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2011. We characterized the proximity of 660 individual fishes with 907 structure-forming invertebrates in the study area. More than 75% of individual fishes were within 1 body length of an adjacent invertebrate. Chi-squared tests suggest a difference in associating groups of fishes between soft-sediment and hard-bottom habitat. Furthermore, regression testing showed significant relationship between structure-forming invertebrates and fish in only the softsediment habitat; however, the relationships observed were weak. Ultimately, the hard substrate provided by wave energy structures in a soft-bottom environment may be more important to demersal fishes than structure-forming invertebrates.
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HABITAT-RELATED FOOD PREFERENCES IN BRUSH MICE (PEROMYSCUS BOYLII) EVIDENCE FROM
FEEDING TRIALS AND ISOTOPESGizelle Hurtado, Karen Mabry.
New Mexico State University, Las Cruces, NM.
Habitat generalists are species that use multiple types of habitat; however, individuals within such generalist species may specialize on particular habitat types or resources within habitats. The brush mouse (Peromyscus boylii) is found in multiple habitat types in western North America. Within this species, individuals exhibit strong preferences for the type of habitat they were born and reared in, and habitat preferences may be partially driven by experience with or preferences for foods associated with that natal habitat type. We used cafeteria trials to investigate food preferences of mice from oak woodland and chamise chaparral habitats. Mice were simultaneously offered 8 food types. There were no significant differences in the amount of each food type that was consumed between mice originating in woodland versus chaparral habitats. However, brush mice from both habitat types preferred acorns to other types of food. In feeding trials, acorns were offered without the outer shell, decreasing handling time. Mice may have favored acorns due to the higher energetic content of acorns as compared to the other food types offered. In addition, a pilot isotope study has been initiated to determine if differences in δ13C and δ15N isotopes in mouse fur samples are linked to habitat of origin.
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PATTERNS OF COSPECIATION AND HOST SWITCHING IN AVIAN MALARIA PARASITES OF AFRICAN
SUNBIRDS (FAMILY NECTARINIIDAE)Elvin Lauron, Ravinder Sehgal.
San Francisco State University, San Francisco, CA.
The malaria parasite Plasmodium falciparum is one of the world’s most devastating and widespread parasites, killing more people than any other parasitic infection. Parasites of this genus can also exploit multiple vertebrate hosts including reptiles, mammals, and birds. Furthermore, malaria parasites of birds are found on all continents of the world except Antarctica. The potential for these widely spread avian plasmodium parasites to leap into new hosts has conservation implications, as was seen in the endemic bird populations of Hawaii. The host-specificity, pathogenenicity, and geographical distribution of avian plasmodium are influenced by the life history of the hostparasite relationships. However, understanding these processes requires an extensive sampling of parasite distributions across hosts. We thus sought to understand the history of avian plasmodium and the widespread
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bird family, Nectariniidae. These birds spread from Asia to Africa. After arriving in Africa, they rapidly diversified. To determine whether Nectariniidae speciation led to congruent parasite speciation in Africa, we generated a threegenome phylogeny of avian plasmodium found in Nectariniidae and performed a cophylogenetic analysis using an existing Nectariniidae phylogeny. Our co-phylogenetic analysis indicates the extent of avian plasmodium parasite cospeciation, host switching, sorting, and duplication events that occurred in the sunbirds.
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THE INFLUENCE OF HABITAT COMPOSITION AND FOOD AVAILABILITY ON MIGRATORY AND RESIDENT
BIRD ABUNDANCE AND DIVERSITY IN A SUBTROPICAL DRY FOREST IN SOUTHEASTERN PUERTO RICOWaleska Vazquez, Fred Schaffner.
Universidad de Turabo, Gurabo, PR.
Habitat selection on the wintering grounds is crucial for migratory bird survival and for a successful migration.
Vegetation features can influence resource availability for birds, an important factor affecting habitat selection. We will identify the use of secondary dry forest by both migratory and resident birds. Using 3 sites with distinct degrees of disturbance and successional stages, we will evaluate the abundance and diversity of avian communities depending on the characteristics of each site, including plant composition and arthropod abundance. For this, fixed-radius point counts and mist netting will be used in order to quantify bird presence and fitness (body condition index, BCI).
For site characterization, plant identification, relative density, frequency, and dominance will be assessed using point-centered quarter methods (PCQM). Arthropod sampling will include branch clippings and leaf litter collection for canopy and floor insect communities. Special focus will be placed on sedentary species, those known to roost in their foraging habitat: 1 migrant (Ovenbird, Seiurus aurocapilla) and 1 resident (Bananaquit, Coereba flaveola), assessing body condition and possible interactions within the habitat. Potential relationships of habitat structure and vegetative composition (or tree dominance) with avian species richness and body condition will be assessed. With this information, habitat use can be evaluated so as to establish better conservation plans for migratory and resident birds, bringing additional information for the restoration and conservation of favorable spaces.
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INFLUENCES OF FOOD WEB STRUCTURE ON VECTOR ABUNDANCE AND CHAGAS DISEASE
TRANSMISSION IN CENTRAL PANAMAChristina Varian, Nicole Gottdenker.
School of Veterinary Medicine, University of Georgia, Athens, GA.
Food webs can provide information on how ecosystem structure influences infectious disease agents; however, understanding how food webs influence pathogen transmission remains unclear, particularly in relation to vectorborne pathogens. Chagas disease (CD), an illness that affects millions of people in the Americas, is caused by a protozoan parasite, Trypanosoma cruzi. The main vector for CD in Panama is the reduviid bug, Rhodnius pallescens, which primarily inhabits the palm tree Attalea butyracea, found in lowland tropical areas throughout Panama. The abundance of R. pallescens increases in areas of anthropogenic disturbance, but the actual mechanism of abundance increase is not understood. The objective of this study is to determine whether there is a significant relationship between food web community/structure and vector dynamics by identifying how variations in palm tree species community and trophic relationships influence R. pallescens abundance, population structure, and infection with trypanosomes across levels of anthropogenic disturbance in Central Panama. Individual Attalea butyracea palms will be cut down and dissected in order to determine palm tree species composition. Floral and faunal species living within the palm crown will be recorded using observation methods. Parasitoids, parasites (including T. cruzi), and Graduate
sequencing (NGS). By incorporating disease and food-web ecology within a network modeling framework, this project can increase our understanding of anthropogenic effects on host-parasite interactions and the indirect impacts habitat disturbance has on disease transmission of multihost, vector-borne pathogens.
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EXAMINING BIVALVE COMMUNITY SHIFTS OVER TIME IN SEVERAL BAYS IN SAN DIEGO, CALIFORNIA, AND
NORTHERN BAJA CALIFORNIA, MEXICOAnai Novoa1, Drew Talley1, Theresa Sinicrope-Talley2.
University of San Diego, San Diego, CA, 2University of California, San Diego, La Jolla, CA.
1 Many bivalves have been depleted from their native estuaries through direct and indirect human effects, including overharvesting, habitat loss and alteration, pollution, and introduced species invasions. The loss of native bivalves can result in the loss of the ecosystem functions that they provide such as water filtration, soil aeration, biodeposition, bioturbation, attachment substrate for epibionts, and refuges for free-living fauna. Shifts in bivalve communities may be especially prevalent in developed coastal ecosystems such as southern California and northern Baja California, where human development and impacts are high. Sporadic studies of the bivalve communities within estuaries throughout this region over the past 50 years indicate dramatic local shifts in bivalve communities. If we hope to predict the future change of these communities and the ecosystem services they provide, we need a better understanding of both the local and regional trends and causes of changes in bivalve communities through time and across gradients of natural variability. In this project, we use historical bivalve datasets with additional sampling to address long-term (30 to 50 yr) regional bivalve community shifts in several bays in San Diego, California, and northern Baja California, Mexico. We expect to see decreases in density and diversity of large, edible species associated with overexploitation; increases in introduced invasive species; and decreases in surface-dwelling species, all of which may be an indirect inhibition response to invasive species.
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ANALYZING CHANGES TO CORAL HEALTH AND METABOLIC ACTIVITY IN AN OXYGEN DEPAUPERATE
ENVIRONMENTJames Murphy, Robert Richmond, Jon-Paul Bingham.
University of Hawaii at Manoa, Honolulu, HI.
Scleractinian corals play a critical role in marine ecosystems by providing essential structure for coral reef habitats.
However, recent investigations have found an alarming increase in coral death as the result of stressors, which threaten the general health of tropical coastal environments. Of particular interest is the effect of invasive algal overgrowth on the health of Hawaiian corals through the effects of anaerobic respiration. The fast-paced growth of Gracilaria salicornia gives this alga the ability to overgrow coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (DO2 2 mg/L) occurring underneath algal mats at night, and the concurrent bleaching and partial tissue loss of shaded corals. This study aimed to simulate hypoxia in a laboratory setting in order to limit the effect of environmental variables on coral health. Analyses of stress in corals due to anoxia were accomplished through the quantification of lactate (LDH), alanopine (ADH), strombine (SDH), and octopine dehydrogenases (ODH). Treatment corals were found to exhibit almost complete tissue loss, severe bleaching, and significantly increased ADH/SDH activity with increasing hypoxia exposure duration. Conversely, control corals were found to exhibit little to no tissue loss, bleaching, or significant increases in enzyme activity throughout the treatment cycle. These findings suggest anoxia as a major source of increased coral stress, which possibly occurs in response to hypoxic conditions, such as invasive algae mat smothering, and provide insight into coral tolerance to controlled, extremely low-oxygen environments.
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BIOACCESSIBILITY, RELEASE KINETICS, AND MOLECULAR SPECIATION OF ARSENIC AND LEAD IN GEODUSTS FROM THE IRON KING MINE FEDERAL SUPERFUND SITE IN HUMBOLDT, ARIZONANazune Menka, Jon Chorover, Rob Root, Eduardo Saez, Clark Lantz, Wendell Ela.
University of Arizona, Tucson, AZ.
Arizona has approximately 60,000 to 100,000 abandoned or inactive mining sites. Mine tailing disposal sites in arid areas such as Arizona are susceptible to wind erosion and become sources of airborne particulate matter or geo-dusts including 10 μm (PM10) and 2.5 μm (PM2.5). These particles are comprised of contaminants such as arsenic and lead that are detrimental to human health. Climate models predict that the southwestern US will
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become increasingly drier, increasing the importance of the harmful effects of these airborne metal and metalloid contaminants. This research aims to use surface tailings to 1) identify the particle size fractions of airborne arsenic due to wind erosion, 2) determine the bioaccessibility of arsenic in simulated lung and gastric fluids, and 3) determine the molecular speciation via post-extraction analysis of the remaining tailings using synchrotron-based X-ray absorption spectroscopy (XAFS and XANES) and x-ray diffraction (XRD). Solutions were analyzed for solubilized arsenic and lead using an acid digestion and ICP-MS. Mine tailing crust samples were collected and sieved to obtain size fractions relevant to ingestion (150 μm) and inhalation (2.5 μm). These size fractions were then extracted with simulated gastric and lung fluids to determine the bioaccessibility of arsenic and lead of the different size fractions. Kinetic studies included short-to-long residence time steps to determine the reaction rate. We hypothesize that 1) smaller particles with greater surface area have accelerated kinetics of arsenic and lead release, and 2) bioaccessibility is a predictable function of the local contaminant-bonding environment as revealed from spectroscopy.
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IMPACTS OF SEA OTTER RECOLONIZATION ON KELP FOREST COMMUNITIES IN SOUTHEAST ALASKASonia Ibarra, Ginny Eckert.
University of Alaska Fairbanks, Fairbanks, AK.