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• 2671. [Article] Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge

  Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental ...

  Citation × Citation Citation Abstract Copy Title: Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge Author: Liu, Yun-gang Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental neutron activation analysis in 37 TS spore samples, and 31 DS spore samples. Aluminum was chosen as a soil contamination indicator to correct for soil contamination. The plot of the concentrations of the ith element [X[subscript i]] versus Al, yielded the biological concentrations of [X.[subscript i]]. The results show that the biological concentrations of Sc, V, La, and Sm are insignificantly small and that their contents in the spores are essentially all derived from soil dust contamination. For Na and Fe, considerable fractions, 0.15 and 0.60, respectively, of their total concentrations are derived from soil contamination. For other elements, the soil contamination contributions are relatively small compared to their biological concentrations. The "student" t-test was used for comparisons of the geometric means of the element concentrations between the TS and DS spore series. The differences between the mean values of Cl, K, Ca, Mn, Zn, and Br for the TS and CS series are not totally due to random errors within the 95% confidence level. The differences for K and Cl between the TS and DS series are large and outside the ±10- limits; therefore, the concentrations of these two elements can be used as reliable criteria for distinguishing these two species. Also, Br may be useful as a diagnostic trace element due to the significant difference between the Br geometric means of the TS and DS spores. Part 2 Forty sediment and four basement basalt samples, taken from a 678 m core drilled by the DSDP (Deep Sea Drilling Project) at Site 525A, Leg 74 (June 10-15, 1980), as well as sixteen selected basalt samples around the south Atlantic Ocean were subjected to instrumental neutron activation analysis. Thirty-two major, minor, and trace elements were determined. The core from the Wavlis Ridge site (2467 m) consisted of 574.6 m of sediment and 103.5 m of basalt. The downcore element concentration profiles and regression analyses show that the rare earth elements (REE) are present in significant amounts in both the carbonate and non-carbonate phases in sediments; Sr is concentrated in the carbonate phase; most of the other elements determined exist mainly in the non-carbonate (mostly clay) phase. The calculated partition coefficients of the REEs between the carbonate phase and the free REE ion concentrations in sea water were high and increased with decreasing REE ionic radii or increasing atomic number from 3.9x10⁶ for La to 15x10⁶ for Lu. Using the partition coefficients of the REEs in the carbonate and non-carbonate (clay) phases, the REE concentrations in Atlantic sea water were calculated, and the results indicate that the lanthanide concentrations have not been changed significantly in south Atlantic sea water over the past 70 m.y.. The Ce anomaly observed in >95% carbonate sediments is related to the Ce⁺³ concentration in sea water; therefore, the Ce anomaly is a redox (reducing-oxidizing) indicator of sea water. (Essentially, >99.99% of soluble Ce in sea water is present as Ce⁺³.) The REE patterns show no Ce depletion in mollusc shell segments from the late Campanian, and a slight Ce depletion in carbonate phases from the late Paleocene sediments. From early Eocene on, the REE patterns in the carbonate phase show a marked Ce depletion, the same as is observed in carbonates from the late Pleistocene to early Holocene (about 0.3 m.y. ago). The abrupt and striking change in the Ce depletion indicates that sea water was anoxic over the Walvis Ridge during the late Campanian. As the gap between northeast South America (northeast Brazil) and west central Africa (near the southwest corner of the upper half of Africa, e.g., near Liberia) widened and the Walvis Ridge subsided between the late Campanian and late Paleocene, sea water flow between the north Atlantic and south Atlantic oceans increased steadily, and gradually flushed out the anoxic water layer over the Walvis Ridge, thereby achieving oxidation conditions at about 54 m.y. ago, that are similar to present day sea water redox conditions: in the world oceans. The chemical compositions of the basement rocks of the core corresponds to alkalic basalts, not MA-Crean Ridge basalts (MORBs). Only a few basement rocks had been recovered from other Walvis Ridge sites. The results add more evidence which supports the hypothesis that the Wavlis Ridge was formed by a series of volcanoes moving over a "hot spot" near the Mid-Atlantic Ridge. These volcanoes migrated eastward as the South American and African continents drifted away. Most of the basalt samples taken from the southeast Brazilian continental margin also are not similar to MORE. From the bulk chemical composition and the REE pattern, one 112 m.y. old basalt has been identified as an early-stage MORB. To date, this is the oldest oceanic tholeiite recovered from the south Atlantic. This direct evidence indicates that the continental split between South America and Africa commenced ≥112 m.y. ago, and is consistent with the suggestion that the rift between the two continents began about 125 m.y. ago. Title: Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge Author: Liu, Yun-gang Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental neutron activation analysis in 37 TS spore samples, and 31 DS spore samples. Aluminum was chosen as a soil contamination indicator to correct for soil contamination. The plot of the concentrations of the ith element [X[subscript i]] versus Al, yielded the biological concentrations of [X.[subscript i]]. The results show that the biological concentrations of Sc, V, La, and Sm are insignificantly small and that their contents in the spores are essentially all derived from soil dust contamination. For Na and Fe, considerable fractions, 0.15 and 0.60, respectively, of their total concentrations are derived from soil contamination. For other elements, the soil contamination contributions are relatively small compared to their biological concentrations. The "student" t-test was used for comparisons of the geometric means of the element concentrations between the TS and DS spore series. The differences between the mean values of Cl, K, Ca, Mn, Zn, and Br for the TS and CS series are not totally due to random errors within the 95% confidence level. The differences for K and Cl between the TS and DS series are large and outside the ±10- limits; therefore, the concentrations of these two elements can be used as reliable criteria for distinguishing these two species. Also, Br may be useful as a diagnostic trace element due to the significant difference between the Br geometric means of the TS and DS spores. Part 2 Forty sediment and four basement basalt samples, taken from a 678 m core drilled by the DSDP (Deep Sea Drilling Project) at Site 525A, Leg 74 (June 10-15, 1980), as well as sixteen selected basalt samples around the south Atlantic Ocean were subjected to instrumental neutron activation analysis. Thirty-two major, minor, and trace elements were determined. The core from the Wavlis Ridge site (2467 m) consisted of 574.6 m of sediment and 103.5 m of basalt. The downcore element concentration profiles and regression analyses show that the rare earth elements (REE) are present in significant amounts in both the carbonate and non-carbonate phases in sediments; Sr is concentrated in the carbonate phase; most of the other elements determined exist mainly in the non-carbonate (mostly clay) phase. The calculated partition coefficients of the REEs between the carbonate phase and the free REE ion concentrations in sea water were high and increased with decreasing REE ionic radii or increasing atomic number from 3.9x10⁶ for La to 15x10⁶ for Lu. Using the partition coefficients of the REEs in the carbonate and non-carbonate (clay) phases, the REE concentrations in Atlantic sea water were calculated, and the results indicate that the lanthanide concentrations have not been changed significantly in south Atlantic sea water over the past 70 m.y.. The Ce anomaly observed in >95% carbonate sediments is related to the Ce⁺³ concentration in sea water; therefore, the Ce anomaly is a redox (reducing-oxidizing) indicator of sea water. (Essentially, >99.99% of soluble Ce in sea water is present as Ce⁺³.) The REE patterns show no Ce depletion in mollusc shell segments from the late Campanian, and a slight Ce depletion in carbonate phases from the late Paleocene sediments. From early Eocene on, the REE patterns in the carbonate phase show a marked Ce depletion, the same as is observed in carbonates from the late Pleistocene to early Holocene (about 0.3 m.y. ago). The abrupt and striking change in the Ce depletion indicates that sea water was anoxic over the Walvis Ridge during the late Campanian. As the gap between northeast South America (northeast Brazil) and west central Africa (near the southwest corner of the upper half of Africa, e.g., near Liberia) widened and the Walvis Ridge subsided between the late Campanian and late Paleocene, sea water flow between the north Atlantic and south Atlantic oceans increased steadily, and gradually flushed out the anoxic water layer over the Walvis Ridge, thereby achieving oxidation conditions at about 54 m.y. ago, that are similar to present day sea water redox conditions: in the world oceans. The chemical compositions of the basement rocks of the core corresponds to alkalic basalts, not MA-Crean Ridge basalts (MORBs). Only a few basement rocks had been recovered from other Walvis Ridge sites. The results add more evidence which supports the hypothesis that the Wavlis Ridge was formed by a series of volcanoes moving over a "hot spot" near the Mid-Atlantic Ridge. These volcanoes migrated eastward as the South American and African continents drifted away. Most of the basalt samples taken from the southeast Brazilian continental margin also are not similar to MORE. From the bulk chemical composition and the REE pattern, one 112 m.y. old basalt has been identified as an early-stage MORB. To date, this is the oldest oceanic tholeiite recovered from the south Atlantic. This direct evidence indicates that the continental split between South America and Africa commenced ≥112 m.y. ago, and is consistent with the suggestion that the rift between the two continents began about 125 m.y. ago. Close

• 2672. [Article] Linking greater sage-grouse habitat use and suitability across spatiotemporal scales in central Oregon

  Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by ...

  Citation × Citation Citation Abstract Copy Title: Linking greater sage-grouse habitat use and suitability across spatiotemporal scales in central Oregon Author: Freese, Mark T. Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by birds. However, little work has evaluated vegetation attributes important for Greater Sage-grouse at a landscape-scale or identified landscape attributes that influence habitat use patterns. Habitat use patterns by Greater Sage-grouse are complex and can occur across relatively large heterogeneous landscapes. This creates a major challenge for managers to interpret and predict habitat use patterns as well as to evaluate habitat suitability and prioritize habitats that are in need of ecological restoration. The goals of this research were to evaluate plot-level habitat characteristics found to be important in sustaining Greater Sage-grouse populations at a landscape-level and to identify landscape-level attributes associated with bird occurrence. Specific questions this research addressed were: 1) what is the variation in vegetation composition and structure at the plot versus landscape-level, 2) how does topography influence the distribution of vegetation composition and structure, and 3) what attributes at the landscape-level are most closely associated with Greater Sage-grouse habitat use? To address these questions we selected a 31,416 ha area in central Oregon surrounding a Greater Sage-grouse lek with a population that has been relatively stable since 1987. In February 2006, 50 Greater Sage-grouse were trapped, radio collared, and then tracked for two consecutive years. Four-hundred eighty bird UTM (Universal Transverse Mercator) coordinate location points were recorded for the entire population of birds during the duration of this study. Each collared Greater Sage-grouse was located on average every 15 ± 0.56 (mean ± SE) days, ranging from 1 to 154 days. Vegetation for the entire study area was mapped by cover types, which were defined by the dominant shrub species. When shrubs were not present in the plant community, cover types were separated by other surface characteristics such as bare ground, water, meadow, etc. A total of 23 cover types were delineated. Cover types were mapped using 0.5-m NAIP (National Agricultural Imagery Program) imagery. In addition to cover type, a set of biophysical predictor variables were created for the entire study area in a GIS (Geographic Information System) to evaluate the association with Greater Sage-grouse location points. These variables included elevation, slope, aspect, curvature, solar radiation, ruggedness index, northing, easting, and distance from roads, leks, and mesic habitats. A stratified random sample with cover types serving as the stratum was used to select random locations for sampling plot-level habitat variables. A total of 352 plots were sampled from 18 cover types across the study area with a minimum of 15 plots per cover type. Vegetation measurements collected were similar to those reported in the habitat guidelines developed by Connelly et al. (2000) and the Bureau of Land Management et al. (2000). Measurements included vegetation cover, height, and density of forbs recognized as important Greater Sage-grouse food species. Plot elevation, slope, aspect, curvature and landscape position were also recorded. Summary statistics were used to describe means and ranges within and between cover types. A combination of multiple linear regression and analysis of variance (ANOVA) were used to evaluate the effects of topographic attributes on the distribution of vegetation composition and structure. To address the third question, maximum entropy software was used to develop models that predict Greater Sage-grouse seasonal habitat use, generate maps from those models, and describe the shapes of the response curves as it relates Greater Sage-grouse habitat preference to individual landscape predictor variables. Total shrub canopy cover across all cover types averaged 19.4%, ranging from 11.6 to 27.7%. Big (mountain and Wyoming) and low sagebrush canopy cover commonly varied between 2.6 and 16 fold within cover types. Deep-rooted perennial tussock grass cover averaged across all upland plots, was 26.7%, ranging from less than 1% to over 50%. Vegetation cover, Greater Sage-grouse food forb density, and sagebrush and grass height were significantly (P < 0.05) correlated with topographic attributes. Cover for the different plant life forms and food forb density increased with elevation. Cover for most of the herbaceous life forms was also greater on north than south aspects. Compared to Connelly et al. (2000) and the BLM et al. (2000) habitat guidelines, < 1% of the study area satisfied breeding and nesting guideline criteria, while < 31% satisfied the brood-rearing guideline criteria. Although most of the study area did not meet habitat recommendations presented in the guidelines, patches imbedded throughout the study area did and most areas satisfied many but not all of the guideline requirements. These results suggests that evaluating only mean values of community structure, both within and among cover types across the study area, limited the ability to fully identify patch variability and landscape heterogeneity as it relates to habitat suitability across large areas. Maximum entropy results suggest Greater Sage-grouse habitat use during the breeding season increases near leks and within cover types of low sagebrush and low sagebrush/mountain big sagebrush complexes. Preferred summer habitat includes areas relatively high in elevation, distances that are close to leks, and within or a close proximity to habitats that harbor succulent vegetation through much of the summer. With Greater Sage-grouse utilizing resources within expansive landscapes, understanding the attributes that can be applied at a landscape-scale that attract disproportionate levels of habitat use can help managers predict where birds are likely to occur across the landscape. With the ability to discriminate between areas that Greater Sage-grouse are likely to use or avoid, managers can allocate limited resources to more effectively create, manipulate, and administer habitat conservation efforts where bird use is predicted and prioritize areas across the landscape in need of ecological restoration. Title: Linking greater sage-grouse habitat use and suitability across spatiotemporal scales in central Oregon Author: Freese, Mark T. Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by birds. However, little work has evaluated vegetation attributes important for Greater Sage-grouse at a landscape-scale or identified landscape attributes that influence habitat use patterns. Habitat use patterns by Greater Sage-grouse are complex and can occur across relatively large heterogeneous landscapes. This creates a major challenge for managers to interpret and predict habitat use patterns as well as to evaluate habitat suitability and prioritize habitats that are in need of ecological restoration. The goals of this research were to evaluate plot-level habitat characteristics found to be important in sustaining Greater Sage-grouse populations at a landscape-level and to identify landscape-level attributes associated with bird occurrence. Specific questions this research addressed were: 1) what is the variation in vegetation composition and structure at the plot versus landscape-level, 2) how does topography influence the distribution of vegetation composition and structure, and 3) what attributes at the landscape-level are most closely associated with Greater Sage-grouse habitat use? To address these questions we selected a 31,416 ha area in central Oregon surrounding a Greater Sage-grouse lek with a population that has been relatively stable since 1987. In February 2006, 50 Greater Sage-grouse were trapped, radio collared, and then tracked for two consecutive years. Four-hundred eighty bird UTM (Universal Transverse Mercator) coordinate location points were recorded for the entire population of birds during the duration of this study. Each collared Greater Sage-grouse was located on average every 15 ± 0.56 (mean ± SE) days, ranging from 1 to 154 days. Vegetation for the entire study area was mapped by cover types, which were defined by the dominant shrub species. When shrubs were not present in the plant community, cover types were separated by other surface characteristics such as bare ground, water, meadow, etc. A total of 23 cover types were delineated. Cover types were mapped using 0.5-m NAIP (National Agricultural Imagery Program) imagery. In addition to cover type, a set of biophysical predictor variables were created for the entire study area in a GIS (Geographic Information System) to evaluate the association with Greater Sage-grouse location points. These variables included elevation, slope, aspect, curvature, solar radiation, ruggedness index, northing, easting, and distance from roads, leks, and mesic habitats. A stratified random sample with cover types serving as the stratum was used to select random locations for sampling plot-level habitat variables. A total of 352 plots were sampled from 18 cover types across the study area with a minimum of 15 plots per cover type. Vegetation measurements collected were similar to those reported in the habitat guidelines developed by Connelly et al. (2000) and the Bureau of Land Management et al. (2000). Measurements included vegetation cover, height, and density of forbs recognized as important Greater Sage-grouse food species. Plot elevation, slope, aspect, curvature and landscape position were also recorded. Summary statistics were used to describe means and ranges within and between cover types. A combination of multiple linear regression and analysis of variance (ANOVA) were used to evaluate the effects of topographic attributes on the distribution of vegetation composition and structure. To address the third question, maximum entropy software was used to develop models that predict Greater Sage-grouse seasonal habitat use, generate maps from those models, and describe the shapes of the response curves as it relates Greater Sage-grouse habitat preference to individual landscape predictor variables. Total shrub canopy cover across all cover types averaged 19.4%, ranging from 11.6 to 27.7%. Big (mountain and Wyoming) and low sagebrush canopy cover commonly varied between 2.6 and 16 fold within cover types. Deep-rooted perennial tussock grass cover averaged across all upland plots, was 26.7%, ranging from less than 1% to over 50%. Vegetation cover, Greater Sage-grouse food forb density, and sagebrush and grass height were significantly (P < 0.05) correlated with topographic attributes. Cover for the different plant life forms and food forb density increased with elevation. Cover for most of the herbaceous life forms was also greater on north than south aspects. Compared to Connelly et al. (2000) and the BLM et al. (2000) habitat guidelines, < 1% of the study area satisfied breeding and nesting guideline criteria, while < 31% satisfied the brood-rearing guideline criteria. Although most of the study area did not meet habitat recommendations presented in the guidelines, patches imbedded throughout the study area did and most areas satisfied many but not all of the guideline requirements. These results suggests that evaluating only mean values of community structure, both within and among cover types across the study area, limited the ability to fully identify patch variability and landscape heterogeneity as it relates to habitat suitability across large areas. Maximum entropy results suggest Greater Sage-grouse habitat use during the breeding season increases near leks and within cover types of low sagebrush and low sagebrush/mountain big sagebrush complexes. Preferred summer habitat includes areas relatively high in elevation, distances that are close to leks, and within or a close proximity to habitats that harbor succulent vegetation through much of the summer. With Greater Sage-grouse utilizing resources within expansive landscapes, understanding the attributes that can be applied at a landscape-scale that attract disproportionate levels of habitat use can help managers predict where birds are likely to occur across the landscape. With the ability to discriminate between areas that Greater Sage-grouse are likely to use or avoid, managers can allocate limited resources to more effectively create, manipulate, and administer habitat conservation efforts where bird use is predicted and prioritize areas across the landscape in need of ecological restoration. Close

• 2673. [Article] Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations

  Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased ...

  Citation × Citation Citation Abstract Copy Title: Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations Author: Piacenza, Susan E. H. Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased 5.7% year⁻¹ since 1973, but wide fluctuations in census counts of nesting females make recovery diagnosis difficult. For effective management planning, it is critical to have the best information possible on vital rates, and to determine the best tools and practices for incorporating vital rate information, particularly variability, into population models to assess population size and status. Process and observation errors, compounded by late maturity, obscure the relationship between trends on the nesting beach and the entire population. Using sea turtle nesting beach surveys as a population index for assessment is problematic, yet often pragmatic because this is the only population index that is easily accessible. It is advantageous to use a modelling approach that estimates interannual variability in life history traits, accounts for uncertainty from individual-level variability, and allows for population dynamics to emerge from individual behaviors. To this end, I analyzed a long-term data set of marked green sea turtles to determine the degree of temporal variability in key life history traits. From this analysis, I built an agent-based model (ABM) to form the basis of a new assessment tool -- Monitoring Strategy Evaluation. In Chapter 2, I evaluated annual changes in demographic indicators (DIs) of 3,677 nesting green turtles from a 38-year tagging program in the Hawaiian Islands to determine if key life history traits are changing over time and in response to nester density. I used linear mixed models and multistate open robust design models to estimate several DIs and correlated them with nesting female counts. Mean nester carapace length and breeding probability were highly variable over time, suggesting shifts in age structure that could be due to recruitment. The top-ranked model predicted constant female survival over time. A significant positive relationship between the nesting population and breeding probability was evident, and breeding probability shows promise as an indicator of population recovery. This work contributes to a growing set of studies evaluating sea turtle demography for temporal variability and is the first for Hawaiian green turtles. In Chapter 3, I develop the Green Sea Turtle Agent-Based Model (GSTABM) to evaluate how recovery processes differ across disturbance types. The GSTABM incorporates individually variable age-at-maturity, clutch frequency and clutch size, annually variable breeding probability, environmental stochasticity and density dependence in hatchling production. The GSTABM simulates the process of population impact and recovery and the monitoring process, with observation error, on the nesting beach. The GSTABM captures the emergent patterns of interannual nesting variation, nester recruitment, and realistic population growth rates. Changes in survival rates of the nearshore age-stage classes directly affected adult and nester abundance, population growth rate and nester recruitment more than any of the other input parameters. In simulating 100 years of recovery, experimentally disturbed populations began to increase but did not fully return to pre-disturbance levels in adult and nester abundance, population growth or nester recruitment. In simulations with different levels of monitoring effort, adult abundance was poorly estimated, was influenced by population trajectory and disturbance type, and showed marginal improvements in accuracy with increased detection probability. Estimating recruitment showed improvements with increasing detection levels. In the GSTABM, variability in the nesting beach does not mirror variability in adult abundance. The GSTABM is an important tool to determine relationships with monitoring, population assessment, and the underlying biological processes driving changes in the population, and especially, changes on the nesting beach. In Chapter 4, I develop a new simulation-based tool: Monitoring Strategy Evaluation (MoSE) to determine which data source yields the most useful information for population assessments. The MoSE has three main components: the simulated "true" operating, observation, and estimation models. To explore this first use of MoSE, I apply different treatments of disturbance, sampling, and detection to the virtual "true" population, and then sample the nests or nesters, with observation error, to test if the observation "data" accurately diagnose population status indicators. Based on the observed data, I estimated adult abundance, nester recruitment, and population trend and compare them to the known values. I tested the accuracy of the estimated abundance when annually varying inputs of breeding probability, detection and clutch frequency were used instead of constants. I also explored the improvement of trend accuracy with increased study duration. Disturbance type and severity can have important and persistent effects on the accuracy of population assessments drawn from monitoring rookeries. Accuracy in abundance estimates may be most improved by avoiding clutch frequency bias in sampling and including annually varying inputs in the estimation model. Accuracy of nester recruitment may be most improved by increasing detection level and avoiding age-bias in sampling. The accuracy of estimating population trend is most influenced by the underlying population trajectory, disturbance type and disturbance severity. At least 10 years of monitoring data are necessary to accurately estimate population trend, and longer if juvenile age classes were disturbed and trend estimates occur during the recovery phase. The MoSE is an important tool for sea turtle biologists and conservation managers and allows biologists to make informed decisions regarding the best monitoring strategies to employ for sea turtles. This modeling framework is designed to provide an evaluation of monitoring program effectiveness to assist in planning future programs for sea turtles. Altogether, my research suggests certain life history traits of green sea turtles have important temporal variation that should be accounted for in population models, understanding the relationships between nesting and the total population is essential, and basing population assessments from nesting beach data alone is likely to result in incorrect or biased estimates of status indicators. The quantitative tools employed here can be applied to other sea turtle populations and will improve monitoring, and result in better estimates of current population trends and enhance conservation for all species of sea turtles. Title: Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations Author: Piacenza, Susan E. H. Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased 5.7% year⁻¹ since 1973, but wide fluctuations in census counts of nesting females make recovery diagnosis difficult. For effective management planning, it is critical to have the best information possible on vital rates, and to determine the best tools and practices for incorporating vital rate information, particularly variability, into population models to assess population size and status. Process and observation errors, compounded by late maturity, obscure the relationship between trends on the nesting beach and the entire population. Using sea turtle nesting beach surveys as a population index for assessment is problematic, yet often pragmatic because this is the only population index that is easily accessible. It is advantageous to use a modelling approach that estimates interannual variability in life history traits, accounts for uncertainty from individual-level variability, and allows for population dynamics to emerge from individual behaviors. To this end, I analyzed a long-term data set of marked green sea turtles to determine the degree of temporal variability in key life history traits. From this analysis, I built an agent-based model (ABM) to form the basis of a new assessment tool -- Monitoring Strategy Evaluation. In Chapter 2, I evaluated annual changes in demographic indicators (DIs) of 3,677 nesting green turtles from a 38-year tagging program in the Hawaiian Islands to determine if key life history traits are changing over time and in response to nester density. I used linear mixed models and multistate open robust design models to estimate several DIs and correlated them with nesting female counts. Mean nester carapace length and breeding probability were highly variable over time, suggesting shifts in age structure that could be due to recruitment. The top-ranked model predicted constant female survival over time. A significant positive relationship between the nesting population and breeding probability was evident, and breeding probability shows promise as an indicator of population recovery. This work contributes to a growing set of studies evaluating sea turtle demography for temporal variability and is the first for Hawaiian green turtles. In Chapter 3, I develop the Green Sea Turtle Agent-Based Model (GSTABM) to evaluate how recovery processes differ across disturbance types. The GSTABM incorporates individually variable age-at-maturity, clutch frequency and clutch size, annually variable breeding probability, environmental stochasticity and density dependence in hatchling production. The GSTABM simulates the process of population impact and recovery and the monitoring process, with observation error, on the nesting beach. The GSTABM captures the emergent patterns of interannual nesting variation, nester recruitment, and realistic population growth rates. Changes in survival rates of the nearshore age-stage classes directly affected adult and nester abundance, population growth rate and nester recruitment more than any of the other input parameters. In simulating 100 years of recovery, experimentally disturbed populations began to increase but did not fully return to pre-disturbance levels in adult and nester abundance, population growth or nester recruitment. In simulations with different levels of monitoring effort, adult abundance was poorly estimated, was influenced by population trajectory and disturbance type, and showed marginal improvements in accuracy with increased detection probability. Estimating recruitment showed improvements with increasing detection levels. In the GSTABM, variability in the nesting beach does not mirror variability in adult abundance. The GSTABM is an important tool to determine relationships with monitoring, population assessment, and the underlying biological processes driving changes in the population, and especially, changes on the nesting beach. In Chapter 4, I develop a new simulation-based tool: Monitoring Strategy Evaluation (MoSE) to determine which data source yields the most useful information for population assessments. The MoSE has three main components: the simulated "true" operating, observation, and estimation models. To explore this first use of MoSE, I apply different treatments of disturbance, sampling, and detection to the virtual "true" population, and then sample the nests or nesters, with observation error, to test if the observation "data" accurately diagnose population status indicators. Based on the observed data, I estimated adult abundance, nester recruitment, and population trend and compare them to the known values. I tested the accuracy of the estimated abundance when annually varying inputs of breeding probability, detection and clutch frequency were used instead of constants. I also explored the improvement of trend accuracy with increased study duration. Disturbance type and severity can have important and persistent effects on the accuracy of population assessments drawn from monitoring rookeries. Accuracy in abundance estimates may be most improved by avoiding clutch frequency bias in sampling and including annually varying inputs in the estimation model. Accuracy of nester recruitment may be most improved by increasing detection level and avoiding age-bias in sampling. The accuracy of estimating population trend is most influenced by the underlying population trajectory, disturbance type and disturbance severity. At least 10 years of monitoring data are necessary to accurately estimate population trend, and longer if juvenile age classes were disturbed and trend estimates occur during the recovery phase. The MoSE is an important tool for sea turtle biologists and conservation managers and allows biologists to make informed decisions regarding the best monitoring strategies to employ for sea turtles. This modeling framework is designed to provide an evaluation of monitoring program effectiveness to assist in planning future programs for sea turtles. Altogether, my research suggests certain life history traits of green sea turtles have important temporal variation that should be accounted for in population models, understanding the relationships between nesting and the total population is essential, and basing population assessments from nesting beach data alone is likely to result in incorrect or biased estimates of status indicators. The quantitative tools employed here can be applied to other sea turtle populations and will improve monitoring, and result in better estimates of current population trends and enhance conservation for all species of sea turtles. Close

• 2674. [Article] In vitro and in vivo evaluations of chemically treated ryegrass straw

  Seven in vitro trials were conducted to compare the effects of soaking annual ryegrass straw in solutions of sodium hydroxide (Na₄OH), potassium hydroxide (KOH), ammonium hydroxide (NH₄OH), or sodium formate ...

  Citation × Citation Citation Abstract Copy Title: In vitro and in vivo evaluations of chemically treated ryegrass straw Author: Anderson, Daniel Craig Seven in vitro trials were conducted to compare the effects of soaking annual ryegrass straw in solutions of sodium hydroxide (Na₄OH), potassium hydroxide (KOH), ammonium hydroxide (NH₄OH), or sodium formate (NaCHO₂) at varying levels. Dry matter digestibility (DDM) was the criterion used to measure treatment response. A 3 x 3 Latin square designed lamb digestion trial, replicated three times, followed these screening trials. Its purpose was to study the effects that NaOH-treated straw had on animal health, feed and water intake, urine excretion and pH, apparent digestibility, nitrogen and energy utilization and sodium and potassium balances. Three feeding trials were also carried out to measure the performance of heifer calves fed untreated, but supplemented ryegrass straw based rations. A 3 x 3 Latin square designed sheep digestion trail supplied additional data on apparent digestibility and nitrogen and energy utilization for three of these rations. Spraying a two percent NaOH solution on straw did not significantly improve DDM while soaking at the same level produced a significant (P<.01) increase. There was no significant difference among particle sizes or treatment times for straw soaked in two percent NaOH. Two, four, six or eight percent levels of either NaOH₂ or KOH solutions significantly (P<.01) enhanced DDM. No significant improvement was noted above the eight percent level. NaCHO₂ significantly (P<.01) increased DDM above native straw, but higher treatment levels were necessary to achieve an equal magnitude of improvement than for NaOH. NH₄OH treatment produced variable results which could not be consistently repeated, but the crude protein (CP) content of treated straw was consistently increased. This was in contrast to NaOH soaking, which significantly (P< .01) degraded CP, acid detergent fiber (ADF) and acid detergent lignin (ADL) with each increase in level. All treatment combinations also produced significant (P< .01) cell wall constituents (CWC) declines below native straw. Straw treated on a solution basis was significantly (P< .01) higher in DDM than that treated on a dry matter basis. However, treated straw DDM was significantly (P< .01) greater in either case than that recorded for untreated straw. Draining off of the NaOH effluent prior to drying significantly (P< .01) reduced DDM. There was a trend for water soaking to depress DDM, but significance was not reached until samples were drained prior to drying. No detrimental effects were noted when lambs consumed unwashed NaOH-soaked straw. Daily dry matter (DM) intake per kg of body weight was significantly (P< .05) reduced for treated straw when compared to untreated. Increased water consumption and urninary excretion (P< .01) were evident when straw soaked in a one percent NaOH solution (ration three) was fed. Urine pH for sheep consuming straw treated on an eight percent dry matter basis (ration two) was significantly (P< .05) reduced below that recorded for urine from sheep fed the other two rations. However, none of the pH's were outside the normal range for ruminants. Treatment two significantly (P< .05) reduced apparent digestibilities for straw, DM, organic matter (OM), energy, CP, ash and cell contents below that for the other two treatments. Treatment three significantly (P< . 05) increased straw, ash, ADF, hemicellulose and CWC apparent digestibilities when compared to untreated straw (ration one). The digestibility of CP was significantly (P< .01) greater in the untreated straw ration. All sheep were in a positive nitrogen balance for the duration of the trials. There was no significant difference in nitrogen balance for lambs fed rations one and three. However, nitrogen retention for lambs receiving ration two was significantly (P< .05) depressed below the quantity retained by lambs on the other two rations. Ration three was clearly superior in terms of either percent nitrogen intake or percent of digested nitrogen. Untreated straw supported a statistically (P<.05) higher level of digestible energy per g DM intake than did either of the treated straw rations. Utilization of the gross energy of ration two was significantly (P< .05) less than that from the other two rations. Ration three supported lower average daily gains than the other two rations (P< .01). No definite conclusions can be drawn from the sodium and potassium balances. Evidently, sodium residue levels were not large enough to cause any problems as there were no observable side effects and potassium excretion was not increased. A series of feeding trials demonstrated that ryegrass straw can successfully comprise from 45 to 86% of a ration for growing heifers. Feeding value of the straw was improved to support gains from 0.38 kg to 0.80 kg per day by the use of a variety of feed ingredients that corrected the straw's deficiencies. Performance data suggested that the maximum level of urea that can be used in such high roughage rations is about 1.5%. Above this level gains and feed efficiency were depressed. Digestion trial data showed that DDM for untreated, supplemented straw was from 47.5 to 50. 4%. From 61.5 to 67.5% of the CP and 39.9 to 43.2% of the CWC was digestible. The CP was least digestible in the ration containing alfalfa. Nitrogen retention ranged from 6.1 to 7.1 g per day. The superior ration in this respect was ration 5, which contained whey. Title: In vitro and in vivo evaluations of chemically treated ryegrass straw Author: Anderson, Daniel Craig Seven in vitro trials were conducted to compare the effects of soaking annual ryegrass straw in solutions of sodium hydroxide (Na₄OH), potassium hydroxide (KOH), ammonium hydroxide (NH₄OH), or sodium formate (NaCHO₂) at varying levels. Dry matter digestibility (DDM) was the criterion used to measure treatment response. A 3 x 3 Latin square designed lamb digestion trial, replicated three times, followed these screening trials. Its purpose was to study the effects that NaOH-treated straw had on animal health, feed and water intake, urine excretion and pH, apparent digestibility, nitrogen and energy utilization and sodium and potassium balances. Three feeding trials were also carried out to measure the performance of heifer calves fed untreated, but supplemented ryegrass straw based rations. A 3 x 3 Latin square designed sheep digestion trail supplied additional data on apparent digestibility and nitrogen and energy utilization for three of these rations. Spraying a two percent NaOH solution on straw did not significantly improve DDM while soaking at the same level produced a significant (P<.01) increase. There was no significant difference among particle sizes or treatment times for straw soaked in two percent NaOH. Two, four, six or eight percent levels of either NaOH₂ or KOH solutions significantly (P<.01) enhanced DDM. No significant improvement was noted above the eight percent level. NaCHO₂ significantly (P<.01) increased DDM above native straw, but higher treatment levels were necessary to achieve an equal magnitude of improvement than for NaOH. NH₄OH treatment produced variable results which could not be consistently repeated, but the crude protein (CP) content of treated straw was consistently increased. This was in contrast to NaOH soaking, which significantly (P< .01) degraded CP, acid detergent fiber (ADF) and acid detergent lignin (ADL) with each increase in level. All treatment combinations also produced significant (P< .01) cell wall constituents (CWC) declines below native straw. Straw treated on a solution basis was significantly (P< .01) higher in DDM than that treated on a dry matter basis. However, treated straw DDM was significantly (P< .01) greater in either case than that recorded for untreated straw. Draining off of the NaOH effluent prior to drying significantly (P< .01) reduced DDM. There was a trend for water soaking to depress DDM, but significance was not reached until samples were drained prior to drying. No detrimental effects were noted when lambs consumed unwashed NaOH-soaked straw. Daily dry matter (DM) intake per kg of body weight was significantly (P< .05) reduced for treated straw when compared to untreated. Increased water consumption and urninary excretion (P< .01) were evident when straw soaked in a one percent NaOH solution (ration three) was fed. Urine pH for sheep consuming straw treated on an eight percent dry matter basis (ration two) was significantly (P< .05) reduced below that recorded for urine from sheep fed the other two rations. However, none of the pH's were outside the normal range for ruminants. Treatment two significantly (P< .05) reduced apparent digestibilities for straw, DM, organic matter (OM), energy, CP, ash and cell contents below that for the other two treatments. Treatment three significantly (P< . 05) increased straw, ash, ADF, hemicellulose and CWC apparent digestibilities when compared to untreated straw (ration one). The digestibility of CP was significantly (P< .01) greater in the untreated straw ration. All sheep were in a positive nitrogen balance for the duration of the trials. There was no significant difference in nitrogen balance for lambs fed rations one and three. However, nitrogen retention for lambs receiving ration two was significantly (P< .05) depressed below the quantity retained by lambs on the other two rations. Ration three was clearly superior in terms of either percent nitrogen intake or percent of digested nitrogen. Untreated straw supported a statistically (P<.05) higher level of digestible energy per g DM intake than did either of the treated straw rations. Utilization of the gross energy of ration two was significantly (P< .05) less than that from the other two rations. Ration three supported lower average daily gains than the other two rations (P< .01). No definite conclusions can be drawn from the sodium and potassium balances. Evidently, sodium residue levels were not large enough to cause any problems as there were no observable side effects and potassium excretion was not increased. A series of feeding trials demonstrated that ryegrass straw can successfully comprise from 45 to 86% of a ration for growing heifers. Feeding value of the straw was improved to support gains from 0.38 kg to 0.80 kg per day by the use of a variety of feed ingredients that corrected the straw's deficiencies. Performance data suggested that the maximum level of urea that can be used in such high roughage rations is about 1.5%. Above this level gains and feed efficiency were depressed. Digestion trial data showed that DDM for untreated, supplemented straw was from 47.5 to 50. 4%. From 61.5 to 67.5% of the CP and 39.9 to 43.2% of the CWC was digestible. The CP was least digestible in the ration containing alfalfa. Nitrogen retention ranged from 6.1 to 7.1 g per day. The superior ration in this respect was ration 5, which contained whey. Close

• 2675. [Article] Factors affecting contraceptive use among women of reproductive age in northern Jordan : a framework for health policy action

  Jordan has a higher fertility rate (3.8) than the averages of countries similar in income to Jordan (2.2) and compared to the Middle East and North Africa region as a whole (2.8) (WHO, WB, UNICEF, & DHS, ...

  Citation × Citation Citation Abstract Copy Title: Factors affecting contraceptive use among women of reproductive age in northern Jordan : a framework for health policy action Author: Hijazi, Heba Hesham Jordan has a higher fertility rate (3.8) than the averages of countries similar in income to Jordan (2.2) and compared to the Middle East and North Africa region as a whole (2.8) (WHO, WB, UNICEF, & DHS, 2011). The findings of the 2009 Jordanian Population and Family Health Survey demonstrated that the total fertility rate (TFR) has stopped declining in the country since 2002 (DOS, 2010b; USAID, 2010). The prevalence of contraceptive use has also shown little change in Jordan over the last decade (DOS, 2010b; USAID, 2010). Given that contraception is one of the proximate determinants of fertility (Rahayu et al., 2009), the main purpose of this study was to investigate which factors are contributing to women's current contraceptive behavior and intention for future contraceptive use. Research questions were developed in a comprehensive framework that considers women's intention and actual behavior as outcomes of various interactive factors within a socio-cultural context. In particular, the study's framework was directed by a theoretical basis adapted from Ajzen and Fishbein's Theory of Reasoned Action (TRA) and an extensive review of the available literature in the research area. Obviously, the social set-up and cultural norms in the study setting, together with attitudes toward children and family, represent a traditional scenario that could help explain the consistency of fertility and contraceptive use in the country. Further, the influences of background characteristics on women's contraceptive behaviors and intentions provide another scenario that could help assess the current situation of family planning (FP) in Jordan. In this study, demographic factors, spousal communication variables and healthcare system-related factors are all defined as background characteristics. Attitudes and social norms reflect the women's behavioral determinants and represent the main constructs of the TRA. In fact, involving a set of factors related to women's beliefs and social norms in the study's framework provided an opportunity to explore how these factors might promote or inhibit a woman's intentions and behaviors in respect to contraceptive use. In a three-manuscript format, this research was designed to achieve a number of objectives. The first manuscript aimed at identifying the major factors associated with the current use of contraception among women of childbearing age in northern Jordan. The second manuscript focused on investigating the main factors that are associated with women's contraceptive method preference (e.g. the choice of modern contraceptives as effective methods in preventing pregnancy versus the choice of traditional contraceptives as methods with high failure rates). The third manuscript attempted to explore the key factors associated with women's intention for future contraceptive use since the existence of such an intention would consequently translate into an actual behavior later. In 2010, original cross-section data were collected by means of a face-to-face interview using a structured pre-tested survey. The study sample included women who were currently married and were between 18 and 49 years old. Applying a systematic random sampling procedure, all respondents were recruited from the waiting rooms of five randomly selected Maternal and Child Health (MCH) centers in the Governorate of Irbid, northern Jordan. Using a list provided by the Ministry of Health, all centers in the Governorate were stratified according to the region (urban vs. rural) and randomly selected in proportion to their number in each region. The final sample size for this research consisted of 536 women surveyed, giving a response rate of 92.4 percent. Utilizing logistic regression analyses, the results of the dissertation manuscripts indicate that women's behaviors and intentions toward the use of contraception are affected by a number of factors at the individual, familial and institutional levels. The findings that emerged from the three manuscripts provide health professionals and policy makers with important information to assist in the design of FP programs and campaigns aimed at increasing current contraceptive use, enhancing the adoption of modern contraception and motivating the intention for future contraceptive use. This research strongly suggests that health professionals develop health policies that both expand the availability of MCH centers and strengthen the role of healthcare providers to dispel the numerous rumors and misconceptions surrounding the use of contraceptives, particularly modern ones. Health workers at the MCH centers need to ensure that women have sufficient information about the benefits and side effects of different types of contraception by offering proper FP counseling. The messages that religious leaders can use in advocating for FP would also help make contraceptive use socially acceptable since their opinions are often followed by the majority. This would be a key step toward removing the barriers to contraceptive use. Moreover, to design effective FP interventions, planners should take into account women's attitudes toward the use of contraceptive methods and the components of those attitudes (e.g. women's approval of contraceptive use for birth spacing and perceptions regarding the value of large family sizes and the importance of having male children in Jordanian families). Title: Factors affecting contraceptive use among women of reproductive age in northern Jordan : a framework for health policy action Author: Hijazi, Heba Hesham Jordan has a higher fertility rate (3.8) than the averages of countries similar in income to Jordan (2.2) and compared to the Middle East and North Africa region as a whole (2.8) (WHO, WB, UNICEF, & DHS, 2011). The findings of the 2009 Jordanian Population and Family Health Survey demonstrated that the total fertility rate (TFR) has stopped declining in the country since 2002 (DOS, 2010b; USAID, 2010). The prevalence of contraceptive use has also shown little change in Jordan over the last decade (DOS, 2010b; USAID, 2010). Given that contraception is one of the proximate determinants of fertility (Rahayu et al., 2009), the main purpose of this study was to investigate which factors are contributing to women's current contraceptive behavior and intention for future contraceptive use. Research questions were developed in a comprehensive framework that considers women's intention and actual behavior as outcomes of various interactive factors within a socio-cultural context. In particular, the study's framework was directed by a theoretical basis adapted from Ajzen and Fishbein's Theory of Reasoned Action (TRA) and an extensive review of the available literature in the research area. Obviously, the social set-up and cultural norms in the study setting, together with attitudes toward children and family, represent a traditional scenario that could help explain the consistency of fertility and contraceptive use in the country. Further, the influences of background characteristics on women's contraceptive behaviors and intentions provide another scenario that could help assess the current situation of family planning (FP) in Jordan. In this study, demographic factors, spousal communication variables and healthcare system-related factors are all defined as background characteristics. Attitudes and social norms reflect the women's behavioral determinants and represent the main constructs of the TRA. In fact, involving a set of factors related to women's beliefs and social norms in the study's framework provided an opportunity to explore how these factors might promote or inhibit a woman's intentions and behaviors in respect to contraceptive use. In a three-manuscript format, this research was designed to achieve a number of objectives. The first manuscript aimed at identifying the major factors associated with the current use of contraception among women of childbearing age in northern Jordan. The second manuscript focused on investigating the main factors that are associated with women's contraceptive method preference (e.g. the choice of modern contraceptives as effective methods in preventing pregnancy versus the choice of traditional contraceptives as methods with high failure rates). The third manuscript attempted to explore the key factors associated with women's intention for future contraceptive use since the existence of such an intention would consequently translate into an actual behavior later. In 2010, original cross-section data were collected by means of a face-to-face interview using a structured pre-tested survey. The study sample included women who were currently married and were between 18 and 49 years old. Applying a systematic random sampling procedure, all respondents were recruited from the waiting rooms of five randomly selected Maternal and Child Health (MCH) centers in the Governorate of Irbid, northern Jordan. Using a list provided by the Ministry of Health, all centers in the Governorate were stratified according to the region (urban vs. rural) and randomly selected in proportion to their number in each region. The final sample size for this research consisted of 536 women surveyed, giving a response rate of 92.4 percent. Utilizing logistic regression analyses, the results of the dissertation manuscripts indicate that women's behaviors and intentions toward the use of contraception are affected by a number of factors at the individual, familial and institutional levels. The findings that emerged from the three manuscripts provide health professionals and policy makers with important information to assist in the design of FP programs and campaigns aimed at increasing current contraceptive use, enhancing the adoption of modern contraception and motivating the intention for future contraceptive use. This research strongly suggests that health professionals develop health policies that both expand the availability of MCH centers and strengthen the role of healthcare providers to dispel the numerous rumors and misconceptions surrounding the use of contraceptives, particularly modern ones. Health workers at the MCH centers need to ensure that women have sufficient information about the benefits and side effects of different types of contraception by offering proper FP counseling. The messages that religious leaders can use in advocating for FP would also help make contraceptive use socially acceptable since their opinions are often followed by the majority. This would be a key step toward removing the barriers to contraceptive use. Moreover, to design effective FP interventions, planners should take into account women's attitudes toward the use of contraceptive methods and the components of those attitudes (e.g. women's approval of contraceptive use for birth spacing and perceptions regarding the value of large family sizes and the importance of having male children in Jordanian families). Close

• 2676. [Article] The geology, geochronology, and geochemistry of the Kaskanak Batholith, and other late Cretaceous to Eocene magmatism at the Pebble porphyry Cu-Au-Mo deposit, SW Alaska

  The Pebble porphyry Cu-Au-Mo deposit in Alaska is one of the world's largest Cu-Au mineral resources. Late Cretaceous magmatic evolution in the Pebble district culminated with the intrusion of the Kaskanak ...

  Citation × Citation Citation Abstract Copy Title: The geology, geochronology, and geochemistry of the Kaskanak Batholith, and other late Cretaceous to Eocene magmatism at the Pebble porphyry Cu-Au-Mo deposit, SW Alaska Author: Olson, Nansen H. The Pebble porphyry Cu-Au-Mo deposit in Alaska is one of the world's largest Cu-Au mineral resources. Late Cretaceous magmatic evolution in the Pebble district culminated with the intrusion of the Kaskanak Batholith and associated porphyry copper-gold-molybdenum mineralization. The Kaskanak Batholith is a multiphase granodiorite intrusion with an estimated footprint of ≥150 km². The batholith is exposed at surface west of the deposit and lies at >600 m depth in the East Zone. The geology, geochemistry, and geochronology of the Pebble district intrusions were investigated to better understand the magmatic processes and their relationship to the formation of this giant ore deposit. The principal zones of mineralization in the Pebble district are the West Zone and East Zone, with prospects containing mineralized porphyry intrusions located at the 38 Zone, 308 Zone, and 65 Zone. Together, they constitute an estimated resource of 1.08 Bt of ore containing 36.5 Mt Cu, 2.54 Mt Mo, and 3340 M gm Au. The main and equigranular granodiorite phase of the Kaskanak Batholith forms a series of porphyritic cupolas along its roof. These cupolas are cross-cut by three distinct porphyry dike sets associated with mineralization in the district. These are: 1) a voluminous granodiorite porphyry plug in the East zone, 2) quartz granite porphyry dikes in the West Zone, East Zone, and 38 Zone, and 3) narrow leucocratic quartz granite porphyry dikes in the 38 Zone and 65 Zone. New SHRIMP-RG and LA-ICP-MS U-Pb analyses of zircon from 25 samples, together with previously published ages establish a period of 9 m.y. for Late Cretaceous magmatism in the district from 98 to 89 Ma. Pre-ore diorite, alkalic monzodiorite and monzonite porphyry intrusions, and granodiorite sills were emplaced between ~98-95 Ma; the main equigranular granodiorite was emplaced at ~91 Ma; and the younger mineralized porphyries were emplaced at ~90-89 Ma (e.g., 90.3±1.0 Ma, 89.4±1.4 Ma; 89.2±1.2 Ma for these porphyries, respectively). New recognition of pre-mineral and post-mineral andesite porphyry dikes are observed in the 1 Gold Zone, the 308 Zone, and in the East Zone. New U-Pb ages on the pre-mineral andesite porphyry dikes in the 308 Zone are 90.6±1.5 Ma and 91.1±1.2 Ma. Following the cessation of hydrothermal activity, the area was magmatically quiescent until the end of the Cretaceous. The age of renewed magmatism is established by new U-Pb age determinations of dacite and andesite dikes of 63.9±1.0 Ma and 65.9±1.4 Ma, respectively. These dikes cross-cut mineralization in the East Zone, but are eroded by a Paleocene erosional unconformity. The maximum age of the erosional unconformity is constrained by the 11 youngest detrital zircons from a sample of basal conglomerates of the Copper Lake Formation that immediately overlies the unconformity (e.g., 61.2±0.8 Ma). Based on petrographic and geochemical evidence, the Kaskanak Batholith was apparently more oxidized and hydrous than earlier local intrusions that predate mineralization. The Kaskanak Batholith is characterized by high ratios of whole rock V/Sc (up to 160), zircon Eu/Eu[subscript CN]* (>0.4) and zircon Ce/Nd[subscript CN] (>40). Zircon trace element compositions of the Kaskanak Batholith are distinct from pre-ore or post-ore Paleocene-Eocene intrusions. Ti-in-zircon geothermometry indicates pre-ore intrusions were hotter (~750-940° C) than Kaskanak Batholith phases (~685-760° C). Zircon Ce/Ce[subscript CN]* and Eu/Eu[subscript CN]* values are elevated in all phases of the Kaskanak Batholith as well as in pre-ore granodiorite sills, and within some zircons of late monzonite porphyry dikes, which reflects an increase in ƒO₂ and H₂O content from early pre-ore intrusions to emplacement of the Kaskanak Batholith. Investigation of apatite SO₃ and halogen concentrations suggest that the Kaskanak Granodiorite melt initially contained 0.1-0.3 wt. % SO₃ and had initial Cl/H₂O ratios of 0.3-0.6. The presence of SO₃-rich apatites hosted in primary biotite, occasionally in magnetite, and commonly within interstitial quartz and K-feldspar was observed. These sulfur-rich apatites may have crystallized from hot andesitic melts that subsequently mixed with the Kaskanak Granodiorite, or by breakdown and release of magmatic anhydrite upon volatile exsolution, or a combination of both. Mafic enclaves have been observed locally within the Kaskanak Granodiorite, but observed andesitic melts in the district make up much less than a fraction of a percent of the volume of the Kaskanak Batholith. On the basis of whole rock major and trace element compositions, the Kaskanak Batholith likely differentiated from hydrous and oxidized calc-alkaline andesitic melts. Compositions of andesitic porphyries from the 1 Gold Zone are inferred to represent parental melt compositions. Raleigh fractionation modeling suggests the Kaskanak Granodiorite can be produced by 10-12 wt. % crystal fractionation of amphibole, biotite, magnetite, apatite, and zircon, and the evolved porphyry dikes could have been produced by an additional 10-14 wt. % fractionation of amphibole, titanite, apatite, and zircon. Titanite fractionation at relatively low temperatures was apparently important for sharply depleting evolved porphyry melts of REEs, Nb, and Ta. Jurassic to Eocene age Pebble district intrusions of basaltic to granitic compositions, all have non-radiogenic initial isotopic signatures (⁸⁷Sr/⁸⁶Sr[subscript i] = 0.70329 - 0.70424 and ¹⁴³Nd/¹⁴⁴Nd[subscript i] = 0.51278 - 0.51284 (ƐNdi = +4.9 - +6.1); t = 180, 90, & 65 Ma) reflecting the age and bulk composition of the crustal section. These intrusions are interpreted to have been derived from homogenous shoshonitic and calc-alkaline andesites parental melts generated by melting of the mantle wedge and overlying lower crust yielding similar Sr and Nd isotopic compositions to those of the Peninsular Terrane in the Talkeetna Mountains. Xenocrystic zircon from Pebble district intrusions were derived primarily from the Kahiltna Basin sediments upon emplacement, but a greater component of Paleozoic and Proterozoic grains have also been observed that are unlikely derived in whole from the Kahiltna Basin sediments, consistent with xenocrystic zircons found in some Talkeetna Arc volcanics along the Alaska Peninsula that pre-date the formation of the Kahiltna Basin sediments. These zircons may have been derived from late Triassic - early Jurassic metamorphosed sediments and volcanics that predate Talkeetna Arc magmatism. During the lifespan of the Kaskanak Batholith, it is estimated that ~2 km of cover rocks were unroofed which produced telescoping advanced argillic ledges on top of potassic alteration in the East Zone. By latest Late Cretaceous – Paleocene time (~67-58 Ma), an additional ~2.5 km were rapidly eroded and subsequently buried by volcanoclastic rocks and tuff deposits of the Copper Lake Formation, which may have been initiated by the subduction of the Kula-Farallon mid-ocean ridge. The bulk of the displacement of the ZG Fault that down-dropped high-grade copper ore in the East Graben likely occurred at this time, and much of the mineralized advanced argillic alteration and epithermal-style mineralization overlying the Pebble deposit had been removed. Subsequent eastward Eocene - Quaternary tilting (~20°) has exposed the Kaskanak Batholith to the bedrock surface at Kaskanak Mountain and in the West Zone. Title: The geology, geochronology, and geochemistry of the Kaskanak Batholith, and other late Cretaceous to Eocene magmatism at the Pebble porphyry Cu-Au-Mo deposit, SW Alaska Author: Olson, Nansen H. The Pebble porphyry Cu-Au-Mo deposit in Alaska is one of the world's largest Cu-Au mineral resources. Late Cretaceous magmatic evolution in the Pebble district culminated with the intrusion of the Kaskanak Batholith and associated porphyry copper-gold-molybdenum mineralization. The Kaskanak Batholith is a multiphase granodiorite intrusion with an estimated footprint of ≥150 km². The batholith is exposed at surface west of the deposit and lies at >600 m depth in the East Zone. The geology, geochemistry, and geochronology of the Pebble district intrusions were investigated to better understand the magmatic processes and their relationship to the formation of this giant ore deposit. The principal zones of mineralization in the Pebble district are the West Zone and East Zone, with prospects containing mineralized porphyry intrusions located at the 38 Zone, 308 Zone, and 65 Zone. Together, they constitute an estimated resource of 1.08 Bt of ore containing 36.5 Mt Cu, 2.54 Mt Mo, and 3340 M gm Au. The main and equigranular granodiorite phase of the Kaskanak Batholith forms a series of porphyritic cupolas along its roof. These cupolas are cross-cut by three distinct porphyry dike sets associated with mineralization in the district. These are: 1) a voluminous granodiorite porphyry plug in the East zone, 2) quartz granite porphyry dikes in the West Zone, East Zone, and 38 Zone, and 3) narrow leucocratic quartz granite porphyry dikes in the 38 Zone and 65 Zone. New SHRIMP-RG and LA-ICP-MS U-Pb analyses of zircon from 25 samples, together with previously published ages establish a period of 9 m.y. for Late Cretaceous magmatism in the district from 98 to 89 Ma. Pre-ore diorite, alkalic monzodiorite and monzonite porphyry intrusions, and granodiorite sills were emplaced between ~98-95 Ma; the main equigranular granodiorite was emplaced at ~91 Ma; and the younger mineralized porphyries were emplaced at ~90-89 Ma (e.g., 90.3±1.0 Ma, 89.4±1.4 Ma; 89.2±1.2 Ma for these porphyries, respectively). New recognition of pre-mineral and post-mineral andesite porphyry dikes are observed in the 1 Gold Zone, the 308 Zone, and in the East Zone. New U-Pb ages on the pre-mineral andesite porphyry dikes in the 308 Zone are 90.6±1.5 Ma and 91.1±1.2 Ma. Following the cessation of hydrothermal activity, the area was magmatically quiescent until the end of the Cretaceous. The age of renewed magmatism is established by new U-Pb age determinations of dacite and andesite dikes of 63.9±1.0 Ma and 65.9±1.4 Ma, respectively. These dikes cross-cut mineralization in the East Zone, but are eroded by a Paleocene erosional unconformity. The maximum age of the erosional unconformity is constrained by the 11 youngest detrital zircons from a sample of basal conglomerates of the Copper Lake Formation that immediately overlies the unconformity (e.g., 61.2±0.8 Ma). Based on petrographic and geochemical evidence, the Kaskanak Batholith was apparently more oxidized and hydrous than earlier local intrusions that predate mineralization. The Kaskanak Batholith is characterized by high ratios of whole rock V/Sc (up to 160), zircon Eu/Eu[subscript CN]* (>0.4) and zircon Ce/Nd[subscript CN] (>40). Zircon trace element compositions of the Kaskanak Batholith are distinct from pre-ore or post-ore Paleocene-Eocene intrusions. Ti-in-zircon geothermometry indicates pre-ore intrusions were hotter (~750-940° C) than Kaskanak Batholith phases (~685-760° C). Zircon Ce/Ce[subscript CN]* and Eu/Eu[subscript CN]* values are elevated in all phases of the Kaskanak Batholith as well as in pre-ore granodiorite sills, and within some zircons of late monzonite porphyry dikes, which reflects an increase in ƒO₂ and H₂O content from early pre-ore intrusions to emplacement of the Kaskanak Batholith. Investigation of apatite SO₃ and halogen concentrations suggest that the Kaskanak Granodiorite melt initially contained 0.1-0.3 wt. % SO₃ and had initial Cl/H₂O ratios of 0.3-0.6. The presence of SO₃-rich apatites hosted in primary biotite, occasionally in magnetite, and commonly within interstitial quartz and K-feldspar was observed. These sulfur-rich apatites may have crystallized from hot andesitic melts that subsequently mixed with the Kaskanak Granodiorite, or by breakdown and release of magmatic anhydrite upon volatile exsolution, or a combination of both. Mafic enclaves have been observed locally within the Kaskanak Granodiorite, but observed andesitic melts in the district make up much less than a fraction of a percent of the volume of the Kaskanak Batholith. On the basis of whole rock major and trace element compositions, the Kaskanak Batholith likely differentiated from hydrous and oxidized calc-alkaline andesitic melts. Compositions of andesitic porphyries from the 1 Gold Zone are inferred to represent parental melt compositions. Raleigh fractionation modeling suggests the Kaskanak Granodiorite can be produced by 10-12 wt. % crystal fractionation of amphibole, biotite, magnetite, apatite, and zircon, and the evolved porphyry dikes could have been produced by an additional 10-14 wt. % fractionation of amphibole, titanite, apatite, and zircon. Titanite fractionation at relatively low temperatures was apparently important for sharply depleting evolved porphyry melts of REEs, Nb, and Ta. Jurassic to Eocene age Pebble district intrusions of basaltic to granitic compositions, all have non-radiogenic initial isotopic signatures (⁸⁷Sr/⁸⁶Sr[subscript i] = 0.70329 - 0.70424 and ¹⁴³Nd/¹⁴⁴Nd[subscript i] = 0.51278 - 0.51284 (ƐNdi = +4.9 - +6.1); t = 180, 90, & 65 Ma) reflecting the age and bulk composition of the crustal section. These intrusions are interpreted to have been derived from homogenous shoshonitic and calc-alkaline andesites parental melts generated by melting of the mantle wedge and overlying lower crust yielding similar Sr and Nd isotopic compositions to those of the Peninsular Terrane in the Talkeetna Mountains. Xenocrystic zircon from Pebble district intrusions were derived primarily from the Kahiltna Basin sediments upon emplacement, but a greater component of Paleozoic and Proterozoic grains have also been observed that are unlikely derived in whole from the Kahiltna Basin sediments, consistent with xenocrystic zircons found in some Talkeetna Arc volcanics along the Alaska Peninsula that pre-date the formation of the Kahiltna Basin sediments. These zircons may have been derived from late Triassic - early Jurassic metamorphosed sediments and volcanics that predate Talkeetna Arc magmatism. During the lifespan of the Kaskanak Batholith, it is estimated that ~2 km of cover rocks were unroofed which produced telescoping advanced argillic ledges on top of potassic alteration in the East Zone. By latest Late Cretaceous – Paleocene time (~67-58 Ma), an additional ~2.5 km were rapidly eroded and subsequently buried by volcanoclastic rocks and tuff deposits of the Copper Lake Formation, which may have been initiated by the subduction of the Kula-Farallon mid-ocean ridge. The bulk of the displacement of the ZG Fault that down-dropped high-grade copper ore in the East Graben likely occurred at this time, and much of the mineralized advanced argillic alteration and epithermal-style mineralization overlying the Pebble deposit had been removed. Subsequent eastward Eocene - Quaternary tilting (~20°) has exposed the Kaskanak Batholith to the bedrock surface at Kaskanak Mountain and in the West Zone. Close

• 2677. [Article] Forestry

  Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2013. All rights reserved.

  Citation × Citation Citation Abstract Copy Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2013. All rights reserved. Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2013. All rights reserved. Close

• 2678. [Article] Range-use estimation and encounter probability for juvenile Steller sea lions (Eumetopias jubatus) in the Prince William Sound-Kenai Fjords region of Alaska

  Range, areas of concentrated activity, and dispersal characteristics for juvenile Steller sea lions Eumetopias jubatus in the endangered western population (west of 144° W in the Gulf of Alaska) are poorly ...

  Citation × Citation Citation Abstract Copy Title: Range-use estimation and encounter probability for juvenile Steller sea lions (Eumetopias jubatus) in the Prince William Sound-Kenai Fjords region of Alaska Author: Meck, Stephen R. Range, areas of concentrated activity, and dispersal characteristics for juvenile Steller sea lions Eumetopias jubatus in the endangered western population (west of 144° W in the Gulf of Alaska) are poorly understood. This study quantified space use by analyzing post-release telemetric tracking data from satellite transmitters externally attached to n = 65 juvenile (12-25 months; 72.5 to 197.6 kg) Steller sea lions (SSLs) captured in Prince William Sound (60°38'N -147°8'W) or Resurrection Bay (60°2'N -149°22'W), Alaska, from 2003-2011. The analysis divided the sample population into 3 separate groups to quantify differences in distribution and movement. These groups included sex, the season when collected, and the release type (free ranging animals which were released immediately at the site of capture, and transient juveniles which were kept in captivity for up to 12 weeks as part of a larger ongoing research program). Range-use was first estimated by using the minimum convex polygon (MCP) approach, and then followed with a probabilistic kernel density estimation (KDE) to evaluate both individual and group utilization distributions (UDs). The LCV method was chosen as the smoothing algorithm for the KDE analysis as it provided biologically meaningful results pertaining to areas of concentrated activity (generally, haulout locations). The average distance traveled by study juveniles was 2,131 ± 424 km. The animals mass at release (F[subscript 1, 63] = 1.17, p = 0.28) and age (F[subscript 1, 63] = 0.033, p = 0.86) were not significant predictors of travel distance. Initial MCP results indicated the total area encompassed by all study SSLs was 92,017 km², excluding land mass. This area was heavily influenced by the only individual that crossed over the 144°W Meridian, the dividing line between the two distinct population segments. Without this individual, the remainder of the population (n = 64) fell into an area of 58,898 km². The MCP area was highly variable, with a geometric average of 1,623.6 km². Only the groups differentiated by season displayed any significant difference in area size, with the Spring/Summer (SS) groups MCP area (Mdn = 869.7 km²) being significantly less than that of the Fall/Winter (FW) group (Mdn = 3,202.2 km²), U = 330, p = 0.012, r = -0.31. This result was not related to the length of time the tag transmitted (H(2) = 49.65, p = 0.527), nor to the number of location fixes (H(2) = 62.77, p = 0.449). The KDE UD was less variable, with 50% of the population within a range of 324-1,387 km2 (mean=690.6 km²). There were no significant differences in area use associated with sex or release type (seasonally adjusted U = 124, p = 0.205, r = -0.16 and U = 87, p = 0.285, r = -0.13, respectively). However, there were significant differences in seasonal area use: U = 328, p = 0.011, r = -0.31. There was no relationship between the UD area and the amount of time the tag remained deployed (H(2) = 45.30, p = 0.698). The kernel home range (defined as 95% of space use) represented about 52.1% of the MCP range use, with areas designated as "core" (areas where the sea lions spent fully 50% of their time) making up only about 6.27% of the entire MCP range and about 11.8% of the entire kernel home range. Area use was relatively limited – at the population level, there were a total of 6 core areas which comprised 479 km². Core areas spanned a distance of less than 200 km from the most western point at the Chiswell Islands (59°35'N -149°36'W) to the most eastern point at Glacier Island (60°54'N -147°6'W). The observed differences in area use between seasons suggest a disparity in how juvenile SSLs utilize space and distribute themselves over the course of the year. Due to their age, this variation is less likely due to reproductive considerations and may reflect localized depletion of prey near preferred haul-out sites and/or changes in predation risk. Currently, management of the endangered western and threatened eastern population segments of the Steller sea lion are largely based on population trends derived from aerial survey counts and terrestrial-based count data. The likelihood of individuals to be detected during aerial surveys, and resulting correction factors to calculate overall population size from counts of hauled-out animals remain unknown. A kernel density estimation (KDE) analysis was performed to delineate boundaries around surveyed haulout locations within Prince William Sound-Kenai Fjords (PWS-KF). To closely approximate the time in which population abundance counts are conducted, only sea lions tracked during the spring/summer (SS) months (May 10-August 10) were chosen (n = 35). A multiple state model was constructed treating the satellite location data, if it fell within a specified spatiotemporal context, as a re-encounter within a mark-recapture framework. Information to determine a dry state was obtained from the tags time-at-depth (TAD) histograms. To generate an overall terrestrial detection probability 1) The animal must have been within a KDE derived core-area that coincided with a surveyed haulout site 2) it must have been dry and 3) it must have provided at least one position during the summer months, from roughly 11:00 AM-5:00 PM AKDT. A total of 10 transition states were selected from the data. Nine states corresponded to specific surveyed land locations, with the 10th, an "at-sea" location (> 3 km from land) included as a proxy for foraging behavior. A MLogit constraint was used to aid interpretation of the multi-modal likelihood surface, and a systematic model selection process employed as outlined by Lebreton & Pradel (2002). At the individual level, the juveniles released in the spring/summer months (n = 35) had 85.3% of the surveyed haulouts within PWS-KF encompass KDE-derived core areas (defined as 50% of space use). There was no difference in the number of surveyed haulouts encompassed by core areas between sexes (F[subscript 1, 33] << 0.001, p = 0.98). For animals held captive for up to 12 weeks, 33.3% returned to the original capture site. The majority of encounter probabilities (p) fell between 0.42 and 0.78 for the selected haulouts within PWS, with the exceptions being Grotto Island and Aialik Cape, which were lower (between 0.00-0.17). The at-sea (foraging) encounter probability was 0.66 (± 1 S.E. range 0.55-0.77). Most dry state probabilities fell between 0.08-0.38, with Glacier Island higher at 0.52, ± 1 S.E. range 0.49-0.55. The combined detection probability for hauled-out animals (the product of at haul-out and dry state probabilities), fell mostly between 0.08-0.28, with a distinct group (which included Grotto Island, Aialik Cape, and Procession Rocks) having values that averaged 0.01, with a cumulative range of ≈ 0.00-0.02 (± 1 S.E.). Due to gaps present within the mark-recapture data, it was not possible to run a goodness-of-fit test to validate model fit. Therefore, actual errors probably slightly exceed the reported standard errors and provide an approximation of uncertainties. Overall, the combined detection probabilities represent an effort to combine satellite location and wet-dry state telemetry and a kernel density analysis to quantify the terrestrial detection probability of a marine mammal within a multistate modeling framework, with the ultimate goal of developing a correction factor to account for haulout behavior at each of the surveyed locations included in the study. Title: Range-use estimation and encounter probability for juvenile Steller sea lions (Eumetopias jubatus) in the Prince William Sound-Kenai Fjords region of Alaska Author: Meck, Stephen R. Range, areas of concentrated activity, and dispersal characteristics for juvenile Steller sea lions Eumetopias jubatus in the endangered western population (west of 144° W in the Gulf of Alaska) are poorly understood. This study quantified space use by analyzing post-release telemetric tracking data from satellite transmitters externally attached to n = 65 juvenile (12-25 months; 72.5 to 197.6 kg) Steller sea lions (SSLs) captured in Prince William Sound (60°38'N -147°8'W) or Resurrection Bay (60°2'N -149°22'W), Alaska, from 2003-2011. The analysis divided the sample population into 3 separate groups to quantify differences in distribution and movement. These groups included sex, the season when collected, and the release type (free ranging animals which were released immediately at the site of capture, and transient juveniles which were kept in captivity for up to 12 weeks as part of a larger ongoing research program). Range-use was first estimated by using the minimum convex polygon (MCP) approach, and then followed with a probabilistic kernel density estimation (KDE) to evaluate both individual and group utilization distributions (UDs). The LCV method was chosen as the smoothing algorithm for the KDE analysis as it provided biologically meaningful results pertaining to areas of concentrated activity (generally, haulout locations). The average distance traveled by study juveniles was 2,131 ± 424 km. The animals mass at release (F[subscript 1, 63] = 1.17, p = 0.28) and age (F[subscript 1, 63] = 0.033, p = 0.86) were not significant predictors of travel distance. Initial MCP results indicated the total area encompassed by all study SSLs was 92,017 km², excluding land mass. This area was heavily influenced by the only individual that crossed over the 144°W Meridian, the dividing line between the two distinct population segments. Without this individual, the remainder of the population (n = 64) fell into an area of 58,898 km². The MCP area was highly variable, with a geometric average of 1,623.6 km². Only the groups differentiated by season displayed any significant difference in area size, with the Spring/Summer (SS) groups MCP area (Mdn = 869.7 km²) being significantly less than that of the Fall/Winter (FW) group (Mdn = 3,202.2 km²), U = 330, p = 0.012, r = -0.31. This result was not related to the length of time the tag transmitted (H(2) = 49.65, p = 0.527), nor to the number of location fixes (H(2) = 62.77, p = 0.449). The KDE UD was less variable, with 50% of the population within a range of 324-1,387 km2 (mean=690.6 km²). There were no significant differences in area use associated with sex or release type (seasonally adjusted U = 124, p = 0.205, r = -0.16 and U = 87, p = 0.285, r = -0.13, respectively). However, there were significant differences in seasonal area use: U = 328, p = 0.011, r = -0.31. There was no relationship between the UD area and the amount of time the tag remained deployed (H(2) = 45.30, p = 0.698). The kernel home range (defined as 95% of space use) represented about 52.1% of the MCP range use, with areas designated as "core" (areas where the sea lions spent fully 50% of their time) making up only about 6.27% of the entire MCP range and about 11.8% of the entire kernel home range. Area use was relatively limited – at the population level, there were a total of 6 core areas which comprised 479 km². Core areas spanned a distance of less than 200 km from the most western point at the Chiswell Islands (59°35'N -149°36'W) to the most eastern point at Glacier Island (60°54'N -147°6'W). The observed differences in area use between seasons suggest a disparity in how juvenile SSLs utilize space and distribute themselves over the course of the year. Due to their age, this variation is less likely due to reproductive considerations and may reflect localized depletion of prey near preferred haul-out sites and/or changes in predation risk. Currently, management of the endangered western and threatened eastern population segments of the Steller sea lion are largely based on population trends derived from aerial survey counts and terrestrial-based count data. The likelihood of individuals to be detected during aerial surveys, and resulting correction factors to calculate overall population size from counts of hauled-out animals remain unknown. A kernel density estimation (KDE) analysis was performed to delineate boundaries around surveyed haulout locations within Prince William Sound-Kenai Fjords (PWS-KF). To closely approximate the time in which population abundance counts are conducted, only sea lions tracked during the spring/summer (SS) months (May 10-August 10) were chosen (n = 35). A multiple state model was constructed treating the satellite location data, if it fell within a specified spatiotemporal context, as a re-encounter within a mark-recapture framework. Information to determine a dry state was obtained from the tags time-at-depth (TAD) histograms. To generate an overall terrestrial detection probability 1) The animal must have been within a KDE derived core-area that coincided with a surveyed haulout site 2) it must have been dry and 3) it must have provided at least one position during the summer months, from roughly 11:00 AM-5:00 PM AKDT. A total of 10 transition states were selected from the data. Nine states corresponded to specific surveyed land locations, with the 10th, an "at-sea" location (> 3 km from land) included as a proxy for foraging behavior. A MLogit constraint was used to aid interpretation of the multi-modal likelihood surface, and a systematic model selection process employed as outlined by Lebreton & Pradel (2002). At the individual level, the juveniles released in the spring/summer months (n = 35) had 85.3% of the surveyed haulouts within PWS-KF encompass KDE-derived core areas (defined as 50% of space use). There was no difference in the number of surveyed haulouts encompassed by core areas between sexes (F[subscript 1, 33] << 0.001, p = 0.98). For animals held captive for up to 12 weeks, 33.3% returned to the original capture site. The majority of encounter probabilities (p) fell between 0.42 and 0.78 for the selected haulouts within PWS, with the exceptions being Grotto Island and Aialik Cape, which were lower (between 0.00-0.17). The at-sea (foraging) encounter probability was 0.66 (± 1 S.E. range 0.55-0.77). Most dry state probabilities fell between 0.08-0.38, with Glacier Island higher at 0.52, ± 1 S.E. range 0.49-0.55. The combined detection probability for hauled-out animals (the product of at haul-out and dry state probabilities), fell mostly between 0.08-0.28, with a distinct group (which included Grotto Island, Aialik Cape, and Procession Rocks) having values that averaged 0.01, with a cumulative range of ≈ 0.00-0.02 (± 1 S.E.). Due to gaps present within the mark-recapture data, it was not possible to run a goodness-of-fit test to validate model fit. Therefore, actual errors probably slightly exceed the reported standard errors and provide an approximation of uncertainties. Overall, the combined detection probabilities represent an effort to combine satellite location and wet-dry state telemetry and a kernel density analysis to quantify the terrestrial detection probability of a marine mammal within a multistate modeling framework, with the ultimate goal of developing a correction factor to account for haulout behavior at each of the surveyed locations included in the study. Close