There are three to five million migrant and seasonal farmworkers in the United States that work in one of the most hazardous industries. They are exposed to numerous occupational and non-occupational injuries and illnesses daily, including but not limited to, pesticide and chemical-related health conditions, heat-related health conditions, muscle and joint pain, eye injuries, diabetes, high blood pressure, obesity, and depression. Furthermore, these farmworkers also experience multiple vulnerabilities including cultural and language barriers and low socioeconomic status. A survey was administered in interview setting to characterize farmworkers’ occupational and non-occupational health conditions, their healthcare-seeking behavior, and their use of preventive measures and health education. Muscle and/or joint pain and eye injuries were the most commonly reported occupational health outcomes, and diabetes and high blood pressure were the most commonly reported non-occupational health outcomes. Farmworker participants requested more information covering prevention, management, and care for these health outcomes. There were low reports of receiving health education regarding common occupational and non-occupational health conditions. Future research efforts and next steps should focus on creating networks between healthcare providers, employers, and other organizations that serve farmworkers as well as continue to host programs that directly involve farmworkers to understand their perceptions of their health and access to healthcare.

The city of Moab, an outdoor recreation hub in eastern Utah, has been encountering both shifts in the seasonality of visitation, and increases in tourist visitation, even with summer temperatures above the normal high. Tourism research describing the effects of climate change on the outdoor recreation industry has focused on winter, snow-dependent activities, while studies in Moab city have focused on the economic value of outdoor recreational activities. Few studies have described the relationship between seasonal tourism and climate change for arid desert locations. The purpose of this study is to describe how the tourism and recreation industry in Moab, Utah is experiencing and adapting to changes in climate. The first part of the research is a regression analysis of existing data, exploring the correlation between monthly national park visitation and climate factors (long-term monthly average temperature and temperature anomaly) that influence tourism seasonality in Arches National Park and Canyonlands National Park. Using an online survey, the second part of the research identifies how seasonality shifts are perceived by different actors in Moab and how they are responding to manifestations of climate change. Regression results indicate that as temperature increases in the region around Moab, national park visitation also increases. Moab businesses are not directly adapting to climate change, but are adapting to perceived increases in visitation throughout the year. The majority of Moab businesses do not attribute the increase in visitation to climate variables, instead visitation increases are believed to be a result of the popularity of the town and the region.

The majority of interior cutthroat trout (Oncorhynchus clarki) subspecies have been extirpated from large rivers by anthropogenic activities that have fragmented habitats and introduced non-native competitors. Selective pressures against migratory behaviors and mainstream river occupation and conservation schemes that isolate genetically pure populations above barriers have restricted gene flow and prevented the expression of fluvial life history traits in many populations. Existing knowledge about the movements and home range requirements of fluvial cutthroat trout is therefore limited. We implanted a total of 55 Bonneville cutthroat trout (BCT) in the Thomas Fork River, Idaho, with radio transmitters and located them weekly or bimonthly from October to April of both 1999/2000 and 2000/2001. Half of these fish were located above a seasonal diversion barrier and half were located below. We found fish to be more mobile than previously reported. Individuals located above the diversion barrier in 2000/2001 occupied significantly larger home ranges (median 3,675 m, range 2,500-8,900 m) and moved more frequently (mean 0.89 movements/contact, range 0.57-1.0) than other fish. Fish occupied habitats in the lower Thomas Fork and Bear River during the winter that were marginal or uninhabitable during other seasons. During the spring of both years we located fish in both upstream and neighboring tributaries up to 84 km away from our study site. Our results document the existence of a fluvial component of BCT in the Bear River and its tributaries and suggest that successful efforts at conservation of these fish will focus on mainstream habitats and the maintenance of seasonal migration corridors.

The effect of seasonal cattle grazing on a newly reintroduced vii population of California bighorn sheep (Ovis canadensis californiana) in Big Cottonwood Canyon, Idaho, was studied. The hypothesis that bighorn sheep avoid cattle was tested. The issue of avoidance between bighorn sheep and livestock is arguable. Some studies have found that bighorn sheep avoid cattle while others have found no response of bighorn sheep to cattle. Evidence was found to document the avoidance of cattle by bighorn sheep. The size of the bighorn's home range and core area decreased with the movement of cattle into areas of high bighorn use. As cattle were moved into bighorn core areas, sheep responded by relocating. Bighorn sheep decreased their distance to escape terrain as cattle moved closer. The level and location of human disturbance on the study area did not have any effect on bighorn sheep movements or how sheep used the habitat. The severity of response observed is in marked contrast with the response of established bighorn populations to cattle. I suggest that newly reintroduced bighorn sheep are extremely sensitive to disturbance as a result of relocation trauma. Sensitivity may diminish over time.

Three experiments were conducted to assess the potential for using Spanish goats to manage Gambel oakbrush winter range, dominated by Gambel oak (Quercus gambelii), for mule deer (Odocoileus hemionus). Summer- time food selection of goats, effects on plant community composition, and consequent effects on mule deer nutrition and foraging behavior were examined. An apparent preference for juvenile oak browse, and low use of oak twigs was observed. Selection for juvenile browse may have been facilitated by the retarded phenology of oak as compared to that of associated flora. This differential was maintained by repeated browsing. Animal performance, reflected in mass-specific gain rates, varied markedly. However, poor performance when observed, was not correlated with high juvenile oak content in diets. Goat browsing did not affect density of any shrub species. Stem size distributions changed in browsed oak populations only; skewness of these increased over time because of sprouting. Sprout weights increased in browsed oak populations, but declined in comparably browsed serviceberry (Amelanchier alnifolia) populations. The only other significant sprout response was a numerical increase in browsed snowberry (Symphoricarpos oreophilus) populations. Relationships between stem size and stem productivity in heavily browsed oak and serviceberry were characterized by lower slopes than those for adjacent control populations. Conversely, relationships in rabbitbrush (Chrvsothamnus viscidiflorus) populations, which were little used, were characterized by higher slopes than those for adjacent control populations. Sagebrush (Artemisia tridentata wvominqensis) production also responded positively, but via increased intercept. Browsing reduced productivity of both serviceberry and oak, but enhanced that of sagebrush. A positive production response was suggested for herbaceous species. Forage-base changes induced by goats caused wintering deer to increase the proportion of sagebrush in their diets under snow-covered conditions but not under snow-free conditions. Under snow-covered conditions, deer using goat-browsed pastures consumed diets higher in dry matter digestibility, but not protein, than those consumed by deer in control pastures. Dietary quality was unaffected by prior goat browsing under snow- free conditions. Furthermore, quality of diets consumed under snow-free conditions was not better than that consumed under snow-covered conditions.

In the summer of 1932, an investigation of some biological, physical, and chemical conditions at the Bear River Migratory Waterfowl Refuge, Utah, was begun at the Utah State Agricultural College to determine some of the factors governing the biological productivity of brackish-water marshes. Unfortunately, lack of funds made it impossible to continue work beyond the first season.

Bear Lake, a large oligotrophic lake (282 km2), was studied from October 1986 to December 1987 to determine the temporal changes in the zooplankton assemblage at one site in the pelagic zone and one in the littoral area. In this study, species composition, abundance, biomass, and size frequency distribution were determined. Additionally, chlorophyll a, water transparency, and temperature and oxygen profiles were measured to help interpret zooplankton changes during the study. The zooplankton species assemblage comprised eight species of cladocera, seven species of copepods, and five species of rotifers. The abundance and biomass of the zooplankton assemblage, particularly that of crustaceans, were very low and comparable with those of oligotrophic systems. Mean densities of crustaceans in the pelagic zone, excluding copepod nauplii, varied from 250 to 1,700 organisms/m3. The analysis of the size structure of the zooplankton indicated the dominance of small organisms and the scarcity of large organisms, particularly cladocera. The zooplankton assemblage in the littoral zone was similar in species composition, abundance, and size structure to that in the pelagic zone. Many results suggest the littoral zooplankton assemblage is an extension of the pelagic assemblage. Low zooplankton food resources and interference of calcium carbonate particles in the feeding behavior of crustaceans are suggested as the primary factors controlling the low abundance and biomass of zooplankton in Bear Lake. Size-selective fish predation probably causes the assemblage to be dominated by small species. The analysis of Epischura nevadensis, the dominant species in the system, indicated that this species is bivoltine in Bear Lake. In the spring and summer, adult E. nevadensis were more abundant in the littoral zone, whereas copepodites were more abundant offshore. The low density, biomass, and small size structure of the zooplankton in Bear Lake limits its importance as a source of food for fishes.

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) numbers have declined throughout the western US and are considered a species of concern in most of the eleven states that are within their range. Sage-grouse habitats have been reduced by approximately 44% since European settlement of the Western United States began (Miller et al. 2011). Loss of habitat has contributed to an average decline of sage-grouse populations by 33% across the range (Connelly and Braun 1997). To expand our knowledge of this species, I monitored 16 radio-collared sage-grouse captured from four leks in Hamlin Valley, Utah, USA in 2011 and 2012 to determine habitat use. The Hamlin Valley population was primarily one-stage migratory but non-migratory behaviors were also observed. Birds from at least one of the leks used seasonal habitats in neighboring Nevada. Sage-grouse evolved in habitats where infrastructure (e.g. vertical structures) was not common. Introduction of infrastructure, such as fences in their habitat, can cause direct mortality via collision but may also indirectly influence productivity by increasing artificial perches for avian predators (e.g. golden eagles (Aquila chrysaetos) , red-tailed hawks (Buteo jamaicensis), and common ravens (Corvus corax). This research focused on collision rates and increased potential for avian predation on two small populations on the southern portion of the range of current occupied sage-grouse habitat in southwestern vi Utah. During 2011-2012, over 450 km of fences were surveyed for signs of collision and use by avian predators during all seasons (breeding, fall migration, and winter). No sage-grouse collisions were observed suggesting that management for sage-grouse in small populations may be better focused on improving habitat and reducing other causes of mortality which may be more prevalent. Fence post width (i.e. the perching surface) was the best predictor of use as perch by avian predators. Additionally, areas farther from other natural perches, with a low density of surrounding vegetation, and fences constructed along defined habitat edges were used by avian predators more frequently. Results of this study suggest that managers should construct fences with small widths to deter avian predators and care should be taken to maintain contiguous vegetation on either side of the posts while maintaining low shrub density.

For several years, residents of Cache County, Utah have suffered from the recurrence of what has come to be known as the winter-inversion, or “red-air-day” season. Each year during this season – which occurs primarily in the months of December, January, and February – particulate matter concentrations measuring two and half micrometers or less (commonly known as PM2.5) rise and languish (for periods of days or even weeks) above federally mandated standards, causing extensive harm to community health and confounding what have thus far been the relatively tepid control efforts undertaken by local and state policymakers. Through time-series regression modeling, we establish a statistical relationship between PM2.5 concentrations and vehicle use in Cache County, and further calculate a gas-price elasticity for the region. Next, we analyze the benefits and costs associated with a potential seasonal gas tax which, if set appropriately and enforced effectively, could decrease vehicle use and thereby lower health costs through concomitant decreases in PM2.5 concentrations. Specifically, we find a relatively strong positive relationship between percentage of vehicle trips reduced and associated reductions in PM2.5concentrations, and a gas price elasticity of approximately -0.31 in what we call a “high price variability environment.” Based upon these results, benefit-cost analysis suggests a potentially positive social net benefit for Cache County associated with imposing a seasonal gas tax to reduce PM2.5 concentrations during the winter-inversion season. Our benefit-cost analysis, which uses quantitative estimation techniques on both sides of the ledger, yields a first-of-its-kind social net benefit estimate for controlling elevated PM2.5 concentrations in Cache County through the imposition of a seasonal gas tax.

Invasive weeds are threatening ecosystem function and productivity all over the world by outcompeting desirable vegetation and reducing species diversity. One option for long-term control of such weeds is biological control using natural insect enemies. Such a program has been developed for management of Dalmatian toadflax (Linaria dalmatica (L.) Miller (Plantaginaceae)) in North America using a stem-mining weevil, Mecinus janthiniformis Toševski and Caldara (Coleoptera: Curculionidae). Although widely effective in northern regions, such as in British Columbia and in the American northwest, this insect has been slow to suppress Dalmatian toadflax in southern most regions of their current range, including areas in Utah and Colorado, and little is known of the limiting factors leading to slow weed suppression in these areas. Using field assessments of insect and plant activity over two growing seasons at several sites, this study aimed to provide degree-day and calendar-date descriptions of insect phenology. In addition, dead, overwintered Dalmatian toadflax stems were dissected to determine overwintering mortality of weevil adults before spring emergence, and living stems were dissected to determine development stages and mortality of weevils during summer development. Degree-day and calendar-date based models independently resulted in consistent trends in weevil phenology between sites and between years in this study, although the degree-day model is likely to be most useful for purposes of predicting weevil life cycle timing. Interestingly, the sexes differed in their phenology in that males consistently emerged from overwintering sites and were found on Dalmatian toadflax stems considerably earlier than females in the spring. Females as well as males tended to peak in abundance on stems in late-May when Dalmatian toadflax stems reached full maturity. Overall mortality of M. janthiniformis during a lifecycle was low for all samples; approximately 83% of adults successfully emerged from overwintered stems in the following spring, and greater than 65% of larvae survived to adulthood before overwintering. This resulted in >50% of weevils surviving larval development, overwintering, and spring emergence as adults. The majority of M. janthiniformis deaths (51%) resulted from parasitism by chalcidoid wasps during summer development to adulthood. These parasitoid wasps, and also M. janthiniformis adults, likely created the peculiar exit holes that were observed in live Dalmatian toadflax stems during the summer. Although M. janthiniformis populations were slow to provide effective control of Dalmatian toadflax at sites in Utah, this study indicates that the phenology and survivorship of M. janthiniformis individuals in Utah are well suited for successful biocontrol. If given enough time to build populations, M. janthiniformis appears to be capable of providing effective Dalmatian toadflax control in southern regions, but other limiting factors, such as precipitation and host plant quality, should be considered in future studies to explain slow weed suppression. Phenology models and estimates of mortality of M. janthiniformis generated by this study at sites in Utah may be helpful in implementing future biocontrol programs of Dalmatian toadflax.