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• 2761. [Article] Vertebral elemental markers in elasmobranchs : potential for reconstructing environmental history and population structure

  Differences in the chemical composition of calcified structures can be used to reveal natal origins, connectivity, metapopulation structure, and reconstruct the environmental history or movement patterns ...

  Citation × Citation Citation Abstract Copy Title: Vertebral elemental markers in elasmobranchs : potential for reconstructing environmental history and population structure Author: Smith, Wade D. Differences in the chemical composition of calcified structures can be used to reveal natal origins, connectivity, metapopulation structure, and reconstruct the environmental history or movement patterns of many marine organisms. Sharks, skates, and rays (elasmobranchs) lack the calcified structures, known as otoliths, that are typically used for geochemical studies of dispersal and natal origin in fishes. If the incorporation of elements into shark and ray vertebrae is related to environmental conditions, the geochemical composition of cartilaginous vertebrae may also serve as natural tags and records of environmental history in elasmobranch populations. I used complementary laboratory and field studies to address several key assumptions regarding the incorporation of elements in elasmobranch vertebrae, providing the first detailed studies to assess relationships between water and vertebral chemical composition and the spatial and temporal variation of vertebral elemental signatures in this subclass of fishes. To validate the uptake and incorporation of elements from water to vertebrae, I conducted two laboratory studies using round stingrays, Urobatis halleri, as a model species. First, I examined the effects of temperature (16°, 18°, 24° C) on vertebral elemental incorporation (Li/Ca, Mg/Ca, Mn/Ca, Zn/Ca, Sr/Ca, Ba/Ca) and found that temperature had strong, negative effects on the uptake (measured as a partition coefficient, D[subscript Element]) of magnesium and Ba and positively influenced manganese incorporation. Second, I tested the relationship between water and vertebral elemental composition by manipulating dissolved barium (Ba) concentrations (1x, 3x, 6x ambient concentrations) and found significant differences among rays from each treament. I also evaluated the influence of natural variation in somatic growth and vertebral precipitation rates on elemental incorporation. Finally, I examined the accuracy of classifying individuals to known environmental histories (temperature and barium treatments) using vertebral elemental composition. There were no significant relationships between elemental incorporation and somatic growth or vertebral precipitation rates for any elements with the exception of Zn. Relationships between somatic growth rate and D[subscript Zn] were, however, inconsistent and inconclusive. Elemental variation of vertebrae reliably distinguished U. halleri based on temperature (85%) and [Ba] (96%) history. These results support the assumption that vertebral elemental composition reflects the environmental conditions during deposition and validates the use of vertebral elemental signatures as natural markers in an elasmobranch. To evaluate the utility of vertebral geochemistry as intrinsic markers of natal origin, I collected vertebrae of young-of-the-year scalloped hammerhead sharks (Sphyrna lewini) from artisanal fishery landings at six sites along the Pacific coast of Mexico and Costa Rica between 2007-2009. A total of 386 vertebrae were used to assess patterns of spatial and temporal variation in elemental composition using laser ablation-inductively coupled plasma mass spectrometry. A protracted pupping period was confirmed for S. lewini, with newborn pups being recorded from May through mid-October. Natal elemental signatures detected in the vertebrae of the sharks varied significantly among sites and could be used to identify source populations. All element-to-calcium ratios included in these analyses (Li/Ca, Mg/Ca, V/Ca, Cr/Ca, Mn/Ca, Rb/Ca, Sr/Ca, Ba/Ca, Pb/Ca) were useful for the discerning natal origins of sharks; however, Ba, Sr, Mn, and Mg ratios most consistently generated the greatest discriminatory power based on step-wise discriminant function analyses. Classification accuracy to putative nursery areas (natal signature) and location of capture (edge signature) based on step-wise discriminant function analysis ranged from low (30-60%) to high (80-100%) depending on the degree of spatial and temporal resolution by which the data were filtered for analysis (e.g. pooled across months, early season, late season). All classification accuracies exceeded chance expectations and assignment to putative nursery areas and sites of capture were accomplished with up to 100% accuracy in several models. I found significant intra-annual differences in natal elemental signatures within the three primary study sites, which likely contributed to the low assignment accuracies when data were grouped across months of collection. Significant differences in natal elemental signatures were also detected across years. However, pair-wise analyses revealed that site-specific inter-annual variation was driven by differences associated with samples collected in 2009. Natal elemental signatures were similar between 2007 and 2009, indicating some consistency in site-specific vertebral chemistry across years. These results confirmed that vertebral elemental signatures can be applied to distinguish individuals across small (5s km), moderate (100s km), and large spatial scales (>1000 km). The potential for intra-annual variation in natal signatures within a year-class highlights the importance of cohort-specific analyses and the development of a spatial atlas of natal vertebral elemental signatures for studies of natal origin and population connectivity. The findings of my laboratory validation experiments and field study establish that geochemical analyses of vertebrae can provide reliable information on the spatial ecology and environmental history of shark and ray populations. The use of elemental signatures offers a new approach for the study and conservation of this historically vulnerable group of fishes. Title: Vertebral elemental markers in elasmobranchs : potential for reconstructing environmental history and population structure Author: Smith, Wade D. Differences in the chemical composition of calcified structures can be used to reveal natal origins, connectivity, metapopulation structure, and reconstruct the environmental history or movement patterns of many marine organisms. Sharks, skates, and rays (elasmobranchs) lack the calcified structures, known as otoliths, that are typically used for geochemical studies of dispersal and natal origin in fishes. If the incorporation of elements into shark and ray vertebrae is related to environmental conditions, the geochemical composition of cartilaginous vertebrae may also serve as natural tags and records of environmental history in elasmobranch populations. I used complementary laboratory and field studies to address several key assumptions regarding the incorporation of elements in elasmobranch vertebrae, providing the first detailed studies to assess relationships between water and vertebral chemical composition and the spatial and temporal variation of vertebral elemental signatures in this subclass of fishes. To validate the uptake and incorporation of elements from water to vertebrae, I conducted two laboratory studies using round stingrays, Urobatis halleri, as a model species. First, I examined the effects of temperature (16°, 18°, 24° C) on vertebral elemental incorporation (Li/Ca, Mg/Ca, Mn/Ca, Zn/Ca, Sr/Ca, Ba/Ca) and found that temperature had strong, negative effects on the uptake (measured as a partition coefficient, D[subscript Element]) of magnesium and Ba and positively influenced manganese incorporation. Second, I tested the relationship between water and vertebral elemental composition by manipulating dissolved barium (Ba) concentrations (1x, 3x, 6x ambient concentrations) and found significant differences among rays from each treament. I also evaluated the influence of natural variation in somatic growth and vertebral precipitation rates on elemental incorporation. Finally, I examined the accuracy of classifying individuals to known environmental histories (temperature and barium treatments) using vertebral elemental composition. There were no significant relationships between elemental incorporation and somatic growth or vertebral precipitation rates for any elements with the exception of Zn. Relationships between somatic growth rate and D[subscript Zn] were, however, inconsistent and inconclusive. Elemental variation of vertebrae reliably distinguished U. halleri based on temperature (85%) and [Ba] (96%) history. These results support the assumption that vertebral elemental composition reflects the environmental conditions during deposition and validates the use of vertebral elemental signatures as natural markers in an elasmobranch. To evaluate the utility of vertebral geochemistry as intrinsic markers of natal origin, I collected vertebrae of young-of-the-year scalloped hammerhead sharks (Sphyrna lewini) from artisanal fishery landings at six sites along the Pacific coast of Mexico and Costa Rica between 2007-2009. A total of 386 vertebrae were used to assess patterns of spatial and temporal variation in elemental composition using laser ablation-inductively coupled plasma mass spectrometry. A protracted pupping period was confirmed for S. lewini, with newborn pups being recorded from May through mid-October. Natal elemental signatures detected in the vertebrae of the sharks varied significantly among sites and could be used to identify source populations. All element-to-calcium ratios included in these analyses (Li/Ca, Mg/Ca, V/Ca, Cr/Ca, Mn/Ca, Rb/Ca, Sr/Ca, Ba/Ca, Pb/Ca) were useful for the discerning natal origins of sharks; however, Ba, Sr, Mn, and Mg ratios most consistently generated the greatest discriminatory power based on step-wise discriminant function analyses. Classification accuracy to putative nursery areas (natal signature) and location of capture (edge signature) based on step-wise discriminant function analysis ranged from low (30-60%) to high (80-100%) depending on the degree of spatial and temporal resolution by which the data were filtered for analysis (e.g. pooled across months, early season, late season). All classification accuracies exceeded chance expectations and assignment to putative nursery areas and sites of capture were accomplished with up to 100% accuracy in several models. I found significant intra-annual differences in natal elemental signatures within the three primary study sites, which likely contributed to the low assignment accuracies when data were grouped across months of collection. Significant differences in natal elemental signatures were also detected across years. However, pair-wise analyses revealed that site-specific inter-annual variation was driven by differences associated with samples collected in 2009. Natal elemental signatures were similar between 2007 and 2009, indicating some consistency in site-specific vertebral chemistry across years. These results confirmed that vertebral elemental signatures can be applied to distinguish individuals across small (5s km), moderate (100s km), and large spatial scales (>1000 km). The potential for intra-annual variation in natal signatures within a year-class highlights the importance of cohort-specific analyses and the development of a spatial atlas of natal vertebral elemental signatures for studies of natal origin and population connectivity. The findings of my laboratory validation experiments and field study establish that geochemical analyses of vertebrae can provide reliable information on the spatial ecology and environmental history of shark and ray populations. The use of elemental signatures offers a new approach for the study and conservation of this historically vulnerable group of fishes. Close

• 2762. [Article] Evaluating the data-poor fishery stock assessment method, DB-SRA

  Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. ...

  Citation × Citation Citation Abstract Copy Title: Evaluating the data-poor fishery stock assessment method, DB-SRA Author: Owashi, Brandon R. Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per annum, rate of natural mortality (M), age at 50% maturity, F[subscript MSY]/M, B[subscriptMSY]/B₀, and the predicted depletion of the stock from its unfished condition. F[subscriptMSY]/M is the rate of fishing mortality associated with the maximum sustainable yield (MSY) divided by the natural mortality rate, and B[subscriptMSY]/B₀ is the biomass level associated with the MSY divided by the unfished level of biomass. DB-SRA performs a Monte Carlo simulation where a large number of random parameter draws are made based on the input parameter’s prior distribution. Based on the catch time series, a biomass trajectory is produced to estimate a feasible set of input parameters and an OFL. The run and corresponding set of input parameters are not retained if the biomass trajectory goes below zero. In instances where the input parameter prior distributions are unknown, Dick and MacCall (2011) proposed a set of default values for two life history types (rockfish and flatfish). Although DB-SRA has been evaluated to some extent and is currently being used for management of data-poor species on the U.S. west coast, further evaluation is warranted. Like other fisheries assessment models, DB-SRA makes several assumptions that may have large influence on outputs and have largely gone untested. First, in essence DB-SRA assumes that only mature fish are caught in the fishery; this is rarely true on the U.S. West Coast and elsewhere, particularly for species with substantial recreational catch. Second, most stock assessment methods, including DB-SRA, are applied to large regions (e.g., U.S. west coast), assuming the population dynamics and fishing behavior remain consistent across the entire area. Market demands and habitat, among other factors, can lead to heterogeneity in population dynamics and fishing behavior. For instance, immature fish are often caught in recreational fisheries, but commercial fisheries tend to target larger fish, causing fishing impact to change across regions. I developed a two-region operating model that simulated data to generate input parameter expected values and a catch time series for each region, then conducted a factorial experiment to investigate the effect of four factors on DB-SRA (version 4) results: (1) different positions of the selectivity curve (the relative vulnerability to fishing of each age class) relative to the maturity curve; (2) spatial scale (separate by region versus combined); (3) exploitation history; and (4) life history type (rockfish and flatfish). The position of the selectivity curve influences the accuracy of the OFL estimates from DB-SRA, whereas the exploitation history has little effect. The OFL estimates are overestimated when the selectivity curve is to the right of the maturity curve and underestimated when the selectivity curve is to the left of the maturity curve. DB-SRA produces higher OFL estimates when two regions are used instead of one large region. Dividing the catch data into multiple regions resulted in higher OFL estimates than one combined region when the same input parameters and catch time series were used. An updated production function, for mimicking population dynamics, was implemented in DB-SRA (version 4), creating separate time lags for mortality and production (recruitment and growth). Instead of setting the time lags for mortality and production equal to the age at 50% maturity (version 3), the time lag for mortality has been changed to one year (version 4). Although the version 4 DB-SRA model has been used for fishery management, it has not been formally evaluated against version 3 to understand the impacts of this change on model results. To investigate the two versions, I looked at different positions of the selectivity curve relative to the maturity curve, different exploitation histories, and varying spatial scale for two life history types. The OFL estimates from version 3 of DB-SRA were larger than the OFL estimates from version 4, which is also evident in the biomass trajectories. The biomass trajectories from version 3 are always greater than the respective biomass trajectories from version 4. Although the OFL estimates from version 4 are not always less biased than those from version 3, the estimates from version 4 are always more precautionary and significantly reduce the chances for overestimating the OFL. The identification of factors that influence DB-SRA OFL estimates could demonstrate how DB-SRA can be adjusted to produce less biased OFL estimates in more situations. The change made in the production function between versions 3 and 4 of DB-SRA makes OFL estimates more precautionary; but does not always reduce the bias in the median OFL estimate. The results from this study could provide information to fisheries managers so that DB-SRA could be potentially improved and is applied in appropriate situations. Title: Evaluating the data-poor fishery stock assessment method, DB-SRA Author: Owashi, Brandon R. Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per annum, rate of natural mortality (M), age at 50% maturity, F[subscript MSY]/M, B[subscriptMSY]/B₀, and the predicted depletion of the stock from its unfished condition. F[subscriptMSY]/M is the rate of fishing mortality associated with the maximum sustainable yield (MSY) divided by the natural mortality rate, and B[subscriptMSY]/B₀ is the biomass level associated with the MSY divided by the unfished level of biomass. DB-SRA performs a Monte Carlo simulation where a large number of random parameter draws are made based on the input parameter’s prior distribution. Based on the catch time series, a biomass trajectory is produced to estimate a feasible set of input parameters and an OFL. The run and corresponding set of input parameters are not retained if the biomass trajectory goes below zero. In instances where the input parameter prior distributions are unknown, Dick and MacCall (2011) proposed a set of default values for two life history types (rockfish and flatfish). Although DB-SRA has been evaluated to some extent and is currently being used for management of data-poor species on the U.S. west coast, further evaluation is warranted. Like other fisheries assessment models, DB-SRA makes several assumptions that may have large influence on outputs and have largely gone untested. First, in essence DB-SRA assumes that only mature fish are caught in the fishery; this is rarely true on the U.S. West Coast and elsewhere, particularly for species with substantial recreational catch. Second, most stock assessment methods, including DB-SRA, are applied to large regions (e.g., U.S. west coast), assuming the population dynamics and fishing behavior remain consistent across the entire area. Market demands and habitat, among other factors, can lead to heterogeneity in population dynamics and fishing behavior. For instance, immature fish are often caught in recreational fisheries, but commercial fisheries tend to target larger fish, causing fishing impact to change across regions. I developed a two-region operating model that simulated data to generate input parameter expected values and a catch time series for each region, then conducted a factorial experiment to investigate the effect of four factors on DB-SRA (version 4) results: (1) different positions of the selectivity curve (the relative vulnerability to fishing of each age class) relative to the maturity curve; (2) spatial scale (separate by region versus combined); (3) exploitation history; and (4) life history type (rockfish and flatfish). The position of the selectivity curve influences the accuracy of the OFL estimates from DB-SRA, whereas the exploitation history has little effect. The OFL estimates are overestimated when the selectivity curve is to the right of the maturity curve and underestimated when the selectivity curve is to the left of the maturity curve. DB-SRA produces higher OFL estimates when two regions are used instead of one large region. Dividing the catch data into multiple regions resulted in higher OFL estimates than one combined region when the same input parameters and catch time series were used. An updated production function, for mimicking population dynamics, was implemented in DB-SRA (version 4), creating separate time lags for mortality and production (recruitment and growth). Instead of setting the time lags for mortality and production equal to the age at 50% maturity (version 3), the time lag for mortality has been changed to one year (version 4). Although the version 4 DB-SRA model has been used for fishery management, it has not been formally evaluated against version 3 to understand the impacts of this change on model results. To investigate the two versions, I looked at different positions of the selectivity curve relative to the maturity curve, different exploitation histories, and varying spatial scale for two life history types. The OFL estimates from version 3 of DB-SRA were larger than the OFL estimates from version 4, which is also evident in the biomass trajectories. The biomass trajectories from version 3 are always greater than the respective biomass trajectories from version 4. Although the OFL estimates from version 4 are not always less biased than those from version 3, the estimates from version 4 are always more precautionary and significantly reduce the chances for overestimating the OFL. The identification of factors that influence DB-SRA OFL estimates could demonstrate how DB-SRA can be adjusted to produce less biased OFL estimates in more situations. The change made in the production function between versions 3 and 4 of DB-SRA makes OFL estimates more precautionary; but does not always reduce the bias in the median OFL estimate. The results from this study could provide information to fisheries managers so that DB-SRA could be potentially improved and is applied in appropriate situations. Close

• 2763. [Article] Northern fur seal reproductive rates and early maternal care

  The majority of the world's breeding population of northern fur seals (Callorhinus ursinus) is found on the Pribilof Islands (St. Paul and St. George) in the Bering Sea, Alaska. Pup production on these ...

  Citation × Citation Citation Abstract Copy Title: Northern fur seal reproductive rates and early maternal care Author: Kunisch, E. (Erin) The majority of the world's breeding population of northern fur seals (Callorhinus ursinus) is found on the Pribilof Islands (St. Paul and St. George) in the Bering Sea, Alaska. Pup production on these islands experienced an irregular but overall decline since the early 1970's. Between 1998 and 2010, pup production declined precipitously at an annual rate of 4.9% on the Pribilof Islands, and 5.5% on St. Paul Island. Specific reasons for this decline remain unknown, and contemporary estimates for many vital rate parameters including reproductive rates are unavailable. This study determined a contemporary estimate of natality and fertility rates, as well as reproductive timing on the Polovina Cliffs rookery of St. Paul Island during the 2008 (30 June-31 August) and 2009 (1 July-25 August) breeding seasons. Natality rate (defined as the number of pups born divided by the number of reproductively mature females) was determined from visual observations of parturition or associated maternal behavior in 208 and 217 individually marked females (via flipper tags) in 2008 and 2009, respectively. Data yielded observed natality estimates of 0.79 in 2008 and 0.88 in 2009. The fertility rate (defined as the number of pups born divided by the total number of females present, irrespective of reproductive maturity/age) was determined for the 2008 breeding season only. This ratio of total pup to female counts was derived from adjusted daily cross-sectional counts conducted through the breeding season. Maximum pup and female counts were derived as asymptotes of sigmoid growth models fitted to corrected daily counts. Live pup counts were corrected for mortalities by estimates of cumulative pup mortalities. Daily counts of females present in the rookery were corrected for reduced detection probabilities resulting from increased maternal foraging trip durations through the season, typical of attendance patterns associated with colonial, income breeders. Daily detection probabilities for individually marked females were generated from Cormack-Jolly-Seber (CJS) open population models using maximum likelihood estimators (MLE) in Program MARK. Multiple a priori models accounting for the effects of possible covariates on detection probabilities were evaluated in an information-theoretic approach using Akaike's Information Criterion (AIC) and AICc model weights. Data yielded a minimum fertility rate estimate of 0.60 in 2008. Detection probabilities derived from the top CJS model for dual flipper-tagged females only were used to adjust the daily cross-section counts of all (marked and unmarked) females. Therefore, the actual fertility rate is probably higher than the estimate presented here, which should be regarded as the lowest likely value for 2008. However, AICc model weights also demonstrated the absence of density effects on detection probability estimates. This supports the applicability of marked female-based detection probabilities for correcting cross-sectional counts of all females and further suggests that the actual fertility estimate likely does not differ much from the presented estimate. Median dates of birth were calculated as the date closest to 50% of modeled corrected pup count asymptotes, yielding median dates of 17 July in 2008 and 15 July in 2009. Pregnant females are highly consistent in their arrival dates, with parturition occurring approximately 1 day after arrival. Median observed dates of arrival from individually marked females resulted in dates of 16 July in 2008 and 15 July in 2009. These dates occurred 5 to 13 days later than historic reports from 1951 through 1995. With median arrival dates 1 day prior to parturition, the observed match between birth dates derived from pup counts and from observed arrival dates of marked females supports the finding of a contemporary delay in the timing of parturition. Median arrival derived as the date closest to 50% of the asymptote from corrected and modeled female counts yielded 13 July in 2008. This earlier data is likely an effect of the inclusion of immature and nulli-parous females. In a subset of 62 females with pregnancy confirmed through a trans-rectal ultrasonography procedure in November 2007 and 29 females in 2008, the return rate for the following reproductive season was 0.92 and 0.76, respectively. In 2008, the return and natality rate was measured by radiotelemetry data, detected from females outfitted with VHF-radio transmitter. In 2009 both rates were determined by observational data. Observed natality rates for returned females of a known pregnancy status were 0.95 in 2008 and 0.96 in 2009. Radiotelemetry data from 76 females was analyzed for early maternal attendance patterns (duration and ratio of presences and absences) in 2008. The mean date of detected return was 18 July. The mean duration of the perinatal period was 7.5 days (+/- 1.3 SD). Excluding the perinatal period, the mean duration of presence on shore for the first five visits was 1.47 days (+/- 0.21 SD). The mean duration of absence at sea for the first five trips was 7.07 days (+/- 0.42 SD). Results presented from this study do not provide any direct evidence of a contemporary reduction in natality or fertility rates in northern fur seals. Since observed rates were comparably high and consistent between 2008 and 2009, it is unlikely that reduced natality rates are contributing to the current population trajectory. Attendance patterns do not provide any evidence of increased maternal foraging effort or secondarily, reduced prey availability. Interestingly, median pupping dates were found to occur significantly later than historical estimates. Potential reasons for this shift could be an increase in younger females within the reproductive female population at this rookery, or a shift in the timing of ocean climate conditions and peak prey availability during the breeding season. Title: Northern fur seal reproductive rates and early maternal care Author: Kunisch, E. (Erin) The majority of the world's breeding population of northern fur seals (Callorhinus ursinus) is found on the Pribilof Islands (St. Paul and St. George) in the Bering Sea, Alaska. Pup production on these islands experienced an irregular but overall decline since the early 1970's. Between 1998 and 2010, pup production declined precipitously at an annual rate of 4.9% on the Pribilof Islands, and 5.5% on St. Paul Island. Specific reasons for this decline remain unknown, and contemporary estimates for many vital rate parameters including reproductive rates are unavailable. This study determined a contemporary estimate of natality and fertility rates, as well as reproductive timing on the Polovina Cliffs rookery of St. Paul Island during the 2008 (30 June-31 August) and 2009 (1 July-25 August) breeding seasons. Natality rate (defined as the number of pups born divided by the number of reproductively mature females) was determined from visual observations of parturition or associated maternal behavior in 208 and 217 individually marked females (via flipper tags) in 2008 and 2009, respectively. Data yielded observed natality estimates of 0.79 in 2008 and 0.88 in 2009. The fertility rate (defined as the number of pups born divided by the total number of females present, irrespective of reproductive maturity/age) was determined for the 2008 breeding season only. This ratio of total pup to female counts was derived from adjusted daily cross-sectional counts conducted through the breeding season. Maximum pup and female counts were derived as asymptotes of sigmoid growth models fitted to corrected daily counts. Live pup counts were corrected for mortalities by estimates of cumulative pup mortalities. Daily counts of females present in the rookery were corrected for reduced detection probabilities resulting from increased maternal foraging trip durations through the season, typical of attendance patterns associated with colonial, income breeders. Daily detection probabilities for individually marked females were generated from Cormack-Jolly-Seber (CJS) open population models using maximum likelihood estimators (MLE) in Program MARK. Multiple a priori models accounting for the effects of possible covariates on detection probabilities were evaluated in an information-theoretic approach using Akaike's Information Criterion (AIC) and AICc model weights. Data yielded a minimum fertility rate estimate of 0.60 in 2008. Detection probabilities derived from the top CJS model for dual flipper-tagged females only were used to adjust the daily cross-section counts of all (marked and unmarked) females. Therefore, the actual fertility rate is probably higher than the estimate presented here, which should be regarded as the lowest likely value for 2008. However, AICc model weights also demonstrated the absence of density effects on detection probability estimates. This supports the applicability of marked female-based detection probabilities for correcting cross-sectional counts of all females and further suggests that the actual fertility estimate likely does not differ much from the presented estimate. Median dates of birth were calculated as the date closest to 50% of modeled corrected pup count asymptotes, yielding median dates of 17 July in 2008 and 15 July in 2009. Pregnant females are highly consistent in their arrival dates, with parturition occurring approximately 1 day after arrival. Median observed dates of arrival from individually marked females resulted in dates of 16 July in 2008 and 15 July in 2009. These dates occurred 5 to 13 days later than historic reports from 1951 through 1995. With median arrival dates 1 day prior to parturition, the observed match between birth dates derived from pup counts and from observed arrival dates of marked females supports the finding of a contemporary delay in the timing of parturition. Median arrival derived as the date closest to 50% of the asymptote from corrected and modeled female counts yielded 13 July in 2008. This earlier data is likely an effect of the inclusion of immature and nulli-parous females. In a subset of 62 females with pregnancy confirmed through a trans-rectal ultrasonography procedure in November 2007 and 29 females in 2008, the return rate for the following reproductive season was 0.92 and 0.76, respectively. In 2008, the return and natality rate was measured by radiotelemetry data, detected from females outfitted with VHF-radio transmitter. In 2009 both rates were determined by observational data. Observed natality rates for returned females of a known pregnancy status were 0.95 in 2008 and 0.96 in 2009. Radiotelemetry data from 76 females was analyzed for early maternal attendance patterns (duration and ratio of presences and absences) in 2008. The mean date of detected return was 18 July. The mean duration of the perinatal period was 7.5 days (+/- 1.3 SD). Excluding the perinatal period, the mean duration of presence on shore for the first five visits was 1.47 days (+/- 0.21 SD). The mean duration of absence at sea for the first five trips was 7.07 days (+/- 0.42 SD). Results presented from this study do not provide any direct evidence of a contemporary reduction in natality or fertility rates in northern fur seals. Since observed rates were comparably high and consistent between 2008 and 2009, it is unlikely that reduced natality rates are contributing to the current population trajectory. Attendance patterns do not provide any evidence of increased maternal foraging effort or secondarily, reduced prey availability. Interestingly, median pupping dates were found to occur significantly later than historical estimates. Potential reasons for this shift could be an increase in younger females within the reproductive female population at this rookery, or a shift in the timing of ocean climate conditions and peak prey availability during the breeding season. Close

• 2764. [Article] Evaluating the Efficacy of Predicting Bycatch Mortality Using Reflex Impairment through an Assessment of Crab Discards

  All animals that interact with fishing gear are not necessarily captured, and all animals that are captured are not necessarily retained. Fishing practices and gear configuration, management regulations, ...

  Citation × Citation Citation Abstract Copy Title: Evaluating the Efficacy of Predicting Bycatch Mortality Using Reflex Impairment through an Assessment of Crab Discards Author: Yochum, Noëlle All animals that interact with fishing gear are not necessarily captured, and all animals that are captured are not necessarily retained. Fishing practices and gear configuration, management regulations, and markets dictate which animals ultimately are retained or discarded. The impact of a fishery and the efficacy of management regulations can depend on the mortality rate of the animals that interact with the gear or are discarded. The Reflex Action Mortality Predictor (RAMP) is a simple, non-invasive, and inexpensive approach that has been used to evaluate this component of fishing mortality. The RAMP approach relates the degree of reflex impairment in an animal to the probability the animal will die. Since its introduction in 2006, the RAMP approach has been utilized in the U.S. and abroad to evaluate mortality for a variety of species, fishing gear types, and stressors. Although there have been numerous applications of the RAMP approach in mortality estimation studies, there has been limited research to directly evaluate RAMP estimates and some skepticism remains in the fisheries science and management communities about the reliability and accuracy of the approach. The goal of this dissertation was to conduct research to assess RAMP and to synthesize findings from previously completed RAMP studies. The three research studies described in this dissertation consider: (1) the accuracy of applying an established relationship between reflex impairment and mortality probability to predict overall mortality attributed to novel stressors; (2) the development and utilization of a RAMP relationship to evaluate discard mortality in a fishery with management regulations that mandate discarding of certain categories of animals; and (3) whether the RAMP approach produces accurate estimates of mortality if survival is determined through laboratory captive holding. The first study estimated a relationship between reflex impairment and mortality probability for Tanner crab (Chionoecetes bairdi) discarded from the groundfish bottom trawl fishery in the Gulf of Alaska. This relationship was then compared to one previously established for Tanner crab in the Bering Sea bottom trawl fishery that encountered the fishing gear, but remained on the seafloor ('unobserved bycatch'). While mortality probabilities were similar between the two studies for crab with no or full reflex impairment, discarded crab with intermediate levels of reflex impairment had lower mortality probabilities than those from the unobserved bycatch study. Results from this study indicate the importance of describing all stressors to which animals are exposed and detailing the study methodology when initially creating a RAMP relationship. Failure to do so may result in inaccurate mortality estimates when the RAMP is applied to animals exposed to stressors not included in the original calibration. The second study developed a RAMP relationship using laboratory captive holding for Dungeness crab (Cancer magister) discarded in the Oregon commercial and recreational Dungeness fisheries and estimated that the discard mortality rate is lower than previously determined. This supports the goal of the '3-S' management strategy currently employed for these fisheries to protect sub-legal males (Size), females (Sex), and soft-shell (Season) crab by discarding them from the catch. For the commercial ocean Dungeness fishery, the estimated overall discard mortality rates (five days after release) varied by sex and shell-hardness, and reflex impairment was a significant predictor of mortality for both the commercial and recreational fisheries. In addition, results indicated that, when evaluating the role of discard mortality in '3-S' management with respect to fishery impact and sustainability, it is important to look not only at mortality rates, but also at the mortality- and bycatch- per retained ratios, and temporal trends relative to changes in effort, animal condition, and catch composition. This study also highlighted the (i) importance of evaluating the influence of biological, environmental, and fishing variables on mortality, (ii) complications that arise when establishing a RAMP relationship for a low impact fishery, and (iii) limitations of determining mortality through laboratory captive holding. The third study used mark-recapture methods to evaluate the reliability of results generated using the RAMP relationship established in the second study, which was based on the survival of crab held in captivity in the laboratory. Given the unnatural conditions for determining survival in captivity and the short-term duration of the experiment, mortality probability estimates may be biased. Similarities in patterns of relative survival rates between the studies lend support to the ability of the RAMP relationship to estimate discard mortality rates using captive holding. The laboratory-based RAMP approach was superior in its ability to provide direct estimates of mortality rates, whereas the mark-recapture study was limited to providing relative survival rates between reflex impairment levels that were imprecise due to low numbers of recaptured crab. This study highlighted the complications associated with tagging discarded animals and conducting a RAMP study with a fishery that has highly variable seasonal fishing effort. A synthesis of the research described in this dissertation and published work by other researchers highlights the limitations of the RAMP approach so that future researchers can avoid pitfalls in its application, and leads to suggestions on how to standardize some of the methodological steps. This analysis aims to increase the reliability of future RAMP studies and their production of high quality estimates of discard mortality rates that promote sustainable fisheries. Title: Evaluating the Efficacy of Predicting Bycatch Mortality Using Reflex Impairment through an Assessment of Crab Discards Author: Yochum, Noëlle All animals that interact with fishing gear are not necessarily captured, and all animals that are captured are not necessarily retained. Fishing practices and gear configuration, management regulations, and markets dictate which animals ultimately are retained or discarded. The impact of a fishery and the efficacy of management regulations can depend on the mortality rate of the animals that interact with the gear or are discarded. The Reflex Action Mortality Predictor (RAMP) is a simple, non-invasive, and inexpensive approach that has been used to evaluate this component of fishing mortality. The RAMP approach relates the degree of reflex impairment in an animal to the probability the animal will die. Since its introduction in 2006, the RAMP approach has been utilized in the U.S. and abroad to evaluate mortality for a variety of species, fishing gear types, and stressors. Although there have been numerous applications of the RAMP approach in mortality estimation studies, there has been limited research to directly evaluate RAMP estimates and some skepticism remains in the fisheries science and management communities about the reliability and accuracy of the approach. The goal of this dissertation was to conduct research to assess RAMP and to synthesize findings from previously completed RAMP studies. The three research studies described in this dissertation consider: (1) the accuracy of applying an established relationship between reflex impairment and mortality probability to predict overall mortality attributed to novel stressors; (2) the development and utilization of a RAMP relationship to evaluate discard mortality in a fishery with management regulations that mandate discarding of certain categories of animals; and (3) whether the RAMP approach produces accurate estimates of mortality if survival is determined through laboratory captive holding. The first study estimated a relationship between reflex impairment and mortality probability for Tanner crab (Chionoecetes bairdi) discarded from the groundfish bottom trawl fishery in the Gulf of Alaska. This relationship was then compared to one previously established for Tanner crab in the Bering Sea bottom trawl fishery that encountered the fishing gear, but remained on the seafloor ('unobserved bycatch'). While mortality probabilities were similar between the two studies for crab with no or full reflex impairment, discarded crab with intermediate levels of reflex impairment had lower mortality probabilities than those from the unobserved bycatch study. Results from this study indicate the importance of describing all stressors to which animals are exposed and detailing the study methodology when initially creating a RAMP relationship. Failure to do so may result in inaccurate mortality estimates when the RAMP is applied to animals exposed to stressors not included in the original calibration. The second study developed a RAMP relationship using laboratory captive holding for Dungeness crab (Cancer magister) discarded in the Oregon commercial and recreational Dungeness fisheries and estimated that the discard mortality rate is lower than previously determined. This supports the goal of the '3-S' management strategy currently employed for these fisheries to protect sub-legal males (Size), females (Sex), and soft-shell (Season) crab by discarding them from the catch. For the commercial ocean Dungeness fishery, the estimated overall discard mortality rates (five days after release) varied by sex and shell-hardness, and reflex impairment was a significant predictor of mortality for both the commercial and recreational fisheries. In addition, results indicated that, when evaluating the role of discard mortality in '3-S' management with respect to fishery impact and sustainability, it is important to look not only at mortality rates, but also at the mortality- and bycatch- per retained ratios, and temporal trends relative to changes in effort, animal condition, and catch composition. This study also highlighted the (i) importance of evaluating the influence of biological, environmental, and fishing variables on mortality, (ii) complications that arise when establishing a RAMP relationship for a low impact fishery, and (iii) limitations of determining mortality through laboratory captive holding. The third study used mark-recapture methods to evaluate the reliability of results generated using the RAMP relationship established in the second study, which was based on the survival of crab held in captivity in the laboratory. Given the unnatural conditions for determining survival in captivity and the short-term duration of the experiment, mortality probability estimates may be biased. Similarities in patterns of relative survival rates between the studies lend support to the ability of the RAMP relationship to estimate discard mortality rates using captive holding. The laboratory-based RAMP approach was superior in its ability to provide direct estimates of mortality rates, whereas the mark-recapture study was limited to providing relative survival rates between reflex impairment levels that were imprecise due to low numbers of recaptured crab. This study highlighted the complications associated with tagging discarded animals and conducting a RAMP study with a fishery that has highly variable seasonal fishing effort. A synthesis of the research described in this dissertation and published work by other researchers highlights the limitations of the RAMP approach so that future researchers can avoid pitfalls in its application, and leads to suggestions on how to standardize some of the methodological steps. This analysis aims to increase the reliability of future RAMP studies and their production of high quality estimates of discard mortality rates that promote sustainable fisheries. Close

• 2765. [Article] Managing Marine Resources in Oregon’s Territorial Sea and Ocean Stewardship Area: The importance of environmental information in planning and decision making

  Oregon has a strong framework for ocean planning rooted in the adoption of Oregon’s Ocean Resources Goal 19 in 1976. Goal 19 establishes that it is the State of Oregon’s policy to conserve marine resources ...

  Citation × Citation Citation Abstract Copy Title: Managing Marine Resources in Oregon’s Territorial Sea and Ocean Stewardship Area: The importance of environmental information in planning and decision making Author: Snow, Patty Oregon has a strong framework for ocean planning rooted in the adoption of Oregon’s Ocean Resources Goal 19 in 1976. Goal 19 establishes that it is the State of Oregon’s policy to conserve marine resources and ecological functions for the purpose of providing long-term ecological, economic, and social value and benefits to future generations. To this end, all actions by local, state and federal agencies that are likely to affect the ocean resources and uses of Oregon’s territorial sea are to be developed and conducted to conserve marine resources and ecological functions. Higher priority is given to the protection of renewable marine resources (living marine organisms) than to the development of non-renewable ocean resources. This ocean planning framework was further codified by the Oregon Ocean Resource Management Act (ORS 196.405 to 196.485) passed in 1991 which created the Oregon ocean governance structure. The Oregon Territorial Sea Plan (TSP) which contains specific polices for state ocean management was originally adopted in 1994. The TSP was modified in 2009 to address policies for managing marine renewable energy development. A process is underway to use spatial planning techniques to identify areas appropriate for marine renewable energy development; adoption of these amendments to the TSP is anticipated in January 2013. Goal 19 also establishes the policy framework for the Ocean Stewardship Area which is defined to include the state’s territorial sea (out to three nautical miles), the continental margin seaward to the toe of the continental slope, and adjacent ocean areas. The Ocean Stewardship area is further addressed in the TSP. Goal 19, the Oregon Ocean Resources Management Act, and the TSP all state that prior to taking an action that is likely to affect ocean resources or uses of Oregon’s territorial sea, state and federal agencies are required to assess the reasonably foreseeable adverse effects of the action. The effects assessment is also to address reasonably foreseeable adverse effects on Oregon’s estuaries and shorelands. The information and protection requirements outlined below apply both on a planning scale (i.e., Territorial sea Plan) and on a permit-by-permit basis (i.e., OPT permit). Information is needed for the territorial sea, the ocean stewardship area and the outer continental shelf. Oregon’s Ocean Resources Goal 19, the Oregon Resources Management Act, and the TSP all require the protection of certain resources: a. Renewable marine resources; b. Biological diversity of marine life and the functional integrity of the marine ecosystem; c. Important marine habitat including areas: 1. Important to the biological viability of commercially or recreationally caught species or that support important food or prey species for commercially or recreationally caught species; or 2. needed to assure the survival of threatened or endangered species; 3. ecologically significant to maintain ecosystem structure, biological productivity, and biological diversity; 4. essential to the life-history or behavior of marine organisms; or 5. especially vulnerable because of size, composition, or location in relation to chemical or other pollutants, noise, physical disturbance, alteration, or harvest; or 6. unique or of limited range within the state: and d. Areas important to fisheries, which are: 1. areas of high catch; or 2. areas where highly valued fish are caught even if in low abundance or by few fishers; or 3. areas that are important on a seasonal basis; or 4. areas important to commercial or recreational fishing activities, including those of individual ports or particular fleets; or 5. habitat areas that support food or prey species important to commercially and recreationally caught fish and shellfish species. 6. Agencies are also to protect and encourage beneficial uses of ocean resources such as navigation, food production, recreation, aesthetic enjoyment, and uses of the seafloor provided that the activities do not adversely affect the resources protected in 1-4 above. To support the TSP spatial planning process and meet Goal 19 planning information requirements, the State of Oregon has developed a spatial decision support tool called MarineMap. It displays Oregon’s Ocean GIS database online and currently encompasses over 200 data layers including: a. Commercial and recreational fisheries data collected through local advisory committees for areas important to fisheries (Winter 2011); b. Ecological data collected by the Oregon Department of Fish and Wildlife (Summer 2011); c. Seafloor bathymetric and image data (Summer 2011); d. Recreational ocean use determined by on-line surveys (Fall 2010); e. Visual assessment inventory information (Summer 2012); f. Other spatial data on human uses, managed resources, physical conditions, and shoreland facilities (Fall 2010). This information has been used as part of the geospatial analysis to develop areas to be protected by Goal 19 in the current TSP mapping process. Currently, the draft recommendation is for six areas or zones: a. Renewable Energy Exclusion Area (REEA); b. Proprietary Use and Management Area (PUMA); c. Resources and Uses Conservation Area (RUCA); d. Resources and Uses Management Area (RUMA); e. Renewable Energy Facility Suitability Study Area (REFSSA); f. Renewable Energy Permit Area (REPA). Standards are the most stringent in the conservation area and least stringent in the study area. In addition, the draft recommendations include two overlay zones and screening standards that would apply across the territorial sea: 1. Visual Resource Area Overlay; 2. Marine Recreation Area Overlay. Information will be needed for permit applications in each of these zones but will be more extensive in conservation areas to ensure that important resources are protected. Permits for marine renewable energy projects in the future will be subject to different screening standards depending on what zone or area they are proposed in. While Oregon has created an innovative marine spatial planning decision support tool, the state continues to need additional information to ground truth assumptions, fill in information gaps, reduce uncertainties, and provide expert opinions. In addition, the state is working with other West Coast states to create a regional data framework that will facilitate regional decision-making and planning efforts. Title: Managing Marine Resources in Oregon’s Territorial Sea and Ocean Stewardship Area: The importance of environmental information in planning and decision making Author: Snow, Patty Oregon has a strong framework for ocean planning rooted in the adoption of Oregon’s Ocean Resources Goal 19 in 1976. Goal 19 establishes that it is the State of Oregon’s policy to conserve marine resources and ecological functions for the purpose of providing long-term ecological, economic, and social value and benefits to future generations. To this end, all actions by local, state and federal agencies that are likely to affect the ocean resources and uses of Oregon’s territorial sea are to be developed and conducted to conserve marine resources and ecological functions. Higher priority is given to the protection of renewable marine resources (living marine organisms) than to the development of non-renewable ocean resources. This ocean planning framework was further codified by the Oregon Ocean Resource Management Act (ORS 196.405 to 196.485) passed in 1991 which created the Oregon ocean governance structure. The Oregon Territorial Sea Plan (TSP) which contains specific polices for state ocean management was originally adopted in 1994. The TSP was modified in 2009 to address policies for managing marine renewable energy development. A process is underway to use spatial planning techniques to identify areas appropriate for marine renewable energy development; adoption of these amendments to the TSP is anticipated in January 2013. Goal 19 also establishes the policy framework for the Ocean Stewardship Area which is defined to include the state’s territorial sea (out to three nautical miles), the continental margin seaward to the toe of the continental slope, and adjacent ocean areas. The Ocean Stewardship area is further addressed in the TSP. Goal 19, the Oregon Ocean Resources Management Act, and the TSP all state that prior to taking an action that is likely to affect ocean resources or uses of Oregon’s territorial sea, state and federal agencies are required to assess the reasonably foreseeable adverse effects of the action. The effects assessment is also to address reasonably foreseeable adverse effects on Oregon’s estuaries and shorelands. The information and protection requirements outlined below apply both on a planning scale (i.e., Territorial sea Plan) and on a permit-by-permit basis (i.e., OPT permit). Information is needed for the territorial sea, the ocean stewardship area and the outer continental shelf. Oregon’s Ocean Resources Goal 19, the Oregon Resources Management Act, and the TSP all require the protection of certain resources: a. Renewable marine resources; b. Biological diversity of marine life and the functional integrity of the marine ecosystem; c. Important marine habitat including areas: 1. Important to the biological viability of commercially or recreationally caught species or that support important food or prey species for commercially or recreationally caught species; or 2. needed to assure the survival of threatened or endangered species; 3. ecologically significant to maintain ecosystem structure, biological productivity, and biological diversity; 4. essential to the life-history or behavior of marine organisms; or 5. especially vulnerable because of size, composition, or location in relation to chemical or other pollutants, noise, physical disturbance, alteration, or harvest; or 6. unique or of limited range within the state: and d. Areas important to fisheries, which are: 1. areas of high catch; or 2. areas where highly valued fish are caught even if in low abundance or by few fishers; or 3. areas that are important on a seasonal basis; or 4. areas important to commercial or recreational fishing activities, including those of individual ports or particular fleets; or 5. habitat areas that support food or prey species important to commercially and recreationally caught fish and shellfish species. 6. Agencies are also to protect and encourage beneficial uses of ocean resources such as navigation, food production, recreation, aesthetic enjoyment, and uses of the seafloor provided that the activities do not adversely affect the resources protected in 1-4 above. To support the TSP spatial planning process and meet Goal 19 planning information requirements, the State of Oregon has developed a spatial decision support tool called MarineMap. It displays Oregon’s Ocean GIS database online and currently encompasses over 200 data layers including: a. Commercial and recreational fisheries data collected through local advisory committees for areas important to fisheries (Winter 2011); b. Ecological data collected by the Oregon Department of Fish and Wildlife (Summer 2011); c. Seafloor bathymetric and image data (Summer 2011); d. Recreational ocean use determined by on-line surveys (Fall 2010); e. Visual assessment inventory information (Summer 2012); f. Other spatial data on human uses, managed resources, physical conditions, and shoreland facilities (Fall 2010). This information has been used as part of the geospatial analysis to develop areas to be protected by Goal 19 in the current TSP mapping process. Currently, the draft recommendation is for six areas or zones: a. Renewable Energy Exclusion Area (REEA); b. Proprietary Use and Management Area (PUMA); c. Resources and Uses Conservation Area (RUCA); d. Resources and Uses Management Area (RUMA); e. Renewable Energy Facility Suitability Study Area (REFSSA); f. Renewable Energy Permit Area (REPA). Standards are the most stringent in the conservation area and least stringent in the study area. In addition, the draft recommendations include two overlay zones and screening standards that would apply across the territorial sea: 1. Visual Resource Area Overlay; 2. Marine Recreation Area Overlay. Information will be needed for permit applications in each of these zones but will be more extensive in conservation areas to ensure that important resources are protected. Permits for marine renewable energy projects in the future will be subject to different screening standards depending on what zone or area they are proposed in. While Oregon has created an innovative marine spatial planning decision support tool, the state continues to need additional information to ground truth assumptions, fill in information gaps, reduce uncertainties, and provide expert opinions. In addition, the state is working with other West Coast states to create a regional data framework that will facilitate regional decision-making and planning efforts. Close

• 2766. [Article] Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire

  Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as ...

  Citation × Citation Citation Abstract Copy Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Close

• 2767. [Article] Three essays on the effectiveness of Oregon's land-use planning system : economic analysis with quasi-experimental methods

  Oregon's land use planning system is often recognized as having been successful in its goals of limiting urban sprawl and protecting resource lands from development. However, it is difficult to quantify ...

  Citation × Citation Citation Abstract Copy Title: Three essays on the effectiveness of Oregon's land-use planning system : economic analysis with quasi-experimental methods Author: Dempsey, Judith Oregon's land use planning system is often recognized as having been successful in its goals of limiting urban sprawl and protecting resource lands from development. However, it is difficult to quantify the impact of these regulations, because we cannot observe what would have happened in the absence of land use planning. The three essays in this dissertation explore the effects of Oregon's land use planning regulations on development patterns in the state, and also examine how the land use regulations are administered at the local level. The first essay in this dissertation asks if Oregon’s land use regulations have successfully restricted sprawl outside of urban areas. Urban containment policies, including Urban Growth Boundaries (UGBs), are a common tool used by city planners to promote compact development. We analyze how well UGBs do in containing development using fine-scale GIS data on cities in Oregon. Earlier studies on UGBs yield mixed results, with some authors finding no effects of UGBs on housing market variables and urbanization rates and others finding significant effects. A challenge in measuring these effects is that the location of the UGB is unlikely to be an exogenous determinant of a land parcel's value for development. The panel structure of our dataset allows us to estimate the UGB's effect on the probability of development using a difference-in-difference estimator. This estimator controls for time-invariant unobservable variables and common temporal effects among parcels, thereby mitigating the potential for biased estimates due to the endogeneity of the UGB's location. We also pursue a novel approach to controlling for time-varying factors inspired by regression discontinuity design. We find that UGBs are effective in containing development in many of the Oregon cities we examine, although there are some cities in which development rates are the same inside and outside of the UGB. Our results show that we would greatly overstate the effects of the UGBs were we to evaluate cross-sectional differences in development rates, as is common in previous studies. Besides the creation of UGBs, another goal of Oregon's land use regulations is to encourage citizen involvement in the planning process. The second essay in this dissertation examines the use of voter annexation as a form of citizen involvement. More specifically, this paper addresses the following two questions. First, does voter annexation cause changes in city demographics and characteristics? Second, assuming that a city votes for amendments and annexations to the UGB and city limits, what factors impact the outcome of the vote? We analyze the first question using the method of propensity score matching, which has not previously been used to explore this topic. This allows us to account for the endogeneity that stems from the fact that cities with certain characteristics may be more likely to use voter annexation in the first place. The second question, which is only evaluated for cities that employ voter annexation, is analyzed with the use of the logit model. Oregon's land use regulations must be approved at the state level, but are administered locally. Therefore, unlike past studies, we are able to isolate specific differences in the way the program is administered, and are not evaluating the stringency of the program itself. Previous studies have found that voter-approved annexation causes developers to provide more public goods and increase the scale of development, thereby shifting community demographics. Once a land use decision is on the ballot, it is also noted that cities that are whiter, wealthier, and more liberal are more likely to pass referenda that promote preservation and restrict development. For the first question, we compare specific demographic indicators between the two groups of cities. Contrary to the results of previous studies, we find no effect of voter annexation on these indicators. Our results for the second question indicate that the characteristics of the voting process itself impact the outcome more than community characteristics, which also differs from the results of previous analyses. The third essay in this dissertation is an extension of the first essay, and focuses on the impact of Oregon's land use regulations on the protection of land in riparian corridors and land that has been designated for exclusive farm use (EFU). Riparian corridors are protected with the use of Oregon Goal 5, which focuses on development of natural resource lands inside of UGBs, while EFU land is protected with the use of Oregon Goal 3, which focuses on protection of agricultural land at the county level. The LCT dataset that was used in the first essay is also used in this essay. EFU land by definition has no probability of development in the initial period. Land located in riparian corridors may also face different initial levels of protection than other land. We deal with this endogeneity, and also account for location inside or outside of a UGB, with the use of the difference -in-difference-in-differences estimator. This is an approach that has not been used to explore the effect of Oregon's land use regulations on these land categories. Most of the past studies that have examined the impact of land use planning on development of agricultural land in Oregon have relied on analysis of general trends and indicators, and have concluded that land use regulations have been successful in protecting this land. Previous research on riparian zone protection has focused on protection of aquatic wildlife, and for the most part has not examined the protection of riparian corridors inside of UGBs. The limited studies that have studied the effect of these regulations in UGBs have determined them to be effective in slowing, but not stopping, development in these areas. Overall, we find that Oregon's land use regulations have been successful in protecting both county level agricultural land and riparian corridors located inside of UGBs from development. It is less clear whether these regulations have protected riparian corridors located inside of UGBs from other anthropogenic uses. Title: Three essays on the effectiveness of Oregon's land-use planning system : economic analysis with quasi-experimental methods Author: Dempsey, Judith Oregon's land use planning system is often recognized as having been successful in its goals of limiting urban sprawl and protecting resource lands from development. However, it is difficult to quantify the impact of these regulations, because we cannot observe what would have happened in the absence of land use planning. The three essays in this dissertation explore the effects of Oregon's land use planning regulations on development patterns in the state, and also examine how the land use regulations are administered at the local level. The first essay in this dissertation asks if Oregon’s land use regulations have successfully restricted sprawl outside of urban areas. Urban containment policies, including Urban Growth Boundaries (UGBs), are a common tool used by city planners to promote compact development. We analyze how well UGBs do in containing development using fine-scale GIS data on cities in Oregon. Earlier studies on UGBs yield mixed results, with some authors finding no effects of UGBs on housing market variables and urbanization rates and others finding significant effects. A challenge in measuring these effects is that the location of the UGB is unlikely to be an exogenous determinant of a land parcel's value for development. The panel structure of our dataset allows us to estimate the UGB's effect on the probability of development using a difference-in-difference estimator. This estimator controls for time-invariant unobservable variables and common temporal effects among parcels, thereby mitigating the potential for biased estimates due to the endogeneity of the UGB's location. We also pursue a novel approach to controlling for time-varying factors inspired by regression discontinuity design. We find that UGBs are effective in containing development in many of the Oregon cities we examine, although there are some cities in which development rates are the same inside and outside of the UGB. Our results show that we would greatly overstate the effects of the UGBs were we to evaluate cross-sectional differences in development rates, as is common in previous studies. Besides the creation of UGBs, another goal of Oregon's land use regulations is to encourage citizen involvement in the planning process. The second essay in this dissertation examines the use of voter annexation as a form of citizen involvement. More specifically, this paper addresses the following two questions. First, does voter annexation cause changes in city demographics and characteristics? Second, assuming that a city votes for amendments and annexations to the UGB and city limits, what factors impact the outcome of the vote? We analyze the first question using the method of propensity score matching, which has not previously been used to explore this topic. This allows us to account for the endogeneity that stems from the fact that cities with certain characteristics may be more likely to use voter annexation in the first place. The second question, which is only evaluated for cities that employ voter annexation, is analyzed with the use of the logit model. Oregon's land use regulations must be approved at the state level, but are administered locally. Therefore, unlike past studies, we are able to isolate specific differences in the way the program is administered, and are not evaluating the stringency of the program itself. Previous studies have found that voter-approved annexation causes developers to provide more public goods and increase the scale of development, thereby shifting community demographics. Once a land use decision is on the ballot, it is also noted that cities that are whiter, wealthier, and more liberal are more likely to pass referenda that promote preservation and restrict development. For the first question, we compare specific demographic indicators between the two groups of cities. Contrary to the results of previous studies, we find no effect of voter annexation on these indicators. Our results for the second question indicate that the characteristics of the voting process itself impact the outcome more than community characteristics, which also differs from the results of previous analyses. The third essay in this dissertation is an extension of the first essay, and focuses on the impact of Oregon's land use regulations on the protection of land in riparian corridors and land that has been designated for exclusive farm use (EFU). Riparian corridors are protected with the use of Oregon Goal 5, which focuses on development of natural resource lands inside of UGBs, while EFU land is protected with the use of Oregon Goal 3, which focuses on protection of agricultural land at the county level. The LCT dataset that was used in the first essay is also used in this essay. EFU land by definition has no probability of development in the initial period. Land located in riparian corridors may also face different initial levels of protection than other land. We deal with this endogeneity, and also account for location inside or outside of a UGB, with the use of the difference -in-difference-in-differences estimator. This is an approach that has not been used to explore the effect of Oregon's land use regulations on these land categories. Most of the past studies that have examined the impact of land use planning on development of agricultural land in Oregon have relied on analysis of general trends and indicators, and have concluded that land use regulations have been successful in protecting this land. Previous research on riparian zone protection has focused on protection of aquatic wildlife, and for the most part has not examined the protection of riparian corridors inside of UGBs. The limited studies that have studied the effect of these regulations in UGBs have determined them to be effective in slowing, but not stopping, development in these areas. Overall, we find that Oregon's land use regulations have been successful in protecting both county level agricultural land and riparian corridors located inside of UGBs from development. It is less clear whether these regulations have protected riparian corridors located inside of UGBs from other anthropogenic uses. Close

• 2768. [Article] Interactive influences of wildfire and nonnative species on plant community succession in Hawaii Volcanoes National Park

  The role of fire as a natural disturbance, its interactions with nonnative species and effects of repeated fires in the Hawaiian Islands have received little investigation. We are unsure of the role fire ...

  Citation × Citation Citation Abstract Copy Title: Interactive influences of wildfire and nonnative species on plant community succession in Hawaii Volcanoes National Park Author: Ainsworth, Alison The role of fire as a natural disturbance, its interactions with nonnative species and effects of repeated fires in the Hawaiian Islands have received little investigation. We are unsure of the role fire played in shaping forest structure and composition as well as affecting evolutionary processes of the native biota. Yet, many species do have adaptations that facilitate their capacity to establish, grow, reproduce, and persist on either the individual or the population level when fire occurs. The objectives of this study were to document individual survival and colonization of native Hawaiian species after fire and to examine the potential interactions of nonnative species and fire. Specifically, I hypothesized that (1) many native Hawaiian species would survive and or colonize the postfire environment because they are adapted to a wide array of disturbance events, (2) the interaction of fire and nonnative species would alter native plant community succession because fire would facilitate nonnative species invasions, and the presence of nonnative species would limit native species recovery, and (3) the occurrence of a second fire within one year would result in a more impoverished native flora because sprouts from native surviving trees would be killed by the second fire. To understand the role of fire in tropical forests of Hawaii and how forest species respond to fire, I established replicate plots (n=5) in burned and unburned areas in five vegetation communities along an elevation/community gradient in Hawaii Volcanoes National Park. At lower elevations the sampled plant communities were two shrubdominated communities (Dodonaea viscosa/ Andropogon virginicus and Dodonaea/ Nephrolepis multiflora) and at higher elevations three forest communities (Metrosideros polymorpha/ Nephrolepis multiflora, Metrosideros/ Dicranopteris linearis, and Metrosideros/ Cibotium glaucum). Fires in all community types were stand-replacing, where >95% of the dominant native woody species were top-killed. Results from this study indicate that many native Hawaiian species had the capacity to survive fire vegetatively and/or established from seed in the postfire environment. Nineteen native tree, shrub and tree fern species survived fire primarily by sprouting from the base. Many of these species also established from seeds or spores postfire. Metrosideros, in particular, both exhibited widespread survival (>50%) primarily via basal sprouting and established from seed postfire. In addition, the effects of fire differed across species, populations and vegetation communities along the elevation gradient. Fire differentially affected the communities with greater differences in composition and structure observed in the three forest communities than the shrubdominated communities. In the forested communities, fire dramatically altered structure from a closed-canopy Metrosideros forest to shrub, fern and herb dominated sites. Understory cover differed between unburned and burned forest sites with reduced cover in the Nephrolepis and Dicranopteris forests and greater cover in the Cibotium forest. In the previously native-dominated Dicranopteris and Cibotium forest communities, nonnative species became increasingly abundant following fire suggesting that fire facilitated nonnative species invasion in these communities. The native fern Dicranopteris linearis was the most abundant understory species in the unburned sites, but nonnative ferns and vines dominated the understory in the burned sites postfire. Species richness, percent nonnative, and understory diversity were greater in the burned sites two years postfire than the unburned sites for each community. In contrast, in the Nephrolepis forest community the nonnative fern Nephrolepis multiflora dominated the understory (>50% cover) in both the unburned and burned sites. Metrosideros survival and recovery, quantified as basal sprout height, elliptical crown area and volume, differed among forest communities. Measures of sprout vigor were greatest two years following fire in the native Dicranopteris forest, where understory recovery was slowest presumably due to the thick litter layer that remained following fire acting as a barrier to understory colonization. Postfire vegetation composition and cover of the understory in the Nephrolepis and Cibotium forests was due largely to vigorous Nephrolepis multiflora sprouting and Paspalum conjugatum grass invasion, respectively. In addition, Cibotium glaucum tree ferns in the subcanopy tier had very high survival rates (>85%) and constitute a large portion of cover in the Cibotium forest community. Lower Metrosideros sprout growth rates in the Nephrolepis and Cibotium forest communities suggest that the high survival of tree ferns (Cibotium forest) and the rapid establishment of a nonnative-dominated understory (Nephrolepis and Cibotium forests) may be limiting Metrosideros tree recovery during early postfire succession. The occurrence of two fires in two years in some Dicranopteris and Cibotium forest communities dramatically increased mortality of Metrosideros. In the Dicranopteris community, 71% of Metrosideros trees survived a single fire, but only 22% survived repeated fires. Similarly in the Cibotium community, Metrosideros survival was reduced from 48% to 6% following repeated fires. Vegetative survival of the native tree fern Cibotium glaucum was also significantly reduced from 93% following a single fire to 56% following a second fire. Metrosideros seedling recruitment did not differ between forests that burned once and forests that burned twice. The composition of the understory in both of the sampled communities following repeated fires differed from that of forests that burned once and unburned control forests. Interestingly, the most abundant species in the understories following repeated fires were native sedges (Cyperus polystachyos) and shrubs (Pipturus albidus). However, these species are typically disturbance oriented short-lived species. Repeated fires resulted in lower Metrosideros survival, no significant increase in native tree seedling establishment, and rapid occupation native herbaceous and shrub species, all of which may delay, or even prevent, recovery to native forest dominance. Fire in the shrub-dominated communities, which were already heavily invaded by nonnative species, had little effect on vegetation composition and structure. These communities were previously modified by past fires (1972 and 1992) and nonnative grass (Andropogon virginicus) and fern (Nephrolepis multiflora) invasions. Notably absent from these communities were young native tree species suggesting that native forest recovery was not occurring. These communities demonstrate how nonnative species invasions coupled with repeated fires may alter successional trajectories such that native forest recovery is less likely. Title: Interactive influences of wildfire and nonnative species on plant community succession in Hawaii Volcanoes National Park Author: Ainsworth, Alison The role of fire as a natural disturbance, its interactions with nonnative species and effects of repeated fires in the Hawaiian Islands have received little investigation. We are unsure of the role fire played in shaping forest structure and composition as well as affecting evolutionary processes of the native biota. Yet, many species do have adaptations that facilitate their capacity to establish, grow, reproduce, and persist on either the individual or the population level when fire occurs. The objectives of this study were to document individual survival and colonization of native Hawaiian species after fire and to examine the potential interactions of nonnative species and fire. Specifically, I hypothesized that (1) many native Hawaiian species would survive and or colonize the postfire environment because they are adapted to a wide array of disturbance events, (2) the interaction of fire and nonnative species would alter native plant community succession because fire would facilitate nonnative species invasions, and the presence of nonnative species would limit native species recovery, and (3) the occurrence of a second fire within one year would result in a more impoverished native flora because sprouts from native surviving trees would be killed by the second fire. To understand the role of fire in tropical forests of Hawaii and how forest species respond to fire, I established replicate plots (n=5) in burned and unburned areas in five vegetation communities along an elevation/community gradient in Hawaii Volcanoes National Park. At lower elevations the sampled plant communities were two shrubdominated communities (Dodonaea viscosa/ Andropogon virginicus and Dodonaea/ Nephrolepis multiflora) and at higher elevations three forest communities (Metrosideros polymorpha/ Nephrolepis multiflora, Metrosideros/ Dicranopteris linearis, and Metrosideros/ Cibotium glaucum). Fires in all community types were stand-replacing, where >95% of the dominant native woody species were top-killed. Results from this study indicate that many native Hawaiian species had the capacity to survive fire vegetatively and/or established from seed in the postfire environment. Nineteen native tree, shrub and tree fern species survived fire primarily by sprouting from the base. Many of these species also established from seeds or spores postfire. Metrosideros, in particular, both exhibited widespread survival (>50%) primarily via basal sprouting and established from seed postfire. In addition, the effects of fire differed across species, populations and vegetation communities along the elevation gradient. Fire differentially affected the communities with greater differences in composition and structure observed in the three forest communities than the shrubdominated communities. In the forested communities, fire dramatically altered structure from a closed-canopy Metrosideros forest to shrub, fern and herb dominated sites. Understory cover differed between unburned and burned forest sites with reduced cover in the Nephrolepis and Dicranopteris forests and greater cover in the Cibotium forest. In the previously native-dominated Dicranopteris and Cibotium forest communities, nonnative species became increasingly abundant following fire suggesting that fire facilitated nonnative species invasion in these communities. The native fern Dicranopteris linearis was the most abundant understory species in the unburned sites, but nonnative ferns and vines dominated the understory in the burned sites postfire. Species richness, percent nonnative, and understory diversity were greater in the burned sites two years postfire than the unburned sites for each community. In contrast, in the Nephrolepis forest community the nonnative fern Nephrolepis multiflora dominated the understory (>50% cover) in both the unburned and burned sites. Metrosideros survival and recovery, quantified as basal sprout height, elliptical crown area and volume, differed among forest communities. Measures of sprout vigor were greatest two years following fire in the native Dicranopteris forest, where understory recovery was slowest presumably due to the thick litter layer that remained following fire acting as a barrier to understory colonization. Postfire vegetation composition and cover of the understory in the Nephrolepis and Cibotium forests was due largely to vigorous Nephrolepis multiflora sprouting and Paspalum conjugatum grass invasion, respectively. In addition, Cibotium glaucum tree ferns in the subcanopy tier had very high survival rates (>85%) and constitute a large portion of cover in the Cibotium forest community. Lower Metrosideros sprout growth rates in the Nephrolepis and Cibotium forest communities suggest that the high survival of tree ferns (Cibotium forest) and the rapid establishment of a nonnative-dominated understory (Nephrolepis and Cibotium forests) may be limiting Metrosideros tree recovery during early postfire succession. The occurrence of two fires in two years in some Dicranopteris and Cibotium forest communities dramatically increased mortality of Metrosideros. In the Dicranopteris community, 71% of Metrosideros trees survived a single fire, but only 22% survived repeated fires. Similarly in the Cibotium community, Metrosideros survival was reduced from 48% to 6% following repeated fires. Vegetative survival of the native tree fern Cibotium glaucum was also significantly reduced from 93% following a single fire to 56% following a second fire. Metrosideros seedling recruitment did not differ between forests that burned once and forests that burned twice. The composition of the understory in both of the sampled communities following repeated fires differed from that of forests that burned once and unburned control forests. Interestingly, the most abundant species in the understories following repeated fires were native sedges (Cyperus polystachyos) and shrubs (Pipturus albidus). However, these species are typically disturbance oriented short-lived species. Repeated fires resulted in lower Metrosideros survival, no significant increase in native tree seedling establishment, and rapid occupation native herbaceous and shrub species, all of which may delay, or even prevent, recovery to native forest dominance. Fire in the shrub-dominated communities, which were already heavily invaded by nonnative species, had little effect on vegetation composition and structure. These communities were previously modified by past fires (1972 and 1992) and nonnative grass (Andropogon virginicus) and fern (Nephrolepis multiflora) invasions. Notably absent from these communities were young native tree species suggesting that native forest recovery was not occurring. These communities demonstrate how nonnative species invasions coupled with repeated fires may alter successional trajectories such that native forest recovery is less likely. Close

• 2769. [Article] Determination of molecular hydrocyanic acid in water and studies of the chemistry and toxicity to fish of metal-cyanide complexes

  A reliable, easy, and inexpensive method for determination of molecular hydrocyanic acid (HCN) in solutions of simple and complex metal cyanides is described. The method was used to determine molecular ...

  Citation × Citation Citation Abstract Copy Title: Determination of molecular hydrocyanic acid in water and studies of the chemistry and toxicity to fish of metal-cyanide complexes Author: Broderius, Steven J. A reliable, easy, and inexpensive method for determination of molecular hydrocyanic acid (HCN) in solutions of simple and complex metal cyanides is described. The method was used to determine molecular HCN concentrations as low as 0.005 milligram per liter, and can be used for determination of even lower levels. It is a modification of a previously published method. A concentration column of glass beads coated with NaOH is employed, on which HCN displaced by air that has been bubbled through solutions under examination is trapped and concentrated for measurement of cyanide by a conventional analytical method. The apparatus could easily be modified for use in both field and laboratory situations where only limited facilities are available. Time periods required for attainment of equilibria upon dilution of solutions of metal-cyanide complexes, and also when metal salts and free cyanide are combined, were quite variable and ranged from several hours for the silver-cyanide complex to many months for iron-cyanide complexes kept in the dark. In solutions in which CuCN and NaCN were combined so that the molar ratio of CN to Cu was either 2.5 to 1 or 3 to 1, constancy of the HCN concentration usually was not attained even 110 days after preparation. The time to attainment of equilibrium through dissociation of the nickelocyanide complex ions generally was longer than that required for equilibrium to be attained in comparable experiments on complex formation, and it increased as the pH or the total cyanide concentration decreased; it is directly related to the percentage of total cyanide present as HCN at equilibrium. Results obtained at high total cyanide concentrations in nickelocyanide formation experiments were anomalous but verifiable by bioassay with fish. The HCN concentrations were at first unexpectedly low and then increased very slowly to the higher equilibrium levels. Cumulative dissociation constants (K[subscript D]) at 20°C for the Ag(CN)₂⁻, Cu(CN)₂⁻, Ni(CN)₄⁻², Fe(CN)₆⁻⁴, and Fe(CN)₆⁻³ complex ions, calculated from equilibrium levels of HCN, are 1.94 ± 2.82 x 10⁻¹⁹, 3.94 ± 1.75 x 10⁻²⁴, 1.00 ± 0.37 x 10⁻³¹, approximately 10⁻⁴⁷, and 10⁻⁵², respectively. The calculated constants for the tetracyanonickelate (II) and dicyanoargentate (I) complex ions inexplicably varied somewhat, increasing slightly with increase in total cyanide concentration and pH. Those for the tetracyanonickelate (II) and dicyanocuprate (I) complex ions showed close agreement with values recently reported in the literature, whereas the constants for the dicyanoargentate (I) and hexacyanoferrate (II) and (III) complex ions were materially different from presently accepted values. Possible unreliability of presently accepted stepwise constants for the cuprocyanide complex ions also was indicated. The acute toxicity of solutions of the different metal-cyanide complexes was generally found to be a function of the molecular HCN level, which increases with increase of total cyanide concentration and with decrease of pH. In some solutions however, a metal-cyanide complex ion per se was shown to be the major toxic component. The 48-hour median tolerance limits for bluegills of the dicyanoargentate (I) and dicyanocuprate (I) ions at 20°C were found to be approximately 9 and 4 mg/l as CN, respectively. The metallocyanide complex ions studied can be arranged in order of decreasing toxicity as follows: Cu(CN)₂⁻, Ag(CN)₂⁻, Ni(CN)₄⁻², and Fe(CN)₆⁻³ or Fe(CN)₆⁻⁴. A published empirical relationship between pH and 48-hour median tolerance limits of the nickelocyanide complex for a fish, determined without assurance that equilibria had been attained in test solutions, was compared with a calculated, theoretical relationship. Considerable divergence of the empirical and theoretical curves at pH values less than about 7.2 is ascribable mostly to the introduction of fish into test solutions long before equilibria had been attained in the solutions of low pH. Divergence at pH values greater than about 7.8 is attributable largely to moderate toxicity of the Ni(CN)₄⁻² complex ion itself. Slightly alkaline solutions of the silver cyanide complex, Ag(CN)₂⁻, become more toxic to sticklebacks with increase of chlorinity. The high toxicity in saline solutions, as compared with the toxicity in fresh water, is clearly attributable, at least in part or in some instances, to a molecular HCN content of the saline solutions much greater than that of comparable solutions prepared with fresh water. The two ligands CN⁻ and Cl⁻ compete for the silver ion, with which both ligands form complexes, and dissociation of the Ag(CN)₂⁻ ion, with production of HCN, consequently increases as the Cl⁻ ion concentration increases. Additional reasons for the observed increase of toxicity of solutions of the complex with increase of chlorinity can be an observed increase of the toxicity of HCN and a possible, similar increase of the toxicity of the complex ion. Experiments with ¹⁴C-labeled cyanide complexed with nickel showed that the complex does not penetrate readily into the body of a bluegill. The ¹⁴C accumulated in gill tissues much more markedly than it did in the blood and in tissues of internal organs sampled. When bluegills were exposed to solutions of the cyanide complexes of copper (I) and silver (I), considerable amounts of the metals accumulated in the blood and in tissues of internal organs, but little accumulation in gill tissues was observed. These results indicate that the cuprocyanide and silver-cyanide complexes enter the body of a bluegill much more readily than does the much less toxic nickelocyanide complex. The silver cation, however, apparently enters even more readily than does the silver-cyanide complex anion, the silver accumulating most markedly in the gill tissues of bluegills exposed to silver nitrate solutions, but also in their internal organ tissues. Title: Determination of molecular hydrocyanic acid in water and studies of the chemistry and toxicity to fish of metal-cyanide complexes Author: Broderius, Steven J. A reliable, easy, and inexpensive method for determination of molecular hydrocyanic acid (HCN) in solutions of simple and complex metal cyanides is described. The method was used to determine molecular HCN concentrations as low as 0.005 milligram per liter, and can be used for determination of even lower levels. It is a modification of a previously published method. A concentration column of glass beads coated with NaOH is employed, on which HCN displaced by air that has been bubbled through solutions under examination is trapped and concentrated for measurement of cyanide by a conventional analytical method. The apparatus could easily be modified for use in both field and laboratory situations where only limited facilities are available. Time periods required for attainment of equilibria upon dilution of solutions of metal-cyanide complexes, and also when metal salts and free cyanide are combined, were quite variable and ranged from several hours for the silver-cyanide complex to many months for iron-cyanide complexes kept in the dark. In solutions in which CuCN and NaCN were combined so that the molar ratio of CN to Cu was either 2.5 to 1 or 3 to 1, constancy of the HCN concentration usually was not attained even 110 days after preparation. The time to attainment of equilibrium through dissociation of the nickelocyanide complex ions generally was longer than that required for equilibrium to be attained in comparable experiments on complex formation, and it increased as the pH or the total cyanide concentration decreased; it is directly related to the percentage of total cyanide present as HCN at equilibrium. Results obtained at high total cyanide concentrations in nickelocyanide formation experiments were anomalous but verifiable by bioassay with fish. The HCN concentrations were at first unexpectedly low and then increased very slowly to the higher equilibrium levels. Cumulative dissociation constants (K[subscript D]) at 20°C for the Ag(CN)₂⁻, Cu(CN)₂⁻, Ni(CN)₄⁻², Fe(CN)₆⁻⁴, and Fe(CN)₆⁻³ complex ions, calculated from equilibrium levels of HCN, are 1.94 ± 2.82 x 10⁻¹⁹, 3.94 ± 1.75 x 10⁻²⁴, 1.00 ± 0.37 x 10⁻³¹, approximately 10⁻⁴⁷, and 10⁻⁵², respectively. The calculated constants for the tetracyanonickelate (II) and dicyanoargentate (I) complex ions inexplicably varied somewhat, increasing slightly with increase in total cyanide concentration and pH. Those for the tetracyanonickelate (II) and dicyanocuprate (I) complex ions showed close agreement with values recently reported in the literature, whereas the constants for the dicyanoargentate (I) and hexacyanoferrate (II) and (III) complex ions were materially different from presently accepted values. Possible unreliability of presently accepted stepwise constants for the cuprocyanide complex ions also was indicated. The acute toxicity of solutions of the different metal-cyanide complexes was generally found to be a function of the molecular HCN level, which increases with increase of total cyanide concentration and with decrease of pH. In some solutions however, a metal-cyanide complex ion per se was shown to be the major toxic component. The 48-hour median tolerance limits for bluegills of the dicyanoargentate (I) and dicyanocuprate (I) ions at 20°C were found to be approximately 9 and 4 mg/l as CN, respectively. The metallocyanide complex ions studied can be arranged in order of decreasing toxicity as follows: Cu(CN)₂⁻, Ag(CN)₂⁻, Ni(CN)₄⁻², and Fe(CN)₆⁻³ or Fe(CN)₆⁻⁴. A published empirical relationship between pH and 48-hour median tolerance limits of the nickelocyanide complex for a fish, determined without assurance that equilibria had been attained in test solutions, was compared with a calculated, theoretical relationship. Considerable divergence of the empirical and theoretical curves at pH values less than about 7.2 is ascribable mostly to the introduction of fish into test solutions long before equilibria had been attained in the solutions of low pH. Divergence at pH values greater than about 7.8 is attributable largely to moderate toxicity of the Ni(CN)₄⁻² complex ion itself. Slightly alkaline solutions of the silver cyanide complex, Ag(CN)₂⁻, become more toxic to sticklebacks with increase of chlorinity. The high toxicity in saline solutions, as compared with the toxicity in fresh water, is clearly attributable, at least in part or in some instances, to a molecular HCN content of the saline solutions much greater than that of comparable solutions prepared with fresh water. The two ligands CN⁻ and Cl⁻ compete for the silver ion, with which both ligands form complexes, and dissociation of the Ag(CN)₂⁻ ion, with production of HCN, consequently increases as the Cl⁻ ion concentration increases. Additional reasons for the observed increase of toxicity of solutions of the complex with increase of chlorinity can be an observed increase of the toxicity of HCN and a possible, similar increase of the toxicity of the complex ion. Experiments with ¹⁴C-labeled cyanide complexed with nickel showed that the complex does not penetrate readily into the body of a bluegill. The ¹⁴C accumulated in gill tissues much more markedly than it did in the blood and in tissues of internal organs sampled. When bluegills were exposed to solutions of the cyanide complexes of copper (I) and silver (I), considerable amounts of the metals accumulated in the blood and in tissues of internal organs, but little accumulation in gill tissues was observed. These results indicate that the cuprocyanide and silver-cyanide complexes enter the body of a bluegill much more readily than does the much less toxic nickelocyanide complex. The silver cation, however, apparently enters even more readily than does the silver-cyanide complex anion, the silver accumulating most markedly in the gill tissues of bluegills exposed to silver nitrate solutions, but also in their internal organ tissues. Close

• 2770. [Article] Age-specific and lifetime reproductive success of known age Northern Spotted Owls on four study areas in Oregon and Washington

  Northern Spotted Owls (Strix occidentalis caurina) are a long-lived forest owl and range-wide declines in their numbers have resulted in the species being listed as threatened under the endangered species ...

  Citation × Citation Citation Abstract Copy Title: Age-specific and lifetime reproductive success of known age Northern Spotted Owls on four study areas in Oregon and Washington Author: Loschl, Peter J. Northern Spotted Owls (Strix occidentalis caurina) are a long-lived forest owl and range-wide declines in their numbers have resulted in the species being listed as threatened under the endangered species act. While many studies have been focused on population trends and reproductive performance of Spotted Owls from different age-classes, none have examined age related performance or lifetime reproductive success of individual owls. Using data from known age Spotted Owls on four long-term demography studies in Oregon and Washington, I conducted separate analyses to examine the functional relationship of age and reproductive success, measured as the number of young fledged (NYF), and to examine lifetime reproductive success. In my age-specific analysis, I used a mixed models approach to account for repeated measures on individual owls. I found that the standard 3-level age-class approach (1-year-old, 2-year-old, adult) often used in Spotted Owl research was a poor fit relative to curvilinear and threshold models that allowed for age-dependent variation beyond age 3. A quadratic age effect was more often supported for males, whereas a threshold effect indicating a linear increase in NYF from ages 1 to 4 was most supported in the analyses of female data. Females tended to achieve a maximum in reproductive performance at earlier ages than males, and there appeared to be a negative relationship between the age when a maximum in mean NYF was reached and overall fecundity, as reported in earlier studies. Temporal variability in numbers of young fledged at each age was best modeled with a categorical year variable as opposed to a cyclic biennial ("even-odd") year effect. Lifetime reproductive success of Spotted Owls, measured as the total numbers of fledglings and recruits produced by individuals, varied widely. For owls with relatively complete data, the number of lifetime fledglings ranged from 0 to 20 and the number of lifetime offspring that were observed as recruits within study areas ranged from 0 to 7. There was a significant positive relationship between the number of lifetime young fledged and the number that later recruited locally. Seventy five percent of females and 67% of males bred at least once. Whereas 17% of females and 16% of males produced 50% of the offspring fledged by each sex, only 9% of females and 7% of males produced 50% of the banded young that were later observed as recruits. Thirty nine percent of females and 30% of males produced no fledglings and 64% of females and 69% of males produced no local recruits. Thus while most owls fledged at least 1 offspring, most did not produce any fledglings that recruited locally during the study. Cumulative proportions of individual owls that first bred at different ages indicated that females tended to initiate their breeding at earlier ages than males. Whereas 36% of females bred first at ages 1 or 2, only 19% of males bred first before age 3. Of the owls that bred, 98% of females and 91% of males bred at least once by age 6. Compared to owls on the three Oregon study areas, owls on the Cle Elum Study Area in the eastern Cascades of Washington bred early (>50% by age 2), had higher mean numbers of fledglings (>1) at most ages, and had short mean lifespans (6 years). On the Oregon study areas, owls first bred at later ages (>50% at age ≥3), had lower mean numbers of fledglings (0.4–0.7) at most ages, and had longer mean lifespans (7–9 years). These patterns appear consistent with a compensatory relationship between reproduction and survival that was suggested in at least one previous study. Life history theory is also consistent with the idea that where lower and more variable non-juvenile survival occurs (as has been documented on Cle Elum), selection pressure for earlier breeding and greater offspring production at each attempt are to be expected. Nevertheless, it is unclear if local conditions such as prey abundance, harsh winter conditions, or predation pressure act proximately to influence reproduction and survival of Spotted Owls in these studies, or if the variability in patterns of age-specific reproductive success and components of lifetime reproduction on these study areas reflect adaptive life history responses among populations of Spotted Owls. It is likely that both plasticity and life history adaptations underlie the differences and patterns that were revealed, but tests of these hypotheses were beyond the scope of my study. Title: Age-specific and lifetime reproductive success of known age Northern Spotted Owls on four study areas in Oregon and Washington Author: Loschl, Peter J. Northern Spotted Owls (Strix occidentalis caurina) are a long-lived forest owl and range-wide declines in their numbers have resulted in the species being listed as threatened under the endangered species act. While many studies have been focused on population trends and reproductive performance of Spotted Owls from different age-classes, none have examined age related performance or lifetime reproductive success of individual owls. Using data from known age Spotted Owls on four long-term demography studies in Oregon and Washington, I conducted separate analyses to examine the functional relationship of age and reproductive success, measured as the number of young fledged (NYF), and to examine lifetime reproductive success. In my age-specific analysis, I used a mixed models approach to account for repeated measures on individual owls. I found that the standard 3-level age-class approach (1-year-old, 2-year-old, adult) often used in Spotted Owl research was a poor fit relative to curvilinear and threshold models that allowed for age-dependent variation beyond age 3. A quadratic age effect was more often supported for males, whereas a threshold effect indicating a linear increase in NYF from ages 1 to 4 was most supported in the analyses of female data. Females tended to achieve a maximum in reproductive performance at earlier ages than males, and there appeared to be a negative relationship between the age when a maximum in mean NYF was reached and overall fecundity, as reported in earlier studies. Temporal variability in numbers of young fledged at each age was best modeled with a categorical year variable as opposed to a cyclic biennial ("even-odd") year effect. Lifetime reproductive success of Spotted Owls, measured as the total numbers of fledglings and recruits produced by individuals, varied widely. For owls with relatively complete data, the number of lifetime fledglings ranged from 0 to 20 and the number of lifetime offspring that were observed as recruits within study areas ranged from 0 to 7. There was a significant positive relationship between the number of lifetime young fledged and the number that later recruited locally. Seventy five percent of females and 67% of males bred at least once. Whereas 17% of females and 16% of males produced 50% of the offspring fledged by each sex, only 9% of females and 7% of males produced 50% of the banded young that were later observed as recruits. Thirty nine percent of females and 30% of males produced no fledglings and 64% of females and 69% of males produced no local recruits. Thus while most owls fledged at least 1 offspring, most did not produce any fledglings that recruited locally during the study. Cumulative proportions of individual owls that first bred at different ages indicated that females tended to initiate their breeding at earlier ages than males. Whereas 36% of females bred first at ages 1 or 2, only 19% of males bred first before age 3. Of the owls that bred, 98% of females and 91% of males bred at least once by age 6. Compared to owls on the three Oregon study areas, owls on the Cle Elum Study Area in the eastern Cascades of Washington bred early (>50% by age 2), had higher mean numbers of fledglings (>1) at most ages, and had short mean lifespans (6 years). On the Oregon study areas, owls first bred at later ages (>50% at age ≥3), had lower mean numbers of fledglings (0.4–0.7) at most ages, and had longer mean lifespans (7–9 years). These patterns appear consistent with a compensatory relationship between reproduction and survival that was suggested in at least one previous study. Life history theory is also consistent with the idea that where lower and more variable non-juvenile survival occurs (as has been documented on Cle Elum), selection pressure for earlier breeding and greater offspring production at each attempt are to be expected. Nevertheless, it is unclear if local conditions such as prey abundance, harsh winter conditions, or predation pressure act proximately to influence reproduction and survival of Spotted Owls in these studies, or if the variability in patterns of age-specific reproductive success and components of lifetime reproduction on these study areas reflect adaptive life history responses among populations of Spotted Owls. It is likely that both plasticity and life history adaptations underlie the differences and patterns that were revealed, but tests of these hypotheses were beyond the scope of my study. Close