• Bat Species Diversity at an Urban-Rural Interface: Dominance by One Species in an Urban Area

      Damm, Jason Philip (2012-01-13)
      The growth of urban areas is known to affect different species of wildlife in varying ways. Many organisms have exhibited declines in abundance due to habitat loss, while overall species diversity decreases. Bats can serve as reliable indicators of habitat quality and level of anthropogenic disturbance. To investigate urbanization impacts on a Midwestern bat community, I analyzed nine years of mist-net captures from a study area on the edge of Indianapolis, Indiana, where the percentage of urbanized ground cover ranged from zero to 26%, within 1.3-km of a net site. I used Pearson correlation statistics to examine the effect of urban ground cover on each species’ abundance, and the Shannon-Wiener Diversity Index was used to quantify species diversity at the study area. To test the effect of urbanization on diversity, linear mixed models were constructed using percentage of urban ground cover and year. A total of 10 species were captured over nine years, seven of them annually. The big brown bat (Eptesicus fuscus) was the dominant species at all urbanized sites and at five of six rural sites. Most species were more common at rural sites than at urbanized sites. Urbanization was significantly and negatively related to bat species diversity, although one species, the northern myotis (Myotis septentrionalis), showed a significant positive correlation with urban ground cover. Two bat species, the eastern pipistrelle (Perimyotis subflavus) and the little brown myotis (Myotis lucifugus) both displayed significant negative correlations with the percentage of urban ground cover. The Indiana myotis (Myotis sodalis) had a marginal negative correlation, but not significant.
    • Breeding Migrations, Survivorship, and Obligate Crayfish Burrow Use by Adult Crawfish Frogs (Lithobates Areolatus)

      Heemeyer, Jennifer L (2011-07-19)
      Movements are risky behaviors to animals, and amphibians are no exception. Being unable to cover long distances quickly, amphibians may find migrations challenging, yet many if not most species exhibit cyclic annual migrations. Crawfish Frogs (Lithobates areolatus), are a relatively understudied species of North American amphibian listed as endangered in Indiana and Iowa, and considered a species of conservation concern throughout much of their range. To better understand the biology of this species, and in particular, to assess the role that movements play in affecting survivorship, I radio tracked 48 Crawfish Frog adults, in 2009 and 2010. My study encompassed a total of 7,898 telemetered-frog days; single frogs were tracked for up to 606 days. These data demonstrate two behaviors previously undocumented in this species: 1) migration distances that averaged nearly ½ km, and for one frog was > 1,187 m; and 2) fidelity to upland burrows excavated by crayfish. Together, these findings indicate that Crawfish Frogs have a remarkable ability to home to distant upland burrow sites. Burrow fidelity in Crawfish Frogs involves, in part, frogs following similar migration routes to and from breeding wetlands. Burrow fidelity also occurs after ranging movements, and often involves individual frogs following the same circuit across years. Further, I demonstrate that movements are risky for Crawfish Frogs (about 12 times riskier than burrow dwelling), and therefore have survival consequences. My data also suggest that adult Crawfish Frogs are likely not dispersing to colonize new sites; instead, it seems more likely that juveniles represent the dispersing stage. To ensure the least impact to Crawfish Frog populations several conservation measures should be taken. First, core habitat and buffers should be established that exclude or limit roads for at least a 1.1-km radius around breeding wetlands. Secondly, burrow destruction should be minimized by limiting new cultivation and other ground disturbance within the core habitat and buffer. Thirdly, prescribed burns should be avoided from mid-March to mid-May, when frogs are out of their burrows migrating to and from wetlands.
    • Characterization of Novel Extracellular Matrix (Ecm) Proteins (Mgp and Lumican) and Their Implications in Vascular Development, Angiogenesis, and Cancer

      Sharma, Bikram (2013-01-30)
      Extracellular matrix (ECM) constitutes a large component of our tissue structure. Primarily, ECM provides structural and adhesive support to our cells, but it also controls cellular signaling and behavior. Homeostasis of extracellular matrix composition and function is maintained by our body through a balanced synthesis, degradation and remodeling of ECM. However, under pathological conditions and genetic mutations, ECM homeostasis is disrupted due to deregulation in ECM synthesis, assembly, remodeling, and degradation. A number of diseases, including cardiovascular diseases and cancer, are found to occur due to alterations in ECM. Therefore, targeting ECM can be an attractive therapeutic approach to treat these diseases, and it requires our complete understanding of the ECM molecules and the molecular mechanism it employs in controlling cellular functions. To this end, this study is aimed at the characterization of two ECM proteins—Matrix Gla Protein (MGP) and Lumican—for their roles in vascular development, angiogenesis, and cancer. Findings from this study show that MGP is a critical ECM regulator that promotes angiogenic resolution by suppressing endothelial sprouting and stabilizing vascular lumen formation. In addition, MGP also inhibits tumor growth by inhibiting tumor angiogenesis. On the other hand, our findings show Lumican suppresses tumor growth and has anti-angiogenic activity in a context specific manner.
    • Cloning and Characterization of Hypothetical Exported Proteins from Community Associated Staphylococcus Aureus

      Kaur, Haninder (2013-01-30)
      Methicillin resistant Staphylococcus aureus (MRSA), a major cause of nosocomial infections, has acquired resistance to beta-lactam and other antibiotics. Recently, community associated MRSA (CA-MRSA) has developed independent of hospital associated MRSA (HA-MRSA). One of the major differences between the hospital and community strains is that the former is multi-resistant to antibiotics while the latter is not as resistant but is significantly more invasive. This increased invasiveness and the ability to cause life-threatening infections, even in immunocompetent individuals, makes CA-MRSA critically important as a public health problem. CA-MRSA is known to cause skin and soft tissue infections; bacteria interact with host skin cells and gain access to deeper tissues causing invasive infections. During this process the bacteria may secrete proteins that aid in the interaction with the host by adhering, invading or causing host cell death and lysis. To understand the virulence mechanisms involved in invasion, we investigated genes described as hypothetical proteins in MSSA476. The bioinformatics-selected proteins showed high probability of being secreted and most were unique to CA-MRSA. Our analysis showed 24 such genes. This study shows primer design for 15 of the genes (7 of the 24 had already been cloned in our laboratory). Using gateway cloning, the 15 genes were cloned into BL-21 expression clones. CA-MRSA’s are known for causing invasive skin infections. To further understand the involvement of our proteins of interest in invasion, human keratinocyte cell lines were used in a study of virulence and interaction with skin. To understand the involvement of our hypothetical secreted proteins, we investigated the mRNA expression level, using RT-qPCR and Livak method, of 20 hypothetical exported proteins in presence of human dermal keratinocyte cell line. Our investigation revealed two genes that showed increased mRNA expression in the presence of keratinocytes, which may be due to factors associated with keratinocytes that may have triggered increased mRNA expression. Keratinocytes are capable of forming cell-cell junctions and producing antimicrobial peptides and cytokines in response to microbes. The increased mRNA expression of two genes may be towards binding to junctions for invasion or may be expressed in response to antimicrobial peptides or cytokines.
    • Cloning and Characterization of SAS1738, a Hypothetical Exported Protein from Community-Associated Strain of Staphylococcus Aureus

      Vijaya Kumar, Deepak Kumar (2010-09-22)
      Methicillin resistant Staphylococcus aureus (MRSA) is a group of S. aureus strains that has acquired resistance to a class of beta lactam antibiotics and is the major cause of hospital associated infections. Their discovery goes back to 1960 when the first cases were identified. Recently community associated MRSA infections have emerged and are caused by strains that are independent of those from the hospital environment, related only because they carry some of the same antibiotic resistance genes. Community associated infections (CA) are more severe, producing pus filled lesions that are painful and capable of invasion of deep tissues. Virulence factors comprised of exported proteins are associated with the invasiveness of CA strains. Most of these proteins are hypothetical in nature with unknown function. The aim of this study is to identify and characterize potential virulence factor proteins that may be involved in the infection pathway of CA-MRSA. This study focuses on a unique gene that encodes an exported protein, SAS1738, found on the chromosome of the CA strain MSSA476. The protein SAS1738 was chosen because it is unique to CA strains and has homology to some proteins identified in other S. aureus strains known for their virulence and host immune evasion. The goal of this work is to characterize SAS1738 and to determine its role in the infection pathway of the organism. The gene of interest has been successfully cloned, expressed, and tested for toxicity in Caenorhabditis elegans, a nematode. The toxicity tests showed that SAS1738 is inhibitory to the growth and development of C. elegans. The actual mode of action of this protein in C. elegans is yet to be established. However, location of SAS1738 using a GFP fusion showed that the highest concentration of the fusion protein was in the gut of the worms. The purified protein when tested in a killing assay against C. elegans, resulted in the death of the worms at an average time point of 8 min after treatment. Microbiological assay results showed that the purified SAS1738 possessed antibacterial activity towards Micrococcus luteus and Proteus vulgaris. This suggests that SAS1738 may play a dual role of antagonizing the commensal flora of the human skin such as Micrococcus luteus and also induce a toxic effect on the human cells as suggested by its toxic effect on C. elegans. Determination of the role of this protein in the infection cycle of CA-MRSA will lead to a better understanding of the pathogenicity of the organism and possible development of new treatment strategies.
    • Cognitive,personality and demographic attributes of student change.

      Henry, Jeanne Marie (2012-04-13)
      This study was an examination as to whether cognitive,personality and demographic attributes of students have changed over time.Archival data for 10 coherts of freshman students from a private Midwest engineering institution were used.Data consisted of Myers-Briggs Type Indicator(MBTI) reults,Learning Enviornment Preferences(LEP) results, and demogrpahics.ANOVA's were performed for all interval data and Chi-Square analysess for all nominal data.Statistical significance was found for MBTI Thinking-Perceiving and Sensing-Intution scales,LEP Cognitive Complexity Index scores, and demographic variables including age,parental education level, and SAT scores.Results are discussed in terms of practical significance,trends evidenced in results,implications for further research and educational service provisions.
    • Diurnal and nocturnal avian antipredator behavior in thermally challenging conditions

      Carr, Jennie M. (2014-03-18)
      Diurnal avian antipredator behavior has been the focus of much past research, yet the influence of the thermal environment on such behaviors is often overlooked. Far less is known about nocturnal avian antipredator behavior, including how these behaviors are influenced by challenging thermal environments. The first portion of my research focused on how the thermal environment influences the diurnal antipredator behavior of wintering birds while (i) exposed to high wind speeds, (ii) foraging in sunlit and shaded microhabitats, and (iii) when using thermoregulatory postures to conserve body heat. In addition to increasing convective heat loss, high wind speeds increase the prevalence of background movements in the environment. My research demonstrated that wintering sparrows exposed to a moving stimulus are less likely to flush to cover on windy days than on calm days, suggesting that wind-driven visual noise may interfere with predator detection. Predator detection may also vary when feeding in sunlight and shade, and the thermal benefits of foraging in direct sunlight on cold winter days may also play an important role in dictating microhabitat choice. Regardless of the thermal benefits of foraging in sunlight, wintering sparrows preferred to feed in shaded microhabitats even at ambient temperatures well below thermoneutrality. However, these birds foraged in sunlight more frequently as ambient temperatures fell, suggesting a trade-off between thermoregulation (solar input) and predation risk. Additional evidence of such a thermoregulation-predation trade-off was evident in the use of heat-conserving thermoregulatory postures by wintering sparrows. Fluffing the feathers or standing on one foot will reduce the amount of heat lost to the environment. However, such postures slow take-off time and likely result in an increase in predation risk. As such, these risky postures were only used when feeding at relatively low ambient temperatures and when near protective cover. In general, these results indicate that characteristics of the thermal environment play an important role in dictating diurnal antipredator behavior. To address how the thermal environment influences nocturnal avian antipredator behavior, I examined the predation-related costs of using energy-saving nocturnal hypothermia. Many species of birds reduce their nighttime body temperature, thus reducing metabolic rate and conserving energy. Such drops in body temperature may be quite substantial and likely influence a bird’s ability to respond to a potential threat during the night. To examine the potential costs of hypothermia, I conducted nocturnal flight tests on hypothermic mourning doves (Zenaida macroura). In general, doves that cooled by more than 5 °C flew poorly or were unable to fly, but were able to fly well once re-warmed to near their normal daytime body temperatures. Thus, low body temperatures during energy-saving hypothermia likely result in an increase in the risk of nocturnal predation. Nocturnal antipredator behavior was also examined in ruby-throated hummingbirds (Archilochus colubris). These hummingbirds frequently use nocturnal torpor (i.e., deep hypothermia), with significant reductions in body temperature and corresponding inability to respond behaviorally to external stimuli. Although hummingbirds altered torpor use seasonally and over the course of the observation period, hummingbirds did not consistently reduce their use of torpor following an experimental increase in perceived predation risk. Thus, although hypothermia is behaviorally costly, further studies are needed to clarify the role of predation on nocturnal behavior in birds.
    • Effect of Tai Chi on Cardiac Autonomic Function and Salivary Cortisol Level in Healthy Adults.

      Kalsaria, Pratik (2012-05-21)
      Introduction: An estimated 8.2 million American adults (1 in 3) have 1 or more types of cardiovascular disease. Heart rate variability (HRV) analysis is considered a non-invasive procedure for analyzing cardiovascular autonomic influence. Depressed HRV has been linked to stress and abnormal cardiovascular autonomic modulation. Purpose: This study evaluated the acute effects of tai chi on cardiac autonomic function and cortisol level in healthy adults. Design: 10 healthy adults, 7 females and 3 males, with an average age of 54 ± 2.04 were included in this study. They were asked not to consume any alcoholic or caffeinated beverages at least 24 hours before the study. Each subject practiced tai chi for 1 hour. HRV measurements were obtained at supine rest using Nexus biofeedback device before and after 10 min, 20 min and 30 min post tai chi exercise. Saliva samples were collected before tai chi and after 45 min post tai chi practice. Results: The cardiac autonomic function was assessed using frequency domain HRV analyses. Repeated measures ANOVA revealed that there is significant difference in means of HR, SDNN, nLF and nHF between the pre tai chi and post tai chi groups. Using student’s T-test, we found that the nHF increased significantly from 42.79 ± 4.12 to 52.82 ± 4.39 after 30 min post tai chi exercise (p<0.05). In contrast, nLF decreased significantly from 57.21 ± 4.12 to 52.82 ± 4.39 after 30 min post tai chi exercise (p<0.05). HR significantly decreased from 73 ± 2 to 67.79 ± 2.94 after 30 min post tai chi exercise. Also, SDNN increased significantly from 34 ± 5.26 to 41.38 ± 6.42 after 30 min post tai chi exercise. No significant changes in cortisol level were observed between pre tai chi and post tai chi groups. Conclusion: Tai chi exercise can modulate cardiac autonomic tone by enhancing the vagal activity and reducing the sympathetic activity. Long-term beneficial effects of tai chi on cardiac autonomic function need further investigation.
    • Effects of Ectoparasites and Reproductive Class on Roost-Switching and Foraging Behavior of Indiana Bats (Myotis sodalis)

      2012-01-19
      Ectoparasites of bats have been known to cause harm to their hosts and to affect roost-switching. Little research exists on effects ectoparasites may have on roosting and foraging behavior of the federally endangered Indiana bat (Myotis sodalis). From 2008 through 2010, I collected ectoparasite data and documented roost-switching and foraging behavior of Indiana bats on habitat restoration lands owned by the Indianapolis International Airport (IND) in central Indiana. I tested for differences in roosting and foraging behavior between bats with varying ectoparasite loads, and for differences in ectoparasite load, roost-switching frequency, and foraging behavior between different reproductive classes of Indiana bats. I used the volume of ectoparasites of each Indiana bat when analyzing data. I found a significant difference in roost-switching frequency and ectoparasite volume between reproductive classes. Neither reproductive class nor ectoparasite load significantly affected any aspect of foraging behavior. Indiana bats in this study apparently maintained moderate loads of ectoparasites which may not affect foraging and roosting, but the insignificant results found in this study may have been due to a small sample size. The significant difference in roost-switching between reproductive classes likely demonstrates variation in bat thermoregulation. Lactating females and pregnant females have a higher need for group thermoregulation and switch roosts less frequently than post-lactating females and volant juveniles. Because ectoparasites have been found to increase in maternity colonies, volant juveniles and post-lactating females may disperse from the main colony roost and switch roosts more often to avoid higher intensities of ectoparasites.
    • Evaluation of an Avian Radar System

      Gerringer, Michael B. (2014-03-18)
      The problem of bird strikes in aviation is becoming an increasing threat, both to aircraft and to human safety. Management efforts have reduced wildlife hazards below 500 feet and within the immediate airport environment, but traditional methods of monitoring bird activity are limited to an observer’s field of view. Avian radar systems could potentially be useful in monitoring bird activity at great distances from the airport, at higher altitudes, and at night (Dolbeer 2006), but little work has been done to validate the tracking capabilities of avian radar systems. Thus, the goal of this research is to evaluate the detection and tracking abilities of the Merlin Avian Radar System provided by DeTect Inc. Radio-controlled (RC) aircraft flights were used to systematically test the tracking abilities of the Merlin System with respect to distance and altitude. Transits by free-flying birds provided an equally important test of the Merlin System, allowing for the assessment of tracking performance as influenced by flock size, altitude, and distance from the radar unit. Overall tracking performance regarding the RC aircraft and single large bird targets was poor across all study distances and altitudes. However, flocks of large birds such as geese and cranes were tracked well, even those several miles away from the radar unit. Given these results, avian radar could be a useful tool for monitoring bird flock activity at airports, but less so for single large bird targets such as thermalling raptors.
    • Extracellular Matrix Proteins: Implications for Angiogenesis

      Williams, Kent Edward (2010-07-20)
      The extracellular matrix (ECM) is an essential requirement for maintaining permanent shape and rigidity in multicellular organisms. The ECM serves two main functions: scaffolding and signaling. Insoluble collagen and soluble proteoglycans, glycosaminoglycans (GAGs), and glycoproteins allow for water retention and flexibility. The signaling role of the ECM is essential for a multitude of events including vascular development and angiogenesis. Via interactions with vascular endothelial cells, proteins of the ECM can induce or repress angiogenesis.
    • Foraging behavior and seasonal movements of the eastern red bat(Lasiurus Borealis)in Central Indiana.

      Everson, Brianne.L (2012-04-13)
      Twenty-four female Eastern red bats(Lasiurus borealis) were captured and tracked to foraging areas near the Indianapolis International Airport during the summers of 2003 and 2004 with full foraging data obtained on 13. A series of multi-azimuth(3-7) triangulations was used to estimate the location of each bat throughout the night.Euclidean distance analysis was used to examine habitat sue by L.borealis.These bats had smaller home ranges than previously noted as well as smaller homes ranges than other species at this location.They foraged over woodlands,newly planted tree fields,open water,park and pasture lands more than predicted by randomly generated points. They avoided highly urban areas such as commercial lands,gravel pits and transportation corridors more than predicted by randomly generated points.Four female L.borealis were tracked leaving the study site between 15 July and 15 August in 2003 and 2004.Simultaneously,signals were lost on four additional radio-tagged bats.Long-term capture rates of adult L.borealis were examined during 3 netting periods(15 May-15 June,15 June-15 July and 15 July-15 August) from 1998-1999,2002-2004.Nearly twice as many adult L.borealis were captured in the third round of netting compared to the previous two rounnds.Based on a comparison of bats radio-tracked leaving the study area with typical home rage sizes of L.borealis at this site, an increase in lost radio tags,and an increase in capture rates of adult female L.borealis during late summer,it appears that L.borealis begins migrating through the study area in late July.Telemetry data indicate their movement through central Indiana is from east tp west,instead of north to south as idicated in large-scale analyses.
    • Impact of Forest Management Techniques on Bats with a Focus on the Endangered Indiana Myotis (Myotis Sodalis)

      Sheets, Jeremy J (2010-07-20)
      Understanding how forest management practices impact bats is important for maintaining a diverse bat community; rare species, especially the federally endangered Indiana myotis (Myotis sodalis) need special consideration. Bats play an important role in the environment because they prey on insects, especially pest species, and conservation of viable foraging and roosting habitats is critical. Positive and negative aspects of the implementation of forest management techniques are discussed for each bat species. Bats were sampled using mist nets at four locations in Morgan-Monroe and five locations in Yellowwood State Forests twice during each summer 2006-2008. Netting locations were adjacent to or in forest stands scheduled for experimental manipulations following conclusion of netting in 2008. This effort produced 342 bats. These data provide a baseline to understand how bats are affected by long-term forest manipulations. An acoustical survey was conducted in summer 2007 to determine forest habitats where bat species occur. Anabat II bat detectors in four habitat types,--interior forest, canopy gap, forest edge, and corridors--produced calls from 7 species, a total of 3113 calls (842 corridor, 681 forest edge, 1075 canopy gap, and 515 forest interior) during 337 sample nights. Occupancy of each habitat by each species was determined; canopy gaps were occupied most, followed by forest edge, corridors, and interior forest. These data are used to predict the response of bats to forest manipulations.
    • Impacts of Different Forest Tree-Harvest Methods on Diets and Populations of Insectivorous Forest Bats

      Caylor, Megan K (2011-09-19)
      The Hardwood Ecosystem Experiment (HEE) in central Indiana presents an excellent opportunity to study species reactions to different forestry practices: clearcutting, shelter wood cutting, and single tree selections. This project focuses on the differences in the populations and diets of the various insectivorous bat species in the HEE management units. Bats studied were Myotis septentrionalis, Lasiurus borealis, Eptesicus fuscus, Perimyotis subflavus, Myotis sodalis, Myotis lucifugus, and Lasionycteris noctivagans. Since insectivorous bats do not simply eat whatever is available, and I hypothesize that the diets of these bats will not change despite their changing environment and changing populations. To test these ideas, guano was collected between years 2006-2010 and ANABAT calls were recorded between years 2007-2010. I analyzed 440 guano samples, and the invertebrate parts were identified visually to the lowest taxonomic level within a reasonable amount of time; this is most often to family, but always order for the Lepidopterans. The data were compared within each species: before and after treatment, across treatment types, between males and females, and across different months. There was no significant change between bat diets before and after treatments, and each species maintained a specific diet across the years. These results reinforce previous conclusions that bats select among available foods and do not simply eat whatever is available. I also analyzed 5346 call minutes using ANABAT bat detectors. There were significant changes in Myotis sodalis, Lasiurus borealis, and Perimyotis subflavus call minutes. This supports the hypothesis that the diets still remain constant despite the changes in the species populations.
    • Insect Abundance and Variability in an Urban-Rural Landscape and Comparison to Foraging Habitat Selection of Bats

      Oehler, Nicole M. (2012-01-19)
      I conducted a study of the relationship between prey availability and foraging habitat selection of Indiana bats (Myotis sodalis), big brown bats (Eptesicus fuscus), eastern red bats (Lasiurus borealis) and evening bats (Nycticeius humeralis) in an urban-rural landscape matrix of southwestern Indianapolis. Insects were collected from nine different habitat types found within the range of these species. Insect data were collected from 2006 to 2008 using sticky traps placed in each habitat type. Habitat types were ranked by importance to each bat species (based on previous studies) and then compared to the average number of prey insects captured per habitat sticky trap. Only the average number of insects captured per habitat sticky trap that were big brown bat and eastern red bat prey varied significantly between all nine habitat types. The average number of prey insects captured per habitat sticky trap that were Indiana bat, big brown bat, eastern red bat and evening bat prey were strongly significantly different between sampling dates within seasons. The average number of prey insects captured per habitat sticky trap that were big brown bat and evening bat prey varied significantly between sampling dates between seasons. The average number of prey insects per habitat type did not correlate significantly with habitat selection by any of the four bat species.
    • Landscape scale and contaminant effects on aquatic assemblage structure.

      Morris, Charles C (2012-05-18)
      Biological surveys are routinely used throughout the United States to identify localized impairments in aquatic ecosystems. This approach however, has had limited acceptance for in situ assessment situations in determining specific sources or causes of observed impairments as required under Section 303(d) of the Clean Water Act. While the best approach for determining the effect of urban impacts on streams is to directly compare biological data before and after urban impacts this approach is rarely used because of the lack of historical or pre-disturbance data. Traditionally, the source-cause investigation focused on using aquatic life chemical criteria as benchmarks, resulting in a "violation perspective" methodology that emphasizes specific water quality criteria being exceeded. Relying solely on this approach can be problematic since not all environmental stressors will have established criteria (e.g., sediment criteria are lacking) and those having criteria may not be sufficiently protective of portions of the aquatic resource (e.g., ammonia). This violation perspective assumes that intermittent chemical sampling and analysis will eventually discover the variables (contaminants) causing the impairment and emphasizes a select few water quality criteria exemplifying the “pollutant” focused approach as opposed to a broader and more comprehensive pollution focused approach. Furthermore, chemical water quality criteria are further removed from the designated use, which is more directly measured by the biota and minimizes type I and II assessment errors that would otherwise be more frequent. Evaluating aquatic systems using the violation perspective becomes increasingly more problematic due to increasing water samples collection costs, increased analysis costs for possible chemical stressors, and determining the identity among the thousands of possible stressors. Imperative to this discussion is that slightly elevated contaminant concentrations, synergistic effects, or sporadic spikes could adversely affect fish assemblage structure. As a result, these factors can potentially result in a biological impairment without the occurrence of specific chemical criteria violations. Nationally, the perception of causality for biologically impaired systems has shifted from point-source influences to more diffuse non-point source influences. Difficulty in tracking these pervasive non point-source impacts, combined with the lack of pre-determined signatory relationships with biological assemblage patterns creates a more complex problem. One way of increasing our knowledge of signatory relationships is through multivariate analysis utilizing the definable relationships between aquatic assemblage structure and quantifiable environmental stressors. The purpose of this research was multifaceted. We investigated the relationship between stressor response models associated with an urban landscape, multiple assemblage response, and fish assemblage nutrient response. Essentially the study area for this research encompassed data collected from across the State of Indiana. The nature of the analysis performed resulted in this volume of data being compartmentalized into discreet spatially driven subsets that were analyzed independently. To determine the responsiveness of fish assemblages to stressors associated with an urban landscape we targeted the Salt Creek Watershed. Salt Creek is a Lake Michigan tributary in Northwest Indiana, USA, which drains a watershed experiencing rapid urbanization as part of the expansion of the Greater Chicago metropolitan area. The watershed supports a managed coldwater fishery comprised principally of the introduced Skamania strain of the steelhead (Oncorhynchus mykiss). The sustainability of this watershed depends on the proper management of warm water tributaries and salmonid water in the Salt Creek mainstem. Twenty-three fish species were collected in the Salt Creek watershed and were numerically dominated by creek chub (Semotilus atromaculatus) and green sunfish (Lepomis cyanellus) both of which are tolerant to a wide range of environmental conditions. Habitat quality, measured using the Qualitative Habitat Evaluation Index (QHEI), showed that the watershed was generally degraded and scores ranged from 12-69. Fourteen parameters were significantly correlated with reach scale ecological health and biological integrity. Factor analysis found three factors explained 69% of the contributed variance in the watershed fish assemblage. The first factor included habitat measures comprised of the QHEI score and three of its metrics (i.e., channel, riparian and instream cover scores) and explained 36 percent of data variability. The second factor was comprised of two contaminants (i.e., TDS and Chloride) and one local-scale land-use variable (Agriculture) that explained an additional 20 percent of the variability. The third factor was comprised of two local scale land-use variables (i.e., riparian zone and water) explaining 13percent of the variability. To evaluate the responsiveness of multiple aquatic assembles to watershed stress we target the Big Oaks National Wildlife Refuge. The Big Oaks National Wildlife Refuge encompasses the northern 51,000 acres of the former Jefferson Proving Ground (JPG) which was used from 1940-1995 as a munitions testing facility. Since 2000 the U.S. Fish and Wildlife Service has utilized the northern 51,000 acres of JPG for ecosystem-based management in conjunction with continued use by the U.S. Department of Army and Indiana Air National Guard for air-to-ground training. An investigation of factors that explained the variance in fish, crayfish, and macroinvertebrate assemblage structure and function was based on catchment and reach-scale land use, habitat, contaminants, and water quality. Habitat quality, measured using the Qualitative Habitat Evaluation Index (QHEI), showed that scores ranged from 25 to 85 (average 61.36 + 10.08). The substrate score, instream cover, riffle-run score, and channel score were the primary factors contributing to declining QHEI scores. Factor analysis found four factors explained 69 percent of the contributed variance in the fish assemblage, two factors accounted for 56 percent of the total variance in macroinvertebrate assemblages, and two factors explained 49 percent of the cumulative variance in crayfish assemblages. Overall drivers of assemblage structure were associated with broad scale issues of wastewater treatment, ground water, and land-use. Our results show that fish, macroinvertebrate, and crayfish assemblages respond to similar broad scale stimulus; however, the specific physical/chemical constituent responsible for the stress may vary, and the realized magnitude of the overall stress on the system may be expressed by each organismal group differently. Our data suggest that varying organismal groups can respond independently and stress reflected in one assemblage may not necessarily be observed in another.Finally, we evaluated nutrient response in fish assemblages targeting a large data set collected from the Indiana portion of the Corn Belt Plain Ecoregion. Due to the complex interactions between the various forms of Nitrogen and Phosphorus within respective cycles, Total Nitrogen (TN) and Total Phosphorus (TP) cycling interactions can no longer be accepted as sole limiting factors in either marine or freshwaters. This study is conducted as part of the U.S. Environmental Protection Agency (USEPA) desire to development regional nutrient thresholds. The first objective of this study is to develop a biotic model capable of determining the contributions of various nutrients, including Nitrogen components and TP, in streams using fish assemblages. The second objective is to establish an approach for designating defensible nutrient biotic index (NBI) score thresholds and corresponding nutrient concentrations, above which fish assemblages show alterations due to increasing nutrient concentrations. Sampling within Indiana’s portion of the Corn Belt and Northern Great Plain Nutrient Ecoregion occurred from 1996-2007 at 1274 sites. Nutrient data were reviewed for outliers and then sorted into three groups relative to drainage class. Each group was arranged into 15 ranges or “bins” using the Jenks optimization method in Arc GIS 9.3. Next, sites were assigned to each bin relative to observed concentrations. These bin assignments were used to populate the species occurrence model for nutrient optima calculation. Nutrient optima were calculated by dividing the sum of the weighted proportion of times a species occurred in each bin by the un-weighted proportion of times a species occurred in each bin. The derived nutrient optima were divided into eleven equal ranges, by nutrient, and tolerance scores (0-10) assigned with respect to each species derived optima. Nutrient tolerance scores were used to calculate Nutrient Biotic Index (NBI) scores for each sampling site by summing the number of individuals of a given species at the site and multiplying times that species tolerance value then dividing by the total number of individuals at the site. A single break point was observed for unionized ammonia, which showed an NBIUnionized Ammonia score shift between 0.003 and 0.03 (mg/L). The mean NBIUnionized Ammonia scores were 3.09 and 3.29, respectively. Nutrient Biotic IndexUnionized Ammonia scores were significantly correlated with IBI score and IBI integrity class. Three break points were observed for Nitrogen, Nitrate+Nitrite, demonstrating a significant NBINitrate+Nitrite score shift at mean concentrations of 0.13 mg/L, 1.09 mg/L, 3.15 mg/L and 6.87 mg/L respectively. The mean NBINitrate+Nitrite scores were 5.58, 5.37, 5.82 and 6.25, respectively. The observed relationship produced a convex curve suggesting an enrichment signature. Nutrient Biotic IndexNitrate+Nitrite scores were significantly correlated with IBI score and IBI integrity class. Two break points were observed for Total Kjeldahl Nitrogen (TKN), which were significant. The mean concentrations of TKN were 0.4 mg/L, 0.68 mg/L, and 1.27 mg/L, respectively. The mean NBITKN scores were 2.73, 3.10, and 3.37, respectively. Nutrient Biotic IndexTKN scores were significantly related to IBI score and IBI integrity class. Two break points observed for TN were significant at concentrations of 0.56 mg/L and 3.30 mg/L. The mean NBITN scores were 4.60 and 4.85, respectively. Nutrient Biotic IndexTN scores were not significantly related to IBI score or IBI integrity class. Two significant break points were observed for TP. The mean concentrations of TP were 0.07 mg/L and 0.32 mg/L, respectively and mean NBITP scores were 3.43 and 3.58, respectively. Nutrient Biotic IndexTP scores were significantly related to IBI score and IBI integrity class. Two break points were observed for Chlorophyll a (periphyton), which were significant. Mean concentrations were 10.15 mg/m2 and 134.14 mg/m2, respectively. Mean NBIPeriphyton scores were 3.75 and 4.20, respectively. Nutrient Biotic IndexPeriphyton scores were not significantly related to IBI score, but were significantly related to IBI integrity class. Four break points were observed for Chlorophyll a (phytoplankton), which occurred at Chlorophyll a (phytoplankton) concentrations of 2.33 μg/L, 10.98 μg/L and 49.13 μg/L, respectively. The mean NBIPhytoplankton scores were 3.43, 3.85 and 5.02, respectively. Nutrient Biotic IndexPhytoplankton scores were significantly related to IBI score and IBI integrity class. Nutrient criteria concentration was interpreted for NBI and IBI integrity class relationships to establish protective nutrient concentration benchmarks. Proposed mean protection values are 3.0 μg/L for Unionized Ammonia, 130 μg/L for Nitrogen, Nitrate+Nitrite, 40 μg/L for TKN, 70 μg/L for TP, and 2.33 μg/L for Chlorophyll a (phytoplankton). Criteria established at or below these benchmarks should protect for both biological integrity of fish assemblages in Indiana as well as nutrient loadings into the Gulf of Mexico.