provided by Paul Moler (FWC), Gary Warren (FWC), Lindsey Reisinger (University of Florida), Katherine Lawlor (FWC), Kristi Lee (FWC), and Kasey Fralick (FWC).

Additionally, peer reviewers including Troy Keller and Chester R. Figiel, Jr. provided valuable input into the analysis and reviews of a draft of this document. We appreciate their input and comments, which resulted in a more robust status assessment and final report.

Suggested reference:

U.S. Fish and Wildlife Service. 2020. Species status assessment report for Procambarus pictus (Black Creek crayfish), Version 1.0. July 2020. Atlanta, Georgia.

EXECUTIVE SUMMARY Black Creek crayfish (Procambarus pictus) are small to medium sized crayfish endemic to four northeastern Florida counties (Clay, Duval, Putnam, and St. Johns) in the Lower St. Johns River Basin. Black Creek crayfish rely on cool, flowing, sand-bottomed, and tannic-stained streams that are highly oxygenated. Locations that fulfill the species’ habitat requirements are typically headwater sections of streams that maintain a constant flow; however, they are found in small and large tributary streams. Within these streams, Black Creek crayfish require aquatic vegetation and debris for shelter with alternation of shaded and open canopy cover where they eat aquatic plants, dead plant and animal material, and detritus. Threats believed to influence Black Creek crayfish vary by location, but may include human development, mining, silviculture, climate change, and competition for space and resources with the conspecific, pioneering white tubercled crayfish. Until more research is conducted, the degree of impact by white tubercled crayfish is still unknown. Early research indicates white tubercled crayfish have the potential to decrease localized occupancy and abundance of Black Creek crayfish at certain sites. Using available occurrence data, we delineated 19 populations using HUC 12 watersheds, 16 on the west side of the St. Johns River and 3 on the east side. For this Species Status Assessment (SSA), we made some assumptions about specific Black Creek crayfish needs and responses to stressors based on currently available knowledge and input from species experts, but further study is needed to test these assumptions. We attempted to be clear and explicit in the SSA about where these assumptions were made and why.

We assessed current resiliency of populations based on three factors: likely habitat and level of protection, habitat quality, and threat of impact from white tubercled crayfish. Populations were assigned a baseline resiliency score associated with the likely habitat predicted within the HUC 12 watershed based on a habitat suitability model and the amount of likely habitat currently under some level of protection and management. The baseline scores could then be lowered or raised based on the habitat quality within the HUC 12 watershed. We determined habitat quality from combining overall watershed water quality and level of urban, agricultural, and silviculture use within the riparian areas surrounding likely habitat. We then calculated two resiliency scores based on potential impact from white tubercled crayfish and without any impacts. Based on this resiliency classification strategy and predicted white tubercled crayfish impact, there are currently 2 very highly resilient populations, 7 highly resilient populations, 6 moderately resilient

iii populations, and 4 populations with low resiliency. If white tubercled crayfish impacts are not considered, there are currently 6 very highly resilient populations, 3 highly resilient populations, 7 moderately resilient populations, and 3 populations with low resiliency. Given the limited distribution of the Black Creek crayfish, the species is very susceptible to catastrophic events because the events would not need to be very large or geographically widespread to affect the entire known population. We evaluated representation based on geographical separation of populations on east and west side of the St. Johns River; the 3 populations on the east side of the St. Johns River have moderate (1) and low (2) resiliency and so redundancy is much higher on the west side of the St. Johns River compared to the east side.

We assessed the future conditions of Black Creek crayfish 30 and 50 years into the future under 6 scenarios:

1. 2050 No WTC Impact: Current development + No impact from white tubercled crayfish 2. 2050 WTC Impact: Current development + Impact from white tubercled crayfish 3. 2070 Trend No WTC Impact: Florida 2070 Trend + No impact from white tubercled crayfish 4. 2070 Trend WTC Impact: Florida 2070 Trend + Impact from white tubercled crayfish 5. 2070 Alternative No WTC Impact: Florida 2070 Alternative + No impact from white tubercled crayfish 6. 2070 Alternative WTC Impact: 2070 Alternative + Impact from white tubercled crayfish

These scenarios explored how varying levels of future conservation effort might interact with current resiliency and risk from sea level rise (SLR), urbanization, and white tubercled crayfish. Impact from sea level rise was incorporated to the amount of likely habitat in 2050 and 2070 to give new baseline resiliency scores. We then analyzed forecasts of future development within each population watershed and within 100 m of likely habitat (riparian). This was done using geospatial data provided by the Florida 2070 mapping project, which predicts both Trend and Alternative development patterns. Trend represents the land use pattern most likely to occur if 2070 population projections are met and counties continue to develop at densities seen in 2010 and Alternative represents a land use pattern that still accommodates the 2070 projected population but with a more compact pattern of development and increased protected lands.

Resiliency scores for each scenarios then incorporated predicted impact and no impact from white tubercled crayfish.

Current Current 2050 2070 2070 2070 2050 2070 Resiliency Resiliency Current Trend Trend Alternate Current Alternate Resiliency - With - Without & No & No & & No & WTC & WTC WTC WTC WTC WTC WTC WTC Impact Impact Impact Impact Impact Impact Impact Impact Very High 2 6 6 0 2 0 4 0 High 7 3 3 6 2 0 4 0 Moderate 6 7 6 4 3 2 1 4 Low 4 3 1 5 1 2 1 4 Total Populations 19 19 16 15 8 4 10 8

Three of the 19 Black Creek crayfish populations (16%) may be extirpated under all future scenarios. Six more populations (32%; 47% total) may be extirpated by 2070. Scenarios that include development without added protections of Black Creek crayfish habitat and other areas important to maintaining good water quality increase the likelihood of extirpation of two additional populations. It is possible that resiliency may be worse than predicted if white tubercled crayfish lead to eventual extirpation of Black Creek crayfish in watersheds occupied by both species in the future. More data are needed to determine the extent and exact time scale of impacts. Redundancy and representation are expected to decrease under all scenarios.

2070 Current Current 2050 2050 2070 2070 2070 Alternate Resiliency - Resiliency - Current & Current Trend & Trend & Alternate Population & No With WTC Without WTC No WTC & WTC No WTC WTC & WTC WTC Impact Imapct Impact Impact Impact Impact Impact Impact

Likely Ates Creek High Very High Very High High Moderate High Low Extirpated

Likely Likely Likely Likely Likely Likely Black Creek - St. Johns River Low Low Extirpated Extirpated Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Clarkes Creek Moderate Moderate Moderate Low Moderate Extirpated Extirpated Extirpated

Likely Likely Likely Likely Durbin Creek* Moderate Moderate Moderate Moderate Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Likely Likely Governors Creek Moderate Moderate Low Extirpated Extirpated Extirpated Extirpated Extirpated

Likely Greens Creek High Very High Very High High Moderate Very High Moderate Extirpated

Likely Likely Likely Likely Likely Likely Julington Creek* Low Low Extirpated Extirpated Extirpated Extirpated Extirpated Extirpated

Kingsley Lake High Very High Very High High High Low Very High Moderate

Likely Likely Likely Likely Lake Geneva Moderate Moderate High Moderate Extirpated Extirpated Extirpated Extirpated

Lower Etonia Creek High High High Moderate High Low High Low

Likely Likely Likely Likely Lower North Fork-Black Creek Low Moderate Moderate Low Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Likely Lower South Fork-Black Creek High High High Moderate Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Likely Peters Creek Moderate Moderate Moderate Low Extirpated Extirpated Extirpated Extirpated

Very Simms Creek Very High Very High Very High High Moderate Very High Moderate High

Likely Likely Likely Likely Likely Likely Trout Creek-St. Johns River* Low Low Extirpated Extirpated Extirpated Extirpated Extirpated Extirpated

Likely Likely Upper Etonia Creek Moderate Moderate High Moderate Low Low Extirpated Extirpated

vii

Likely Likely Upper North Fork-Black Creek Very High Very High Very High High High Low Extirpated Extirpated

Very Upper South Fork-Black Creek High Very High Very High High Moderate Very High Moderate High

Likely Yellow Water Creek High High High Moderate Moderate High Low Extirpated

viii

TABLE OF CONTENTS

ACKNOWLEDGEMENTS ii

EXECUTIVE SUMMARY iii

CHAPTER 1 – INTRODUCTION 4

CHAPTER 2 – SPECIES BIOLOGY AND INDIVIDUAL NEEDS 8 2.1 Taxonomy 8 2.2 Species Description 9 2.3 Life History and Demography 9 2.4 Habitat 11 2.5 Activity 12 2.6 Prey and Predators 13 2.7 Historic and Current Distribution 14 2.8 Genetics 19 2.9 Current abundance 19

CHAPTER 3 – SPECIES NEEDS FOR VIABILITY 23 3.1 Individual Level 23 3.2 Population Level 23 3.3 Species Level 23

CHAPTER 4 – INFLUENCES ON VIABILITY 24 4.1 Water Withdrawal 25 4.2 Water Quality 27 4.2.1 Urbanization 27 4.2.2 Mining 30 4.2.3 Other Influences on Water Quality 32 4.3 Interactions with White Tubercled Crayfish 33 4.4 Climate Change 40 4.5 Other Threats 42 4.6 Conservation 44

4.6.1 Protection and Management of Habitat 44 4.6.2 Other Existing Regulatory Mechanisms 48

CHAPTER 5 – CURRENT CONDITION 51 5.1 Delineating Populations 51 5.2 Estimating Current Condition 52 5.2.1 Baseline Score: Potential Habitat & Level of Protection 53 5.2.2 Habitat Quality 56 5.2.3 Presence of White Tubercled Crayfish 59 5.2.4 Current Population Resiliency 61 5.3 Current Resiliency 61 5.3.1 Potential Habitat 62 5.3.2 Water Quality 63 5.3.3 White Tubercled Crayfish 69 5.3.4 Summarized Resiliency 70 5.4 Current Redundancy and Representation 73

CHAPTER 6 – FUTURE CONDITIONS AND VIABILITY 75 6.1 Future Considerations 75 6.1.1 Sea Level Rise (SLR) 75 6.1.2 Development 75 6.1.3 White Tubercled Crayfish 76 6.2 Models and Scenarios 77 6.3 Results 78 6.3.1 SLR and Future Baseline Scores 78 6.3.2 Development 80 6.3.3 White Tubercled Crayfish 82 6.4 Future Resiliency Results 83 6.4.1 Future Scenarios: 2050 83 6.4.2 Future Scenarios: 2070 85 6.4.3 Future Scenarios: Summary 89 6.5 Future Redundancy and Representation 93 6.6 Future Research Needs 94

Literature Cited 96

Appendix A. Black Creek Crayfish Habitat Model (Barrett 2018) 103

Appendix B. ACRONYMS 111

CHAPTER 1 – INTRODUCTION

The Black Creek crayfish (Procambarus pictus) is endemic to four northeastern Florida counties (Clay, Duval, Putnam, and St. Johns) in the Lower St. Johns River Basin (Fig. 1.1). This small to medium sized crayfish has dark claws and a dark carapace with a white or yellowish mid-dorsal stripe, white spots or streaks on its sides, and a rust-colored abdomen (Hobbs 1940, pp. 419-423; Franz et al. 2008, p. 5). The Black Creek crayfish occurs in flowing, sand-bottomed, tannic- stained streams which contain cool, unpolluted water, and maintain a constant flow of highly oxygenated water (5-8 ppm) (Franz and Franz 1979, p. 16; Franz 1994, p. 212). The Black Creek crayfish is considered a Species of Greatest Conservation Need according to Florida’s State Wildlife Action Plan (Florida Fish and Wildlife Conservation Commission [FWC; see Appendix B for acronyms used in this document] 2019a, p. 91), is listed by the State of Florida as Threatened on the Florida Endangered and Threatened Species List (FWC 2018, p. 8), and is currently petitioned to be federally listed under the Endangered Species Act, as amended (Center for Biological Diversity [CBD] 2010, pp. 946-948).

Figure 1.1. Counties occupied by Black Creek crayfish.

The Species Status Assessment (SSA) framework (U.S. Fish and Wildlife Service [Service] 2016, entire) summarizes the information compiled and reviewed by the Service, incorporating the best available scientific and commercial data, to conduct an in-depth review of the species’ biology and threats, evaluate its biological status, and assess the resources and conditions needed to maintain long-term viability. The intent is for the SSA to be easily updated as new information becomes available and to support all functions of the Ecological Services Program of the Service, from Candidate Assessment to Listing to Consultations to Recovery under the Endangered Species Act (ESA). As such, the SSA Report will be a living document that may be used to inform ESA decision making, such as listing, recovery, Section 7, Section 10, and reclassification decisions (the latter four decision types are only relevant should the species warrant listing under the ESA). Therefore, we have developed this SSA Report to summarize the most relevant information regarding life history, biology, and factors influencing viability for the Black Creek crayfish. In addition, we describe the current condition and forecast the possible response of the species to various future factors and environmental conditions to formulate a complete risk profile for the Black Creek crayfish.

For the purpose of this assessment, we define viability as the ability of the species to sustain populations in its range over time. Using the SSA framework (Fig. 1.2), we consider what the species needs to maintain viability by characterizing the status of the species in terms of its resiliency, redundancy, and representation (Service 2016, entire).

• Resiliency describes the ability of populations to withstand stochastic disturbance events (arising from random factors). We can measure resiliency based on metrics of population health, for example, birth versus death rates and population size. Highly resilient populations are better able to withstand disturbances such as random fluctuations in birth rates (demographic stochasticity), variations in rainfall (environmental stochasticity), or the impacts of anthropogenic activities.

• 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 can bounce back from catastrophic events (such as a rare destructive natural event or episode involving many populations; for example, drought).

• Representation describes the ability of a species to adapt to changing environmental conditions. Representation can be measured by the breadth of genetic or environmental diversity within and among populations and 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 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.

Figure 1.2. Species Status Assessment Framework

To evaluate the biological status of Black Creek crayfish, we compiled available information from the literature and species experts about the species’ biology and needs, and assessed the

6 species’ resiliency, redundancy, and representation (together, the 3 Rs) under current conditions and multiple plausible future scenarios. The format for this SSA includes: (1) species biology and needs, (2) species needs for viability, (3) influences on viability, (4) current conditions, and (5) future conditions. This document is a compilation of the best available scientific and commercial information and a description of past, present, and likely future risk factors to Black Creek crayfish. We attempted to be clear and explicit in the SSA about where assumptions and estimations were made and why.

This SSA Report provides a thorough assessment of what is known of the 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 Black Creek crayfish. Importantly, this SSA Report does not result in, nor predetermine, any decisions by the Service under the ESA. This SSA Report does not determine whether the Black Creek crayfish warrants protections of the ESA, nor whether it should be proposed for listing as a threatened or endangered species under the ESA. That decision will be made by the Service after reviewing this document along with any other relevant scientific information, and all applicable laws, regulations, and policies. The results of the decision will be announced in the Federal Register. The contents of this SSA Report provide an objective, scientific review of the available information related to the biological status of the Black Creek crayfish.

CHAPTER 2 – SPECIES BIOLOGY AND INDIVIDUAL NEEDS

In this chapter, we provide biological information about the Black Creek crayfish, including its taxonomic history, morphological description, historical and current distribution and range, and known life history. We then outline the resource needs of individuals.

2.1 Taxonomy

The Black Creek crayfish was first described in 1940 by Horton H. Hobbs, Jr. (Hobbs 1940, p. 419) and was further refined taxonomically by Hobbs in 1958 (Hobbs 1958, entire). It belongs to the family Cambaridae, order Decapoda, and has no recognized subspecies. Black Creek crayfish are closely related to some cave crayfish in peninsular Florida and, though distantly related, similar in form to ancestral cave crayfishes in the subgenus Procambarus (Lonnbergius) in Putnam, Orange, and Seminole counties (P. Moler 2020, pers. comm.). Propictus crayfish that colonized peninsular Florida are believed to be a “relict” from an insular landmass, which persisted through higher sea levels during the Pleistocene (Hobbs 1958, p. 87). Hobbs (1972, p. 9) placed Black Creek crayfish in the subgenus Ortmannicus.

The currently accepted taxonomic ranking for Black Creek crayfish is described below:

Kingdom: Animalia Subkingdom: Bilateria Infrakingdom: Protostomia Superphylum: Ecdysozoa Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Subclass: Eumalacostraca Superorder: Eucarida Order: Decapoda Suborder: Pleocyemata Infraorder: Astacidea Superfamily: Astacoidea Family: Cambaridae Subfamily: Cambarinae Genus (Subgenus) Species: Procambarus (Ortmannicus) pictus Common names: Black Creek crayfish; spotted royal crayfish

*Retrieved 5/20/2019 from the Integrated Taxonomic Information System on-line database, http://www.itis.gov

2.2 Species Description

Figure 2.1. Black Creek crayfish Photo credit: Barry Mansell

Black Creek crayfish (Fig. 2.1) are small to medium sized crayfish with dark claws (chelae) and a dark carapace that is bisected by a white to light yellow dorsal stripe. They average 7.6 cm (3 in) in total body length but can be found up to 8.9 cm (3.5 in) long in late summer (Franz 1994, p. 212). The abdomen is rust colored with black banding and there are white spots, streaks or flecking present on its sides, which is a pattern unique to live Black Creek crayfish; no other cambarid crayfish look similar (Franz et al. 2008, p. 1). Black Creek crayfish have a series of ten bumps present on their claws, a rostrum with lateral spines, a broad areola with 7-10 punctuations in the narrowest part, and ridges behind the eyes terminating forward in sharp spines (Florida Natural Areas Inventory [FNAI] 2001, p. 1). Black Creek crayfish have small gill chambers, which are an adaptation for using highly oxygenated streams (Franz et al. 2008, p. 16).

2.3 Life History and Demography

Black Creek crayfish hatch in late summer and likely live a maximum of 16 months (Franz 1994, p. 212), limiting a female to 1 clutch of eggs in her lifetime. Male Black Creek crayfish alternate between a reproductively ready form (Form I), observed from January to September, and a non- reproductive form (Form II). Reproductive female Black Creek crayfish, observed from June to

August, carry between 47 and 146 eggs on the underside of their abdomen (Fig. 2.2; Franz 1994, p. 212). Eggs stay attached to the female for 2 to 3 weeks (Fig. 2.3). Hatching begins in July and young are recruited into the population in August (Franz 1994, p. 212).

Figure 2.2. Black Creek crayfish life stages based on historical and current collections and general crayfish biology (Franz 1994, p. 212).

Figure 2.3. Female Black Creek crayfish carrying eggs (Nelson and Floyd 2011, p. 51).

2.4 Habitat

Black Creek crayfish rely on cool, flowing, sand-bottomed, and tannic-stained streams that are highly oxygenated (Franz and Franz 1979, p. 14; Franz 1994, p. 212). These high quality streams typically originate in sandhills and may flow through swampy terrain (Franz and Franz 1979, p. 14; Brody 1990, pp. 8-11; FNAI 2001, pp. 102; Nelson and Floyd 2011, p.1). Black Creek crayfish are not found in water with temperatures over 30°C (86℉; Warren et al. 2019, unpublished data). Locations that fulfill the species’ habitat requirements are typically headwater sections of streams that maintain a constant flow; however, they are found in small and large tributary streams that fulfill other habitat criteria (e.g., high oxygen levels, sandy bottom) (Franz and Franz 1979, p. 14). Within these streams, Black Creek crayfish require aquatic vegetation and debris for shelter with alternation of shaded and open canopy cover. In forested sections of habitat (Fig. 2.4a), surrounding riparian areas provide shade which cools the air and water temperature, and provides woody detritus which serves as refuge and a food source (Franz et al. 2008, p. 16; FWC 2013, pp. 2, 19). In open stretches of habitat (Fig. 2.4b), Black Creek crayfish rely on aquatic vegetation for cover.

(a)

(b)

Figure 2.4. Black Creek crayfish stream habitat in (a) forested areas and (b) open stream habitat. Photo credit: Paul Moler.

Black Creek crayfish are occasionally found with other crayfish species, including the slough crayfish Procambarus fallax, the peninsula crayfish P. paeninsulanus, the brushpalm crayfish P. pubischelae, and the white tubercled crayfish P. spiculifer, a species that has recently expanded its range into the current range of the Black Creek crayfish (Franz 1994, p. 212, Franz et al. 2008, pp. 14, 16; Nelson and Floyd 2011, pp. 5-6). See Section 4.3 for discussion about white tubercled crayfish and its interactions with Black Creek crayfish.

2.5 Activity

Black Creek crayfish are active at night and are found crawling on the sandy bottom of cool, flowing, tannic-stained streams (Franz 1994, p. 212). During the day, Black Creek crayfish hide in submerged detritus, tree roots, and vegetation (Franz 1994, p. 212) as well as in undercut banks (G. Warren 2020, pers. comm.).

2.6 Prey and Predators

Black Creek crayfish have food habits similar to those of other stream-dwelling crayfish. They eat aquatic plants, dead plant and animal material, and detritus (FWC 2013, p. 4). Potential predators of Black Creek crayfish include fish, softshell (Apalone ferox) and snapping turtles (Chelydra serpentina), birds, and raccoons (Procyon lotor); however, healthy populations should be resilient to the pressures of naturally occurring depredation (FWC 2010, p. 2).

2.7 Historic and Current Distribution

Figure 2.5. Black Creek crayfish historic (black) and currently occupied HUC 12 watersheds and year last detected.

The historical range of this species is unknown. Prior to 1976, Black Creek crayfish were only known from two streams, Governors Creek and Peters Creek, in Clay County (Fig. 2.5; Hobbs 1942a). Major fieldwork with the species did not occur until the late 1970s, when the species was found to inhabit the extensive Black Creek drainage originating in western Clay County. The current range of the Black Creek crayfish is restricted to four counties in northeastern Florida, all within the single watershed basin encompassing the lower St. Johns River (Fig. 1.1). The majority of Black Creek crayfish detections in recent years (2008-2020) have been on the west side of the St. Johns River, primarily within the boundaries of Camp Blanding Joint Training Center (CBJTC) and Jennings State Forest in Duval and Clay counties along North Fork Black Creek and South Fork Black Creek (Figs. 2.6 and 2.7). Two sub-watersheds where Black Creek crayfish were located historically do not have any recent detections (i.e., Clapboard Creek [Raleys Creek] and Little Black Creek; Fig. 2.5). Black Creek crayfish have not been detected in 5 HUC 12 watersheds within the Black Creek drainage (Upper North Fork of Black Creek, Lower North Fork of Black Creek, Black Creek – St. Johns River, Greens Creek, Lake Geneva) in 8 or more years despite more recent surveys (Fig. 2.5).

In 2019 and the beginning of 2020, surveys for Black Creek crayfish took place in 13 of the 19 HUC 12 watersheds within the currently known range of the Black Creek crayfish. Surveyors detected Black Creek crayfish in Peters Creek (Fig. 2.6), Clarkes Creek (Fig. 2.7), Ates Creek (Fig. 2.7), Upper South Fork of Black Creek (Fig. 2.7), Governors Creek (Fig. 2.6), Simms Creek (Fig. 2.7), Trout Creek (Fig. 2.8), and Kingsley Lake (Fig. 2.6) (Warren et al. 2019, unpublished data; P. Moler 2020, pers. comm.). Black Creek crayfish were not detected in Lower South Fork of Black Creek, Black Creek-St. Johns River, Lower North Fork of Black Creek, Greens Creek, or Lake Geneva in 2019-2020 surveys (Warren et al. 2019, unpublished data). More surveys are needed to understand if Black Creek crayfish are disappearing from these sub- watersheds; however, there is some evidence that locations formally occupied by Black Creek crayfish are now occupied by either white tubercled crayfish (P. spiculifer) or slough crayfish (P. fallax; Warren et al. 2019, unpublished data).

Figure 2.6. HUC 12 watersheds, streams, and Black Creek crayfish detections in the northwest portion of the current Black Creek crayfish range.

Figure 2.7. HUC 12 watersheds, streams, and Black Creek crayfish detections in the southwest portion of the current Black Creek crayfish range.

Figure 2.8. HUC 12 watersheds, streams, and Black Creek crayfish detections on the east side of the St. Johns River.

2.8 Genetics

There is very little genetic information for Black Creek crayfish. Breinholt and Crandall (2010, entire) sampled 4 Black Creek crayfish, 3 specimens from the west side of the St. Johns River (Clay County) and 1 specimen from east side of the St. Johns River (Big Davis Creek in Duval County; Fig. 2.7), in a study aimed at describing the phylogenetic relationships of Florida’s cave crayfish. It was determined that there is a genetic separation of Black Creek crayfish on the east and west side of the St. Johns River based upon the few samples that were analyzed (Breinholt and Crandall 2010, Figure 3, p. 10); however, all occurrences of Black Creek crayfish are currently considered one species.

2.9 Current abundance

There have been no recent range-wide surveys or consistently used survey techniques across time and, therefore, total and population level abundance for the Black Creek crayfish across its range is largely unknown. Estimates from the Biological Status Review estimated the Black Creek crayfish population in 2011 to be greater than 10,000 individuals in a maximum area of occurrence that is less than 2736 km2 (1700 mi2; FWC 2011, p. 6). Nelson and Floyd (2011, p. 16) observed 760 Black Creek crayfish at 128 sites, out of 243 surveyed, at CBJTC. Franz et al. (2008, p. 5) detected 97 Black Creek crayfish by using dip nets at 40 survey points within CBJTC and Jennings State Forest and Black Creek crayfish were detected at several new survey sites (Franz et al. 2008, p. 10). In 2008, Black Creek crayfish were not observed at 12 of 14 historical sites along the North Fork of Black Creek (Franz et al. 2008, pp. 10-11).

In 2019, 10 of the 19 occupied sub-watersheds were surveyed for Black Creek crayfish (Warren et al. 2019, unpublished data). Warren et al. (2019, unpublished data) observed 89 Black Creek crayfish in sweeps and traps from 13 of 43 (30%) hydrated stream sites across the Black Creek basin (Fig. 2.9). Of the 753 net sweeps and 72 traps sampled in 2019, 80 and 9 Black Creek crayfish were captured, respectively (Warren et al. 2019, unpublished data). Catch per unit effort (CPUE) at sites occupied by Black Creek crayfish ranged from 0.05 – 0.9 Black Creek crayfish per dip and averaged 0.33 crayfish per dip (Fig. 2.9; Warren et al. 2019, unpublished data). The

19 highest CPUE in 2019 was located in both Upper South Fork of Black Creek and Peters Creek (Fig. 2.9).

Figure 2.9. Black Creek crayfish survey locations and catch per unit effort (CPUE) in 2019 (Warren et al. 2019, unpublished data).

Franz et al. (2008, p. 8) developed methodology to determine CPUE of Black Creek crayfish, which was calculated by dividing the number of Black Creek crayfish captures during the first 10 dips of the net at each site divided by 10 (Nelson and Floyd 2011, p. 5). Nelson and Floyd (2011, p. 6) found a CPUE of 0.4 (n = 128 sites) at Camp Blanding Joint Training Center. This is higher than the CPUE of 0.15 (n = 34 sites) observed by Franz et al. (2008), and similar to detections by Brody (1990, p. 15; CPUE = 0.3, n = 25 sites). Recent surveys of Black Creek crayfish on Camp Blanding have resulted in CPUE ranging from 0.24 to 0.62 (Table 2.1; CBJTC 2019, unpublished data); however, it should be noted that sampling was conducted using different netting techniques and by different groups of researchers for years prior to 2016 so comparisons should be made with caution. Sites sampled at CBJTC in 2019 by Warren et al. (2019, unpublished data) found very low abundances at 2 sampling locations (CPUE = 0.07 and 0.05) and 0 Black Creek crayfish were sampled at 7 other sites. It is unclear why Warren et al. (2019, unpublished data) and CBJTC (2019, unpublished data) diverge in CPUE in the same year; however, behavior and occupancy likely change throughout the year based on stream flow and riparian changes. Sampling at more locations at CBJTC may be needed to understand how abundance is changing over time. There are no long-term abundance data available at any locations outside of CBJTC, which represents only a portion of the total area occupied by Black Creek crayfish.

Table 2.1. Total number of Black Creek crayfish (BCC) detected (dip net and trap) and catch per unit effort (CPUE) dip at Camp Blanding Joint Training Center from 1990 to 2019.

Sites Total Number Sampled of BCC found CPUE 1990 25 55 0.30 2008 34 97 0.15 2011 128 95 0.40 2016 10 60 0.24 Year 2017 10 54 0.24 2018 10 56 0.29 2019 10 139 0.62 Mean (SD) 79 (32) 0.32 (.15) Note - various netting techniques were utilized across years.

CHAPTER 3 – SPECIES NEEDS FOR VIABILITY

3.1 Individual Level

At an individual level, the Black Creek crayfish requires aquatic vegetation, leaf litter, tree roots, or undercut banks for shelter as well as aquatic plants, dead plant and animal material, and detritus for food. Additionally, individuals need clean and cool, highly oxygenated, flowing water to survive because of their small gill chambers.

3.2 Population Level

For resilient populations (populations defined in Section 5.1) to persist, the needs of individuals (suitable shelter, food sources, mates) must be met at a larger scale. Connected areas of habitat must be large enough to support a large enough reservoir of potential mates with which the crayfish can breed while avoiding severe inbreeding depression. For the Black Creek crayfish, suitable habitat is dependent upon protection of highly oxygenated, sand-bottomed, tannic- stained headwater streams from the effects of various human land uses (i.e., development, agriculture, silviculture) and ground water withdrawals.

3.3 Species Level

For the species to be viable, there must be adequate redundancy (suitable number and distribution of populations for the species to withstand catastrophic events) and representation (genetic and environmental diversity to allow the species to adapt to changing environmental conditions). In general, redundancy improves with increasing numbers of populations (natural or reintroduced) distributed across the species’ range, and connectivity (either natural or human- facilitated) allows nearby populations to expand their range and colonize areas after catastrophes cause the extirpation of the previously existing population. Representation improves with increasing population size, the heterogeneity of occupied habitats, and the persistence of populations spread across the range of genetic and/or ecological diversity within the species. Long-term viability requires resilient populations to persist into the future; for the Black Creek crayfish, this will mean protection of high quality headwater streams with maintained forested overstory and mitigating the impacts of interspecific competition and disease, to support redundant populations across the species’ range.

CHAPTER 4 – INFLUENCES ON VIABILITY

Black Creek crayfish populations need high-quality streams to maintain viability within their range (Fig. 4.1). In order to maintain these conditions, the basins in which they reside as well as nearby floodplains and wetlands need to be protected from disturbance and pollution. The petition to list Black Creek crayfish under the ESA cited habitat destruction and inadequacy of existing regulatory mechanisms as threats (CBD 2010, pp. 946-947). Influences on the Black Creek crayfish viability vary by location, but negative influencing factors may include human development, mining, silviculture (e.g., timber harvest), and a changing climate. The species also may be negatively influenced by another crayfish species of the same genus, which is now being regularly detected in the Black Creek crayfish’s range, the white tubercled crayfish (Procambarus spiculifer). Positive influences on Black Creek crayfish viability include habitat protection and, potentially, water management plans.

Figure 4.1. Influence diagram illustrating relationships between key habitat and population factors, influences on these factors, and species viability.

4.1 Water Withdrawal Water withdrawal for use in public water systems (i.e., residential and nonresidential uses supplied by public and private utilities), agricultural irrigation, recreational irrigation, commercial/industrial use, and thermoelectric power generation has the potential to decrease both surface and groundwater supply, thus potentially affecting Black Creek crayfish habitat. In 2003, the St. Johns River Water Management District (SJRWMD) prepared a water supply assessment to identify future water supply needs (through 2025) and to identify areas where those needs could not be met by the water supply plans without unacceptable impacts to water resources and natural systems within the range of the Black Creek crayfish (SJRWMD 2003, p. 1). The SJRWMD and the neighboring Suwannee River Water Management District (SRWMD) together completed a similar supply plan with future analyses in 2017, which evaluated water use predictions through the year 2035 (SJRWMD and SRWMD 2017, entire).

There is a projected increase in total water use based upon assumed average rainfall conditions from 1995 to 2025 (Table 4.1; SJRWMD 2003, p. 34). Similarly, updated projections of water usage increases from 2015 to 2035 predicted an increase in each occupied county except for Putnam (SJRWMD and SRWMD 2017, p. 23). These predicted percentages increased appreciably in drought years (SJRWMD 2003, p. 34).

Table 4.1. Predicted percent change in total water use and primary source of water withdrawal by county in the St. Johns River Water Management District.

Percent Primary Source of Primary Source of Percent Change County Change Water Withdrawal Water Withdrawal (1995-2025)1 (2015-2035)2 (1995-2025)1 (2015-2035)2

Clay 135% 50% Groundwater Groundwater Duval 37% 14% Groundwater Groundwater Putnam 9% -23% Surface Groundwater St. Johns 61% 51% Groundwater Groundwater 1 source: SJRWMD 2003 2 source: SJRWMD and SRWMD 2017

The primary source for these increases was predicted to be from groundwater extraction in Clay, Duval, and St. Johns counties and from surface water withdrawal in Putnam County in the earlier evaluation (Table 4.1; SJRWMD 2003, p. 34); however, water use in Putnam County switched to primarily groundwater extraction in recent years and is expected to continue through 2035 (SJRWMD and SRWMD 2017, p. 23). The greatest use of fresh water from groundwater sources in the future is for public supply followed by agricultural use (SJWMD 2003, p 31; SJRWMD and SRWMD 2017, p. 9); however, agricultural water use is expected to decline from current volumes (SJWMD 2003, p. 33; SJRWMD and SRWMD 2017, p. 10). SJRWMD (2003, pp. 89- 90) assessed the likelihood of harm to native vegetation related to groundwater withdrawal and found the areas most likely to be impacted by 2025 were outside the range of the Black Creek crayfish.

In 2017, the U.S. Army Corps of Engineers began assessing implementation of the Black Creek Water Resource Development Project, which would transport 10 million gallons of water per day from the South Fork of Black Creek to Alligator Creek. The purpose of this project is to recharge the upper Floridan Aquifer by moving surface water from a region of relatively low aquifer recharge to an area with greater recharge potential (FWC 2019b, p, 1). The construction phase of the project, occurring in the southwest corner of CBJTC in Clay County, is expected to be completed by 2021, at which time the SJRWMD will monitor and manage water quality and water levels within the project areas. The proposed water intake location, just north of the State Road (SR) 16 bridge over the South Fork of the Black Creek, is a historical location for Black Creek crayfish occupancy; however, Warren et al. (2019a, p. 3) determined that the site is currently conducive to Black Creek crayfish occupancy but found no specimens at the site. White tubercled crayfish were found to be abundant at all sampling sites (Warren et al. 2019a, p. 3). No Black Creek crayfish were located in Alligator Creek in 2018, likely due to the lack of permanent flow through the area (Warren et al. 2019a, p. 4). Black Creek crayfish had previously been detected at one site at the north end of Alligator Creek (Nelson and Floyd 2011, p. 7), which is located upstream of the proposed outflow site (Bernatis 2018, pp. 4-5). Ongoing analyses of this project concluded it is unlikely to impact current Black Creek crayfish populations (FWC 2019b, pp. 1-2); however, it is unclear how decreasing underground water

26 levels in the watershed and potential subsequent impacts to small tributaries would impact Black Creek crayfish in the future (K. Fralick 2020, pers. comm.).

4.2 Water Quality

Within the range of the Black Creek crayfish, pollution from nonpoint sources stemming from urbanization, mining, agriculture, silviculture, and runoff from roads and road construction has been documented in the past (Brody 1990, p. 21; Franz and Franz 1990, p. 294; FNAI 2001, p. 2; Franz et al. 2008, pp. 17-18; Nelson and Floyd 2011, pp. 6-7). These impacts can cause direct mortality to crayfish, but can also degrade the physical habitat used for foraging, sheltering, and spawning (Center for Watershed Protection [CWP] 2003, pp. 93-97).

4.2.1 Urbanization

Urbanization is a significant source of water quality degradation that can reduce the survival of native aquatic organisms, including the Black Creek crayfish (Brody 1990, p. 19; Stranko et al. 2010, p. 603). Urban development can stress aquatic systems in a variety of ways, including by increasing the frequency and magnitude of high flows in streams, increasing sedimentation and nutrient loads, increasing contamination and toxicity, decreasing the aquatic diversity and changing stream morphology and water chemistry (Coles et al. 2012, entire; CWP 2003, pp. 93- 94). Sources and risks of an acute or catastrophic contamination event, such as a leak from an underground storage tank or a hazardous materials spill on a highway, increase as urbanization increases.

Road crossings can be sources of toxic substances from illegal dumping and weed control (Franz et al. 2008, pp. 17-18). Roadwork associated with bridges being newly constructed, repaired, or retrofitted is a potential source of impact to water quality, primarily through siltation and other construction-related pollution. Plans for the construction of Jacksonville’s First Coast Outer Beltway, a project that will pass through a portion of the Black Creek crayfish range (U.S. Department of Transportation et. 2013, entire; http://firstcoastexpressway.com/) and has the potential to impact stream crossings with Black Creek crayfish habitat. Construction on the southwest portion of the Beltway commenced in 2019. Best management practices (BMPs) are in place to avoid erosion issues (e.g., silt fences, stormwater ponds).

As with bridges, construction and maintenance activities on utility corridors and associated infrastructure (e.g., substations, transmission rights of way, and equipment maintenance yards) have the potential to negatively impact streams that they cross or which occur adjacently. Urbanization and development, including industrial and residential land, also increase pressures on water resources. Most urban land within the Black Creek crayfish range is concentrated in southeast Duval County, northeastern Clay County, and northern St. Johns County around the city of Jacksonville and surrounding areas (Fig. 4.2; Florida Department of Environmental Protection [DEP] 2008, p. 16).

Figure 4.2. Urbanized areas within the Black Creek crayfish range.

4.2.2 Mining

A mine is defined as an area of land upon which mining operations have been conducted, are being conducted, or are planned to be conducted, which includes areas necessary for site preparation, extraction, waste disposal, storage, or reclamation, but does not include prospecting. Previous research indicates that an increase in metal concentration in surface water, sediment, and detritus from mining can reduce or eliminate crayfish populations (Allert et al. 2012, pp. 568-569). Similarly, improperly controlled effluent from mining sites could degrade water quality, leading to decreased forage, shelter, reproduction and survivorship, and negatively impact Black Creek crayfish populations.

Figure 4.3. Currently regulated mining sites and Black Creek crayfish locations. Data from the Florida Department of Environmental Protection, accessed 9/3/2019 (https://geodata.dep.state.fl.us/).

Mines focused on heavy minerals extraction make up the majority of the currently regulated mining operations within the Black Creek crayfish range (Fig. 4.3), and may have impacted Black Creek crayfish in the past. For example, Brody (1990, p. 21) reported the lack of crayfish and other stream fauna from a stream (Boggy Creek) that receives effluent from the mine tailing ponds of a titanium extraction operation. This stream is a tributary to the North Fork of Black Creek just north (and downstream) of CBJTC in Clay County (Fig. 4.3). There has been significant restoration of longleaf pine forest at CBJTC in recent years (Service et al. 2017, p. 10) as well as other efforts to decrease impacts of mining operations to waterways in the area by enhancing the quality of habitat through best management practices (Service et al. 2017, pp. 8-9). More information about these conservation strategies are discussed below (Section 4.6).

4.2.3 Other Influences on Water Quality

Other factors that have historically affected Black Creek crayfish habitat include adjacent agriculture and logging. Forestry operations and road construction (i.e., highway and bridge construction) are sources of nonpoint pollution when best management practices (BMPs) are not followed to protect streamside management zones (Florida Department of Agriculture and Consumer Services [FDACS] 2008, entire). Logging can cause erosion, sedimentation, and streambed structural changes from the introduction of tree slash. Forestry road construction, stream crossings, and bridge replacements can also result in increased sedimentation, and runoff may introduce toxic chemicals into streams.

Like surface mining and logging, agriculture has potentially influenced water quality in the Black Creek crayfish range in the past. Impacts from agriculture include the loss of riparian buffer zones and canopy cover, channelization of streams, erosion, and both point source and nonpoint source pollution, and the application of fertilizers and pesticides. This pollution tends to increase nutrient loads in streams, and can lead to algal blooms, sedimentation caused by erosion, and decreases in abundance and diversity of other species, including the food of the crayfish. Agriculture also relies on water withdrawal (see Section 4.1). Protection of upland areas adjacent to Black Creek crayfish habitat, as well as the implementation of BMPs, have alleviated many of the threats associated with siltation and other water quality impacts from agriculture and forestry in recent years (see Section 4.7.4).

4.3 Interactions with White Tubercled Crayfish

The white tubercled crayfish (Procambarus spiculifer), a species native to northeast Florida but not previously recorded in the St. Johns River drainage, was first detected in areas known to be historically occupied by Black Creek crayfish in 2008 (Franz et al. 2008, p. 16). It is still unclear if white tubercled crayfish expanded its range from the north and west or if they were brought in as fishing bait. Trail Ridge, a sandy uplift running north to south from North Florida through South Georgia, could have been a potential barrier to white tubercled crayfish expansion (G. Warren 2020, pers. comm.); however, there is currently no direct evidence that white tubercled crayfish have been used as bait in the Black Creek basin or that they have been released there.

Since the initial observations of white tubercled crayfish at CBJTC in 2008, the species has been encountered during surveys both within CBJTC and in other sub-watersheds within the range of the Black Creek crayfish (Fig. 4.4; Nelson and Floyd 2011, p. 11; Warren et al. 2019b, entire; CBJTC 2019, unpublished data). Subsequent to the observations of white tubercled crayfish within the range of the Black Creek crayfish, there has been concern that the species is potentially influencing Black Creek crayfish relative abundance and occupancy in sites where they overlap. Potential impacts from alien crayfish to native crayfish include altering of native plant life (Olsen et al. 1991, entire; Lodge et al. 1994, entire), alteration local of food webs (Bobeldyk and Lamberti 2010, pp. 650-651; Klose and Cooper 2012, pp. 532-533; Twardochleb et al. 2013, entire), introduction of outside parasites or pathogens (Longshaw 2011, entire), and general declines in abundance or displacement of native crayfish (Jansen et al. 2009, entire; DiStefano et al. 2015, p. 406).

Figure 4.4. Change in white tubercled crayfish occupancy by HUC 12 watershed within the Black Creek crayfish range 2008-2019.

White tubercled crayfish, the largest crayfish in Florida (Hobbs 1942b, p. 123), is native and abundant in streams and springs in the panhandle and tolerate a wider range of stream temperatures than does the Black Creek crayfish (Warren et al. 2019b, pp. 8-9). Both crayfish species require high dissolved oxygen levels and generally overlap in many aspects of their resource needs. Although the reasons for potential displacement of Black Creek crayfish by white tubercled crayfish are not yet fully understood, it may be that white tubercled crayfish are able to outcompete Black Creek crayfish for food resources and space because of their larger size. Also, perhaps the Black Creek crayfish can persist in smaller tributaries unsuitable to the white tubercled crayfish. White tubercled crayfish may also have an advantage over Black Creek crayfish because they may have a longer lifespan than the Black Creek crayfish, which means they can reproduce multiple times during a lifetime while female Black Creek crayfish can only reproduce one time in their life cycle (Fig. 2.2; Franz 1994, p. 212; Hightower and Bechler 2013, pp. 86-87). It is also possible that changing environmental factors are enhancing the white tubercled crayfish’s ability to move into and dominate areas once dominated by Black Creek crayfish. For example, there is anecdotal evidence that after a severe drought white tubercled crayfish recolonize rehydrated streams more rapidly than Black Creek crayfish (Smith-Hicks 2020, p. 1). More research is needed to fully understand the life histories and resource needs for both species, the extent of their interspecific competition for resources, and their behavioral ecology.

In 2018, biologists conducting surveys in Clay County documented an apparent decrease in occupied Black Creek crayfish habitat, which they believe to be related to the range expansion of the white tubercled crayfish into the Black Creek watershed (Warren et al. 2019b, p.1). In light of new evidence of habitat occupation by white tubercled crayfish and the suspected negative impact on Black Creek crayfish occupancy, biologists from FWC and University of Florida (UF) commenced surveys with the goal of (1) documenting the present ranges of the Black Creek crayfish and the white tubercled crayfish within the Black Creek basin in Clay County, Florida and (2) determining if the number of sites occupied by the Black Creek crayfish within the basin has declined (Fig. 4.5; Warren et al. 2019, unpublished data). Of the 28 sampled locations known to have historical Black Creek crayfish occurrences (1976-2011), 10 (36%) were found to be still occupied by Black Creek crayfish in 2019 (Fig. 4.5; Warren et al. 2019, unpublished data). Sites

35 previously occupied by Black Creek crayfish but now occupied by only white tubercled crayfish constituted 13 (46%) of sites sampled (Warren et al. 2019, unpublished data). There were 5 previously sampled locations (18%) currently occupied by both Black Creek crayfish and white tubercled crayfish (Warren et al. 2019, unpublished data). Of the remaining sites previously occupied by Black Creek crayfish sampled, 2 (7%) were either dry or no crayfish species were detected in 2019 and 3 had only detections of P. fallax or P. seminolae (Warren et al. 2019, unpublished data).

Figure 4.5. Sampling locations and Black Creek crayfish (BCC), white tubercled crayfish (WTC), slough crayfish (SC), and Seminole crayfish (SEM) detected in 2019 by Warren et al. (2019, unpublished data).

A review of crayfish surveys conducted 2011-2019 at CBJTC indicates that the presence of white tubercled crayfish potentially influences Black Creek crayfish relative abundance and, to a small extent, occupancy of previously occupied stream reaches (Fig. 4.6; Table 4.2). Ten sites at CBJTC have been consistently sampled for occupancy and abundance for both species since

2011 (CBJTC 2020, unpublished data; Table 4.2). Only Black Creek crayfish occupied all annually monitored sites in 2011 (Table 4.2; Fig. 4.6). Thirty percent were still occupied by only Black Creek crayfish in 2019, and Black Creek crayfish and white tubercled crayfish occupied half of the sites, indicating 80% of sites are still occupied by Black Creek crayfish (Fig. 4.6). One site (10%) has been consistently occupied by only white tubercled crayfish since 2017 and one site remained unoccupied by either crayfish in 2019 (Fig. 4.6). Table 4.2. Relative abundance (# captured per dip; #/Dip) and occupancy (Present) for Black Creek crayfish (BCC) and white tubercled crayfish (WTC) at 10 closely monitored study sites at Camp Blanding Joint Training Center in Clay County, Florida, in 2011 and 2016-2019. #/Dip Present Site Name Year BCC WTC BCC WTC 2011 0.05 0 Yes No 2016 0.15 0 Yes No ST01 2017 0.25 0 Yes Yes 2018 0.3 0.2 Yes Yes 2019 0.05 0.6 Yes Yes 2011 0.1 0 Yes No 2016 0.5 0 Yes No ST02 2017 1.65 0 Yes No 2018 1.7 0 Yes No 2019 1.55 0 Yes No 2011 0.1 0 Yes No 2016 1 0 Yes No ST03 2017 0 0.15 Yes Yes 2018 0.1 0 Yes Yes 2019 0.3 0.4 Yes Yes 2011 0.1 0 Yes No 2016 0.05 0 Yes No ST04 2017 0 0 No No 2018 0.65 0.4 Yes Yes 2019 0.15 0.7 Yes Yes 2011 0.15 0 Yes No 2016 0 0 No No ST05 2017 0 0 No Yes 2018 0 0.65 No Yes 2019 0 1.9 No Yes 2011 0.05 0 Yes No ST06 2016 0 0 No No 2017 0 0 No No

2018 0 0 No No 2019 0.05 0 Yes No 2011 0 0 Yes No 2016 0.6 0 Yes No ST07 2017 0.45 0 Yes No 2018 0.1 0 Yes No 2019 3.75 0 Yes No 2011 0 0 No No 2016 0 0 Yes No ST08 2017 0 0 No No 2018 0 0 No No 2019 0 0 No No 2011 0.05 0 Yes No 2016 0.05 0 Yes No ST09 2017 0 0 No No 2018 0.05 0 Yes No 2019 0.25 0.35 Yes Yes 2011 0.55 0 Yes No 2016 0.05 0 Yes No ST10 2017 0 0 No No 2018 0 0 No No 2019 0.05 0.5 Yes Yes

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2011 2016 2017 2018 2019 % of Sites with only BCC % of Sites with both BCC and WTC % of Sites with only WTC % of Sites with neither

Figure 4.6. Change in site occupancy by Black Creek crayfish (BCC) and white tubercled crayfish (WTC) at Camp Blanding Joint Training Center, Florida, from 2011 to 2019 (n = 10 sites).

Black Creek crayfish CPUE within areas known to also be occupied by white tubercled crayfish are similar to historical CPUE across annually monitored sites at CBJTC (Table 4.2.; CBJTC 2019, unpublished data). Black Creek crayfish CPUE fluctuates from year to year regardless of presence of white tubercled crayfish (Table 4.2). Warren et al. (2019, unpublished data) show many stream reaches at CBJTC have low Black Creek crayfish CPUE in occupied sampling locations (Fig. 2.9). Additionally, CPUE was higher on average in annually monitored sites not also occupied by white tubercled crayfish in the past 3 years (CBJTC 2019, unpublished data; Fig. 4.7).

Black Creek crayfish CPUE prior to appearance of white tubercled crayfish at CBJTC in 1990 and 2008 was 0.3 and 0.15, respectively. It is possible that white tubercled crayfish are affecting both Black Creek crayfish activity and sampling detection rates, accounting for the lower detections of Black Creek crayfish in previously occupied sites. Trapping was also done at the 10 sites over a 24-hour period from 2016 to 2019 at CBJTC and, notably, Black Creek crayfish and white tubercled crayfish were never trapped together (CBJTC 2019, unpublished data). It is also possible that differences in sampling techniques and personnel are causing these discrepancies in

CPUE over time; however, it is also possible that white tubercled crayfish are causing declines in Black Creek crayfish abundance and occupancy. More research and data are imperative to determine the extent of impacts by white tubercled crayfish on Black Creek crayfish.

2.0 1.8 1.6 1.4 1.2 Black Creek Crayfish Relative 1.0 Abundance 0.8 0.6 0.4 0.2 0.0 2011 2016 2017 2018 2019 Sites Occupied by Both Species Sites Only Occupied by Black Creek crayfish

Figure 4.7. Average Black Creek crayfish relative abundance for sites also occupied by white tubercled crayfish and sites only occupied by Black Creek crayfish at Camp Blanding Joint Training Center, Florida.

4.4 Climate Change Climate change has the potential to increase vulnerability of the Black Creek crayfish to random catastrophic events or to alter habitat suitability within the species’ range. The climate in the southeastern United States has warmed about 1°C (about 2 °F) from a cool period in the 1960s and 1970s, and is expected to continue to rise (Carter et al. 2014, pp. 398-399; Carter et al. 2018, pp. 749-750). Various emissions scenarios suggest that, by the end of the 21st century, average global temperatures are expected to increase 0.3 °C to 4.8 °C (0.5 °F to 8.6 °F), relative to the period 1986–2005 (Intergovernmental Panel on Climate Change [IPCC 2014], entire). By the end of 2100, it is extremely likely that there will be more frequent hot and fewer cold temperature extremes over most land areas on daily and seasonal timescales, and it is very likely that heat waves and extreme precipitation events may occur with higher frequency and intensity (IPCC 2014, pp. 15–16; Carter et al. 2018, pp. 750-752). Projections for future precipitation

40 trends in the Southeast are less certain than those for temperature, but suggest that overall annual precipitation may decrease, and that tropical storms may occur less frequently, but with more force (more category 4 and 5 hurricanes) than historical averages (Carter et al. 2014, p. 398). Warmer temperatures and decreased precipitation may increase water temperatures and concurrently decrease dissolved oxygen levels, change runoff regimes, and increase frequency, duration, and intensity of droughts in the southeastern United States (Carter et al. 2018, pp. 746, 773, 775). Droughts cause decreases in water flow and dissolved oxygen levels and increases in temperature in stream systems and can lead to increases in the concentration of pollutants. These issues may be exacerbated by increases in groundwater withdrawals that may likely coincide with human population increases (see Section 4.1).

The restricted range of the species along with the lack of use of burrows may indicate a narrow tolerance for temperature increases resulting from climate change in northeastern Florida. The direct influence of temperature changes to crayfish habitat depends on the species’ thermal range, geographical distribution, and general ability to acclimate (Carmona-Osalde et al. 2003, p. 306). Previous research indicates increased temperature can lead to decreased survival, growth rates, and reproduction (Carmona-Osalde et al. 2003, pp. 308-313), as well as behavioral modifications (Seals et al. 1997, pp. 136-137) in other Procambarus spp. There are no direct studies to indicate the impact higher water temperatures would have on Black Creek crayfish populations; however, there are some early indications that Black Creek crayfish are disappearing from previously occupied streams and their congener, slough crayfish (Procambarus fallax), are replacing them in streams with >30°C (86℉) (Warren et al. 2019, unpublished data), particularly near lake outflows (G. Warren 2020, pers. comm).

Predicted sea level rise (SLR) in Mayport, Florida (the nearest National Oceanic and Atmospheric Administration [NOAA] monitoring station), under various scenarios range between a lowest possible SLR in 2100 of 3.77 ft (1.15 m; intermediate scenario) and a highest possible rise of 10.5 ft (3.2 m; extreme) (NOAA 2017, n.p.). Under these scenarios, areas supporting Black Creek crayfish habitat (between 56 and 84 km linear habitat) may become partially or completely inundated (i.e., under water) at some point during this century. However, decades prior to surface inundation, habitat may undergo vegetation shifts triggered by changes to hydrology (wetter), salinity (higher), and more frequent storm surge and king tide events (pulse events causing massive erosion and salinization of soils; Saha et al. 2011, p. 181 – 182).

Sea level rise could also cause saltwater intrusion of groundwater within the range of the Black Creek crayfish, increasing salinity and decreasing oxygen levels, even in areas not directly impacted by higher tide levels and inundation.

The Service’s Florida Ecological Services Offices utilize the intermediate and high scenarios from Sweet et al. (2017, entire) when considering climate change effects. Higher fall and winter rainfall (increases of about 20 percent), lower spring and summer rainfall (decreases of about 30 percent) and warmer temperatures by 3-7°F (1.7 – 3.9°C) are also to be considered (Miller and Traxler 2019, p. 37) for regions of Florida.

Dredging to maintain the shipping channel in the lower St. Johns River also has the potential to affect salinity gradients and water quality within the basin (Brodie et al. 2013, p. 12). Indeed, the salinity has already been changing in the St. Johns River due to climate change (i.e., SLR, drought; U.S. Army Corps of Engineers [USACE] 2014, pp. 16, 103). Hydrodynamic model simulation does show high tide salinity >1 ppt may occur at 25% or greater frequency north of Black Creek inflow on the St. Johns River; however, freshwater inflow from the Black Creek is expected to prevent salinity increases in Black Creek or upstream of the mouth (USACE 2014, p. 225).

4.5 Other Threats Other threats historically associated with potential Black Creek crayfish declines include damming of water systems, a microsporidian disease, and run-off from agricultural practices (Franz and Franz 1979, p. 16; Brody 1990, p. 23; FWC 2013, pp. 5-6). Damming, a potential threat to Black Creek crayfish in the future which would be subject to permitting by SJRWMD, immediately changes the character of a stream, which changes its suitability for Black Creek crayfish by reducing oxygen, increasing siltation, and increasing water temperatures.

Specimens with an apparent microsporidian disease have been reported by Franz et al. (2008, p. 13), Nelson and Floyd (2011, p. 6), and as recently as 2020 (Smith-Hicks 2020, p. 1) Infected specimens have chalky white muscle tissues visible through the exoskeleton on the underside of the abdomen (Fig. 4.8). Franz stated this condition is believed to be highly contagious and often fatal to cambarid crayfishes, but the impact on crayfish populations is unknown (Franz et al.

2008, p 13) and no observable impacts to Black Creek crayfish populations have been observed since the disease was first detected. Further research on this condition is warranted.

Figure 4.8. Black Creek crayfish with fungus (source: Nelson and Floyd 2011, p. 74).

4.6 Conservation

4.6.1 Protection and Management of Habitat

In 2013, FNAI indicated that 40% of Black Creek crayfish habitat was protected (FNAI 2013, p. D- 7). The range of the Black Creek crayfish largely overlaps public lands managed by the Florida Army National Guard, CBJTC, and the Florida Forest Service (FFS), specifically 2 state forests (SF): Jennings SF and Etoniah Creek SF (Fig. 4.9). These lands are wildlife management areas wherein wildlife is managed by the FWC and the FFS. Additional conservation lands with occurrence records for Black Creek crayfish include parcels owned by the SJRWMD and mitigation banks (Fig. 4.9). It should be mentioned that land managers of public conservation lands do not necessarily manage stream habitat and the fauna that live in it. Populations on public lands may receive some protection, but no range-wide conservation actions have yet been undertaken for the Black Creek crayfish. Management of the upland habitat adjacent to Black Creek crayfish habitat is provided by CBJTC and the FFS, while SJRWMD has regulatory authority regarding water quality.

Figure 4.9. Currently protected land and Black Creek crayfish locations.

4.6.1.1 Camp Blanding Joint Training Center

CBJTC, the property with the largest known occurrence of Black Creek crayfish (Fig. 4.9), is owned by the State of Florida and managed by the Florida Army National Guard. In 2017, CBJTC entered into a 15-year Candidate Conservation Agreement with Assurances (CCAA) to protect Federal candidate and FWC listed species (Service et al. 2017, entire). Enrolled lands include 46,507 acres of the total 73,000-acre installation (Service et al. 2017, p. 2) and encompass 121 miles of streams, many of which are occupied by the Black Creek crayfish. The objectives for the CBJTC CCAA are as follows:

- Objective 1. To maintain or enhance the quality of habitat for the Covered Species on the Enrolled Lands. - Objective 2. To reduce or eliminate disease transmission to the Covered Species on the Enrolled Lands. - Objective 3. To reduce or eliminate exotic and invasive species on the Enrolled Lands.

Objective 3 may or may not apply to the intrusion of the white tubercled crayfish given that it is still unclear if it moved into CBJTC on its own or was introduced as bait (M. Corby 2020, pers. comm.). Other funding and cooperation measures may need to be implemented in the future to address issues related to white tubercled crayfish impacts on Black Creek crayfish at CBJTC.

During the tenure of the CCAA, hydrologic measurements may be taken and invasive species monitored in areas known to be occupied by Black Creek crayfish at CBJTC (Service et al. 2017, p. 24). Additionally, Black Creek crayfish will be surveyed at least once every five years in order to evaluate the success of conservation actions and implementation of BMPs (Service et al. 2017, p. 24). All monitoring data will be compared to baseline data collected in the first reporting year and the CCAA will be deemed successful if the Black Creek crayfish are continually found to be stable or increasing in abundance (Service et al. 2017, p. 25). In addition to the CCAA, CBJTC has an ongoing program to purchase lands within 3 miles of the installation, preferably to be managed by other state agencies, to create a buffer for the localized effects of loud training exercises (Fig. 4.8). These purchases would not fall within the purview of the CCAA, and Black Creek crayfish habitat on these lands would not be afforded the same protections as those that occur on the installation.

4.6.1.2 Florida State Forests

On a broader scale, there is also an ongoing program to protect an essential wildlife corridor called “O to O” (Ocala to Osceola Wildlife Corridor or O2O) in North Central Florida. The Service, Natural Resources Conservation Service, Army National Guard, Florida Department of Agriculture and Consumer Services via the Florida Forest Service, Florida Department of Environmental Protection, Putnam Land Conservancy, North Florida Land Trust, Conservation Trust for Florida, are partnering with the Florida Department of Environmental Protection’s Office of Greenways and Trails and other partners to ensure that “O to O” fish and wildlife habitat is protected from future development. The project is called “O to O” as shorthand for describing its path from the Ocala National Forest southeast of Gainesville to the Osceola National Forest and Okefenokee National Wildlife Refuge in northeast Florida and southeast Georgia. In total, The Natural Resources Conservation Service granted Federal funding for this project in 2018 and 2020. In total, the Natural Resources Conservation Service will allocate more than $11 million dedicated to “O to O” land protection under the agency, which compliments the $33 million already expended or committed by partner programs. This project entails what is likely one of the largest and longest proposed network of protected conservation lands in the eastern United States. If fully successful, it would result in a functionally connected conservation land network spanning over 200 miles and potentially 2 million acres from the Wekiva River basin just north of Orlando to the Okefenokee Swamp in southeast Georgia [(the conservation corridor does cover 16 of 19 (84%) of the Black Creek populations (populations west of the St. Johns River)]. The “O to O” initiative would not only connect two of the five remaining large populations of the Florida black bear; it would also protect habitat for myriad other listed and increasingly rare animals and plants such as red-cockaded woodpecker, flatwoods salamander, wood stork, eastern indigo snake, southeastern American kestrel, gopher tortoise, gopher frog, Sherman’s fox squirrel, Florida pine snake, Florida mouse, American swallow-tailed kite and Bartram’s ixia. Protection of ecosystem services such as flood control and water quality are also important aspects of this project. It spans the watershed divide between the Suwannee River and St. Johns River watersheds, two of Florida’s largest and most significant rivers. The project would protect important headwater wetlands and tributaries of these river systems including Black Creek and the New River, which both contain significant aquatic biodiversity. The primary project areas are encompassed by three existing Florida Forever land conservation projects that are located Marion, Putnam, Clay, Duval, Bradford, Union, and Baker Counties: Camp Blanding-Osceola Greenway, Northeast Timberlands, and Etoniah/Cross Florida Greenway. If protected these three Florida Forever projects would protect a viable ecological connection from Ocala National Forest to Osceola National Forest and Okefenokee National Wildlife Refuge which would include a large portion of the Black Creek crayfish range.

4.6.2 Other Existing Regulatory Mechanisms

4.6.2.1 Basin Management Action Plans (BMAPs)

The DEP coordinates development and implementation of basin management action plans (BMAPs) to assess, monitor, and improve the water quality of water bodies in the basin that are considered “impaired” by pollution. Total maximum daily loads (TMDLs) are water quality targets for specific pollutants (such as fecal coliforms) that are established for impaired waterbodies that do not meet their designated uses based on Florida water quality standards (DEP 2008, p. 1). A BMAP prepared for tributaries to the Lower St. Johns River (DEP 2008, entire) addresses water quality issues for some drainages in or near the range of the Black Creek crayfish. Two streams in urbanizing areas, Big Davis Creek and Durbin Creek, in southeastern Duval and northwestern St. Johns counties (Fig. 2.8) are locations where TDMLs have been established (DEP 2008, p. 87).

4.6.2.2 Florida Fish and Wildlife Conservation Commission Conservation Measures

The Black Creek crayfish was listed by the State of Florida as a state threatened species in 2018 (FWC 2018, p. 8) and is afforded protections per Rules 68A-27.003(2)(a), F.A.C. and 68A- 27.001(4), F.A.C. which made it illegal to take, possess, transport, or sell Black Creek crayfish except as authorized by permit from FWC. Subsequently, FWC has also drafted Species Conservation Measures and Permitting Guidelines for the Black Creek crayfish (FWC 2019c, entire). Intentional take permits authorizing the take of state-designated Threatened species are issued for scientific or conservation purposes that will benefit the survival potential of the species, or as described in Rule 68A-27.007, F.A.C.. Incidental take permits are issued when there is a scientific or conservation benefit and only after showing that the permitted activity will not negatively impact the species.

The FWC has also drafted a Species Action Plan (SAP; FWC 2013, entire) as a way to guide conservation actions for the benefit of the Black Creek crayfish across its range. The Black Creek crayfish SAP details the actions deemed necessary to improve the species’ conservation status, including: 1) working with land managers and landowners to protect, monitor, and enhance the habitat quality of known crayfish sites; 2) drafting and disseminating stream-

48 centered habitat management recommendations to reduce threats and safeguard crayfish and riparian corridors; and 3) continuing to survey to determine the extent of occupied stream reaches and to identify additional occupied drainages that extend the known range of the species, decentralize its vulnerability to threats, and reduce its overall risk of extinction.

4.6.2.3 Florida Forestry and Florida Agriculture Wildlife Best Management Practices (WBMPs)

In order to avoid activities that could degrade or alter riparian zones adjacent to areas inhabited by Black Creek crayfish, as well as to prevent upland erosion into streams and rivers, some actions require measures to avoid “take” of the species. These include following guidelines for activities that do not require FWC permits, including avoidance of degradation of Black Creek crayfish habitat through the State of Florida BMPs for stormwater runoff and the FDACS silviculture BMPs. Modern forestry operations in Florida have a (self-reported) compliance rate of 100% for following Wildlife Best Management Practices (WBMPs) for state imperiled species, including the Black Creek crayfish. Forestry protection of special management zones (SMZs) may reduce its contribution to nonpoint source pollution (FDACS and FWC 2018, p. 4). SMZs are meant to provide shade for temperature regulation, a natural vegetation strip, intact ground cover, large and small woody debris, leaf litter, and a variety of tree species and age classes, most of these benefitting Black Creek crayfish (FDACS 2014, p. 5). For the sites following WBMPs across the state of Florida in 2017, 19% were located on private non- industrial forestlands, 64% on forest industry lands, and 17% on public lands (FDACS and FWC 2018, p. 4). According to Florida’s BMPs for forestry, SMZs should be 35 ft wide (200 ft for Outstanding Florida Waters (OFWs)), but selective logging is permitted in this zone (FDACS 2008, p. 9).

4.6.2.4 Florida Department of Environmental Protection Regional Water Supply Planning

The North Florida Regional Water Supply Plan (NFRWSP), which includes all counties within the Black Creek crayfish range, was created by a partnership in 2011 through a formal agreement by the DEP and the water management districts (SJRWMD and SRWMD 2017, p 2). The purpose of the NFRWSP includes projecting water demands, potential water resource impacts, and providing project options to meet future water needs and avoid unacceptable water resource impacts (SJRWMD and SRWMD 2017, p. 3). The NFRWSP provides an avenue so that the

49 water management districts within the plan area fulfill the legal mandate (Section [s.] 373.709, F.S) to conduct water supply planning when it is determined that existing sources of water are not adequate to supply water for all existing and future reasonable-beneficial uses and to sustain the water resources and related natural systems through 2035 (SJRWMD and SRWMD 2017, p. 5).

4.6.2.5 Other Federal Regulatory Mechanisms

The Federal Clean Water Act (CWA) of 1972 protects water quality in federally protected waterways such that it will be supportive of aquatic plants, fish, and wildlife (CWA 1972, entire). This statute regulates dredge and fill activities that adversely affect wetlands, but not the headwater streams which Black Creek crayfish primarily use. These and other wetland protection laws and policies such as wetland mitigation banks and incentives may benefit Black Creek crayfish; however, rules that allow mitigation of destruction or disturbance of wetlands by conserving an existing wetland elsewhere can result in a net loss of Black Creek crayfish habitat.

CHAPTER 5 – CURRENT CONDITION

The population is the unit of resiliency, which is then scaled up to redundancy and representation at the species scale. Accurately defining and delineating populations is a crucial step to assess species viability. After delineating populations, we then assessed the resiliency of each population as described in the following sections by synthesizing the best available information about the amount of habitat available to each population and its general quality, the persistence of crayfish within that habitat, and the level of protection. Resiliency of populations was then scaled up to describe current redundancy and representation for the Black Creek crayfish.

5.1 Delineating Populations

Black Creek crayfish populations were delineated using HUC12 (12-digit hydrologic unit code) hydrologic units, taken from the USGS Water Boundary Dataset. HUC12 hydrologic units correspond to sub-watersheds, while units with fewer digits (e.g., HUC8 or HUC10) correspond to larger units (watershed or basin, respectively). Hydrologic units of smaller sizes (more digits) are nested within units of larger sizes (fewer digits). Home range sizes and dispersal distances for Black Creek crayfish are not well known, but they are believed to be small based on observations of other native, non-invasive crayfish (Bubb et al. 2006, p. 1363) and general observations in the field. Based on these presumed small home range sizes, unknown dispersal distances, and stream habitat heterogeneity, it is possible that multiple crayfish populations exist within HUC12 sub- watersheds. However, we do not have adequate data to support delineating smaller populations at this time; additional research could inform a change in population delineations in the future. If Black Creek crayfish had been observed from 2008 to 2020 in a HUC12 unit, a population was considered to be present in that unit.

Using HUC12 delineations, 19 extant Black Creek crayfish populations were identified (Fig. 5.1): 1) Ates Creek, 2) Black Creek – St. Johns River, 3) Clarkes Creek, 4) Durbin Creek, 5) Governors Creek, 6) Greens Creek, 7) Julington Creek, 8) Kingsley Lake, 9) Lake Geneva, 10) Lower Etonia Creek, 11) Lower North Fork – Black Creek, 12) Lower South Fork – Black Creek, 13) Peters Creek, 14) Trout Creek – St. Johns River, 15) Upper Etonia Creek, 16) Upper North Fork – Black Creek, 17) Upper South Fork – Black Creek, 18) Simms Creek, and 19) Yellow Water Creek.

Figure 5.1 Black Creek crayfish populations, defined by HUC12 hydrologic units.

5.2 Estimating Current Condition

Resiliency for Black Creek crayfish populations, the ability to withstand stochastic events or disturbances, is influenced by the number of individuals in a population, reproductive rates, and distribution. Despite survey efforts in recent years, there are currently no abundance or reproductive data available for a large portion the current Black Creek crayfish range (i.e., only 12 of the 19 populations have current abundance information). Therefore, current resiliency for each population was assessed by aggregating likely habitat within each watershed, current riparian health and water quality, conservation and protection of habitat, and population persistence of Black Creek crayfish associated with the presence of the white tubercled crayfish. Because it is unclear if white tubercled crayfish have a significant effect on abundance or occupancy at this time, we also present current resiliency without the potential influence of white tubercled crayfish for all populations of Black Creek crayfish.

5.2.1 Baseline Score: Potential Habitat & Level of Protection

Population size is both a direct contributor to and an indirect indicator of resiliency. Small populations are more susceptible to demographic and environmental stochasticity than larger populations. Small populations are also more likely to suffer from allele effects or decreased fitness as a result of low genetic diversity from inbreeding or genetic drift (Willi et al. 2005, p. 2260). There are no current estimates of population sizes for Black Creek crayfish; however, there is a recent habitat suitability model available to compare the amount of likely habitat in each population across the range of the Black Creek crayfish. The 2018 habitat suitability model (HSM; detailed below and in Appendix A; Barrett 2018, n.p.) utilizes stream characteristics, riparian health (i.e., forested riparian area), and water quality (i.e., Total Dissolved Solids Concentrations [TDS]) to calculate potential habitat for Black Creek crayfish. To conservatively estimate likely Black Creek crayfish habitat, potential habitat within this SSA was limited to stretches in the HSM as having “Fair-Good” or better habitat index values (≥ 4). Only including habitat indices of ≥ 4 limits predictions to the 10-percentile threshold which generally provides a good cutoff for indicating potential habitat. We excluded any potential habitat that occurred within a watershed but was cut off from the rest of the population by major geographical barriers. For example, habitat on the east side of the St. Johns River in the Clarkes Creek and Governors Creek watersheds was excluded because it is separated from the majority of the

53 habitat by a major river that would likely not be traversed by Black Creek crayfish and there are no current detections of Black Creek crayfish at those sites.

For purposes of this SSA, we only used habitat within HUC12s where Black Creek crayfish have been observed since 2008. We did this for several reasons. First, we did not want to use outdated information in assuming a population was still present. Second, we wanted to be consistent in what we considered “current” for categorizing resiliency. It is important to note that some HUC12 watersheds were excluded from our analysis, but are indicated as having likely habitat based on the HSM, and might have Black Creek crayfish. Regardless, we conservatively limited our assessment of current condition to those populations for which data are available from 2008 or later.

There are currently no data indicating how much habitat is needed within the range of a population to maintain resiliency levels. However, it can be inferred that, in the absence of other limiting factors (e.g., stochastic events, unknown alterations to water quality, interspecific competitors) the greater amount of likely linear habitat (hereafter “likely habitat”) within a HUC12 watershed indicates greater likelihood of both occurrence and high abundance. Therefore, we used amount of habitat available within a HUC12 watershed to determine a baseline score for the Black Creek crayfish.

Conservation of Black Creek crayfish habitat through best management practices, direct protection of areas occupied by the crayfish, and water management programs have an impact on the ability of the crayfish to persist within an area (see Section 4.6). The more habitat that is protected within a population, the more likely the population will remain viable into the future. Larger populations are more likely to persist without protection; therefore, we only incorporated protection into baseline scores for populations with less than 50 km likely linear habitat within the watershed (i.e., “Low”). Populations with “low” levels of potential habitat were lowered one baseline score if less than 50% of their likely habitat is currently protected. Black Creek crayfish habitat considered protected includes habitat that occurs on federal and state-owned lands (e.g., Camp Blanding, state forests) or occur within conservation areas (e.g., conservation easement, conservation area, preserve, mitigation bank, SJRWMD).

We estimated the amount likely habitat available for each population and amount of protection and created four categories as follows: • Very High—populations with >100 km of likely habitat. • High—populations with 50-100 km of likely habitat. • Moderate—populations with 20-50 km of likely habitat; >50% existing likely habitat protected. • Low—populations with <50 km of likely habitat and <50% existing likely habitat protected; populations with <20 km of likely habitat, regardless of amount of habitat protection.

5.2.1.1 Likely Habitat: Habitat Suitability Model

Barrett (2018, n.p.) built a habitat model using 396 sites (n=211 presence sites and n = 185 absence sites) collected over 8 years to predict Black Creek crayfish habitat in northeastern Florida (see Appendix A for details). He used a combination of two types of models to identify potential habitat of Black Creek crayfish: Maxent and Fuzzy Logic. He used occurrence records of Black Creek crayfish that were stored on a Geographic Information System (GIS) database (point shapefile) maintained by FWC. The database contains records collected between 1976 and 2015. However, for his model, he only used relatively recent records from 2008 to 2015. Although he did not use absence locations in model development, he did use them for model validation. Six variables used in the model included two stream attributes, two forest conditions, geology type, and a water quality index. The two stream attributes were gradient and sinuosity (see Appendix A for details).

The Maxent model was a relatively good fit based on average area-under-the-curve (AUC) of 0.841 from the 10 replicate models. He used the Maxent output of variable importance based on jackknife results of leave-one-out variable analysis, which indicated the most influential variable was stream gradient followed by geology type and mean forest canopy. The values that the model most strongly indicated as potential habitat for these three variables were between 5 and 18 m/km for stream gradient, medium sand silt and to a lesser degree sand for geology type, and >0.6 for mean forest canopy.

Likely habitat was considered as the Fair-Good index class or above, the classes where both models are in agreement (Appendix A; Table A-1). Based on this designation, the model comprised 1,749.4 km of likely stream habitat, which is 45.1% of available streams in the analysis extent (Appendix A; Figure A-1). The amount of Best (top index class) potential habitat is 15.2% of available streams, which contained 50.2% of presence locations. The model predicted 1,092.8 km likely habitat when restricted to HUC12 watersheds currently known to be occupied by Black Creek crayfish. See Appendix A for detailed model description and results.

5.2.2 Habitat Quality

As mentioned above, water quality is an important component of Black Creek crayfish population resiliency because it affects how well they survive and reproduce. In the absence of site-specific habitat and water quality measurements taken at Black Creek crayfish locations within each population, we used data available at the subwatershed scale (HUC 12; hereafter watershed) by U.S. Geological Survey (USGS) and the Environmental Protection Agency (EPA) to characterize potential pollution due to urban development, agriculture, mining, and forestry for each occupied watershed (details below). We do not currently have data regarding thresholds for when contaminants levels or disturbance in and around habitat may begin to negatively impact Black Creek crayfish. Instead, we relied on natural breaks in the data and previous studies evaluating human disturbances and observed impacts on water quality. We assessed water quality by combining several metrics within each watershed: watershed health assessed by the general water quality in the watershed and disturbance of the riparian area surrounding likely habitat from urbanization, agriculture, forestry, or mining. We then combined scores for each of these metrics to give an overall water quality score for each population.

5.2.2.1 Habitat Quality: Watershed Health

In order to assess overall water quality in each occupied watershed, we examined transport of total nitrogen, total phosphorus, and suspended sediment estimated by the Spatially Referenced Regression On Watershed (SPARROW) models (Schwarz et al. 2006, entire). SPARROW is a watershed modeling technique utilized by USGS to relate water-quality measurements to streams and in-stream processing with the purpose of describing transport of contaminants from point and non-point sources on land to rivers and streams. Sources of nutrient run-off included in the

56 models include agriculture, census data, land cover, and other contaminant sources known to exist on the landscape (e.g., sewage treatment plants, aquaculture). This information is combined with basin characteristics (e.g., soil type, topography) and actual contaminant information that has been collected to estimate contaminant yields in streams (i.e., mass of nutrients entering a stream per acre of land).

We used SPARROW (Schwarz et al. 2006, n.p.) to collect estimated mean-annual transport of total nitrogen (TN), total phosphorus (TP), and suspended sediment (SS) in streams within each of our population watersheds. We used these three variables because they are linked to the primary activities believed to affect Black Creek crayfish habitat: urban development (i.e., impervious cover, sewer runoff) and agriculture (i.e., fertilizer, animal waste). Once we collected estimated TN, TP, and SS for each occupied watershed, we classified each amount according to the natural class breaks (i.e., ranges where like data are grouped together to minimize variation within each range) (Table 5.1) in the distribution of TN, TP, and SS in all HUC12 watersheds in Florida that are also available through SPARROW interactive online mapper for the southeast (http://sparrow.wim.usgs.gov/sparrow-southeast-2012/).

Table 5.1. Natural class breaks provided by SPARROW interactive online mapping interface (Schwarz et al. 2006, n.p.) based upon total phosphorous, total nitrogen, and suspended sediment estimates in HUC12 watersheds across Florida.

Total Total Suspended Phosphorous Nitrogen Sediment Very Low (1) 0 - 15.9 0 - 268 0 - 3.87 Low (2) 15.9 - 22.5 268 - 327 3.87 - 5.84 Moderate (3) 22.5 - 32.4 327 - 396 5.84 - 8.82 High (4) 32.4 - 66.7 396 - 522 8.82 - 17.1 Very High (5) > 66.7 > 522 > 17.1

Once each nutrient level was classified for each Black Creek crayfish population, the corresponding values (Table 5.1; 1-5) were added together to calculate overall watershed health for each population. Overall watershed health was calculated for each population by totaling values for TP, TN, and SS for each population and were ranked as Good (3-5), Fair (6-10), and Poor (>10). Good watershed health indicates there are no adverse impacts from urbanization or

57 agriculture. Fair watershed health indicates some impacts from urbanization or agriculture which are potentially impacting Black Creek crayfish health, food sources, and reproduction, thus decreasing overall resiliency. Poor watershed health indicates areas where Black Creek crayfish may be struggling to survive and maintain populations because of impacts from urbanization and agriculture on water quality.

5.2.2.2 Habitat Quality: Riparian Health

Riparian impairment, either through urban development, agriculture, or other land use, can augment negative impacts of nonpoint source pollution within the watershed as well as impact stream quality independent of land use within the watershed. Indeed, Black Creek crayfish are highly susceptible to alterations in stream flow due to habitat alterations brought on by building and maintaining roadways (Brody 1990, pp. 19-20). Like urban use impacts in riparian zones, agriculture impacts can directly decrease riparian vegetation cover and health. Agricultural land cover within the riparian zones can further impact water quality and aquatic organisms via increased exposure to chemical fertilizers, pesticides, livestock waste, and sedimentation, which have been implicated in amphibian malformation, and declines in population numbers, reproductive success, and biodiversity (Beja and Alcazar 2003, entire; Montag et al. 2019, entire; Burkholder et al. 2007, pp. 309-310). General damage to, or removal of, riparian areas can be detrimental to Black Creek crayfish; specifically, excess removal of tree canopy can increase water temperature and deplete dissolved oxygen levels (Franz et al. 2008, p. 18).

In order to assess current riparian health, we analyzed current land use within 100 m of likely habitat (see Section 5.1) using the 2018 Florida Land Cover Classification (Kawula and Redner 2018, entire). The land cover map classifies land use into 45 habitat types developed from hybridization of classification systems from FWC, Florida Natural Areas Inventory, and Florida Department of Transportation. Land use was calculated for urban development, non-forestry agriculture, mining, and plantation forestry use. We then used percentage of both urban development and general riparian disturbance to calculate riparian health for each HUC12 population.

Diamond et al. (2002; entire) assessed the relationship between human land uses (urban and agriculture) and fauna in the Clinch and Powell River watersheds in Tennessee. They found that when urban areas and major highways approached 12.2% cover near the stream, the stream was more likely to be classified as impaired, while unimpaired sections of those streams averaged 5.6% urban cover (Diamond et al. 2002, p. 1151). We calculated percent cover of urban land use within 100 m of each stream in each watershed and converted percentages to a good(<6%)- fair(6-12%)-poor(>12%) scale.

There is little information regarding the threshold for agricultural, mining, and forestry land use within a riparian area that may begin to have an impact on stream quality. Therefore, we placed general utilization percentages into categories based upon natural breaks in the data: good(<15%)-fair(15-28%)-poor(>28%). Urban development (roads, structures, impervious cover) is likely to negatively influence Black Creek crayfish habitat more over the long-term than other riparian disturbances, so we weighted it more in the overall riparian health score (Table 5.2). For example, a watershed with a large amount of forestry disturbance within riparian areas but very little urban development would likely be healthier than a watershed with very little forestry and high impervious cover within riparian areas.

Table 5.2. Riparian health rank based on both urban development and total amount of human utilization within 100 m of likely Black Creek crayfish habitat.

Total Utilization Good (<15%) Fair (15-28%) Poor (>28%) Good (<6%) Good Good Fair Urban Fair (6-12%) Fair Fair Poor Development Poor (>12%) Poor Poor Poor

5.2.3 Presence of White Tubercled Crayfish

Presence of white tubercled crayfish, a pioneering congeneric species that is currently expanding its range and competing with Black Creek crayfish within the western part of Black Creek crayfish’s native range (see Section 4.3), was assessed for potential impacts to the current population resiliency of Black Creek crayfish. Presence of white tubercled crayfish and subsequent current condition of each population were based on current presence or absence

59 within the boundary of a population (watershed), in an adjacent watershed, or susceptibility to white tubercled crayfish expansion due to lack of major geographic barriers (i.e., St. Johns River). Recent surveys indicate that white tubercled crayfish decrease Black Creek crayfish abundance in areas where they overlap; therefore, the closer the white tubercled crayfish’s range is to Black Creek crayfish occurrences, the more likely the population may experience lower resiliency over time. The data used to determine presence of white tubercled crayfish includes surveys done from 2008-2019 and encompassed 12 of the 19 watersheds that currently support Black Creek crayfish (see Section 4.3; Warren et al. 2019, unpublished data; P. Moler 2020, unpublished data).

We categorized risk of impact from white tubercled crayfish in order to modify the current baseline score. Risk was based on several parameters: presence or absence of white tubercled crayfish in the watershed, in an adjacent watershed, geographic barriers to white tubercled crayfish dispersal, and data-based evidence that Black Creek crayfish populations have been impacted by the presence of white tubercled crayfish. Populations that occur on the east side of the St. Johns River were considered at “very low” risk of impacts from white tubercled crayfish because the latter do not currently occur on that side of the river and it is believed the river is a barrier to their expansion. Populations on the west side on the St. Johns River that are not known to be occupied by white tubercled crayfish, and not adjacent to a watershed occupied by white tubercled crayfish, were ranked as having “low” risk. Populations at “moderate” risk of lowered resiliency occur in watersheds currently occupied or adjacent to those occupied by white tubercled crayfish and where recent survey data indicate no decrease in abundance or Black Creek crayfish occurrence at overlapping sites. Populations at “high” risk are those that currently overlap with the white tubercled crayfish range and where survey data indicate Black Creek crayfish abundance or occurrence has decreased at sites occupied by white tubercled crayfish.

We synthesized the amount of likely risk for each population based on proximity of white tubercled crayfish to the population and whether or not white tubercled crayfish are currently impacting the population, and created four categories as follows:

• High—confirmed white tubercled crayfish within watershed; evidence of decrease in abundance or occurrence of Black Creek crayfish.

• Moderate—confirmed white tubercled crayfish within the watershed or adjacent watershed; no evidence of decrease in abundance or occurrences of Black Creek crayfish. • Low—no confirmed white tubercled crayfish within adjacent watershed; watershed on west side of the St. Johns River. • Very Low— no confirmed white tubercled crayfish within adjacent watershed; watershed on east side of the St. Johns River.

5.2.4 Current Population Resiliency The current condition category is a qualitative estimate based on the availability of habitat within the watershed, which establishes the baseline score, and then is modified based on habitat quality and risk from the white tubercled crayfish. To summarize overall current population resiliency of the Black Creek crayfish, we ranked each population into a current condition category (Very High, High, Moderate, Low; Table 5.3) based on factors outlined above. Classification of habitat quality could raise the baseline score by two levels (Very High) or one level (High) or lower it by one level (Low). Moderate habitat quality left the baseline score unchanged. Risk from white tubercled crayfish only lowered the baseline score if the population was at high risk.

Table 5.3. Potential resiliency score ranks and definitions for current and future conditions scenarios. Resiliency Score Likelihood of Population Persistence Very high probability of persistence for next 20-30 years at or Very High above the current available habitat. High probability of persistence for next 20-30 years at or above the High current available habitat. Moderate probability of persistence for next 20-30 years at or above Moderate the current available habitat. Low probability of persistence for next 20-30 years at or above the Low current available habitat. Likely Extirpated High probability of extirpation in the next 20-30 years.

5.3 Current Resiliency

Resiliency refers to the ability of populations to withstand stochastic events, whether demographic, environmental, or anthropogenic. For this SSA, empirical data are not available to associate resiliency categories with specific quantitative extinction risks or probabilities of persistence. Rather, we are limited to providing qualitative definitions of each resiliency category based upon assumptions about available habitat and its health, protection of habitat, and the unconfirmed, but potential impact of the white tubercled crayfish. Populations with very low resiliency are highly vulnerable to stochastic events and face a high risk of extirpation within the next few decades. Populations with low resiliency are less likely to be extirpated within the next few decades, but require additional growth (with help of regular habitat management and/or restoration) to become more self-sustaining and resilient to stochastic events. Populations with moderate resiliency are unlikely to be extirpated within the next few decades in the absence of catastrophes or significant declines in habitat quality. Populations with high resiliency are the most robust and resistant to stochastic fluctuations.

5.3.1 Potential Habitat

There is a total of 1,149 km of likely linear habitat within watersheds that are currently occupied by Black Creek crayfish and 47% is currently under some level of management or protection (Table 5.4). Of the 19 extant populations of Black Creek crayfish, three populations have more than 100 km of likely habitat according to the habitat suitability model and a “very high” baseline score (Table 5.4). Seven populations have less than 50 km of likely habitat and five of those have less than 50% protection (Table 5.4). The majority of Black Creek populations (63%) have “high” or “very high” baseline resiliency scores.

Table 5.4. Amount of total and likely linear habitat within each population boundary, amount of likely habitat that is currently protected, and current baseline score.

Total Likely Population Total Likely Habitat % Likely Baseline Habitat Habitat Protected Habitat Resiliency (km) (km) (km) Protected Score Ates Creek 98.7 82.9 53.2 64% High Black Creek - St. Johns River 27.8 26.6 0.8 3% Low Clarkes Creek 82.0 63.9 14 22% High Durbin Creek 24.4 22.6 8.3 37% Low

Governors Creek 92.0 55.0 7.5 14% High Greens Creek 99.2 83.3 50.4 61% High Julington Creek 44.5 39.0 18.2 47% Low Kingsley Lake 99.3 84.4 73.2 87% High Lake Geneva 14.5 9.0 7.9 88% Low Lower Etonia Creek 95.2 75.0 18.1 24% High Lower North Fork-Black 74.0 Creek 88.0 34.1 46% High Lower South Fork-Black Very 107.9 Creek 124.4 40 37% High Peters Creek 39.2 36.1 0 0% Low Simms Creek 71.7 56.2 0 0% High Trout Creek-St. Johns River 13.2 12.1 0 0% Low Upper Etonia Creek 13.9 7.5 6 80% Low Upper North Fork-Black Very 126.5 Creek 145.9 55.1 44% High Upper South Fork-Black Very 109.1 Creek 134.6 89.5 82% High Yellow Water Creek 88.3 77.9 60.6 78% High Total 1396.8 1149.0 536.9 47% na

5.3.2 Water Quality

5.3.2.1 Watershed Health

The majority of Black Creek crayfish populations have “fair” watershed health according to SPARROW estimates of TP, TN, and SS (Table 5.5). Four populations, Clarkes Creek, Governors Creek, Julington Creek, and Trout Creek – St. Johns River, all have “poor” overall watershed health (Table 5.5).

Table 5.5 Total phosphorus, total nitrogen, and suspended sediment within each Black Creek crayfish population watershed boundary and watershed health score.

Total Total Suspended Phosphorus Nitrogen Sediment Watershed Population (kg/km2) (Kg/km2) (MT/km2) Health Ates Creek 18.0 262 6.98 6 - Fair Black Creek - St. Johns River 33.9 382 7.57 10 - Fair Clarkes Creek 25.2 770 7.58 11 - Poor

Durbin Creek 31.8 370 3.73 9 - Fair Governors Creek 41.3 887 16.9 13 - Poor Greens Creek 14.3 255 6.34 5 - Good Julington Creek 47.9 475 8.27 11 - Poor Kingsley Lake 14.4 225 6.87 5 - Good Lake Geneva 24.2 327 7.78 8 - Fair Lower Etonia Creek 18.5 262 6.97 6 - Fair Lower North Fork-Black Creek 27.5 341 9.18 10 - Fair Lower South Fork-Black Creek 21.5 304 8.69 7 - Fair Simms Creek 19.2 265 5.04 5 - Good Peters Creek 23.9 361 8.25 9 - Fair Trout Creek-St. Johns River 52.7 417 8.59 11 - Poor Upper Etonia Creek 24.7 374 5.85 9 - Fair Upper North Fork-Black Creek 16.0 289 8.61 7 - Fair Upper South Fork-Black Creek 20.9 268 7.39 6 - Fair Yellow Water Creek 25.8 339 7.56 9 - Fair

5.3.2.2 Riparian Health

Urban development within 100 m of likely habitat is high in Julington Creek, Lower North Fork – Black Creek, and Lower South Fork – Black Creek watersheds (Table 5.6). Overall utilization of riparian areas is also high in Clarkes Creek, Greens Creek, Lower Etonia Creek, and Yellow Water Creek (Table 5.6). Half of the current Black Creek crayfish populations have good riparian health (Table 5.6).

Table 5.6 Total area within 100 m of likely habitat utilized for urban development, agriculture, mining, and forestry for each Black Creek crayfish population and the riparian health score.

Total Area % Non- % Area within 100 % forestrey % % Tree Currently Riparian Population m (km2) Developed Agriculture Mining Plantation/Forestry Utilized Health Ates Creek 15.874 2.5% 1.1% 0.1% 20.5% 24.3% Good Black Creek - St. Johns River 5.32 11.3% 2.6% 0.1% 9.6% 23.6% Fair Clarkes Creek 13.196 8.2% 0.9% 0.0% 24.8% 33.8% Poor Durbin Creek 4.557 4.3% 0.3% 0.1% 5.6% 10.2% Good Governors Creek 11.02 9.8% 3.3% 0.3% 10.9% 24.2% Fair Greens Creek 16.913 1.9% 0.3% 0.0% 30.7% 32.8% Fair Julington Creek 8.001 26.2% 0.0% 0.4% 1.2% 27.7% Poor Kingsley Lake 16.186 3.2% 0.2% 0.2% 10.9% 14.4% Good Lake Geneva 2.297 2.9% 0.0% 0.0% 3.3% 6.2% Good Lower Etonia Creek 14.461 3.3% 1.3% 0.1% 26.9% 31.6% Fair Lower North Fork-Black Creek 15.491 19.2% 1.0% 0.1% 1.6% 21.9% Poor Lower South Fork-Black Creek 21.304 13.2% 1.5% 0.3% 15.6% 30.6% Poor Peters Creek 6.897 3.7% 1.1% 0.1% 14.2% 19.1% Good Simms Creek 10.91 2.3% 7.0% 0.4% 19.7% 23.1% Good Trout Creek-St. Johns River 2.426 5.9% 1.9% 0.0% 15.7% 23.5% Good

Upper Etonia Creek 1.624 4.7% 0.0% 0.0% 3.0% 7.6% Good Upper North Fork-Black Creek 25.096 7.1% 2.5% 0.6% 17.1% 27.3% Fair Upper South Fork-Black Creek 21.245 1.9% 0.4% 0.1% 21.1% 23.4% Good Yellow Water Creek 16.632 5.5% 2.8% 0.2% 28.8% 37.2% Fair

5.3.2.3 Overall Habitat Quality

Of the 19 Black Creek crayfish populations, seven have “high” overall habitat quality. The five populations with “low” habitat quality have a lot of urban development within their riparian areas except for Clarkes Creek, which has a large amount of forestry use in the riparian areas along with a fair amount of urban development (Table 5.7). Kingsley Lake and Simms Creek populations have good watershed and riparian health, making them the only populations with “very high” habitat quality (Table 5.7; Fig. 5.2). Habitat quality was generally better in the southern and western part of the range than in the northern part of the range (Fig. 5.2).

Table 5.7 Overall habitat quality for each Black Creek crayfish population based on the overall health of the watershed and amount of habitat utilized within the riparian zone near likely habitat.

Watershed Riparian Habitat Population Health Health Quality Ates Creek Fair Good High Black Creek - St. Johns River Fair Fair Moderate Clarkes Creek Poor Poor Low Durbin Creek Fair Good High Governors Creek Poor Fair Low Greens Creek Good Fair High Julington Creek Poor Poor Low Kingsley Lake Good Good Very High Lake Geneva Fair Good High Lower Etonia Creek Fair Fair Moderate Lower North Fork-Black Creek Fair Poor Low Lower South Fork-Black Creek Fair Poor Low Peters Creek Fair Good High Simms Creek Good Good Very High Trout Creek-St. Johns River Poor Good Moderate Upper Etonia Creek Fair Good High Upper North Fork-Black Creek Fair Fair Moderate Upper South Fork-Black Creek Fair Good High Yellow Water Creek Fair Fair Moderate

Figure 5.2 Overall habitat quality for each Black Creek crayfish population based on watershed water quality and riparian quality around likely habitat.

5.3.3 White Tubercled Crayfish

Five of the Black Creek crayfish populations are currently potentially under high risk from white tubercled crayfish because the latter occurs within the watershed and has already shown to be negatively influencing Black Creek crayfish occurrences (Table 5.8). Nine populations are currently potentially at moderate risk from white tubercled crayfish because they occur near current Black Creek crayfish occupied habitat (Table 5.8). Only five populations are currently potentially at low or very low risk from white tubercled crayfish (Table 5.8).

Table 5.8 Current potential risk of negative impacts from white tubercled crayfish (WTC) to Black Creek crayfish (BCC) populations.

Adjacent to Decrease in Confirmed Watershed BCC Side of St. WTC Occupied by Occurrence or Johns Population Presence WTC Abundance River Risk Ates Creek Yes - Yes West High Black Creek - St. Johns River No Yes - West Moderate East and Clarkes Creek No Yes - West Moderate Very Durbin Creek No No - East Low East and Governors Creek No No - West Low Greens Creek Yes - Yes West High Very Julington Creek No No - East Low Kingsley Lake Yes - Yes West High Lake Geneva No Yes - West Moderate Lower Etonia Creek No Yes - West Moderate Lower North Fork-Black Creek Yes - Yes West High Lower South Fork-Black Creek Yes - - West Moderate Peters Creek No Yes - West Moderate Simms Creek No Yes - West Moderate Trout Creek-St. Johns Very River No No - East Low Upper Etonia Creek No No - West Low Upper North Fork-Black Creek No Yes - West Moderate Upper South Fork-Black Creek Yes - Yes West High Yellow Water Creek No Yes - West Moderate

5.3.4 Summarized Resiliency

Of the 19 extant Black Creek crayfish populations, 47% have a high or very high resiliency regardless of impacts of white tubercled crayfish (Table 5.9; Fig. 5.3). Despite having a high amount of likely habitat, the Lower North Fork-Black Creek population has low resiliency because of its impaired habitat, primarily from urban development, and the high risk of potential impacts from white tubercled crayfish. The other populations currently at high risk from white tubercled crayfish (i.e., Ates Creek, Greens Creek, Kingsley Lake, Upper South Fork-Black Creek) have high resiliency because they currently have a large amount of likely habitat, which is generally protected, while also benefitting from high quality habitat (Table 5.9; Fig. 5.3). The other populations with low current resiliency (i.e., Black Creek-St Johns River, Trout Creek-St. Johns River, and Julington Creek) have limited suitable habitat, probably because they occur in watersheds occurring close to the city of Jacksonville in areas that are already heavily urbanized (Fig. 5.3).

Table 5.9. Current classified resiliency of each Black Creek crayfish populations based on baseline score, overall habitat quality, and risk from white tubercled crayfish (WTC).

Current Total Current Resiliency - Likely Baseline Resiliency - Without Habitat Resiliency Habitat Risk from With WTC WTC Population (km) Score Quality WTC Impact Impact Ates Creek 82.9 High High High High Very High Black Creek - St. Johns River 26.6 Low Moderate Moderate Low Low Clarkes Creek 63.9 High Low Moderate Moderate Moderate Durbin Creek 22.6 Low High Very Low Moderate Moderate Governors Creek 55.0 High Low Low Moderate Moderate Greens Creek 83.3 High High High High Very High Julington Creek 39.0 Low Low Very Low Low Low Kingsley Lake 84.4 High Very High High High Very High Lake Geneva 9.0 Low High Moderate Moderate Moderate Lower Etonia Creek 75.0 High Moderate Moderate High High Lower North Fork-Black Creek 74.0 High Low High Low Moderate Lower South Fork-Black Creek 107.9 Very High Low Moderate High High Peters Creek 36.1 Low High Moderate Moderate Moderate Simms Creek 56.2 High Very High Moderate Very High Very High Trout Creek-St. Johns River 12.1 Low Moderate Very Low Low Low Upper Etonia Creek 7.5 Low High Low Moderate Moderate Upper North Fork-Black Creek 126.5 Very High Moderate Moderate Very High Very High Upper South Fork-Black Creek 109.1 Very High High High High Very High Yellow Water Creek 77.9 High Moderate Moderate High High

Figure 5.3 Current resiliency of Black Creek crayfish populations with and without potential impacts from white tubercled crayfish.

5.4 Current Redundancy and Representation

Redundancy describes the ability of a species to withstand catastrophic events. Measured by the number of populations, their resiliency, and their distribution, redundancy gauges the probability that the species has a margin of safety to withstand or return from catastrophic events (such as a rare destructive natural event or episode involving many populations). Catastrophic events could include, among others, droughts, disease outbreaks, or impacts from hurricanes, each of which cause impacts at different spatial scales. Given the limited distribution of the Black Creek crayfish, the species is very susceptible to catastrophic events because the events would not need to be very large or geographically widespread to affect the entire known population.

Representation describes the ability of a species to adapt to changing environmental conditions. Representation can be measured by the breadth of genetic or environmental diversity within and among populations and gauges the probability that a species is capable of adapting and/or acclimatizing to environmental changes. The more representation, or diversity, a species has, the more it is capable of adapting to changes (natural or human caused) in its environment. In the absence of species-specific genetic and ecological diversity information, we evaluate representation based on geographical separation of populations on east and west side of the St. Johns River (Fig. 5.1).

Black Creek crayfish, which typically occupy small streams with clear, highly oxygenated water, are not known to traverse large water bodies such as lakes and large rivers. The St. Johns River was formed around 100,000 years ago when sediment was deposited from the Appalachians; however, the St. Johns River, as it currently exists, was formed between 5,000 and 7,500 years ago during the last ice age. Breinholt and Crandall (2010, entire) determined a genetic separation of Black Creek crayfish on the east and west side of the St. Johns River based upon four samples; therefore, for this SSA we have separated the Black Creek crayfish into two representative units: one on the east side of the St. Johns River and one on the west side of the St. Johns River (Fig. 5.1).

The “East” representative unit contains 3 Black Creek crayfish populations and the “West” representative unit contains 16 populations (Fig. 5.1), so redundancy is much higher on the west side of the St. Johns River compared to the east side (Table 5.10) The three populations that occur on the east side of the St Johns River have moderate or low resiliency. Indeed, casual detections of Black Creek crayfish (i.e., not systematic surveys) have identified them in 10 locations on the east side of the St. Johns River in the past 10 years: 9 Black Creek crayfish in Durbin Creek, 11 in Julington Creek, and 9 in Trout Creek (P. Moler 2020, pers. comm.).

Table 5.10. Summary of resiliency ranks tallied across all Black Creek crayfish populations and representative units.

West of East of Resiliency Class All Populations St Johns River St Johns River Very High 2 2 0 High 7 7 0 Moderate 6 5 1 Low 4 2 2 Total 19 16 3

CHAPTER 6 – FUTURE CONDITIONS AND VIABILITY

We have considered what the Black Creek crayfish needs for viability and the current condition of those needs (Chapters 3 and 5), and we reviewed the factors that are driving the current and future conditions of the species (Chapter 4). We now consider what the species’ future condition is likely to be. We apply our future forecasts to the concepts of resiliency, representation, and redundancy to describe the future viability of Black Creek crayfish in 30 and 50 years. We developed 4 future scenarios for both 2050 and 2070 to assess the future viability of Black Creek crayfish in terms of resiliency, redundancy, and representation, which encompass future urbanization, impacts from white tubercled crayfish, and SLR.

6.1 Future Considerations 6.1.1 Sea Level Rise

Because Black Creek crayfish habitat is expected to be impacted by global climate change and sea level rise in the near future, we calculated SLR both for 30 and 50 years into the future. SLR could potentially influence Black Creek crayfish resiliency by removing potential habitat, thus further decreasing the range, and by lowering overall habitat quality due to increased occurrences of saltwater inundation. We assessed impacts to likely habitat from the habitat suitability model (see Section 5.2.1). We used localized projections of SLR at Mayport, Florida, approximately 15 miles northeast of the nearest population, obtained online using NOAA Sea Level Rise Viewer (https://coast.noaa.gov/digitalcoast/tools/slr.html; accessed 5 February 2020; NOAA 2017, n.p.). Scenarios used were based on Service guidance (Johnson 2018, entire) and a technical report provided by NOAA that provides both global and regional sea level rise scenarios for the U.S. (Sweet et al. 2017, entire). Based on this guidance, future scenarios were restricted to intermediate projections of sea level rise and above (i.e., intermediate-high, high, and extreme). We used intermediate and extreme predictions in SLR in both 2050 and 2070 to get a complete view of the range of impact to Black Creek crayfish habitat. Amount of habitat loss from SLR was used to calculate new baseline scores for 2050 and 2070.

6.1.2 Development

Urban development within the subwatersheds occupied by a Black Creek crayfish population can impact water quality, groundwater and surface water availability, and riparian health. To

75 calculate future habitat quality for each population, we analyzed forecasts of future development within each population watershed and within 100 m of likely habitat (riparian). This was done using geospatial data provided by the Florida 2070 mapping project, which provides varying projections of the development distribution based upon statewide and regional development patterns to accommodate the projected increase of 14.9 million people by 2070 (Carr and Zwick 2016, entire). The Florida 2070 project is a collaboration between 1000 Friends of Florida, the University of Florida GeoPlan Center, and FDACS, and it models predicted development, conservation lands, and water demand in Florida for the year 2070. Two different development conditions are included in our 4 scenarios: trend and alternative. Trend 2070 represents the land use pattern most likely to occur if 2070 population projections are met and counties continue to develop at densities seen in 2010 (Carr and Zwick 2016, p.1). Alternative 2070 represents a land use pattern that still accommodates the 2070 projected population but with a more compact pattern of development and increased protected lands (Carr and Zwick 2016, p. 1). Because no similar data are available for future prediction of urban development in 2050, we used current development within the watershed and riparian zones (see Section 5.3) in 2050 scenarios. Habitat quality scores for 2050 were based on urban, agriculture, mining, and forestry use. However, we only used urban development for these calculations in 2070 because it is difficult to accurately predict future agriculture, mining, and forestry use in Florida in 50 years. Methods for calculating habitat quality based on future indicators for riparian and watershed water quality for 2050 and 2070 were the same methods outlined in Chapter 5.

6.1.3 White Tubercled Crayfish

It is currently unclear to what extent white tubercled crayfish may impact Black Creek crayfish populations in the future; therefore, we calculated future resiliency for populations under scenarios both with and without risk of impact from white tubercled crayfish. Potential risk of impacts from white tubercled crayfish was determined based on the area that species’ range may likely encompass in 2050 and 2070. At the current rate of expansion, it is likely that all watersheds west of the St. Johns River could be occupied by 2050 (see Figure 4.4). Therefore, we predict that all populations on the west side of the St. Johns River could be at risk from white tubercled crayfish and that populations on the east side of the river may not be at risk. We increased the level of impact to Black Creek crayfish between 2050 and 2070: resiliency was

76 decreased by one level in 2050 and by 2 levels in 2070 under scenarios where white tubercled crayfish impacts are predicted.

6.2 Models and Scenarios

Future predictions of SLR (intermediate-high and extreme scenarios), are aligned with emissions-based, conditionally probabilistic and global model projections (Sweet et al. 2017, entire). There were no differences in baseline scores resulting from SLR predictions from each scenario (see Section 6.3.1; Table 6.1); therefore, impacts from SLR and subsequent baseline score are the same for each future scenario. Future predictions of urbanization in 2050 include current development within subwatersheds occupied by Black Creek crayfish. Future predictions of urbanization in 2070 include both (1) current development pattern (i.e., trend) and (2) an alternative pattern of development, which includes more compact development and increases in protected land (Carr and Zwick 2016, entire). Future predictions of impacts of white tubercled crayfish on Black Creek crayfish resiliency rely on both the location of watershed within the future predicted range of the pioneering crayfish and whether the white tubercled crayfish may actually have long term impacts on Black Creek crayfish (yes/no). Given that all SLR scenarios deliver the same baseline score outcome, the 6 future scenarios for 2050 and 2070 are as follows:

Each of these scenarios contemplates potential 30 or 50-year projections for Black Creek crayfish resiliency levels.

6.3 Results

6.3.1 SLR and Future Baseline Scores

SLR predictions for 2050 and 2070 only changed the baseline score for one population, Governors Creek (High to Moderate; Table 6.1). The population is predicted to drop below 50 km of likely habitat under the future SLR scenarios. All SLR predictions (intermediate and extreme) for the other populations for 2050 and 2070 resulted in the same general impact in loss of habitat and subsequent baseline score (Table 6.1); therefore, only one baseline score for each population was used for all future scenarios.

Table 6.1. Black Creek crayfish current and future baseline scores based on three sea level rise (SLR) scenarios.

Future Habitat Remaining

Current Current 3 ft SLR; Current 2050 Extreme 5 ft SLR; Total Likely 2 ft SLR; 2050 Current Future % Likely & 2070 2070 Population Likely Habitat Intermediate- Baseline Baseline Habitat Intermediate- Extreme Habitat Protected High Scenario Score Score Protected High Scenario (km) (km) (km) Scenarios (km) (km)

Ates Creek 82.9 53.2 64% 82.9 82.9 82.9 High High Black Creek - St. Johns River 26.6 0.8 3% 17.3 16.4 15.8 Low Low Clarkes Creek 63.9 14 22% 60.4 58.6 57.2 High High Durbin Creek 22.6 8.3 37% 10.3 9.5 6.2 Low Low Governors Creek 55.0 7.5 14% 50.0 49.5 47.3 High Moderate Greens Creek 83.3 50.4 61% 83.3 83.3 83.3 High High Julington Creek 39.0 18.2 47% 24.3 23.5 21.4 Low Low Kingsley Lake 84.4 73.2 87% 84.4 84.4 84.4 High High Lake Geneva 9.0 7.9 88% 9.0 9.0 9.0 Low Low Lower Etonia Creek 75.0 18.1 24% 74.1 73.7 73.0 High High Lower North Fork-Black Creek 74.0 34.1 46% 69.2 68.6 67.8 High High Lower South Fork-Black Creek 107.9 40 37% 107.6 107.5 107.1 Very High Very High Peters Creek 36.1 0 0% 34.5 33.1 32.3 Low Low Simms Creek 56.2 0 0% 52.7 52.4 52.4 Very High Very High Trout Creek-St. Johns River 12.1 0 0% 8.7 8.1 7.5 Low Low Upper Etonia Creek 7.5 6 80% 7.5 7.5 7.5 Low Low Upper North Fork-Black Creek 126.5 55.1 44% 126.5 126.5 126.5 Very High Very High Upper South Fork-Black Creek 109.1 89.5 82% 109.1 109.1 109.1 Very High Very High Yellow Water Creek 77.9 60.6 78% 77.9 77.9 77.9 High High Total 1149.0 536.9 47% 1037.0 1029.0 1016.0 na na

6.3.2 Development

6.3.2.1 Current and Trend Development

Of the 19 Black Creek crayfish populations, all are predicted to decrease in habitat quality under the trend urbanization in 2070 (Table 6.2). Ten populations are predicted to have very low habitat quality in 2070 (Table 6.2).

Table 6.2. Current and 2070 trend urban development in riparian zones and watersheds occupied by Black Creek crayfish populations and overall habitat quality (black= Very Low; gray = Low; orange = Moderate; blue = High; and green = Very High).

% % Trend % Currently % Currently Current Developed Developed 2070 Population Developed- Developed- Habitat 2070 Trend 2070 Trend Habitat Riparian Watershed Quality - Riparian -Watershed Quality

Ates Creek 2.5% 4.3% 29.1% 45.2% High Low Black Creek - St. Johns 11.3% 22.4% 75.6% 72.5% Moderate Very Low River Clarkes Creek 8.2% 3.3% 54.6% 41.6% Low Very Low

Durbin Creek 4.3% 24.1% 48.1% 58.1% High Very Low

Governors Creek 9.8% 13.3% 60.3% 51.1% Low Very Low

Greens Creek 1.9% 2.2% 20.5% 25.2% High Low

Julington Creek 26.2% 47.1% 50.6% 65.2% Low Very Low

Kingsley Lake 3.2% 7.4% 13.3% 14.7% Very High Moderate

Lake Geneva 2.9% 15.8% 14.4% 53.7% High Very Low

Lower Etonia Creek 3.3% 8.4% 11.0% 14.2% Moderate Moderate Lower North Fork-Black 19.2% 26.8% 54.6% 64.5% Low Very Low Creek Lower South Fork-Black 13.2% 20.5% 45.1% 60.3% Low Very Low Creek Peters Creek 3.7% 3.6% 27.0% 36.9% High Low

Simms Creek 2.3% 6.8% 11.3% 16.4% Very High Moderate Trout Creek-St. Johns 5.9% 16.3% 85.7% 84.3% Moderate Very Low River Upper Etonia Creek 4.7% 15.5% 5.9% 41.1% High Moderate Upper North Fork-Black 7.1% 7.2% 43.2% 54.1% Moderate Very Low Creek Upper South Fork-Black 1.9% 5.8% 12.3% 12.9% High Moderate Creek Yellow Water Creek 5.5% 14.8% 15.4% 19.6% Moderate Low

6.3.2.1 Current and Alternative Development

Six populations’ habitat quality scores remained the same as current scores under the alternative 2070 development predictions (Table 6.3). Eight populations are predicted to have very low habitat quality in 2070 under the alternative 2070 scenario.

Table 6.3. Current and 2070 alternative urban development in riparian zones and watersheds occupied by Black Creek crayfish populations and overall habitat quality.

% % % Developed % Developed Population Currently Currently 2070 2070 Current Alternative Developed - Developed - Alternative Alternative - Habitat 2070 Habitat Riparian Watershed - Riparian Watershed Quality Quality Ates Creek 2.5% 4.3% 11.7% 24.1% High Moderate Black Creek - St. Johns 11.3% 22.4% 75.6% 72.5% Moderate Very Low River Clarkes Creek 8.2% 3.3% 54.6% 35.4% Low Low

Durbin Creek 4.3% 24.1% 44.5% 56.4% High Very Low

Governors Creek 9.8% 13.3% 60.3% 49.4% Low Very Low

Greens Creek 1.9% 2.2% 4.0% 7.3% High High

Julington Creek 26.2% 47.1% 50.6% 65.2% Low Very Low

Kingsley Lake 3.2% 7.4% 3.3% 7.4% Very High Very High

Lake Geneva 2.9% 15.8% 14.4% 53.6% High Very Low

Lower Etonia Creek 3.3% 8.4% 8.0% 10.6% Moderate Moderate Lower North Fork-Black 19.2% 26.8% 54.6% 64.5% Low Very Low Creek Lower South Fork-Black 13.2% 20.5% 42.7% 56.3% Low Very Low Creek Peters Creek 3.7% 3.6% 27.0% 36.9% High Low

Simms Creek 2.3% 6.8% 11.3% 16.1% Very High Moderate

Trout Creek-St. Johns River 5.9% 16.3% 63.5% 70.0% Moderate Very Low

Upper Etonia Creek 4.7% 15.5% 5.9% 40.2% High Moderate Upper North Fork-Black 7.1% 7.2% 14.0% 17.5% Moderate Low Creek Upper South Fork-Black 1.9% 5.8% 2.2% 3.5% High High Creek Yellow Water Creek 5.5% 14.8% 7.3% 13.0% Moderate Moderate

6.3.3 White Tubercled Crayfish

Based on the modeled rate of expansion of white tubercled crayfish and its predicted range in 2050 and 2070, all populations on the west side of the St. Johns River (16) are at risk from the potential exposure to white tubercled crayfish in future scenarios (Table 6.4). Durbin Creek, Julington Creek, and Trout Creek – St Johns River are not at risk under any future scenario.

Table 6.4. Risk of exposure from white tubercled crayfish (WTC) for each Black Creek crayfish population in 2050 and 2070.

Current Risk Confirmed from WTC Side of St. WTC Population Presence Johns River Impact Ates Creek Yes West Yes Black Creek - St. Johns River No West Yes Clarkes Creek No West Yes Durbin Creek No East No Governors Creek No West Yes Greens Creek Yes West Yes Julington Creek No East No Kingsley Lake Yes West Yes Lake Geneva No West Yes Lower Etonia Creek No West Yes Lower North Fork-Black Creek Yes West Yes Lower South Fork-Black Creek Yes West Yes Peters Creek No West Yes Simms Creek No West Yes Trout Creek-St. Johns River No East No Upper Etonia Creek No West Yes Upper North Fork-Black Creek Yes West Yes Upper South Fork-Black Creek Yes West Yes Yellow Water Creek No West Yes

6.4 Future Resiliency Results 6.4.1 Future Scenarios: 2050

Figure 6.1. Predicted future Black Creek crayfish population resiliency in 2050 with and without potential exposure to white tubercled crayfish.

Three populations are likely to be extirpated in 2050, regardless of impacts from white tubercled crayfish (Fig. 6.1; Table 6.5). One population, Governors Creek, is more likely to become extirpated if white tubercled crayfish impact Black Creek crayfish when they move into the watershed (Table 6.5). It is likely that some populations may be more threatened than predictions in Table 6.5 because there could be more development pressure within some watersheds and subsequent decreases in habitat quality by 2050.

Table 6.5. Predicted future resiliency of Black Creek crayfish populations in 2050.

Exposed to Baseline Habitat white Population Future Resiliency Resiliency Quality tubercled crayfish No Very High Ates Creek High High Yes High No Likely Extirpated Black Creek - St. Johns River Low Moderate Yes Likely Extirpated No Moderate Clarkes Creek High Low Yes Low No Moderate Durbin Creek Low High No Moderate No Low Governors Creek Moderate Low Yes Likely Extirpated No Very High Greens Creek High High Yes High No Likely Extirpated Julington Creek Low Low No Likely Extirpated No Very High Kingsley Lake High Very High Yes High No Moderate Lake Geneva Low High Yes Low No High Lower Etonia Creek High Moderate Yes Moderate No Moderate Lower North Fork-Black Creek High Low Yes Low No High Lower South Fork-Black Creek Very High Low Yes Moderate No Moderate Peters Creek Low High Yes Low No Very High Simms Creek Very High Very High Yes High No Likely Extirpated Trout Creek-St. Johns River Low Moderate No Likely Extirpated No Moderate Upper Etonia Creek Low High Yes Low No Very High Upper North Fork-Black Creek Very High Moderate Yes High No Very High Upper South Fork-Black Creek Very High High Yes High No High Yellow Water Creek High Moderate Yes Moderate

6.4.2 Future Scenarios: 2070

Figure 6.2. Predicted future Black Creek crayfish population resiliency in 2070 under trend development scenario with and without potential impacts from white tubercled crayfish.

Eleven of the 19 populations could be extirpated in 2070 regardless of impacts of white tubercled crayfish under trend development predictions (Fig. 6.2; Table 6.6), primarily because of high urban development in these watersheds and subsequent decreases in habitat quality (Table 6.6). Impacts from white tubercled crayfish increase the number of population predicted to be extirpated to 14 (Fig. 6.2, Table 6.6).

Table 6.6. Predicted future resiliency of Black Creek crayfish populations in 2070 under trend 2070 development.

Risk Trend from Baseline Population Habitat white Future Resiliency Resiliency Quality tubercled crayfish No Moderate Ates Creek High Low Yes Likely Extirpated No Likely Extirpated Black Creek - St. Johns River Low Very Low Yes Likely Extirpated No Likely Extirpated Clarkes Creek High Very Low Yes Likely Extirpated No Likely Extirpated Durbin Creek Low Very Low No Likely Extirpated No Likely Extirpated Governors Creek Moderate Very Low Yes Likely Extirpated No Moderate Greens Creek High Low Yes Likely Extirpated No Likely Extirpated Julington Creek Low Very Low No Likely Extirpated No High Kingsley Lake High Moderate Yes Low No Likely Extirpated Lake Geneva Low Very Low Yes Likely Extirpated No High Lower Etonia Creek High Moderate Yes Low Lower North Fork-Black No Likely Extirpated High Very Low Creek Yes Likely Extirpated Lower South Fork-Black No Likely Extirpated Very High Very Low Creek Yes Likely Extirpated No Likely Extirpated Peters Creek Low Low Yes Likely Extirpated No Very High Simms Creek Very High Moderate Yes Moderate No Likely Extirpated Trout Creek-St. Johns River Low Very Low No Likely Extirpated No Low Upper Etonia Creek Low Moderate Yes Likely Extirpated Upper North Fork-Black No Likely Extirpated Very High Very Low Creek Yes Likely Extirpated Upper South Fork-Black No Very High Very High Moderate Creek Yes Moderate No Moderate Yellow Water Creek High Low Yes Likely Extirpated

Figure 6.3 Predicted future Black Creek crayfish population resiliency in 2070 under alternative development scenario with and without potential impacts from white tubercled crayfish.

Nine of the 19 Black Creek crayfish populations may be extirpated in 2070 under the alternate (i.e., more land protected) development scenario (Fig. 6.3, Table 6.7). Even with more protections, many of the watersheds may be highly developed in 2070 which may drastically decrease habitat quality. When potential white tubercled crayfish impacts are factored in, 2 more populations (i.e., 11 of 19 populations) may be extirpated in 2070, even if more land is protected.

Table 6.7. Predicted future resiliency of Black Creek crayfish populations in 2070 under alternate 2070 development.

Risk from Alternative Baseline white Population Habitat Future Resiliency Resiliency tubercled Quality crayfish No High Ates Creek High Moderate Yes Low No Likely Extirpated Black Creek - St. Johns River Low Very Low Yes Likely Extirpated No Moderate Clarkes Creek High Low Yes Likely Extirpated No Likely Extirpated Durbin Creek Low Very Low No Likely Extirpated No Likely Extirpated Governors Creek Moderate Very Low Yes Likely Extirpated No Very High Greens Creek High High Yes Moderate No Likely Extirpated Julington Creek Low Very Low No Likely Extirpated No Very High Kingsley Lake High Very High Yes Moderate No Likely Extirpated Lake Geneva Low Very Low Yes Likely Extirpated No High Lower Etonia Creek High Moderate Yes Low No Likely Extirpated Lower North Fork-Black Creek High Very Low Yes Likely Extirpated No Likely Extirpated Lower South Fork-Black Creek Very High Very Low Yes Likely Extirpated No Likely Extirpated Peters Creek Low Low Yes Likely Extirpated No Very High Simms Creek Very High Moderate Yes Moderate No Likely Extirpated Trout Creek-St. Johns River Low Very Low No Likely Extirpated No Low Upper Etonia Creek Low Moderate Yes Likely Extirpated No High Upper North Fork-Black Creek Very High Low Yes Low No Very High Upper South Fork-Black Creek Very High High Yes Moderate No High Yellow Water Creek High Moderate Yes Low

6.4.3 Future Scenarios: Summary

Three populations (16%) may be extirpated under all future scenarios (Table 6.8). Six more Black Creek crayfish populations (32%; 47% total) may be extirpated by 2070 (Table 6.8). Scenarios that include development without added protections of Black Creek crayfish habitat and other areas important to maintaining good water quality increase the likelihood of extirpation for two additional populations (Table 6.8). Kingsley Lake, Lower Etonia Creek, Simms Creek, and Upper South Fork – Black Creek populations are likely to persist under all future scenarios (Table 6.8). It is possible that resiliency may be worse than predicted if white tubercled crayfish lead to eventual extirpation of Black Creek crayfish in watersheds occupied by both species in the future. More data are needed to determine the extent and time scale of impacts.

Table 6.8. Current and future Black Creek crayfish population resiliency under all scenarios in 2050 and 2070.

2050 2070 Current Current 2050 2070 2070 2070 Current Alternate Resilience - Resilience - Current Trend & Trend & Alternate Population & No & No Not WTC WTC & WTC No WTC WTC & WTC WTC WTC Imapct Impact Impact Impact Impact Impact Impact Impact

Likely Ates Creek Very High High Very High High Moderate High Low Extirpated

Likely Likely Likely Likely Likely Likely Black Creek - St. Johns River Low Low Extirpated Extirpated Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Clarkes Creek Moderate Moderate Moderate Low Moderate Extirpated Extirpated Extirpated

Likely Likely Likely Likely Durbin Creek* Moderate Moderate Moderate Moderate Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Likely Likely Governors Creek Moderate Moderate Low Extirpated Extirpated Extirpated Extirpated Extirpated

Likely Very Greens Creek Very High High Very High High Moderate Moderate Extirpated High

Likely Likely Likely Likely Likely Likely Julington Creek* Low Low Extirpated Extirpated Extirpated Extirpated Extirpated Extirpated

Very Kingsley Lake Very High High Very High High High Low Moderate High

Likely Likely Likely Likely Lake Geneva Moderate Moderate Moderate Low Extirpated Extirpated Extirpated Extirpated

Lower Etonia Creek High High High Moderate High Low High Low

Lower North Fork-Black Likely Likely Likely Likely Moderate Low Moderate Low Creek Extirpated Extirpated Extirpated Extirpated

Lower South Fork-Black Likely Likely Likely Likely High High High Moderate Creek Extirpated Extirpated Extirpated Extirpated

Likely Likely Likely Likely Peters Creek Moderate Moderate Moderate Low Extirpated Extirpated Extirpated Extirpated

Very Very Simms Creek Very High Very High Very High High Moderate Moderate High High

Likely Likely Likely Likely Likely Likely Trout Creek-St. Johns River* Low Low Extirpated Extirpated Extirpated Extirpated Extirpated Extirpated

Likely Likely Upper Etonia Creek Moderate Moderate Moderate Low Low Low Extirpated Extirpated

Likely Likely Upper North Fork-Black Creek Very High Very High Very High High High Low Extirpated Extirpated

Very Very Upper South Fork-Black Creek Very High High Very High High Moderate Moderate High High

Likely Yellow Water Creek High High High Moderate Moderate High Low Extirpated

*Populations on the east side of the St. Johns River

6.5 Future Redundancy and Representation

Table 6.9. Summary of resiliency ranks tallied across all Black Creek crayfish populations for the current condition and future condition (in 30 and 50 years) under 6 future scenarios.

2050 2070 2070 2070 Current Current 2050 2070 Current Trend Trend Alternate Resiliency Resiliency Current Alternate Resiliency & No & No & & No - No WTC - WTC & WTC & WTC WTC WTC WTC WTC Impact Impact Impact Impact Impact Impact Impact Impact Very High 6 2 6 0 2 0 4 0 High 3 7 3 6 2 0 4 0 Moderate 7 6 6 4 3 2 1 4 Low 3 4 1 5 1 2 1 4 Total Populations 19 19 16 15 8 4 10 8

Redundancy is expected to decrease under all scenarios, primarily because at least 4 of the 19 populations may be extirpated under all future scenarios (Table 6.9). Populations that remain extant may decrease in resiliency, primarily because urban development may continue to impact populations, especially in the northern and eastern side of the range. This may likely concentrate population centers in a few watersheds and decrease the species’ ability to withstand catastrophic events such as major droughts or major impacts from a hurricane. If white tubercled crayfish impact Black Creek crayfish by decreasing their abundance and, eventually, extirpating them from previously occupied habitat, then redundancy may decrease until most of the populations are gone by 2070. Clear and substantial information is not available to support that this is likely to occur. More research is needed to better understand how Black Creek crayfish populations may react to the presence of white tubercled crayfish over time under varying habitat conditions.

Representation may be significantly decreased in future scenarios because all eastern populations may be extirpated in 2050 and 2070 (Table 6.9). Eastern populations, which are currently small and have low resiliency, may also endure the majority of the SLR change and urban development in the future. The loss of Black Creek crayfish populations on the eastern side of the St. Johns River may decrease genetic diversity and decrease the species’ ability to adapt to changing environmental conditions, which are likely because of climate change, including increases in drought frequency and intensity as well as higher temperatures.

6.6 Future Research Needs

More research is needed to better understand the distribution and movements of Black Creek crayfish, their interactions with white tubercled crayfish, and how climate change may impact resilience and redundancy on a fine scale. For example, the species habitat model indicates potential habitat outside the currently known range. Indeed, recent observations of Black Creek crayfish in Simms Creek (P. Moler 2020, pers. comm.) indicate that this species may occur in more HUC 12 watersheds than presented in this SSA. Occupied watersheds on the periphery of the range may be less likely to be occupied by white tubercled crayfish and, therefore, more likely to persist into the future. In addition, it is currently unclear if white tubercled crayfish completely displaces Black Creek crayfish within a region or if the impacts may be less severe. For example, some experts believe that the Black Creek crayfish may persist in the smaller tributaries where white tubercled crayfish don’t occur. If so, these areas may provide refuges for Black Creek crayfish and allow them to persist within the same watershed. Another important avenue of research relates to the potential for white tubercled crayfish removal. FWC recently received approval to spend Section 6 funds on a project investigating the relationship between Black Creek crayfish and white tubercled crayfish and research is likely to commence in October of 2020 (D. Cook 2020, pers. comm.).

More research is needed to better understand the extent of individual Black Creek crayfish populations. One key assumption in this SSA is that crayfish populations are defined by HUC 12 watersheds. A change in the choice of scale, if future research indicated it should be changed, for defining populations would have implications for redundancy and resiliency. The currently defined 19 populations would drop or rise significantly if populations were differentiated at larger or smaller basins (e.g., HUC8 or HUC14/16, respectively), which would significantly impact population size and genetic diversity. In addition, many rivers in the US are fragmented by dams, road crossings, and utilities. These barriers can influence crayfish movements (Foster and Keller 2011, entire) and could limit gene flow, subdividing formerly contiguous populations (Barnett et al. 2019, entire). Future versions of this SSA should take new data on Black Creek crayfish movement and genetics into account to better define populations for the species.

A likely significant influencer which was not included in the future scenarios in this SSA is the impact of increasing water temperature and subsequent dissolved oxygen levels on Black Creek crayfish occupancy given the known limits of their thermal tolerances. Currently, there are no fine scale models which indicate how increasing ambient temperatures in Florida may change water temperatures in small streams occupied by Black Creek crayfish; therefore, there was no way to determine which populations are more or less likely to be impacted by increasing temperatures into the future. Once data or models becomes available, they should be incorporated into future scenarios for the Black Creek crayfish. Until then, it should be noted that resiliency for some and perhaps most populations may decrease in the future due to rising temperatures in northeast Florida.

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Appendix A. Black Creek Crayfish Habitat Model (Barrett 2018) Source Data and Model Variables All spatial analyses were conducted within ArcMap 10.5.1 (ESRI). For aquatic layers, we used the National Hydrography Dataset (NHD; U.S. Department of Agriculture and Natural Resources Conservation Service [USDA and NRCS] 2016, n.p.) geodatabase. The analysis area was bounded by the Lower St. John’s Watershed (HUC 8) and two sub-watersheds (HUC 10), Upper St Mary’s River and Thomas Creek (Figure A-1). The area of the analysis extent is 7,429 km2, which excludes the St. John’s River water surface area. All three watersheds either contain known occurrences of Black Creek crayfish or have been sampled for Black Creek crayfish. Within the watersheds, streams were designated with the NHD Flowline layer. Large rivers (using NHD Area) and lakes and reservoirs (using NHD Waterbodies) were omitted from the NHD flowline footprint. Based on the NHD Flowline parent features, we retained natural streams (StreamRiver, Swamp/Marsh, Connector) and removed other segments (CanalDitch, Coastline, Pipeline, Reservoir) not considered Black Creek crayfish habitat. However, one small flowline segment labeled as CanalDitch was retained because it contained Black Creek crayfish locations and occurred in a natural area with forest canopy; other CanalDitches predominately occurred around urban or agricultural areas with no natural tree canopy. The length of streams available to model for potential habitat was 3,876.7 km.

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Figure A-1. Potential habitat model extent for Black Creek crayfish. Red lines indicate a HUC 8 and two smaller HUC 10s (northern end) as extent boundaries. Gray lines in the inset map indicate Florida counties.

We used occurrence records of Black Creek crayfish that were stored on a GIS database (point shapefile) maintained by the FWC. The database contains records collected between 1976 and 2015. However, for our model, we only used relatively recent records from 2008 to 2015. Our sample size of collection events was 396 (n = 211 presence sites and n = 185 absence sites). The sample sites were snapped (intersected) to the NHD Flowline based on two distance scenarios: <50m or >50m from the flowline. Most sites were < 50m and were automatically snapped to the flowline. Sites >50m from the flowline were inspected and either manually snapped to the

104 nearest NHD Flowline or, if a stream segment was missing from the NHD, we generated a flowline by examining aerial imagery, shaded relief maps, and topo maps available from ESRI Basemap layers.

Six variables used in the model included two stream attributes, two forest conditions, geology type, and a water quality index. The two stream attributes were gradient and sinuosity. Gradient, a substitute for stream flow, was derived from the NHD Flowline and a 30-m resolution elevation model (USGS 2002, n.p.) using a rise/run computation. To determine gradient, elevations were extracted at the endpoints of stream reaches and the difference in elevation (m) was calculated between the endpoints and divided by the reach length (km). Gradient ranged from 0-96.7 m/km, though most values were <30 (mean = 3.4). Sinuosity was calculated by dividing the stream reach length (km) by the valley length (km), which is the Euclidian distance between endpoints of the stream reach. Sinuosity ranged from 0.29-198.6 (dimensionless) though most values were <2.0 (mean = 2.2). Forest conditions were based on a 10-m resolution FWC Cooperative Land Cover (CLC) layer (v3.2.5). Forest riparian cover might be beneficial to Black Creek crayfish by reducing siltation, providing shade (cooler water), and providing detritus and structure from fallen limbs/leaves in nearby streams. Therefore, we ran a moving window analysis with a circular 50m radius and calculated the mean forest cover value from three generalized functional groups that were assigned weights (higher weights equal higher value to Black Creek crayfish habitat): forested wetlands = 1.0, upland forests = 0.75, and tree plantations = 0.4. Mean forest cover ranged from 0-1 with a mean of 0.64. Sandhill might be influential to stream conditions for Black Creek crayfish, so we identified the presence of sandhill within NHD HUC 12 watersheds as a binary variable (yes/no), and all flowlines within the HUC 12s were labeled similarly. Out of 70 HUC 12 in the analysis extent, 46 (66%) contained sandhill. A simplified geology layer was created for each Florida county based on groundwork by the Florida Geological Survey in 2001 (DEP 2001, n.p.). Geology classes that occurred within the analysis extent include (and their approximate % of the area): sand (45.4), medium fine sand silt (42.2), peat (11.1), other (1.1), and clayey sands (0.1). Finally, a water quality indicator developed by the St. Johns Water Management District (2010; https://www.sjrwmd.com/data/water-quality/) was used that described concentration levels of total dissolved solids (TDS) in the upper Floridian aquifer. Higher TDS concentrations could

105 negatively impact Black Creek crayfish by increasing water temperatures and decreasing dissolved oxygen. The TDS layer had four categories measured in mg/L: 0-500, 501-1000, 1001- 3000, and >3000. Within the analysis extent, the TDS class of 0-500 accounts for 78.7% of the area.

All variable layers were converted to 10-m resolution rasters. The rasters were then extracted to the NHD Flowlines we developed (see above). These rasters (streams) were used in the potential habitat models.

Model Development

We used a combination of two types of models to identify potential habitat of Black Creek crayfish: Maxent and Fuzzy Logic. One model was a presence-only predictive model using a maximum entropy algorithm within Maxent software (version 3.3e). We used default Maxent parameters and 10-fold cross-validation. The 10-fold cross-validation procedure was used to test model performance on training data, and on test data by withholding 10% of data points from each training model run; the test data were run to make sure the model was not over fit and to develop prediction thresholds. The 10 replicate runs are averaged to create a mean logistic output of the likelihood of potential habitat ranging from 0 to 1.

The other model we used was a Fuzzy Logic approach to define Black Creek crayfish potential habitat. Fuzzy logic is a rules-based type model using information from expert input/literature or case data. It employs a fuzzy membership of data values instead of crisp values for variables. Input variables are transformed into a 0 to 1 scale, indicating the strength of a membership in a set, based on a specified fuzzification algorithm. A value of 1 indicates full membership in the fuzzy set, with membership decreasing to 0, indicating it is not a member of the fuzzy set. We extracted all variable values to the Black Creek crayfish location points and plotted frequency graphs to determine how best to convert values to 0 to 1 scale using fuzzy logic parameters. Regarding Fuzzy Membership parameters, gradient was assigned a Small membership type with a midpoint of 25 and a spread of 5; sinuosity was assigned a Small membership type with a midpoint of 2 and a spread of 5; and mean forest cover was assigned a Large membership type with a midpoint of 0.40

106 and a spread of 2. The remaining variables were categorical, so weights were assigned to convert them to 0 – 1 as follows: sandhill presence = 1, sandhill absence = 0; for geology type, medium fine sand silt = 1, sand = 1, the remainder = 0; and for water quality, a TDS class range of 0-500 = 1, the remainder = 0. We combined variables with the Fuzzy Overlay “And” operator, which selects the minimum of the fuzzy memberships from the input fuzzy rasters.

Both models output a continuous scale map with potential habitat ranging from 0 to 1. We created binary outputs from the continuous outputs of each model by using three thresholds that determine potential habitat at different levels of inclusiveness: 5 Percentile is most relaxed, 10 Percentile is intermediate, and Equal Sensitivity and Specificity is most restrictive. The 5 Percentile threshold is defined as at least 95% of presence points occurring within predicted streams; the 10 Percentile threshold is defined as at least 90% of presence points occurring within predicted streams; and the Equal Sensitivity and Specificity threshold is defined as a balance of presence and absence locations being included in predicted streams. Combinations of these three threshold classes were used to create a potential habitat index ranging from poor to best.

Although we did not use absence locations in model development, we did use them for model validation. A True Skills Statistic (TSS) was calculated with the presence and absence locations and the binary prediction of potential habitat using the intermediate threshold, the 10 Percentile. The TSS test is calculated as sensitivity + specificity – 1 that results in a 0 – 1 scale with a 1 indicating the highest model accuracy. Sensitivity is the proportion of presence locations correctly predicted and specificity is the proportion of absence locations correctly predicted.

Results The Maxent model was a relatively good fit based on average area-under-the-curve (AUC) of 0.841 from the 10 replicate models. We used the Maxent output of variable importance based on jackknife results of leave-one-out variable analysis, which indicated the most influential variable was stream gradient followed by geology type and mean forest canopy (Figure A-2). The values that the model most strongly indicated as potential habitat for these three variables were between 5 and 18 m/km for stream gradient, medium sand silt and to a lesser degree sand for geology

107 type, and >0.6 for mean forest canopy. The Fuzzy Logic model had an AUC of 0.725, but as a rules-based model it does not calculate variable importance.

Figure A-2. Variable importance based on a leave-one-out jackknife procedure in Maxent. Plots include the mean training gain and upper and lower confidence intervals from the 10-replicate model runs. Because the plot represents the loss in training gain when the variable is removed, lower training gain values indicate a higher variable influence on the model, i.e., stream gradient had the highest influence. The combined model (Maxent and Fuzzy Logic) had a TSS of 0.474 indicating a relatively low accuracy, though this was mainly due to absence points occurring in predicted habitat (Table A- 1). Whether these sites are true absences has not been determined. Contrarily, 97.2% of presence locations were correctly predicted by the combined model.

Table A-1. Confusion Matrix of the number of surveyed locations that were present or absent that occurred within predicted habitat from the combined potential habit model. The model threshold was defined by the 10 Percentile cutoff.

Confusion Model Threshold Matrix Present Absent Species Present 205 6 Survey Absent 141 44

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Likely habitat was considered as the Fair-Good index class or above, the classes where both models are in agreement (Table A-2). Based on this designation, the model comprised 1,749.4 km of likely stream habitat, which is 45.1% of available streams in the analysis extent (Figure A- 2). The amount of Best (top index class) potential habitat is 15.2% of available streams, which contained 50.2% of presence locations.

Table A-2. Habitat index based on which of three model thresholds (or combinations thereof) are representing potential habitat on stream segments and whether the segments contain output from a single model or both models. The length (km) of stream in each index class was summed.

Model Index Habitat Threshold Stream Value km Neither 0 Poor Below all thresholds 1,751.8 Maxent 1 Marginal 5 Percentile only 111.3 Fuzzy only 1 Marginal 5 Percentile Maxent 2 Marginal- 10 Percentile only Fair 100.8 Fuzzy only 2 Marginal- 10 Percentile Fair Maxent 3 Fair Equal Sensitivity and Specificity only 163.4 Fuzzy only 3 Fair Equal Sensitivity and Specificity Both 4 Fair-Good Both = 5 Percentile Both 4 Fair-Good One = 5 Percentile; One = 10 132.0 Percentile Both 5 Good Both = 10 Percentile Both 5 Good One = 5 Percentile; One = Equal 455.7 Sensitivity and Specificity Both 6 Good-Best One = 10 Percentile; One = Equal 574.1 Sensitivity and Specificity Both 7 Best Both = Equal Sensitivity and 587.6 Specificity

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Figure A-2. Potential habitat index based on combinations of binary thresholds between Maxent and Fuzzy Logic models.

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Appendix B. ACRONYMS AUC area-under-the-curve

BMPs Best management practices

BMAPs Basin Management Action Plans

BCC Black Creek crayfish

CBD Center for Biological Diversity

CBJTC Camp Blanding Joint Training Center

CCAA Candidate Conservation Agreement with Assurances

CLC Cooperative Land Cover

CWA Clean Water Act

CWP Center for Watershed Protection

DEP Florida Department of Environmental Protection

EPA Environmental Protection Agency

ESA Endangered Species Act

FDACS Florida Department of Agriculture and Consumer Services

FDOT Florida Department of Transportation

FFS Florida Forest Service

FNAI Florida Natural Areas Inventory

FWC Florida Fish and Wildlife Conservation Commission

GIS geographic information system

HSM habitat suitability model

HUC hydrologic unit code

IPCC Intergovernmental Panel on Climate Change

NED National Elevation Dataset

NFRWSP North Florida Regional Water Supply Plan

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NHD National Hydrography Dataset

NOAA National Oceanic and Atmospheric Administration

NRCS Natural Resources Conservation Service

SAP Species Action Plan

Service U.S. Fish and Wildlife Service

SF state forest

SJRWMD St. Johns River Water Management District

SLR sea level rise

SMZs special management zones

SPARROW Spatially Referenced Regression on Watershed

SRWMD Suwannee River Water Management District

SS suspended sediment

SSA Species Status Assessment

TDS total dissolved solids

TMDLs total maximum daily loads

TN total nitrogen

TP total phosphorus

TSS True Skills Statistic

USDA U.S. Department of Agriculture

USGS U.S. Geological Survey

WBMPs Wildlife Best Management Practices

WTC White tubercled crayfish

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