ABSTRACT. On the occasion of the 50th annual Desert Fishes Council meeting, this session is dedicated to Dr. Lee H. Simons, who devoted much of his adult life to the study and protection of native species and ecosystems. Dr. Simons is honored here today because he exemplified the spirit and soul of the Desert Fishes Council – working together to protect and preserve our native species and natural ecosystems. As a positive force toward these goals, Dr. Simons spent a third of his natural resources career focused on the protection and recovery of federally listed endangered desert fishes in Arizona and Nevada. From 1985 to 1988 Lee worked for Arizona Game and Fish, much of that time focused on recovery activities of Gila topminnow. After earning his PhD at U.C. Davis and working in research, science education and natural resources, Dr. Simons renewed his work with desert fishes from 2008-2016. As Senior Fish Biologist for the Las Vegas Office of the U. S. Fish and Wildlife Service, he concentrated on recovery actions for Devil’s Hole Pupfish, Moapa Dace, and Pahranagat Roundtail Chub. Those of us who worked with Lee on endangered desert fish recovery appreciated his intellect, kind manner, leadership, infectious enthusiasm, and all his accomplishments. Remembrance of Dr. Simons’s all too short, but stellar desert fish career will be briefly covered by four co-workers representing four different agencies.

ABSTRACT. As the Environmental Services lead fish biologist for the United States Fish and Wildlife Service Southern Nevada Field Office, Lee was responsible for recovery of 12 listed fish species. His leadership and kindness at recovery team meetings consolidated agency leads, academics, and local shareholders to cooperate towards ongoing restoration and increasing population numbers. He gave expedient consultation on restoration projects for Pahrump Poolfish Empetrichthys latos, Ash Meadows National Wildlife Refuge, Devils Hole, and other listed fish species in the pluvial White River system while also getting in the mud to complete the work. Lee was instrumental in acquiring two national competitive funding opportunities through Cooperative Recovery Initiative (CRI) funding. The Muddy River CRI funding completed two new fish barriers, and hired two new temporary employees entirely devoted to the restoration and monitoring of the Muddy River system. Moapa Dace, Moapa coriacea Snorkel counts are currently four times greater than at the time of his arrival with Virgin River Chub, Gila seminuda existing in the upper Muddy River for the first time since pre non-native fish invasion. The Pahranagat Cooperative Recovery Initiative funding initiated a Pahranagat Roundtail Chub, Gila robusta jordani PIT tag monitoring program, stabilized the refuge population at Key Pittman, and developed a new refuge habitat at Cottonwood Spring. During the 2013 low count of 35 Devils Hole Pupfish, Cyprinodon diabolis Lee took charge to bring the multi-agency command team together. He would then praise the recovery response to others in his team. Non-natives removal projects and restoration projects are complete or ongoing in The Virgin River, Muddy River, Pahranagat, Ash Meadows, and at Pahrump Poolfish refuge populations, including a new refuge site initiated in 2018 as a result of his leadership.

ABSTRACT. Desert fishes that evolved in simple communities, are hypothesized to be vulnerable to non-native species introductions. Such is the case for the Pahrump Poolfish, Empetrichthys latos latos, whose conservation has been frustrated by colonization of invasive species including both Red Swamp Crayfish, Procambarus clarkii, and Western Mosquitofish, Gambusia affinis, in refuge habitats. We examined the direct effects of crayfish and mosquitofish on poolfish adult survivorship, and juvenile recruitment under semi-natural conditions in 300-gallon mesocosms. We found that allopatric poolfish populations had significantly higher adult survival (95.6%.03%) than when held in sympatry with crayfish (53.1%.16%; z = -3.2; p < 0.005) or when sympatric with crayfish and mosquitofish (55.1.21%; z = -2,98; p < 0.010). Crayfish had no effect on poolfish juvenile recruitment (17.54.12 juveniles per adult) compared to juvenile recruitment for allopatric poolfish populations (13.611.74 juveniles per adult; z=.6; p > 0.05). However, the combined effects of crayfish and mosquitofish led to significant declines in juvenile recruitment (0.47.13 juveniles per adult; z = -2.79; p = 0.015). These results mimicked earlier experiments that showed severe impacts of mosquitofish on poolfish juvenile recruitment (Goodchild & Stockwell 2016, Trans. Am. Fish. Soc. 145 (2); 264-268). Thus, our findings combined with earlier work may explain how poolfish have co-persisted with crayfish for numerous years at the Corn Creek refuge, while the dual invasion of crayfish and mosquitofish was associated with a rapid population decline of the largest Pahrump Poolfish refuge population at Spring Mountain Ranch.

ABSTRACT. Species that evolve in habitats with limited predation are predicted to have reduced investment in antipredator traits, such as the production and detection of chemical alarm cues. Our study focused on epithelial club cells, which are presumed to contain injury-released alarm cues and are present in numerous fish taxa. This evaluation was carried out on four desert fishes in the Cyprinodontiformes; Pahrump Poolfish, Empetrichthys latos latos, White River Springfish, Crenichthys baileyi, Amargosa Pupfish, Cyprinodon nevadensis, and White Sands Pupfish, Cyprinodon tularosa. We also sampled three cyprinid species: Hot Creek Valley Tui Chub, Suphateles bicolor ssp., and two non-insular species, Fathead Minnow, Pimephales promelas, and Zebrafish, Danio rerio. Club cell densities per mm2 of epithelial tissue differed significantly among species (X2 = 91.81, df = 6, p < 0.0001), and pairwise comparisons revealed no differences among Cyprinds or among Cyprinodontiformes. As expected, Fathead Minnows and Zebrafish displayed relatively high densities of club cells (446.5 ± 100.3; 310.4 ± 51.3; mean ± SE, respectively). By contrast, mean club cell densities were low for Pahrump Poolfish (17.1 ± 8.5), White Sands Pupfish (17.1 ± 9.0), Amargosa Pupfish (1.0 ± 0.6), and White River Springfish (0.0 ± 0.0). In comparison, however, the Hot Creek Valley Tui Chub, a desert cyprinid, displayed club cell densities similar to non-insular cyprinids sampled (137.9 ± 56.3). Thus, phylogeny, and not locality or history of predation, may be the primary driver for expression of club cells and antipredator behaviors present in populations.

ABSTRACT. The Pahranagat Roundtail Chub, Gila robusta jordani, is a federally endangered species whose native habitat resides entirely within an active cattle ranch of the Pahranagat Valley, Lincoln County, Nevada. The current distribution consists of 2.2 miles of stream channel and 1.5 miles of a cement-lined irrigation ditch. Working through the USFWS’s Partners for Fish and Wildlife Program, we have developed a working relationship with the landowner, allowing us to implement five restoration projects over the last nine years. Some projects directly benefit chub, while others help the landowner manage resource concerns that otherwise hinder the cattle operation. Since 2014, we have intensified research in the field, including implementing seasonal snorkeling surveys, mark-recapture studies of adults, larval fish monitoring, and evaluating fish habitat. Important results of these studies lead to the discovery that juvenile fish are lost to the system during the irrigation season, which has led to yearly salvaging of juveniles. Through these studies we significantly improved our understanding of this species and needs for future recovery efforts. This conservation program was made possible by funds from the USFWS’s Cooperative Recovery Initiative (CRI) program. Finally, we acknowledge Lee Simons for his leadership in writing the CRI Proposal in 2013, developing the monitoring program, and for his strong support of conservation on private lands.

ABSTRACT. The headwaters of the Muddy River, Clark Co., Nevada, is formed by discharge of numerous thermal springs and seeps, and the sole habitat of the endangered cyprinid, Moapa coriacea. The species was common when described, but early reports indicate its decline in the middle 1960s, a result of the combined threats of habitat modification and exotic invasive species. When the USFWS acquired several springs in 1979 to establish the Moapa Valley National Wildlife Refuge, much the habitat had been converted to modified channels and swimming pools used for aquatic recreation. The process to return the habitat to natural flowing channels and reduce non-native fishes is ongoing, and a story of gradual success. Here, we review the history of research, major management actions, and the recovery program that established partnerships central for the recovery of habitat and species. Particularly noteworthy for the recent accomplishments in the upper Muddy River is the role of biologist Lee Simons (USFWS, Las Vegas). His leadership provided the coordination responsible to direct and fund an extensive series of fish barrier construction projects, monitoring, salvage operations and stream renovation efforts. Today, the working group and partnerships enhanced by Lee’s work continue to benefit the resource.

ABSTRACT. The Moapa Warm Springs in Southern Nevada is a regional spring complex that form the headwaters of the Muddy River. These thermal springs, and associated streams, are habitat for an endemic suite of thermophilic aquatic species that includes the federally-endangered Moapa Dace (Moapa coriacea). Currently, the Southern Nevada Water Authority (SNWA) and stakeholders are undertaking recovery actions for the Moapa Dace and its habitat. These include construction of fish barriers, reduction in or removal of non-native and invasive species, riparian and aquatic habitat restoration, and development of an ecological model for the Moapa Dace. To facilitate recovery of the dace and other native species, SNWA purchased the 1,218-acre Warm Springs Ranch in September 2007 and designated it the Warm Springs Natural Area for conservation and environmental stewardship purposes.

In 2008, Moapa Dace numbers suddenly declined to a record low of 459 individuals. Working with the US Fish and Wildlife Service (USFWS), Nevada Department of Wildlife (NDOW), and other stakeholders and researchers, SNWA is conducting stream restoration work and intensive habitat improvements to reverse the population’s decline. Following the February 2008 nadir, dace numbers recovered somewhat but have yet to reach recovery levels. NDOW and SNWA has successfully treated the Upper Muddy River with rotenone to control the invasive and predatory Blue Tilapia (Oreochromis aureus). Furthermore, stream restoration and clearing of dense stands of invasive Tamarisk (Tamarix spp.) and Fan Palms (Washingtonia filifera), is facilitating the re-establishment of native riparian vegetation, providing prevention of future wildfires, and continued improvement in Moapa dace numbers.

In 2015, a removable fish barrier was opened which allows this fish access to its entire historical range. Moapa Dace numbers are currently stable and work continues to improve dace habitat, improve stream connectivity, and to monitor for invasive species.

ABSTRACT. From 1993 through 2017, BIO-WEST, Inc., with funding and support from various agencies, has monitored the lower Virgin River to assess the long-term fish community dynamics and the success of stocking efforts to establish and enhance Woundfin, Plagopterus argentissimus populations. Native fish relative abundance increased in the upper study reaches following flood events, while nonnative fish abundance declined during these post-flood periods. Reaches above the Bunkerville Diversion are still considered the source of all native fishes within the lower Virgin River. A historical comparison of both native and nonnative fish species captured in the lower Virgin River since 1998 shows species composition to be similar across years indicating that positive trends associated with flooding are short-lived. Long-term catch rate analysis for the lower Virgin River show that native fish abundance has not significantly changed, but nonnative fish abundance has declined significantly in the last two decades. A similar analysis of habitat shows little variation in habitat types, substrate, or cover present at sampling locations within the study area. This monitoring yields a long-term perspective to assess fish populations within the lower Virgin River by providing Virgin River Chub, Gila seminuda population estimates, and provide a holistic understanding of the fish community in anticipation of future nonnative fish species removal. Consistent data collection will continue to be important in monitoring the rare fishes of the lower Virgin River and update recovery goals, particularly given the growing water demand in the region.

ABSTRACT. Devils Hole has a history of conservation and recovery efforts dating back to the late 1940s. Since this time several individuals have played leading roles in keeping the iconic Devils Hole Pupfish Cyprinodon diabolis from becoming extinct. One such person was Dr. Lee Simons, a naturalist and desert fishes specialist, who during his tenure at the US Fish and Wildlife Service’s Las Vegas office significantly influenced management decisions. Lee was an integral part of the Devils Hole Pupfish team for five years. During this time, Lee witnessed the species decline to the lowest count on record of 35 observable pupfish in the spring of 2013 and increase to one of the highest counts in the last 10 years: 131 fish in fall 2015. Lee was instrumental in developing a captive propagation effort entitled “Recovery and Husbandry of Devils Hole Pupfish Eggs from Devils Hole” that is still in use today, and the guiding document to establish the refuge population at Ash Meadows. Lee will always be remembered for his critical thinking, camaraderie, and contributions of experimental design to the recovery teams on which he served. Even though Lee’s time involved with Devils Hole was too brief, his efforts afforded lasting impacts on how managing agencies address recovery efforts in the future. P.S. Don’t forget your knee pads!

ABSTRACT. Devils Hole is a tectonic cavern partially filled with deeply sourced groundwater from the Death Valley Regional Flow System (DVRFS). A single skylight in this vast underground system is the sole natural habitat for the critically endangered Devils Hole Pupfish, Cyprinodon diabolis. In Devils Hole, this fish survives under conditions (e.g. high temperatures and low dissolved oxygen concentrations) that would be lethal to most fish. The water of Devils Hole is highly oligotrophic, with extremely low productivity and organic carbon and nutrient concentrations. Like most cave-dominated systems, with the possible exception of the summer when direct sunlight reaches the water surface, the foundations of the food web in Devils Hole are primarily microbial. In the mid-2010s, the Ash Meadows Fish Conservation Facility (AMFCF), a full-scale replica of the uppermost 6.7 m of Devils Hole, was constructed by management agencies to establish a backup population of C. diabolis. To gain a more predictive understanding of the capacity of these unique paired natural and manmade environments to support fish, we evaluated their physical parameters and chemistry in combination with next-generation DNA sequencing of planktonic and benthic bacterial and archaeal communities (16S rRNA gene libraries). Major ion concentrations were consistent between the two systems, but water temperature and dissolved oxygen dynamics differed. Bioavailable nitrogen (primarily nitrate) was 5x lower in AMFCF. Devils Hole and AMFCF nitrogen:phosphorus molar ratios were 107:1 and 22:1, indicative of different nutrient control mechanisms. Both sites possess extraordinarily high microbial diversity, with over 40 prokaryotic phyla represented at each; with 37 shared between them and nearly half deriving from candidate phyla – so-called microbial dark matter lineages. The abundance and composition of predicted photosynthetic primary producers (Cyanobacteria) was markedly different between sites: Devils Hole planktonic and sediment communities were dominated by large and visually conspicuous Oscillatoria spp. (13.2% mean relative abundance), which proved virtually undetectable in AMFCF. Conversely, AMFCF was dominated by a predicted heterotroph from the Verrucomicrobiaceae family (31.7%); which was comparatively rare (<2.4%) in Devils Hole. We propose that the paucity of bioavailable nitrogen in AMFCF, perhaps resulting from physical isolation from allochthonous environmental inputs, is reflected in the microbial assemblage disparity, influences biogeochemical cycling of other dissolved constituents, and may ultimately impact survivorship and recruitment of refuge populations of the Devils Hole Pupfish. This work was dedicated to Lee Simons in a recent publication in PLOS One (Sackett, et al. 2018 13(3):e0194404). Our project was in large measure inspired by conversations with Dr. Simons, who contributed to both its conceptual design and provided insightful comments during preparation of the manuscript. His advocacy and friendship will be missed.

ABSTRACT. Water was a critical fuel for economic and population growth in the post-World War II North American West and its appropriation for human use brought new challenges to aquatic organisms that had evolved in harsh environments but were little prepared for extensive alteration of fragile aquatic habitats. At that time, neither the general public nor natural resource agencies had much regard for native fish species if they had no immediate and tangible worth to humans. But an increasing awareness by resource managers and academics of the plight of this vanishing fauna spawned the Desert Fishes Council in 1969. With passage of the Endangered Species Act in 1973, additional impetus for conservation of native aquatic organisms was provided. So began The Battle Against Extinction, a seminal book published in 1991 that chronicled progress and issues in arid-land native fish conservation. Since then, new technologies and evolving strategies provide new opportunities, but climate change exacerbates lingering threats. Now we launch a new effort to examine the ecology, policies and politics of desert fish conservation. As W.L. Minckley and Jim Deacon noted, it is not a lack of scientific expertise that prevents progress in conservation, rather, it is the lack of will by society to implement needed actions. The fate of many arid-land aquatic species and ecosystems now hangs in the balance.

ABSTRACT. The battle to save desert fishes has been fortunate to have some of the most dedicated and thoughtful advocates for conservation. Today, I will reflect on the pioneers of the Desert Fishes Council: Carl Hubbs, Bob Miller, Salvador Contreras-Balderas, W.L. Minckley, Jim Deacon, Clark Hubbs, and Bob Behnke. Biographies of these seven, as well as one for myself, are included in the upcoming book Standing Between Life and Extinction. Join me for some great times with these giants of desert fish conservation.

ABSTRACT. Desert ecosystems are particularly susceptible to anthropogenic influences. This is especially true where limited water resources can be impaired by excessive water mining and concomitant depletion of aquifers. Herein, the decline of aquatic habitats throughout the Chihuahuan Desert of Texas is discussed and observations on relationships among declining aquifer levels, aquatic habitat degradation, and status of native fishes are presented. Examples from the Big Bend reach of the Rio Grande, Balmorhea Springs Complex, Pecos River, and Devils River reveal a decline in distribution and abundance of native fishes. Ongoing and impending land-use practices and increased demands on groundwater and surface water resources point to future reductions. However, activities are underway that represent a source of optimism for conservation of aquatic habitats and native fishes in the region. Native Fish Conservation Areas are being established to enhance management of desert ecosystems to restore and maintain functional watersheds, conserve aquatic habitats, and support populations of native fishes. Increased landowner awareness of the value of cooperative conservation of aquatic resources and their inclusion in management decisions are critically important, particularly in Texas where the majority of land is privately owned. Ultimately, archaic Texas water laws need revision and reformulation if desert aquatic systems are to be restored and preserved.

ABSTRACT. Native fishes of desert aquatic ecosystems have been dramatically impacted by nonnative species. Over time, habitat modification and degradation have set the stage for the influx of many nonnative taxa. Traditionally, nonnative fish control has meant attempting to eliminate every individual nonnative from the habitat of interest. In larger systems, complete elimination has proven impossible, and managers have sought ways for nonnative and native species to coexist or to reduce the stress of nonnative taxa on native species. This paper is the result of a chapter contribution to the new book, Standing Between Life and Extinction, and describes the nonnative fish dilemma, lessons learned, and possible pathways for remediation while providing several examples from the Colorado River basin. We suggest that habitat complexity and more natural flow regimes can help enable native fishes to persist in the face of nonnative fishes. We conclude that a multiplicity of tools, techniques, and education remain important if we are to benefit and maintain our native fish fauna.

ABSTRACT. One of the primary priorities of conservation is to prevent extinctions. Thirty-three fishes and 23 aquatic invertebrates are recorded as recently extinct within the desert and adjacent regions of the United States and Mexico. Additionally, five fishes are listed as extinct in the wild. The process of extinction often begins with habitat degradation or other disturbance that diminishes local populations or causes local extirpations that lead to the entire species or subspecies being more susceptible to loss. Extinction itself is often linked to some catastrophic change in water supply, such as water diversion or spring failure due to over withdrawal of groundwater. Introductions of nonnative species that may prey on, compete with, or hybridize with native species, are more common in extinction of desert fishes than for aquatic invertebrates. Increasing numbers of endangered and extinct species are a cautionary account about our own future. The question for humans is whether the warning signs will be obeyed or whether society proceeds headlong into a future where our own species may be at risk.

ABSTRACT. Specimen collections are critically important for modern ecological, evolutionary, and biogeographical studies and are increasingly aiding in conservation decision-making. The information collections contain in the form of specimen-backed occurrences, field notes and images can provide insights and guidance for researchers and resource managers, and serve as a verifiable base-line representing historical conditions. The Fishes of Texas Project is a regional, quality-controlled, database of museum specimens compiled from many collections and an online user interface allowing users to view, map and download data. It has enhanced conservation decision-making for aquatic species in Texas and might serve as a template for similar regional projects.

ABSTRACT. The preservation of the Devils Hole ecosystem and the recovery of the Devils Hole Pupfish (Cyprinodon diabolis) was a great success story for the Desert Fishes Council and for the scientists and resource managers involved in the conservation efforts. “Battle Against Extinction” described the collaborative ecosystem-level research that led to the Supreme Court decision setting a minimum water level in Devils Hole. This minimum water level reflected the best available scientific information at the time, and as the water level in Devils Hole recovered the C. diabolis population tracked that recovery closely. As the C. diabolis population appeared to stabilize through the 1980s and early 1990s, ecosystem-level monitoring in Devils Hole was phased out in favor of other priorities. The lack of contemporary data, however, left resource managers unprepared to proactively address the unexpected and unexplained decline in the C. diabolis population that began in the mid-1990s. This decline became an existential crisis in 2006, when a spring survey counted just 38 individuals, and again in spring 2013 with a survey of just 35 fish. In this talk, we review the responses of both scientists and resource managers to these crises, as well as the role played by scientific research in formulating management responses. In 2006, most of the research on the Devils Hole ecosystem was 20-30 years old, and the lack of current knowledge hampered the management response to the critically low population survey. The 2006 survey, though, spurred further research in the ecosystem, and the management response to the 2013 survey was both better informed and more effective than the 2006 response. Using Devils Hole as a case study, we argue that research into threatened and endangered ecosystems – even when they appear to be stable – is critical to the management and conservation of these resources.

ABSTRACT. Since the publication of Battle Against Extinction in 1991 there have been substantial changes to the natural and anthropogenic landscapes of the desert southwest. Environmental impacts have accelerated with increasing human populations but, unfortunately, scant attention is given to long-term changes in natural aquatic biotas. Beginning in 1963, W.L. Minckley, colleagues, and students monitored and studied fish assemblages of Aravaipa Creek, Arizona. Minckley’s monitoring efforts continued until his death in 2001 and since then by the authors of this chapter. This represents the longest continuous record of abundance and distribution of any fish assemblage in the region. Considerable scientific information has been gained from these efforts and forms the basis for much that is known about several iconic native desert fishes. These data provide a comparative baseline to characterize responses to biotic and abiotic events and modifications of Aravaipa Creek. Data obtained provide critical information on fish assemblage dynamics, species ecology, impacts of human-induced alterations and management, and insights on potential consequences of global warming. Herein we present results from 54 years of Aravaipa Creek fish monitoring and illustrate how fish populations respond to changes in the Aravaipa catchment.

ABSTRACT. Restoration of a species to historically occupied habitats is a common conservation strategy, especially for interior North American salmonids. An essential early, if not first, step is to determine the historical range of target organism. For many southwestern fishes this has proven difficult as historical habitats were compromised or destroyed by European settlers before scientific investigations catalogued the native fauna of the region. Further complicating accurate delineation of native ranges were paucity of historical collections, introduction of nonnative species, and the shifting taxonomic designations of remnant populations. Following its description in 1950, Gila Trout Oncorhynchus gilae was the presumptive native trout of the entire Gila River drainage in New Mexico and Arizona. But the description of Apache Trout O. apache from a Gila River tributary in 1972 interjected uncertainty to the historical range of Gila Trout. Was Gila Trout limited to the upper Gila River in New Mexico and were the native trout of the Agua Fria and Verde drainages taxonomically distinct from Gila Trout? Absence of uncompromised specimens from Arizona streams precludes definitive resolution of this question, but historical accounts and several museum specimens support a close affinity of these populations with Gila Trout. Consequently, Gila Trout conservation efforts should continue to include its restoration to suitable habitats throughout the Gila River drainage, exclusive of Apache Trout streams.

ABSTRACT. Razorback Sucker Xyrauchen texanus, a historically widespread and abundant warmwater fish endemic to the Colorado River basin, has declined dramatically. Habitat alteration, dams that block migration routes and alter natural sediment, stream flow, and thermal regimes, channel change, and nonnative fish predation are reasons for decline of Razorback Sucker. Lack of recruitment was evident more than 50 years ago and all wild fish were eventually extirpated, with the possible exception of the small Lake Mead population. Extensive restoration efforts have had mixed outcomes. Various propagation programs have restored reproducing adults in lakes Mohave, Havasu, and Powell in downstream basin reaches, and the San Juan, Colorado, and Green rivers in the upper Colorado River basin. However, nonnative predators reduce survival of stocked fish and recruitment is non-existent except in Lake Mead. Localized recruitment in Lake Mead, and new strategies to enhance juvenile production in isolated lower Colorado River backwaters and connected Green River floodplain wetlands offer examples of recent successes. Further progress toward restoration of large-river fishes including razorback sucker requires additional flow, habitat, and nonnative fish management, and continued long-term support for conservation programs.

ABSTRACT. The future of southwestern aquatic habitats and their native species is uncertain, due to possible impacts of climate-induced drought, population growth, and overutilization of scarce water resources, but also to politically and ideologically motivated attacks on the U. S. Endangered Species Act, and federal land management and regulatory authority. However, a potentially more profound danger is the development of a “post-truth” culture that accepts the notion of “alternative facts” and distrusts science. Such attitudes mean that the practice of science, as well as its findings, have political implications, a development that will make it difficult to develop effective approaches to counter likely, future droughts in the American Southwest, and consequent threats to regional aquatic biodiversity. Crafting a sustainable future for the Southwest and its native species and ecosystems will require a robust scientific understanding of the region’s natural variability and system complexity, and advances in public policy and management. However, it also will require effective political action, and that a critical mass of people transcend blinding ideology, convention, and human short-sightedness. Finally, we must imagine the realms of our possible futures, and consider the historical context of past, present, and future efforts to protect regional aquatic biodiversity in the American Southwest.

ABSTRACT. Lineages of desert fishes that have persevered millions of years, through droughts exceeding any in the historical record, now collectively spiral toward extinction in the industrialized desert signaling the loss of functioning aquatic ecosystems. A century of large-scale water-resource development for agricultural and urban expansion has diminished these ecosystems to a point that exceeds prehistoric megadroughts, although the accompanying climate is relatively wet. Anthropogenic habitat degradation and introductions of nonnative species exacerbate ecological depreciation. Persistent impacts create an ecological ratchet that now elevates extinction risks for remnant populations. Full restoration of natural habitats may be impossible today, but preservation and rehabilitation of remnant ecosystems and functions are critical. Collaborative approaches to reverse ratchet-like impacts could reduce extinction risks but need more public support and wider application. This is a wicked problem because resource managers face many limitations and require cooperation among numerous private and governmental organizations representing diverse values and priorities. Greater fusion of science, environmental ethics, and ecological economics could unveil common ground among stakeholders, which will be critical to forestall looming threats.

ABSTRACT. Survival of early life stage fish is affected by multiple factors including environmental conditions, biotic interactions, and starvation. Low survival of early life stage Razorback Sucker, Xyrauchen texanus, in the San Juan River, NM & UT is thought to cause a recruitment bottleneck. Conversely, two other native sucker species, Flannelmouth Sucker, Catostomus latipinnis, and Bluehead Sucker, C. discolobus, recruit to adulthood successfully. To explore a potential factor leading to this discrepancy among species survival, we used museum specimens collected from the San Juan River in 2007 to investigate diets of co-occurring early life-stage (< 30 mm SL) Bluehead, Flannelmouth, and Razorback Sucker. We evaluated both the diversity of diet (number of diet categories) and frequency of occurrence of different diet items. Bluehead and Flannelmouth Sucker did not differ in diet diversity, but on average had 40% and 42%, respectively, more diverse diet compared to Razorback Sucker. Discriminant function analysis (DFA) correctly classified species by frequency of occurrence of diet items 65% of the time, and accuracy varied among species. A low frequency of occurrence of most diet items in Razorback Sucker drove most of the variation (76%) explained by DFA. Razorback Sucker might be less efficient foragers compared to Bluehead and Flannelmouth Sucker. The lack of some diet items (i.e., sand, adult diptera) from Razorback Sucker diets suggests more constrained diet and potential habitat differences compared to other sucker species. Findings from this study shed light on differences in feeding ecology among species that have potential to influence success of early life stages through resource use or predation mechanisms.

ABSTRACT. Detection of endangered Razorback Sucker Xyrauchen texanus larvae by light traps is used to prompt flow releases to inundate Green River floodplain wetlands, habitat which may increase survival of those early life stages. However, little is known about the efficacy of light traps to capture or retain larvae. In the laboratory, we investigated effects of light trap set time, release distance from trap, light presence, and turbidity on capture and retention rates of four early life stages of Razorback Sucker. Mean capture rates of protolarvae prior to the development of a swim bladder (7-9 mm total length [TL]) was 40% (28-55%) over the various treatment effects, but rose to 76% (73-80%) after protolarvae formed a swim bladder (9-10 mm TL). Mesolarvae (11-17 mm TL), the most commonly captured life stage in field sampling, had similar mean capture rates as later protolarvae at 86% (82-90%). Capture rates of metalarval (mean = 42%, range 21-63%; 15-24 mm TL) and juvenile (mean = 24%, range 20-28%; 22-37 mm TL) life stages were lower. Retention rates were generally > 75% and increased to 97% for juveniles. The relationship between set time and distances of 1-5 m on capture indicated longer set times positively influenced capture rates while distance had little effect.  Light traps may be a useful gear to detect first presence of Razorback Sucker larvae in riverine backwaters each spring, timing of which is used to begin high flow releases from Flaming Gorge Dam to inundate Green River, Utah, floodplain wetlands.

ABSTRACT. Relationships between temporal variation in groundwater levels and the distribution and habitat use of two cyprinid fishes, Least Chub (Iotichthys phlegethontis) and Utah Chub (Gila atraria), were examined at a spring complex (Leland Harris Spring Complex) in the Snake Valley of the Great Basin, Utah, USA in which groundwater has been monitored since 2009. Seasonal declines in shallow groundwater were associated with protracted periods of high evapotranspiration during 2009-2017. Temporal changes in groundwater levels explained 97% of the variation in the mean values of surface water levels obtained from measurements taken over a three-year period at 47 monitoring points. Bathymetric data, combined with data from surface water monitoring, indicated that the volume of surface water present in springs and spring-fed ponds when groundwater levels were at their lowest was only 19% of the volume of water present during peak groundwater levels. Visual and minnow trap surveys indicated that Least Chub and Utah Chub were usually associated with relatively deep water, but migrated annually from deep springs to ponds, which were used as spawning and juvenile habitat, when groundwater and surface water levels were high, returning to core spring habitats as ponds receded during the late summer and early fall. Populations of both species became increasingly fragmented as groundwater and surface water levels declined. Least Chub and Utah Chub tended to use the same core habitats from one year to the next during the late summer and fall, and were positively associated at both the habitat and microhabitat level. The strong relationship between surface water and groundwater levels, and the dependence of Least Chub and Utah Chub on seasonal expansion of lentic habitats for reproduction, indicate that predicted reductions in groundwater levels resulting from proposed groundwater withdrawal projects would eliminate most of the spawning and juvenile habitat in the spring complex.

ABSTRACT. We have examined the population structure and diversity of relict dace within Goshute, Butte, Steptoe, Spring, and Ruby valleys in eastern Nevada. We used RAD sequencing on our samples, a method of interrogating the entire genome of each individual. Our results concur with the recent Housten et al. (2015) paper, in that there is a major split within the relict dace range: Ruby and Butte valleys are similar, and Goshute, Steptoe, and Spring valleys are similar. However this is relative, because nearly all populations are highly distinct within the valleys. We will discuss our results and provide recommendations for management.

ABSTRACT. In many rivers altered by dams, native fishes have been extirpated or persist at small fractions of their original abundance and distribution, despite extensive recovery programs. The Colorado River is one of the most regulated rivers in the world, and native fish populations in the Colorado River basin have declined due to threats from invasive species and habitat change (e. g., dams, water diversions). However, over the past 19 years within the Grand Canyon, native fishes have increased in abundance and expanded their ranges in the highly regulated Colorado River. We used data from a long term monitoring program (2000-2018) to describe changes in native and nonnative fish abundance and spatial distribution. Fish were sampled using boat electrofishing and baited hoop nets at randomly selected sites (stratified by ~ 8km reaches) between Glen Canyon Dam and Lake Mead (406-503 river kilometers). Catch per unit effort was calculated as an index of relative abundance. Native fishes increased in abundance during the study period; conversely most non-native species decreased in abundance. Non-native species comprise most of the species assemblage in cold tailwater habitat between Glen Canyon Dam and the Little Colorado River Confluence, but downstream of the Little Colorado River, native fish outnumber non-native fish. Western (downstream) reaches of the Grand Canyon appear to provide particularly important habitat for native fish. Native fishes increased in abundance with increasing river mile, and most age-1 and younger fish were captured in western Grand Canyon. We hypothesize that a combination of an increasing amount of riverine habitat as Lake Mead recedes, tributary refugia, impediments to establishment of warmwater predators, and modifications to Glen Canyon Dam operations, has contributed to the native fish recovery observed in the Colorado River in Grand Canyon.

ABSTRACT. Bonita and Aravaipa Creeks are located within southeastern Arizona and are unique in that they still support intact native fish assemblages and exceptional riparian and aquatic values. Past native fish recovery actions, including construction of fish barriers that prevent or hinder future upstream incursions of nonnative fishes from downstream sources, have benefitted both creeks. However, both native fisheries are still threatened by the presence of nonnative predatory and competitive fish species. To reduce the threat of nonnative fishes in both systems, the BLM, Safford Field Office, collaborated with federal, state, private, and non-governmental partners to begin mechanical removal of Green Sunfish in 2009 at Bonita Creek and 2010 at Horse Camp Canyon, Aravaipa Creek. Green Sunfish were targeted due to their highly piscivorous nature and their ability to thrive in these two systems. In Bonita Creek, nonnative fishes were removed from a 1.9 mile reach dominated by beaver dam pools and glides. Beaver dams effectively reduce the movement of Green Sunfish within the removal area. In Horse Camp Canyon, nonnative fishes were removed from a 0.5 mile reach that is characterized by boulder-strewn bedrock pools and slots. Boulders and other natural features restrict movement of fish into the removal reach of Horse Camp Canyon except during seasonal flood events when a surface connection exists to Aravaipa Creek. Baited Gee metal minnow traps, collapsible Promar traps, and hoop nets were the primary removal methods used at both creeks. Occasionally seines, dip nets, and backpack electrofishers were used to augment and assess efforts. Total effort using Gee metal minnow traps, collapsible Promar traps, hoop nets, and custom and crab traps was 46,677 overnight net sets from 2009-2017, which resulted in the removal of 22,709 Green Sunfish from Bonita Creek. In 2018, 1,146 overnight net sets at Bonita Creek resulted in zero Green Sunfish captured. No Green Sunfish have been seen or captured from Bonita Creek since October 2017.  A total of 3,910 Green Sunfish were removed from Horse Camp Canyon from 2010-2015, and 2018.  The majority (n=2,675) were captured with Gee metal minnow traps and Promar collapsible nets.  Seining, dip netting, and backpack electrofishing captured 1,235 Green Sunfish.  No Green Sunfish have been seen or captured since October 2015.  Results to date, suggest Green Sunfish have been eliminated from both systems above their barriers.

ABSTRACT. A literature review of phylogenetic diversity indicates that North America hosts 333 lineages of fishes restricted to the desert region (i.e., the region with <0.65 aridity index). These ‘desert endemics’ have diverse distributions from large river basins to small springs. A comparison of endemic-lineage distributions with modern and prehistoric drainage boundaries reveals 30 distinct areas of endemism, with endemic lineages per area ranging from 1 to 43 (mean = 15 ± 11 SD). Faunal composition in each area is unique. Although some ‘widespread’ endemics occupy multiple areas of endemism that have a history of interconnection, 82% of endemics are restricted to single areas, and no endemics occupy more than five areas. A major biogeographic boundary subdivides the region into Northern Great Basin-Colorado Plateau (13 areas) and Southern Desert-Eastern Steppes (17 areas). Only 3% of desert-endemics span this boundary. These either dispersed between the upper & lower Colorado River basin following the formation of the Grand Canyon or crossed between the Lahontan and Mojave areas of endemism via Mono Lake. Thus, desert-fish conservation should target all areas of endemism individually and collectively to ensure preservation of native biodiversity.

ABSTRACT. Desert-endemic fishes represent 53 clades from 14 families (based on a literature review). Many clades produced multiple endemic lineages (mean = 6 ± 8.2 SD). Estimates for timing of lineage origins are asynchronous (with some exceptions). Initiation of desert-endemism spanned a period of 23 million years, depending on lineage. Some clades diversified sequentially (e.g., Exoglossum; Moxostoma; Cyprinodon). Faunal dissimilarity among areas of endemism indicates that most lineage diversity arose independently, by area. Our conceptual model of faunal assembly illustrates a 2- or 3-step process in which an incipient-endemic lineage can diverge at any time, independent from other lineages, and an area of endemism may provide habitats in headwaters, alluvial streams & rivers, or springs. Step one: Founders colonize areas of endemism via passive (barrier formation) or active (dispersal) mechanisms. Step two: Persistence, possibly with adaptation, establishes residency. Areas with endemics become centers of survival. Step 3 (optional): Over time, areas accumulate diverse faunas through periodic colonization and/or in situ diversification. Areas accruing faunas become centers of accumulation. Areas with in situ diversification become centers of origin. Because of this process, each area of endemism has a unique assemblage with its own history. Hence, each area is a self-contained target for desert-fish conservation.

ABSTRACT. Aquatic conservation issues in deserts of the American West center on nonnative species, altered surface-flow dynamics, and overexploitation of inherently scarce water. Resulting levels of degradation are effectively irreversible except locally. Consequently, restoration success is relative to might have been, or would be, without the effort. Presented here are case studies of such successes. One non-desert project is included because it involves the first federally delisted, non-extinct fish (Oregon Chub) and exemplifies restoration of a western, floodplain species in its natural habitat. Other studies include two primarily floodplain species (Gila Topminnow and Desert Pupfish) transplanted into semi-wild refuges (e.g., stock tanks, ponds, and protected springs); stream-dwelling species (Modoc Sucker and Fossil Creek, Arizona, assemblage) positively affected by habitat restoration or restored stream-flow; and assemblages of species endemic or native to springs. The latter include one instance of rescue and transplantation of endemics from a now-dry spring system (Rancho Nuevo springs, Chihuahua) and examples of expanded habitat via marsh (ciénega) restoration (El Pandeño, Chihuahua) or creation of artificial ciénegas (Balmorhea area, Texas). Keys to these successes are governmental inter-agency cooperation, conservation oriented NGOs, and engagement of private landowners and other stakeholders. Most successes are short-term without the political and societal will to protect and restore natural systems.

ABSTRACT. All volumes of the Desert Fishes Council Proceedings have been available online for many years, but as a large collection of single-year separate files in diverse formats, making exploration of the total content inefficient. Recognizing the considerable potential value of the now 50 years of knowledge relevant to the DFC mission, we have made at least some progress toward making all of the Proceedings content more readily accessible and useful and report on that here.

Prior to 1992, the content of all volumes is in graphic-based PDF files (usually one file for each year), so their text is not searchable by computers. All abstracts from 2008 - 2017 have been searchable in a partially normalized database made available online as a Google Fusion Table so relatively rigorous online searching and summarization of that content is facilitated. The 1992-2007 content originated in digital format starting with abstract submission by authors on 5 1/2 inch floppy disks sent via Post (and later via email) to the editor. However, formatting of the published content varied over those years, and it was edited in text processors, not in the database, so final content is now available only in the format of the PDFs used for printing each volume.

Significant manual work by humans would still be required to extract all content into a single, fully normalized database, but on the occasion of the 50th anniversary of the Council, the first author applied automated Optical Character Recognition to all pre-1992 graphics-based content, and then concatenated all Proceedings volumes and all abstracts from 1969-2017 into a single, massive (152 mb) text-based, downloadable and searchable PDF file now permanently archived on the web:

Hendrickson, Dean A., Edwin P. Pister, Lloyd T. Findley, and Gary P. Garrett. 2018. “Compiled Proceedings of the Desert Fishes Council” Volume 1 (1969–2017): 4057 pages.  https://doi.org/10.15781/T2QB9VR0N.

Though work should continue toward getting all DFC Proceedings content extracted, fully normalized into a single, easily analyzed database accessible to both computers and humans, we here report on our own applications of this now somewhat more accessible knowledgebase. This new fully text-based format clearly has the potential to help counter shifting conservation baselines by easily exposing often forgotten or simply overlooked, previously "gray" or "dark" biodiversity data. We welcome input from users of this resource before we add all content from the 2018 meeting to produce and publish version 2 of this file.

ABSTRACT. The Lower Colorado River Area encompasses five states in the United States and two in Mexico.  The drainages comprising this Area arise in both countries and are unique yet connected to each other.  In the waters of the Area, many native invertebrates, fish, amphibians, and reptile species live here, competing with human land and water use as well as the introduction of nonnative plants and animals.

The science we do is complex, and its release is largely contained within the group of agencies and involved parties.  But we do not spend a lot of time and effort to reach out to the public about what we do.  So, this poster looks at some of those efforts that are attempting to educate the can to some extent, their interest in the conservation of native aquatic species is a factor.  At DFC and other professional meetings, we present the science to each other; we do not often consider the outreach and education efforts that reach the public and can have tremendous impact on how our efforts are supported.

Three efforts are shown; two are ongoing and one is the result of the interest of news media to educate the public.  These are:

Marsh Education’s Sharing Tails

The Lower Colorado River Multi Species Conservation Program Outreach Program

The Arizona Republic 3-day series on the Grand Canyon

If we want to be relevant to the larger world, we need to focus our efforts at educating the public about native aquatic species.

ABSTRACT. Light traps have been shown to be valuable in the conservation and monitoring of endemic desert fishes. To use this method sampling in Rio San Bernardino, Sonora, Mexico, a trap was developed that is of a robust, power-efficient design. This trap disassembles and nests into itself for safe storage and transport and can be easily assembled in the field without tools. Using two lithium coin cells as a power source, light from a light emitting diode is diffused by the translucent high-density polyethylene quatrefoil trap body. Initial field tests indicate this to be an effective design and a possible alternative to more typical quatrefoil light traps of acrylic or polycarbonate construction.

ABSTRACT. We present new information regarding the status of some endemic freshwater fishes of México from eight states and 24 localities. From earlier descriptions summarized in 1991, two fishes were known extinct, but by 2017, the total increased to 15 taxa either extinct or gone from the wild and present only in captive populations. Species in the genus Cyprinodon are the most threatened taxa at the sites we visited. Main reasons for rapid declines or extinctions are spring drying due to increased water consumption by domestic, industrial, and agricultural practices, and negative effects of nonnative species. The destruction of aquatic habitats occurs everywhere in Mexico and requires more protected areas for fishes. The future of this group of vertebrates, especially in arid zones, is in jeopardy of disappearing forever. The number of species declining or extinct continues to rise, increasing the importance of protection by Mexican laws.

ABSTRACT. In 2012, BIO-WEST, Inc. (BIO-WEST) researchers observed sonic-tagged Razorback Suckers moving from the Colorado River inflow area of Lake Mead upstream into the lower Grand Canyon. As tracking efforts attempted to define movement patterns and habitat use, it became apparent that these fish were using the Colorado River in the lower Grand Canyon. Small-bodied sampling began in the Grand Canyon in 2014 from river mile (RM) 179.1 (Lava Falls Rapid) to RM 280.0 (Pearce Ferry) and continued through 2015 until researchers learned that Razorback Sucker spawning was occurring upstream of this area. Since 2016, small-bodied fish community sampling in the Grand Canyon has been conducted from RM 88.5 (Phantom Ranch) to RM 280.0. These efforts have resulted in the capture of four native (Bluehead Sucker Catostomus discobolus, Flannelmouth Sucker Catostomus latipinnis, Humpback Chub Gila cypha, and Speckled Dace Rhinichthys osculus) and eight nonnative fish species, as well as documentation of young-of-the-year (age-0) catostomids and cyprinids. These results show that approximately 90% of the Grand Canyon fish community is comprised of native species and demonstrates the need for continued research throughout the Grand Canyon to determine mechanisms allowing for native fish domination.

ABSTRACT. The Longfin Dace (Agosia chrysogaster) is a small fish (<10 cm) native to the southwestern United States and northern Mexico.  Populations are widespread, and many are reduced, existing in uncertain conditions, impacted by introduced fishes, the over-use of ground water, and climate change which continues to impact freshwater ecosystems.  As a result, the population in the Rio Sonoyta, a tributary of the Colorado River, present along the US-MX border, is faced with extinction.  This prompted concerned scientists at CEDO, the Intercultural Center for the Study of Deserts and Oceans, in Puerto Penasco, the U.S. Fish & Wildlife, Arizona Game and Fish Department, and non-governmental environmental groups to establish several new populations in man-made refuge ponds in and around Puerto Penasco, Sonora, Mexico. 

Today, the species is extirpated from the Sonoyta River and one population remains, at CEDO, where, for 11 years, a population of Longfin Dace has thrived in a small pond with the native, endangered Sonoyta River Pupfish, Cyprinodon eremus.  In the fall of 2018, because of concern with interspecies competition and predation, in the small habitat, CEDO built a new pond for longfin dace using funds provided by Ms. Terri Hamstra and a Conservation Grant from the Desert Fishes Council.  The pond was constructed with volunteer labor provided by Dennis Caldwell, a pond designer, and the CEDO staff.  Longfin Dace were introduced into the pond in late August, and by 22 October 2018, several fry were observed in the pond.  Based on this success, CEDO is moving forward with ongoing conservation efforts for these native fish.  Phase II of this recovery program involves creating an interpretive display about the importance of freshwater habitats in the Sonoran Desert and showcasing the endangered and physiologically unique fishes occurring in this unique ecosystem.

ABSTRACT. The Desert Fishes Council and North American Native Fish Association provided funding for the development of a holding pond for the Yaqui catfish, Ictalurus pricei, as part of an ongoing effort to recover this species in Mexico by UNISON and interested persons.  The pond was constructed in July 2018 is 50 X 30 meters.  The eastern third is shallow (.05 – 1 m); the western side is 2-m deep.  Water is supplied by a continuously flowing artesian well located to the north.  The pond is on San Bernardino Ranch, Sonora, Mexico, about 25 km east of Douglas, Arizona – Agua Prieta, Sonora.  It is immediately across the International Border from San Bernardino-Leslie Canyon National Wildlife Refuge.   Its purpose is to hold this species temporarily until they can be moved to a hatchery.

The Yaqui Catfish is the only described species of catfish native to the United States, west of the continental divide.  Yaqui catfish is functionally extinct in the United States, and experiencing widespread population declines in Mexico.  It is listed as threatened under the Endangered Species Act in the United States and is subject to special protection by SEMRNAT in Mexico.

The pond also contains a population of Yaqui Topminnow, Poeciliopsis sonoriensis, and Yaqui Chub, Gila purpurea.  Aquatic vegetation consists of Potomogeton sp., Typha sp., Schoenoplectus sp., and Najas sp.

ABSTRACT. The Moapa (Muddy) River of southern Nevada once held a healthy assemblage of native species that included the Virgin River Chub Gila seminuda, Moapa Dace Moapa coriacea, Woundfin Plagopterus argentissimus, Moapa Speckled Dace Rhinichthys osculus moapae, Desert Sucker Catostomus clarkii, Flannelmouth Sucker Catostomus latipinnis, and Moapa White River Springfish Crenichthys baileyi moapae. By the 1960s only one native fish species, the Virgin River Chub, was captured below the Wells Siding Diversion, and sampling through the 1970s indicated that the fish assemblage in this section of river consisted predominantly of nonnative species. Above the Wells Siding Diversion, only the Virgin River Chub remains as a sustainable population, stocking of Moapa Speckled Dace is required to maintain the species, and the Moapa White River Springfish and the Moapa Dace are found only in the uppermost reaches of the river. We make comparisons of the present day fish community composition, relative abundance, and distribution to historical collections stemming from the 1960s and 1970s, which indicate an overall decline in the abundance and distribution of native fishes. Floods in the past 12 years have shown benefits for the chub population in years following flood events, while populations decrease again after a couple years post-flood. To date, PIT tagging data shows Virgin River Chub exhibit life spans of at least 6 years in the Muddy River, which perhaps allows the population as a whole to outlast difficult conditions between flood events. Further difficulties for native fish include connectivity issues due to diversion dams as well as summer temperatures that often remain above 30.0°C, which is above the optimal temperature for Virgin River Chub of 24°C (critical maximum temperatures between 28°C and 36°C). Nonnative species are a principle concern within the Muddy River at this time, but are being mitigated through the use of rotenone by the Nevada Department of Wildlife upstream of the Wells Siding Diversion. The Virgin River Chub holds no special protection within the Muddy River at this time, despite being the same endangered species that occurs in the Virgin River.

ABSTRACT. There is an increasing concern and need for the conservation of springsnails and other endemic mollusks and for the unique spring and springbrook habitats on which they depend (Hershler et al 2014; Abele 2011). Nationwide, several of these species have been listed as endangered or threatened under provisions of the ESA; others are undergoing review by the U.S. Fish and Wildlife Service (USFWS) for possible future listing actions. These species can be particularly susceptible to localized threats such as water diversion, capping, groundwater pumping, invasive or exotic species, development, or trampling by ungulates. These threats can be addressed but development and implementation of consistent and appropriate strategies and actions are needed. Firm commitments from agencies and entities responsible for management of occupied sites, including private landowners, are also needed so management actions can be applied effectively.

This poster describes the development of a comprehensive Conservation Agreement and Strategy (CAS) for springsnails and their associated habitats in Nevada and Utah. A Conservation Agreement (Agreement) between multiple agencies, stakeholders, and other interested parties was completed in 2017. The corresponding Strategy is currently being drafted and is expected to be completed in October, 2019. The conservation actions described in the Strategy are expected to lead to the protection and enhancement of these unique species and their associated habitats. In Utah and Nevada, Conservation Agreements and Strategies (CAS) have been an important conservation tool for more than 20 years and, in many cases, have resulted in precluding the need to list at-risk species.

ABSTRACT. Refuge populations play a critical role in the conservation of threatened and endangered species in the southwest. Through a successful partnership between Arizona Game and Fish Department and Black Canyon City, the pond at Black Canyon City Heritage Park holds refuge populations of Gila Topminnow (Poeciliopsis o. occidentalis) and Desert Pupfish (Cyprinodon macularius). These captive populations provide an important dual purpose; a source population for translocations by the Arizona Game and Fish Department, and a conservation, restoration, and public education opportunity for Black Canyon City. The pond was initially stocked with Gila Topminnow and Desert Pupfish in 2011 and 2012. Unfortunately, nonnative Mosquitofish (Gambusia affinis) and Tilapia (Tilapia sp) were discovered in 2015. The pond was drained to remove the nonnative fish, which are known to prey upon and compete with topminnow and pupfish. After drying for about a month, the pond was refilled, and left fallow for a few months to allow for natural recolonization by insects, algae, and aquatic vegetation (food resources for fish). In March 2017, 122 salvaged Desert Pupfish were returned to the pond and in June 2018 we stocked 734 Gila Topminnow. We monitored the pond in August 2018 and found the Gila Topminnow population greatly increased, with 1,429 individuals captured. Desert Pupfish are also doing well and appear to be re-established as we captured 504 individuals. In this poster, we provide an overview of this cooperative project, as well as future plans for the pond.

ABSTRACT. Loach Minnow, Tiaroga cobitis, and Spikedace, Meda fulgida, are two endangered fishes endemic to the Gila River Basin of Arizona and New Mexico. Habitat degradation and the introduction of non-native fishes have resulted in population declines, and as such captive propagation is an important facet for continued recovery. However little information exists on the spawning of these fishes, both in the wild and in captivity. Therefore the goal of this study was to determine whether a relationship existed between broodstock density and larval production to guide future propagation efforts. Three different broodstock densities (low, medium, and high) were used for both Loach Minnow and Spikedace. Both species were spawned in linear raceways (1m × 1m × 4.5m) with each tank receiving separate artesian water flow and programmable recirculation pump to mimic natural conditions. Each spawning tank was prepared identically, respective for each species. We found that lower broodstock densities resulted in the highest larval fish production per raceway for both species. However, future replicates are needed to confirm these results, and thus experiments will continue for at least one additional year.

ABSTRACT. I would like to compare and contrast pupfish, bass, and catfish. I will teach you about fish. I am going to compare and contrast the habitats, food webs, and how they live.

ABSTRACT. Lee Simons, Ph.D., served as the Senior Fish Biologist at the Southern Nevada Fish and Wildlife Office from 2008 to 2016. During his tenure, he was invaluable to recovery efforts for the Devils Hole Pupfish, Cyprinodon diabolis, Moapa Dace, Moapa coriacea, and Pahranagat Roundtail Chub, Gila robusta jordani, in addition to several other desert fishes. Lee was exceptional at building collaborative partnerships, as partners on the Devils Hole Incident Command Team and Muddy River Biological Advisory Committee strongly attest. He excelled at bringing funding and other resources to southern Nevada that resulted in recovery actions for many of the listed fish species. Lee was successful at writing grants for species conservation and obtained several Cooperative Recovery Initiative Grants, funding from the National Fish Passage Program, and several Southern Nevada Public Lands Management Act grants. Lee was active within the research community and facilitated research on desert fishes with the U.S. Geological Survey, University of Nevada Reno, UC Berkley, University of Arizona, and other institutions. Lee not only held a passion for natural resources, but for life in general. Lee was a friend and mentor for those both inside and outside the USFWS, and always took the time to lend an ear or provide help to others. Many of the projects Lee started continue today and illustrate a legacy in southern Nevada.

ABSTRACT. The Mohave Tui Chub, Siphateles bicolor mohavensis, was extirpated from the Mojave River drainage in California and listed as endangered in 1970. A source population of Mohave Tui Chub exists at MC Spring in Zzyzx and has been used for several reestablishment efforts in subsequent decades. Two potential habitats within the Mojave National Preserve with perennial sources of water have been identified by the National Park Service as candidates for Mohave Tui Chub reestablishment: West Pond and Rainbow Wells Pond. West Pond, an artificial pond at Zzyzx near MC Spring, contained a population of Mohave Tui Chub which died off in 1985 due to changes in water quality. The pond was rehabilitated in the past several years through re-excavation and by pumping fresh groundwater into the pond. Rainbow Wells Pond is an abandoned excavated mine site located on Cima Dome. The bottom of the excavation intersects the water table, forming a pond. In cooperation with the National Park Service, the U.S. Geological Survey conducted a study to monitor water-quality conditions at West Pond and Rainbow Wells for one year and characterize their suitability for reestablishment of Mohave Tui Chub populations. Water quality and sediment chemistry were determined through discrete quarterly sampling. Temperature was monitored continuously with deployed loggers. Data were also collected at three existing Mohave Tui Chub habitats in Mojave National Preserve to provide further information on the range of acceptable physical and chemical conditions. Initial water quality results at West Pond indicate that the pond is favorable habitat for the Mohave Tui Chub. Initial water quality results at Rainbow Wells Pond suggest that the dissolved oxygen concentrations are lower than the long-term tolerable ranges for Mohave Tui Chub.

ABSTRACT. Invasive crayfish species threaten the persistence of numerous desert fishes, but how crayfish density influences native fish persistence is not well understood. One hypothesis predicts that negative impacts increase with higher crayfish densities (Rogowski & Stockwell 2006; Biol. Invasions 8:79-87), while an alternative hypothesis predicts that impacts decrease with higher crayfish densities, presumably due to interference competition (Taylor & Thomas 2013; Freshwater Sci.32:1309-1317). To test these hypotheses we established experimental populations of Amargosa Pupfish, Cyprinodon nevadensis amargosae, and Red Swamp Crayfish, Procambarus clarkii, that included allopatric pupfish (control); pupfish + low-density crayfish; pupfish + high-density crayfish and pupfish + high-density tethered crayfish. The latter two treatments were compared to evaluate if conspecific interactions among crayfish affected impacts on pupfish. We found significant effects of crayfish on pupfish adult survival (X2 = 11.8; P < 0.01). Adult survival did not differ between the control (97 ± 8.0%) and low-crayfish treatments (84 + 13%; P > 0.05). Adult survival was significantly lower for the high-density crayfish treatment (69 ± 14%; P < 0.02) compared to the control. However, adult survival did not differ between the low-crayfish and high-crayfish treatments (P > 0.05), nor between the high-crayfish and high-density tethered treatments (P > 0.05). Crayfish had significant effects on juvenile productivity (X2 = 15.8; P < 0.002). Juvenile productivity did not differ between the control (705 ± 92 juveniles / tank) and low-crayfish treatment (704 ± 167; P > 0.05), while both of these treatments had higher juvenile productivity than the high-crayfish treatment (271 ± 107%; P < 0.006 and P < 0.006, respectively). When comparing the two high-density crayfish treatments, tethering resulted in significantly higher juvenile productivity (494 + 156; P < 0.03). Our results show density-dependent effects of crayfish on experimental pupfish populations. Limiting conspecific interactions among crayfish did not affect adult survival, but increased juvenile production. Our results suggest that short-term solutions to crayfish invasion may be simply to reduce crayfish densities.

ABSTRACT. Reclamation and other stakeholders perform a variety of conservation related activities in the region. The conservation of Bonytail Chub, Gila elegans, and other native fish species is currently managed under the Multi-Species Conservation Program (MSCP) Fisheries Program. There are three components to the Fisheries Program; continued monitoring of existing Bonytail populations, population augmentation through repatriation, and hatchery research and efficiency. Existing population monitoring indicates that fish are not self-replacing in the wild (Minckley et al. 2003). This lack of success on the part of native fish has largely been attributed to predation of larvae and juveniles by non-native fish (Minckley 1983, Minckley 1991). The augmentation effort has attempted to circumvent this predation risk by releasing hatchery stock at the sub-adult stage (>300mm) which should be large enough to avoid predation by non-native fish (Mueller 1995). However, MSCP staff are now concerned with avian predation of repatriated sub-adult fish. The Lower Colorado River is used by several resident and migratory piscivorous (fish-eating) bird species including cormorants, Phalacrocorax spp., Great Blue Herons, Ardea herodias, and Osprey, Pandion haliaetus. Other species of interest include American White Pelican, Pelecanus erythrorhynchos, Great Egrets, Ardea alba, Common Mergansers, Mergus merganser, and grebes, Aechmophorus spp. Currently, the effects of avian predation are unknown. However, if the threat level could be determined, MSCP could attempt to mitigate for it by altering release strategies or altering stocking numbers. This report details on-the-ground and remotely sensed avian predation monitoring conducted in 2015, 2016, and 2017 as part of the MSCP at Laughlin Lagoon, NV. The goals of this study are to 1) determine the minimum number of fish from each Bonytail Chub stocking effort that are eaten by birds, and 2) determine the relative abundance of piscivorous bird species at the Laughlin Lagoon release site.

ABSTRACT. The Arizona Game and Fish Department’s Aquatic Research and Conservation Center in Cornville, Arizona serves the primary function of housing and propagating rare lineages of small-bodied desert fishes, such as the endangered Loach Minnow and Spikedace, supporting conservation efforts in Arizona and New Mexico. The facility also conducts research and provides resources and space for emergency salvage operations. The facility was built incrementally with limited grant funding and has been largely built using military surplus shipping containers as tanks. While adequate for meeting current conservation needs, the existing systems limited production levels and research capabilities and were insufficient for future conservation goals. Thus, a renovation was initiated in 2014, with the objectives of expanding and improving holding and spawning capacity for fish, modernizing fish culture and hatchery infrastructure, and increasing biosecurity. To date, $1.2 million has been contributed to the project and two of three planned phases have been completed, improving overall functionality and performance of the facility.

ABSTRACT. The Sonoyta Pupfish is an endemic species from the Sonoyta River basin (Sonora) and the Quitobaquito Spring (Organ Pipe National Monument) along the international border. Anthropogenic impact has been the main cause of the reduction of Sonoyta Pupfish populations. As a conservation strategy, refuge populations were established in Sonora and Arizona. However, there is a lack of studies of the refuge populations of Mexico and the United States, and they were established without considering the genetic variation and the structure of the populations of origin. The isolation of each refuge population can cause its reduction in genetic variability, making it impossible to use it in future reintroductions in natural habitats. The goal of this work is to evaluate the genetic variability and the population structure of the refuge and wild populations of the Sonoyta Pupfish. For the genetic evaluation, wild specimens’ populations and existing artificial refuges have been collected (Centro Ecológico de Sonora y Centro Intercultural de Estudios de Desiertos y Océanos) and DNA extractions were performed. The PCR protocol for 10 microsatellites was standardized to evaluate the number of alleles (A), the heterozygosity observed (Ho), the genetic differentiation estimates of the microsatellite data (Rst). As advances, 565 PCR products from 10 microsatellite loci have been obtained, where polymorphism has been found.

El cachorrito del Sonoyta es una especie endémica de la cuenca del río Sonoyta (Sonora) y el manantial de Quitobaquito (Monumento Nacional Organ Pipe) a lo largo de la frontera internacional. El impacto antropogénico ha sido la principal causa de la reducción de las poblaciones del cachorrito del Sonoyta. Como estrategia de conservación, se establecieron poblaciones de refugio en Sonora y Arizona. Sin embargo, se carece de estudios exhaustivos de las poblaciones de refugio de México y Estados Unidos, ya que se establecieron sin considerar la variación genética y la estructura de las poblaciones de origen. El aislamiento de cada población de refugio puede causar su reducción en la variabilidad genética imposibilitando su uso en futuras reintroducciones en hábitats naturales. El objetivo de este trabajo es evaluar la variabilidad genética y la estructura poblacional de las poblaciones de refugio y silvestres del cachorrito del Sonoyta. Para la evaluación genética, se han colectado ejemplares de poblaciones silvestres y de los refugios artificiales existentes (Centro Ecológico de Sonora y Centro Intercultural de Estudios de Desiertos y Océanos) y se realizaron las extracciones de ADN. Se estandarizó el protocolo de PCR para 10 microsatélites para evaluar el número de alelos (A), la heterocigosidad observada (Ho), las estimaciones de diferenciación genética de los datos de microsatélites (Rst). Como avances se han obtenido 565 productos de PCR de 10 loci microsatélites, donde se ha encontrado polimorfismo.

ABSTRACT. Interspecific competition for resources can promote adaptive radiations through the processes of competitive exclusion and character displacement. The expectation is that if similar species co-occur (sympatry), they will evolve distinct dietary niches to avoid negative effects due to competition. In this study, we investigated trophic resource use in two congeneric livebearers fishes, Poeciliopsis prolifica and P. latidens that co- occur in western Mexico. We compared the digestive tract weight, length, and gut content between sympatric and allopatric populations of both species. We expected to find less dietary overlap in both species when they were found in sympatry than when found alone in allopatry. We will discuss the most prominent food items in each species and potential contribution of dietary niche differentiation to the stable coexistence of these two closely-related species. This work will aid our understanding of how species can coexist and what promotes species divergence in resource use when species occur in sympatry. Additionally, this study will provide important ecological information of these species, as it is the first dietary description for both species.

ABSTRACT. The Yaqui Catfish, a species threatened species in Mexico and with different status in the United States of America (USA), has been of interest to different agencies in recent years. For conservation purposes, members of the Desert Fishes Council (DFC) have initiated activities for the systematic evaluation of their populations in Northwest Mexico, including several academic institutions and NGO´s in Mexico and the USA. Additionally, there is a sacred and commercial interest in using the Yaqui Catfish as a marketing strategy by the Pascua Yaqui tribe. Collections in the Bavispe River Subbasin, found Yaqui Catfish only in Arroyo Cajón Bonito. We reported those collections in report for the scientific collection permit to SEMARNAT, and applied for renewal the permit with the following objectives for the Yaqui Catfish recovery and management plan in Northwest Mexico. The initial objectives of the plan are evaluation of the population status of the Yaqui Catfish in its current distribution; evaluation of the genetic integrity of wild populations using nuclear and mitochondrial markers; detection of Yaqui Catfish populations throughout their historical distribution by means of eDNA; capture of live Yaqui Catfish and their transport to a pond within the Yaqui River basin in Mexico to create a captive breeding stock; evaluation of the genetic integrity of individuals of the Yaqui Catfish reproductive stock for future use as a breeding population; development of a joint binational strategy between USFWS and Institute of Aquaculture of the State of Sonora (IAES) to promote the reproduction of the stock in captivity in facilities of the IAES in the lower basin of the Yaqui River; detection and selection of historical extirpation localities for the Yaqui Catfish within its historical range for future repopulation. The Yaqui Catfish recovery and management plan aims to achieve establishment of a captive reproductive population of Yaqui Catfish within its natural range for use in conservation of the species. So far the institutions involved are DICTUS University of Sonora, Cuenca Los Ojos A.C., Institute of Aquaculture of the State of Sonora, Faculty of Sciences of the Autonomous University of Baja California, CIBNOR La Paz, and Oklahoma State University.

El bagre Yaqui, una especie amenazada de extinción en México y considerada con diferentes estatus en Estados Unidos de Norteamérica (USA), ha sido interés de diferentes agencias en los últimos años. Para fines de conservación, integrantes del Desert Fishes Council (DFC) han iniciado actividades de evaluación sistemática de sus poblaciones en el Noroeste de México, incluyendo varias instituciones académicas y ONG´s en México y USA. Adicionalmente, existe un interés sagrado y comercial de utilizar el bagre Yaqui como estrategia de mercadeo por la tribu Pascua Yaqui. Como resultado de recolectas en la Subcuenca del Río Bavispe, se reporta la existencia de bagre Yaqui sólo en el arroyo Cajón Bonito. Se cumplió con la entrega del informe de la licencia de recolecta científica ante la SEMARNAT y se sometió la solicitud de licencia de recolecta científica para los objetivos que se enlistan para el programa de recuperación y manejo del bagre Yaqui en el Noroeste de México. Los objetivos iniciales del programa son la evaluación del estatus poblacional del bagre Yaqui en toda su distribución actual, la evaluación de la integridad genética de las poblaciones silvestres utilizando marcadores nucleares y mitocondriales, la detección de poblaciones de bagre Yaqui a lo largo de toda su distribución histórica por medio de eDNA, la captura de ejemplares vivos de bagre yaqui y su transporte a un estanque dentro de la cuenca del Río Yaqui en México para crear un stock reproductivo en cautiverio, la evaluación de la integridad genética de los individuos del stock reproductivo de bagre Yaqui para su uso futuro como población reproductora, el desarrollo de una estrategia binacional conjunta entre el USFWS y el Instituto de Acuacultura del Estado de Sonora (IAES) para promover la reproducción del stock en cautiverio en instalaciones del IAES en la cuenca baja del Río Yaqui y la detección y selección de localidades de extirpación histórica registradas para el bagre Yaqui en cuencas de su distribución histórica con fines de repoblamiento futuro. El programa de recuperación y manejo del bagre Yaqui pretende lograr el establecimiento de una población reproductiva en cautiverio del bagre Yaqui al interior de su distribución natural para utilizarla con fines reproductivos para su conservación. Hasta el momento las instituciones involucrados son el DICTUS Universidad de Sonora, Cuenca los Ojos A.C., Instituto de Acuacultura del Estado de Sonora, Facultad de Ciencias Universidad Autónoma de Baja California, CIBNOR La Paz, Oklahoma State University.

ABSTRACT. Comprehensive lists of the modern native and non-native mollusk fauna in the Middle Snake River Sub-Basin were compiled over two decades ago (Bowler and Frest, 1991; Bowler, 1992; Frest and Bowler, 1993; Frest and Johannes, 1993). Subfossils recovered from sand, basalt cobble, and Melon Gravel substrates at the confluence of the Malad and the Snake Rivers reveal a diversity of species present as a holocene fauna. The collection site is above the present elevations of both rivers and its sediments were deposited after the Bonneville Flood approximately 14,500 years ago. Fourteen native taxa were identified and two of these species are currently Federally listed as Threatened (Taylorconcha serpenticola, Hannan, 2016; Bogan, 2000) or Endangered Species (Physa natricina Taylor, endangered throughout its distribution; Rabot/U.S. Fish and Wildlife Service, January 22, 2018). Several species no longer occur in either river at the confluence. Subsequently introduced non-native mollusks present near the site include the New Zealand Mudsnail (Potamopyrgus antipodarum, which appeared in the Middle Snake River in ca. 1986 (Bowler, 1991) and is abundant in the Snake and Malad Rivers), Ferrisia rivularis (Malad River), and Corbicula fluminea (Snake River at the mouth of the Malad River).

ABSTRACT. In the Permian Basin region of Texas, salinization has occurred in the Pecos River as natural saline inputs have been exacerbated by flow-regime change and other anthropogenic impacts. Recent studies have shown that fish diversity has declined with salinization in the Pecos River, but impacts on benthic macroinvertebrate assemblages have not been examined in recent decades as salinization has intensified. In this study, we deployed Hester-Dendy multi-plate samplers for 6-8 weeks in summer and fall 2017 to assess the structure of colonizing benthic macroinvertebrate assemblages at three sites in the lower Pecos River (two in the salinized Permian Basin region, one in the Edwards Plateau region). Invertebrate biomass and taxonomic richness was lowest in the salinized Permian Basin sites, with assemblages dominated by dipteran taxa. As specific conductance decreased and habitat heterogeneity increased in the Edwards Plateau reach, more diverse benthic macroinvertebrate assemblages colonized the samplers. Additionally, diversity of benthic macroinvertebrates and biomass increased from summer to fall. Results of this work add to our understanding of how river salinization affects ecological communities. Because river salinization is a common issue in dryland regions, and it is expected to increase with climate change, such information is important for conservation and management.

ABSTRACT. Relative water quality sensitivities of 59 native and introduced freshwater mollusk species from thirteen families within the Middle Snake River sub-basin, southern Idaho, are presented. When ranked on a scale of ascending tolerance from 0 - 10, within the native fauna 11 taxa are very sensitive to water quality and fall within the 0 - 2 range, 13 species lie within the 2 - 5 range, and a group of 16 species can tolerate water quality within the 6 - 10 range. Three exotic species are very pollution tolerant, as is another group of six non-native taxa occurring primarily in thermal plumes from warmwater hatcheries. The most sensitive species have declined significantly within the mainstem river and many now are abundant only in tributary springs. Several are locally extirpated and are known only from shells, and several are federally listed as Threatened or Endangered taxa. Other rare endemics such as Stagnicola hinkleyi (F.C. Baker, 1906) are near extinction. Even within the second tier of species, there has been continuing decline. The Idaho Department of Fish and Game studies in the late 1940s and early 1950s suggest an historic fauna dominated by Fluminicola spp. and other sensitive taxa, which was dramatically reduced by severe diurnal instream flow fluctuations from the operation of hydroelectric dams. Continued, though less severe, “load-following” dam operations and chronic subsequent poor water quality shifted the fauna to more pollution tolerant, ubiquitous taxa. The New Zealand mudsnail, Potamopyrgus antipodarum (Gray, 1843), is currently the dominant macroinvertebrate at most sites. Water quality tolerances are reported for 10 other native taxa in tributaries or elsewhere in the Snake River system.

ABSTRACT. The livebearing fish Xenophallus umbratilis shows an unusual form of handedness, where the male intromittent organ (gonopodium) terminates with either a dextral or sinistral twist. We tested the hypothesis that these two morphs are maintained in the wild by negative frequency-dependent selection, wherein males with the rare morph are favored in a mating context when they are uncommon. We sampled males from multiple populations and found that some populations show a clear dextral bias in the gonopodium, where others show a sinistral bias. However, the ratio of left- to right-handed males appears to be dynamic as evidenced by our sampling of a single population over time wherein we found an extreme shift in the ratio of left- to right-handed males over a relative short period of time, from March to June. In addition to presenting these field results, we will also present our findings from two laboratory experiments exploring the mechanism by which rare males morphs have a mating advantage when they are rare. First, we show that mature females actively avoid male mating attempts by positioning their bodies to the side of males in such a way that the most common male morph is not able to successfully mate with females, but the rare morph is. Second, to determine if different male morphs vary in how they approach potential mates, we used a detour test where males are forced to approach from either the left or right side. This is a key first step in determining if this species exhibits behavioral laterality that is linked to gonopodial morphology. We present our results to date on these questions, and outline several additional experiments that are in progress that we anticipate will throw light on the evolution of brain lateralization in fishes, and potentially help explain why handedness has evolved in bilaterally symmetrical organisms.

ABSTRACT. Temperature is one of the most important habitat parameters for freshwater organisms. Water temperature can limit growth, reproduction, and the distribution of aquatic species. In some areas, climate change is increasing air temperature and reducing snowpack, resulting in an increased need for cold water refugia in stream ecosystems. In the last few decades the North American beaver (Castor canadensis), once almost completely extirpated from the United States, has seen population increases due to decreased trapping and a changing narrative about their importance to stream ecosystems. Yet, there is still a lack of understanding of how beaver dam building activities affect stream temperature dynamics. In this study, I tested the hypothesis that beaver ponds decrease stream temperatures more than riffle habitat. In addition, I investigated whether beaver ponds stratify and create cold water refugia. Research was conducted in Kimball Creek, a third order stream in the Colorado River basin. At 1800m in elevation, it is considered a high desert ecosystem that gets approximately 10 inches of precipitation per year and is degraded because of current and historic cattle grazing and agricultural activities. Kimball Creek has a dense beaver population with approximately 20 dams per stream kilometer. To investigate the effects of beaver pond habitats on stream temperature, I choose 10 beaver ponds with 10 corresponding riffle habitats of similar length, and installed temperature loggers at the inflow and the outflow of each habitat. In seven of the beaver ponds, I installed temperature loggers at the deepest point of the pond, with 2-3 loggers spaced equally from the bottom to the top of the water column. Preliminary results indicate that beaver ponds do not increase stream temperature more than riffle habitats and that they do create cold water refugia that differs from the surface temperature by up to 5℃. These beaver-mediated cold water refugia could allow for greater survivability and species distribution for cold water species in desert aquatic ecosystems.  

ABSTRACT. With many thanks to a number of co-authors (not all were available at time of abstract submission, but to be acknowledged during the presentation); Nevada waters contain 16, endangered and 6 threatened species of fishes as well as numerous undescribed At-risk fish taxa. A summary, overview and status of Nevada’s desert fishes, current research and management projects in the state will be addressed.

ABSTRACT. What structures ecological communities? This is one of the predominant questions asked in community ecology. Traditionally, ecologists have tackled this question by investigating the contemporary biotic and abiotic factors that govern community assembly, such as predation, competition, and environmental filtering. Though informative, this approach neglects historical factors and may be overlooking important assembly drivers such as shared dispersal histories or climatic alterations that can have lasting effects on community pattern. However, modern phylogeographic techniques are now able to estimate and model species responses to historical phenomena and therefore can be used to examine historical community assembly.

We investigated the contemporary and historical factors governing community assembly of freshwater fishes in the Bonneville Basin in Utah. The Bonneville Basin is composed of several isolated, closed drainage basins that over the past 30,000 years have been temporarily connected by large lakes due to climatic change during the last glacial maximum. Approximately 14,500 to 16,000 years ago, the entire Bonneville Basin was covered by Lake Bonneville, thereby connecting all of the separate basins and presumably allowing aquatic species to migrate throughout the Bonneville Basin. Because its geologic history, as well as its fish taxa, are well studied, Lake Bonneville is an ideal system for studying both the historic and contemporary factors that govern community assembly.

To investigate the historic factors governing community assembly, we gathered sequence and allozyme data from Genbank and the literature and used them in coalescent simulations to test whether fish species were able to migrate through Lake Bonneville. To determine the contemporary factors working on community assembly, we used co-occurrence null models to analyze whether species are randomly or non-randomly structured in respect to each other. Co-occurrence null models were run on historic occurrence data collected before 1940 in order to minimize the effects of non-native introductions on communities. These methods allowed us to analyze two sets of hypotheses. If Lake Bonneville allowed migration to occur, we hypothesized that communities would be structured randomly due to ecological drift. If Lake Bonneville did not allow migration, we hypothesized that communities would be structured non-randomly, likely due to biotic and abiotic habitat requirements.

We found that fish species had independent responses to the rise of Lake Bonneville. Some species were able to migrate while others did not. Likewise, the co-occurrence null models indicated that fish communities are structured randomly. These results support our hypothesis that Lake Bonneville allowed homogenization of communities across the Bonneville Basin. Current membership in communities seems to be structured due to ecological drift as lake levels dropped and communities became isolated. Our results further show how phylogeographic methods can be implemented to investigate the historical aspects of community assembly.

ABSTRACT. The Ash Meadows Fish Conservation Facility (AMFCF) was established, in part, to maintain a captive population of Devils Hole Pupfish. Part of this effort included creation of a 100,000 gallon ecosystem simulation which was stocked with algae and invertebrates from Devils Hole, in addition to fish raised from eggs collected from Devils Hole. While the refuge tank has successfully maintained the fish population through multiple generations, efforts to recover eggs from the refuge tank have been largely unsuccessful. Predacious diving beetles (Dytiscidae) have been observed in the laboratory and in the refuge tank consuming both eggs and larvae. Beetle traps were designed and deployed in an attempt to reduce the numbers of beetles. Several treatments with varying substrate and baits were tested for effects on capture efficiency and retention. No treatments differed from controls, however, the traps proved effective in capturing substantial numbers of beetles. Two species of beetles were routinely captured in the traps, and these populations seemed to roughly segregate spatially within the tank. The apparent effects of beetle trapping on egg recovery success were immediate and dramatic. This work has allowed AMFCF to begin propagating additional fish derived from refuge tank eggs without being wholly reliant on wild-collected eggs.

ABSTRACT. Texas Parks and Wildlife has been working on education and outreach opportunities to engage elementary age children, the general public, and a trial educational program in a state prison unit. Pecos Pupfish (Cyprinodon pecosensis) continues to be at risk of extirpation from Texas. Partners continue to work with the Fort Worth Zoo to maintain a refuge population and to work with landowners to set up new populations in isolated locations. Texas Parks and Wildlife and the University of Texas continue to lead collaborative planning and conservation efforts through the Native Fish Conservation Area workshops and planning meetings. This area report will also provide updates for research on Rio Grande Blue Sucker (Cycleptus elongatus), Rio Grande Shiner (Notropis jemezanus), Rio Grande watershed mussels, Balmorhea Springs complex fish, and habitat restoration projects.

ABSTRACT. Competition has long been recognized as a central force in shaping evolution, particularly through the mechanism of character displacement. However, research on character displacement is biased as it has focused almost exclusively on pairs of interacting species while ignoring multispecies interactions. Yet communities are seldom so simple that only pairs of species interact, and it is not clear if inferences from pairwise interactions are sufficient to explain patterns in nature. A more realistic approach is to ask how traits evolve when multiple species interact. Here we test for character displacement in a natural system of freshwater fishes in western Mexico that contains different combinations of up to four closely related species of the genus Poeciliopsis. We focus on three fundamental questions in this system: (1) is there character displacement in the different species of Poeciliopsis, (2) how does number of co-occurring species affects character displacement in each species, and finally, (3) does number of co-occurring species affects trait displacement equally for all species. This work is important because it recognizes that trait evolution can differ as a function of number of species interacting, but could also be different for each of the interacting species. Our work suggests that future studies of character displacement should move beyond pairwise competitive interactions to provide a more realistic understanding of how species evolve in natural fish communities in the wild.

ABSTRACT. Activities continue in an effort to improve the status of many native fishes of the Upper Colorado River Basin. These activities are guided principally by four programs: the Upper Colorado River Endangered Fish Recovery Program, the San Juan River Basin Recovery Implementation Program, the Range-wide Conservation Agreement for the Colorado River Cutthroat Trout, Oncorhynchus clarkii pleuriticus, and the Range-wide Conservation Agreement and Strategy for the “Three Species” (Roundtail Chub, Gila robusta, Bluehead Sucker, Catostomus discobolus, and Flannelmouth Sucker, C. latipinnis). The two recovery programs, which collectively work towards the recovery of Colorado Pikeminnow, Ptychocheilus lucius, Razorback Sucker, Xyrauchen texanus, Bonytail, Gila elegans, and Humpback Chub, Gila cypha, use the protection of in-stream flow, habitat restoration, nonnative fish control, propagation, life history monitoring, and information and education to bring benefits to the four “big river fishes.” Both Humpback Chub and Razorback Sucker have been recommended for downlisting in the last year. Tasks to assist the species under Conservation Agreements included multiple remote sensing projects in tributaries throughout the basin; tamarisk control and watershed habitat restoration efforts are occurring; distribution and density monitoring throughout their ranges; and renovation of trout streams and reintroduction of the Colorado River Cutthroat Trout continue in Colorado, Utah, and Wyoming.

ABSTRACT. The eDNAtlas is an open-access database developed through crowd-sourced field surveys that provides precise spatial information on the occurrence locations of aquatic species in the U.S. The eDNA samples constituting the database are collected using a standardized field sampling protocol by numerous natural resource agencies and non-governmental organizations partnered with the National Genomics Center for Wildlife and Fish Conservation (NGC), which is a science collaborative within the Rocky Mountain Research Station of the U.S. Forest Service. The eDNAtlas database contains results from thousands of sites and dozens of species and is annually updated with additional results for a growing list of species. Many markers are being developed for desert fish and other aquatic species. Initial results indicate that eDNA is a powerful tool for detection of cryptic species especially in lotic environments.