REU - Potential Projects

Summer 2005

Below please find potential research projects for each faculty mentor.  These projects only  represent ideas meant to get students thinking about research topics.  Students are encouraged to contact mentors to discuss research possibilities.

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Dr. Michelle Arnold - Environmental toxicology of the GSLE.  The health of the GSLE is dependent on the quality of the lake water.  Recently, there has been concern of heavy metal contamination (e.g. lead, selenium, arsenic, mercury etc.) from industrial discharge, lake bottom sediment contaminants, and surface water inflows.  Unfortunately, little is known on the effects of heavy metal contaminants on the GSLE.  In addition, no data exist on the volumes of waterborne nutrients and heavy metals entering the lake after it flows through adjacent marshes.  These data are essential for understanding how species are affected by these inflows.  Students can develop research projects to survey waterborne nutrients and heavy metals entering the lake via marshes, or examine heavy metal contamination in organisms found with the GSLE.  A new technique for studying heavy metal contamination is x-ray fluorescence (XRF).   XRF could be used to measure the concentration of several heavy metals such as lead, arsenic, nickel and copper. This technique could be used by students to determine the concentration of various heavy metals in the eggshells, or bones of birds that utilize the GSL for feeding (e.g. California Gulls, Eared Grebes, Wilson's Phalaropes, White-faced Ibis, American Avocets, Black-necked Stilts).  Variation in levels among bird species could be compared between those that feed exclusively in the lake with those species that feed primarily in upland marshes or between species that utilize the lake only during migration and those that are summer residents.  In addition, data could be collected to determine how environmental levels for heavy metals within the GSLE compare with other regions of the Great Basin.  Heavy metal contamination within an ecosystem affects the development of almost all species, and monitoring these levels will provide crucial information for managing the GSL.  

Dr. Diego Bernal - Salinity stress in fish of the GSLE.  Rainbow trout, Oncorhynchus mykiss, have the ability to migrate over prolonged periods of time (i.e., weeks to months) between freshwater and marine environments.  However, in freshwater trout aquaculture, fishes may be exposed to immersions in saline water (10-15 ppt) for short periods of time (i.e., hours). These immersions assist in the removal of ectoparasites and in the reduction of transport-related mortality, however, little is known about the potential physiological molecular stress-response arising from these salinity treatments. During times of stress, trout erythrocytes are capable of expressing heat shock protein 70 (i.e., Hsp70) that help in the folding of other proteins and maintaining normal cell function.  Recent work in our lab has shown that short-term (2 hr) exposures to 5ppt or higher salinities increase levels of Hsp70 in trout blood but that these fishes appear to control total blood plasma osmolarity and chloride concentrations up to treatments of 15ppt.  The proposed summer project will continue to work on fish stress and will try to understand the mechanism that trigger molecular stress response in trout blood.

Dr. John Cavitt - Effects of urbanization and habitat fragmentation on bird populations.  Throughout the GSL valley, urbanization has become a critical issue for the sustainability and health of the GSLE.  The sale of farm and ranch land to developers has resulted in the conversion of upland habitats to disconnected plots of tract housing.  Habitat fragmentation is generally suggested to negatively affect bird populations.  Recent data suggests that the effects of fragmentation may not be generalizeable to all landscapes (Cavitt and Martin 2002).  Unfortunately, no information exists on the effects of fragmentation on bird populations of the GSLE.  There are many potential projects that could be developed within this area of research by comparing bird populations within fragmented and unfragmented sites.  For example, students could examine the effects of fragmentation on the relative abundance of bird species, on the behavior and selection of foraging sites, on the nesting success of shorebirds, marsh-nesting passerines or upland breeding birds.  Students could also investigate the effects of fragmentation on food availability, abundance of nest predators or on parental behavior.  Potential research areas involving shorebirds have the added benefit of being areas of “critical research need” as defined by the Intermountain West Regional Shorebird Conservation Plan (Oring et al. 2003).  This would allow students to make important contributions to the conservation of threatened or sensitive species.      

Dr. Jonathan Clark - Analysis of genetic variation of organisms within the Greater Salt Lake Ecosystem. The GSL is an excellent system in which to study the relationships between genetic variation, degree of isolation and dispersal ability.  For example, the GSL contains several large islands with resident amphibian, reptile and small mammal populations.  The surrounding saline waters reduces dispersal between islands and immigration from  mainland sources.  Species with low vagility, such as these may provide interesting subjects for REU students interested in population genetics.  Other unique systems exist as well.  Because of the extreme salinity gradients within the GSL, species adapted to narrow ranges of salinity are also potentially isolated from one another.  For example, brine flies are the most conspicuous inhabitants of the GSL. Two species, belonging to the family Ephydridae, are known, Ephydra cinerea (=gracilis) and E. hians.  Both species are fairly tolerant of high salinity and hypoxic conditions, with E. cinerea more tolerant of increased salinity. Historically, E. cinerea has been the most abundant species, but a reduction in the salinity of the southern arm of the lake due to the construction of a causeway has resulted in E. hians becoming more dominant. REU students could determine the amount and distribution of genetic variation in both E. cinerea and E. hians and correlate this differentiation with the distribution and life histories of each species. The information obtained will permit an assessment of the effect of changing salt concentration on the distribution of the two species. 

Dr. Ron Deckert - Anatomy and symbioses of plants of the GSLE.  Plants of the GSLE face a variety of environmental challenges, particularly of an abiotic nature.  Two of the most important of these challenges are aridity, and saline soils.  Often, the solution to these problems lies in anatomical adaptation.  Alternatively, or additionally, environmental stress can promote the establishment of mutualistic symbioses in which two or more organisms of distant taxonomic relationship (e.g. plants and fungi) facilitate the survival of the other by ‘pooling’ their own particular evolutionary adaptations.  REU students could examine the anatomical structure of drought-tolerant (xerophytic) and salt-tolerant (halophytic) plants of the GSLE to determine the morphological features that aid their survival.  The relative importance of mutualisms or other symbioses that these plants establish with fungi in their roots (mycorrhizas) and leaves (endophytes) could also be documented using microscopy, cultural techniques, and experiments.  For example, root colonization rates of mycorrhizal fungi for a particular shrub species could be compared in saline and non-saline soils.  Because some of these plants are alien invading species, this research could increase insight into the mechanisms by which plant species establish in resource-poor environments.

Mr. Adam Kozlowski - Status and distribution of Townsend's Big-eared Bat within the GSLE.  Townsend's big-eared bat, Corynorhinus townsendii, occurs in western North America, from southwestern Canada to Mexico. Isolated populations of the species also occur in areas of the central and eastern United States. The species occurs state-wide in Utah at elevations below 9,000 feet. Unfortunately, Towsend's big-eared bat populations in Utah are thought to be declining, and the species is therefore included on the Utah Sensitive Species List. Townsend's big-eared bat can occur in many types of habitat, but the species is often found near forested areas. Caves, mines, and buildings are used for day roosting and winter hibernation. Consequently, human disturbances of caves and the closures of abandoned mines may constitute threats to the species. REU students could examine the status and distribution of this species throughout the Greater Salt Lake Ecosystem, including a known colony on Antelope Island.

Dr. Ron Meyers - Limb posture in birds of the GSLE.  Muscles specialized for posture have been described for mammal limbs (which must bear weight constantly when the animal is standing). In contrast, such mechanisms in bird wings are less apparent. In part this is because the wing does not normally bear weight when at rest. During gliding and soaring flight, however, the wing must sustain prolonged isometric contractions. Previous work in my laboratory has investigated the shoulder region and wing of a number of species of birds and has shown the presence of slow contracting muscle fibers (specialized for prolonged contraction and possessing resistance to fatigue) that function during these postural behaviors. We discovered that these muscles function in wing-drying posture in cormorants (Meyers, 1997) and soaring wing posture in albatrosses (Meyers and Stakebake, 2005). We also discovered that gulls lack substantial populations of slow muscle fibers and suggested that they utilize aerobic fast fibers for maintaining isometric contractions (Meyers and Mathias 1997).
The avian hindlimb is little studied with respect to postural specializations, and should be more similar to the mammalian hindlimb with respect to the ability to support standing posture as well as posture during flight. Students can participate in my laboratory’s on-going iinvestigation of vertebrate limb posture by studying the biomechanics and anatomical specializations for hindlimb posture in a variety of birds inhabiting the GSLE, including American Robins, Black-necked Stilts, and California Gulls.

Dr. Craig Oberg - Microbial Nutrient Cycling.   Microorganisms in the biosphere perform the majority of nutrient recycling for carbon, nitrogen, sulfur and phosphorus. Phosphorus is essential for organisms because it is an indispensable component of nucleic acids, and a major component of both the “energy currency” of cells and of cell membranes. The pool of biologically available phosphorus controls ecosystem productivity to a considerable extent. Microbial activities affect phosphorus retention and release through enzymatic reactions and the capacity to alter the pH of their growth environment. Little is known concerning phosphorus cycling in halophilic environments such as the GSL. The characterization of enzyme diversity and their metabolic rates in various halophilic ecological contexts should allow a better integration of information on microbial activities providing a model of phosphorus cycling in the GSL. REU students could develop projects surveying the availability of phosphorus (including bioavailable forms), the effect of various phosphorus forms and concentrations on microbial communities, and how microbial nutrient cycling might affect the cycles of higher organisms. Additional projects could include investigating whether halophiles utilize conventional or unique enzymes for phosphorus uptake, does phosphorus act as a rate-limiting nutrient for biocycles, and investigating the effect of metal ions (as enzyme cofactors) on the phosphorus cycle in the GSL.   

Dr. Nicole Okazaki - Reproductive physiology of the brine-shrimp Artemia.   Female brine shrimp (Artemia) have the ability to produce encysted eggs in response to environmental cues announcing harsh conditions.  These eggs undergo metabolic preparations sometimes during their development.  The goal of this study is to establish when and where the fate of the eggs is determined.  A marker protein, p26, found in cyst only is a perfect marker for this study.  The appearance of p26 will be monitored in maturing and mature females exposed to larval and cyst making conditions.   

Dr. Barbara Trask - Giardia sp. in the Greater Salt Lake Ecosystem.  Giardia are primitive fresh-water protozoans that represent an evolutionary link between prokaryotic and eukaryotic cells.  While the most commonly studied of these organisms is G. lamblia (a.k.a., G. intestinalis), at least 40 different species of Giardia have been described.  In their trophozoite form, these organisms are capable of parasitizing the mammalian intestinal tract when cysts are ingested, resulting in giardiasis characterized by gastrointestinal distress and diarrhea.  Giardia sp. are found worldwide and within every region of the United States.  For this reason, Giardia infection has been named by the CDC as one of the most common causes of waterborne human disease in the United States.  Still, others claim that the incidence of human giardial infection is grossly exaggerated.  The prevalence of Giardia sp. in the GSLE is largely unknown, as is the relative abundance of each giardial species.  To investigate this issue, REU students could sample water from various locations within the GSLE and examine the Giardia populations within those samples via molecular techniques such as polymerase chain reaction (PCR).  Different giardial species contain unique DNA sequences and, therefore, protocols able to distinguish between them can be developed using this technique.  A semi-quantitative PCR assay might also be developed to allow for more rapid water sampling.  A longer-term goal of this research might be to explore relative Giardia sp. prevalence in association with climatic variables such as annual rainfall and/or temperature. 

Dr. Samuel Zeveloff - Social behavior of mesocarnivores of the GSLE.  The GSLE has many carnivores with interesting social behaviors including, badgers, coyotes and raccoons.  Various forms of polygyny occur, from “loose” arrangements, in which males mate with several females seemingly at random, to more organized ones such as those in which the male defends a harem in a defined space. The raccoon (Procyon lotor) clearly engages in the looser form of this mating system (Zeveloff 2002). In fact, its social structure may be so loosely organized in some populations that it has been described as promiscuous and their mating arrangements may vary between both systems.  The raccoon’s mating system has only been studied in depth in a few vastly different environments, such as the North Dakota prairie, and a semi-tropical region of Texas. REU students could examine this aspect of its biology in the arid environment of the GSLE.  Additional projects could explore mating systems of other mesocarnivores, the degree of sexual dimorphism in these populations, or population age structure.