Search

Search Results

• 21. [Article] Global Trends in Capture Fisheries, With an Estimate of Global Losses in Marine Fisheries Resource Rents

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Global Trends in Capture Fisheries, With an Estimate of Global Losses in Marine Fisheries Resource Rents Author: Franz, Nicole, Arnason, Ragnar, Willmann, Rolf, Kelleher, Kieran Abstract only. Title: Global Trends in Capture Fisheries, With an Estimate of Global Losses in Marine Fisheries Resource Rents Author: Franz, Nicole, Arnason, Ragnar, Willmann, Rolf, Kelleher, Kieran Abstract only. Close

• 22. [Article] Price and Quantity Indices for Aquaculture Production in Europe

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Price and Quantity Indices for Aquaculture Production in Europe Author: Millán, Joaquín A., Aldaz, Natalia Research Paper Title: Price and Quantity Indices for Aquaculture Production in Europe Author: Millán, Joaquín A., Aldaz, Natalia Research Paper Close

• 23. [Article] Investigation of Age-Related Incidence Patterns in Adult Cancers

  One of the most commonly diagnosed illnesses in the elderly population is cancer. Despite research to explain the consistent increase in incidence rates with age, the mechanisms are largely unknown. In ...

  Citation × Citation Citation Abstract Copy Title: Investigation of Age-Related Incidence Patterns in Adult Cancers Author: Fulton, Stephanie E. One of the most commonly diagnosed illnesses in the elderly population is cancer. Despite research to explain the consistent increase in incidence rates with age, the mechanisms are largely unknown. In order to explore the patterns in age-specific cancer incidence through visualization, tables and graphs were generated via SEER*stat of incidence statistics for each reported type of cancer, including all subtypes. More specifically, data from the Surveillance, Epidemiology, and End Results (SEER) program was used to calculate age-specific rates by sex and race/ethnicity. Patterns were compared to a general trend line of the total cancer incidence from the years 1975-2013, with a focus on incidence in the age group 85+. Results varied substantially by cancer type. We defined four patterns within the cancers: an increasing trend with increasing age; a decreasing trend in older ages, a mixed pattern (some increasing, while others decrease within the same cancer type), and a bimodal curve which included peaks in childhood/adolescence and in older age. Trends varied greatly depending on the type of cancer, the age at which the cancers were diagnosed, the sex of the individual, and the race/ethnicity of the individual. Age-specific patterns in African-American populations were particularly noteworthy and are presented separately. Title: Investigation of Age-Related Incidence Patterns in Adult Cancers Author: Fulton, Stephanie E. One of the most commonly diagnosed illnesses in the elderly population is cancer. Despite research to explain the consistent increase in incidence rates with age, the mechanisms are largely unknown. In order to explore the patterns in age-specific cancer incidence through visualization, tables and graphs were generated via SEER*stat of incidence statistics for each reported type of cancer, including all subtypes. More specifically, data from the Surveillance, Epidemiology, and End Results (SEER) program was used to calculate age-specific rates by sex and race/ethnicity. Patterns were compared to a general trend line of the total cancer incidence from the years 1975-2013, with a focus on incidence in the age group 85+. Results varied substantially by cancer type. We defined four patterns within the cancers: an increasing trend with increasing age; a decreasing trend in older ages, a mixed pattern (some increasing, while others decrease within the same cancer type), and a bimodal curve which included peaks in childhood/adolescence and in older age. Trends varied greatly depending on the type of cancer, the age at which the cancers were diagnosed, the sex of the individual, and the race/ethnicity of the individual. Age-specific patterns in African-American populations were particularly noteworthy and are presented separately. Close

• 24. [Article] Trends in Fishery Ecn Edu-Publications.docx

  Citation × Citation Citation Abstract Copy Title: Trends in Fishery Ecn Edu-Publications.docx Author: Webster, Janet G., Sylvia, Gil Title: Trends in Fishery Ecn Edu-Publications.docx Author: Webster, Janet G., Sylvia, Gil Close

• 25. [Article] Interacting effects of climate, forest dynamics, landforms, and river regulation on streamflow trends since 1950 : examples from the Willamette Basin and forested headwater sites in the US

  Streamflow patterns are a result of the interaction of many factors, including climate, vegetation, geology, and topography. Analyses indicate that streamflow patterns have changed around the United States ...

  Citation × Citation Citation Abstract Copy Title: Interacting effects of climate, forest dynamics, landforms, and river regulation on streamflow trends since 1950 : examples from the Willamette Basin and forested headwater sites in the US Author: Hatcher, Kendra L. Streamflow patterns are a result of the interaction of many factors, including climate, vegetation, geology, and topography. Analyses indicate that streamflow patterns have changed around the United States over the past century, raising questions about the possible role of climate variability as a driver of water yield. This thesis examines streamflow trends in two separate analyses: a study of streamflow trends and the physical characteristics of large basins in the Willamette River Basin, and a study of streamflow trends in small headwater basins around the United States. In the Willamette River basin, as in much of the western US where summer precipitation is low, declining streamflow will exacerbate the task of water management to meet varying demands for water. Although regional climate warming over the past half-century in the Pacific Northwest is a plausible cause of declining streamflow, climate is only one of several factors that determine the hydrologic regime of the Willamette River basin. This study quantified trends in streamflow from 1950 to 2010 in ten sub-basins of the Willamette, including seven 60-600 km² predominantly forested sub-basins above dams in the Willamette National Forest, and three gages downstream of dams in urban areas of the Willamette valley (Albany, Salem, and Portland). Trends at the annual, seasonal, and daily time scales were estimated using linear regression with appropriate transformation of variables and the Mann-Kendall non-parametric test. Trends in streamflow and runoff ratios in the Willamette Basin were compared to geology, topography, and changes in forest cover above dams. Data on forest cover by age class were obtained from Willamette National Forest. Up to 29% of area in sub-basins above dams was clearcut since the 1930s. From 1 to 51% of basin area above dams is on young (<7 ma) volcanic rocks of the High Cascades, which have longer water residence times than the older (7-25 ma) volcanic rocks of the western Cascades, which make up the remainder of basin area above dams. From 71 to 93% of basin area above dams is above 800 m elevation, where seasonal snowpacks are controlled by winter temperature and precipitation. Over the study period (1950-2010), precipitation in the Willamette River basin did not change significantly at the seasonal or annual time scale. Declining streamflows in spring and summer were found in low elevation basins above dams. These trends may be attributed to climate-warming-induced increases in the rain:snow ratio and earlier snowmelt, or changes in water use by vegetation in response to climate warming, or both. More rapid declines in summer and fall discharge and runoff ratios occurred in basins which experienced relatively rapid conversion of old to young forest in the past half-century and have relatively large proportions of young forest today. Declining flows can be attributed to increasing evapotranspiration in young forests and shallow flow paths in Western Cascades-dominated basins that intersect the rooting zone. High-elevation basins with greater percentages of High Cascades geology are less susceptible to declining discharge, even if they have substantial areas in young forest. In contrast to the trends in streamflow above dams, trends over time in streamflow downstream of dams in the Willamette basin have been largely influenced by management of reservoirs and flow. Flow downstream of the dams has become more homogenized throughout the year, with higher flows in the fall and declines in the later winter/early spring. However, discharge has declined at the annual time scale, and in the spring and summer. These trends may be a result of flow management, decreasing spring streamflow upstream of the dams, or a recent trend of relatively dry years. Although historical water yields may not be representative of future water yields, long term historical climate and discharge records from instrumented sites provide the basis for understanding the effects of climate variability on water yield from headwater systems. This study quantified trends in climate and streamflow data from eight predominantly forested headwater basins in the US to understand the complex relationships between climate change, basin geography, vegetation, history, and hydrology. Data were obtained for up to 70-year periods from the Long Term Ecological Research (LTER) network and US Forest Service system of Experimental Forests and Ranges (EFR). Trends in precipitation, temperature, discharge, and runoff ratios were calculated for annual, seasonal, and daily data using linear regression of appropriately transformed data and Mann-Kendall non-parametric tests. Linear regression with appropriate transformation of variables produced similar results to the Mann-Kendall analysis. The first day of spring (defined as the last day of freezing temperature) has moved earlier by 0.31 to 1.98 days/year at all sites, except the alpine site. Most sites experienced significant increases in spring minimum air temperature, but only a few sites experienced an associated change in spring runoff ratios. Spring runoff ratios decreased in sites with snowpacks and near-zero mean spring air temperature (AND). Fall baseflow increased at the alpine, non-forested site (NWT), apparently as a result of increased permafrost melt. Earlier snowmelt and decreases in spring discharge and runoff ratios are expected to lead to increases in winter streamflow and reductions in summer streamflow. However, despite increases in summer minimum air temperature at most sites, summer runoff ratios did not change at most sites, and some sites (HBR, FER) experienced increases in summer and fall runoff ratios. The expected reduction in summer runoff ratios in response to warmer temperature at these sites may have been mitigated by reductions in leaf area due to disturbance or forest succession after logging in the early 1900s. These findings indicate that both climate change and hydrologic response to climate change varies across the US. The lack of expected streamflow responses apparently is the result of ecosystem processes that produce counteracting trends in vegetation water use in response to climate trends; these processes deserve further study. Title: Interacting effects of climate, forest dynamics, landforms, and river regulation on streamflow trends since 1950 : examples from the Willamette Basin and forested headwater sites in the US Author: Hatcher, Kendra L. Streamflow patterns are a result of the interaction of many factors, including climate, vegetation, geology, and topography. Analyses indicate that streamflow patterns have changed around the United States over the past century, raising questions about the possible role of climate variability as a driver of water yield. This thesis examines streamflow trends in two separate analyses: a study of streamflow trends and the physical characteristics of large basins in the Willamette River Basin, and a study of streamflow trends in small headwater basins around the United States. In the Willamette River basin, as in much of the western US where summer precipitation is low, declining streamflow will exacerbate the task of water management to meet varying demands for water. Although regional climate warming over the past half-century in the Pacific Northwest is a plausible cause of declining streamflow, climate is only one of several factors that determine the hydrologic regime of the Willamette River basin. This study quantified trends in streamflow from 1950 to 2010 in ten sub-basins of the Willamette, including seven 60-600 km² predominantly forested sub-basins above dams in the Willamette National Forest, and three gages downstream of dams in urban areas of the Willamette valley (Albany, Salem, and Portland). Trends at the annual, seasonal, and daily time scales were estimated using linear regression with appropriate transformation of variables and the Mann-Kendall non-parametric test. Trends in streamflow and runoff ratios in the Willamette Basin were compared to geology, topography, and changes in forest cover above dams. Data on forest cover by age class were obtained from Willamette National Forest. Up to 29% of area in sub-basins above dams was clearcut since the 1930s. From 1 to 51% of basin area above dams is on young (<7 ma) volcanic rocks of the High Cascades, which have longer water residence times than the older (7-25 ma) volcanic rocks of the western Cascades, which make up the remainder of basin area above dams. From 71 to 93% of basin area above dams is above 800 m elevation, where seasonal snowpacks are controlled by winter temperature and precipitation. Over the study period (1950-2010), precipitation in the Willamette River basin did not change significantly at the seasonal or annual time scale. Declining streamflows in spring and summer were found in low elevation basins above dams. These trends may be attributed to climate-warming-induced increases in the rain:snow ratio and earlier snowmelt, or changes in water use by vegetation in response to climate warming, or both. More rapid declines in summer and fall discharge and runoff ratios occurred in basins which experienced relatively rapid conversion of old to young forest in the past half-century and have relatively large proportions of young forest today. Declining flows can be attributed to increasing evapotranspiration in young forests and shallow flow paths in Western Cascades-dominated basins that intersect the rooting zone. High-elevation basins with greater percentages of High Cascades geology are less susceptible to declining discharge, even if they have substantial areas in young forest. In contrast to the trends in streamflow above dams, trends over time in streamflow downstream of dams in the Willamette basin have been largely influenced by management of reservoirs and flow. Flow downstream of the dams has become more homogenized throughout the year, with higher flows in the fall and declines in the later winter/early spring. However, discharge has declined at the annual time scale, and in the spring and summer. These trends may be a result of flow management, decreasing spring streamflow upstream of the dams, or a recent trend of relatively dry years. Although historical water yields may not be representative of future water yields, long term historical climate and discharge records from instrumented sites provide the basis for understanding the effects of climate variability on water yield from headwater systems. This study quantified trends in climate and streamflow data from eight predominantly forested headwater basins in the US to understand the complex relationships between climate change, basin geography, vegetation, history, and hydrology. Data were obtained for up to 70-year periods from the Long Term Ecological Research (LTER) network and US Forest Service system of Experimental Forests and Ranges (EFR). Trends in precipitation, temperature, discharge, and runoff ratios were calculated for annual, seasonal, and daily data using linear regression of appropriately transformed data and Mann-Kendall non-parametric tests. Linear regression with appropriate transformation of variables produced similar results to the Mann-Kendall analysis. The first day of spring (defined as the last day of freezing temperature) has moved earlier by 0.31 to 1.98 days/year at all sites, except the alpine site. Most sites experienced significant increases in spring minimum air temperature, but only a few sites experienced an associated change in spring runoff ratios. Spring runoff ratios decreased in sites with snowpacks and near-zero mean spring air temperature (AND). Fall baseflow increased at the alpine, non-forested site (NWT), apparently as a result of increased permafrost melt. Earlier snowmelt and decreases in spring discharge and runoff ratios are expected to lead to increases in winter streamflow and reductions in summer streamflow. However, despite increases in summer minimum air temperature at most sites, summer runoff ratios did not change at most sites, and some sites (HBR, FER) experienced increases in summer and fall runoff ratios. The expected reduction in summer runoff ratios in response to warmer temperature at these sites may have been mitigated by reductions in leaf area due to disturbance or forest succession after logging in the early 1900s. These findings indicate that both climate change and hydrologic response to climate change varies across the US. The lack of expected streamflow responses apparently is the result of ecosystem processes that produce counteracting trends in vegetation water use in response to climate trends; these processes deserve further study. Close

• 26. [Article] Trends in Fish Price Volatility: Icelandic Whitefish

  For centuries, the Icelandic people has relied on its abundance of natural resources and fisheries in particular. In today’s volatile and homogenous economy of Iceland, fisheries is one of its main export ...

  Citation × Citation Citation Abstract Copy Title: Trends in Fish Price Volatility: Icelandic Whitefish Author: Asche, Frank, Jonsson, Erlendur, Dahl, Roy Endré For centuries, the Icelandic people has relied on its abundance of natural resources and fisheries in particular. In today’s volatile and homogenous economy of Iceland, fisheries is one of its main export industries, together with power-intensive manufacturing and tourism. Consequently, movements in fish prices have a significant effect on the economy as a whole, making the small nation of Iceland vulnerable to fish price volatility.  In this study, we investigate market price uncertainty of exported whitefish in Iceland. Among whitefish, cod is the most important fish species for the Icelandic fisheres, with haddock and pollack following. We model the price volatility for a set of whitefish speiees and establish empirically that price volatility is stable or in a downward trend. Contributing factors such as the food price trends and trends in world whitefish markets are discussed. In addition, we account for other contributing factors to volatility such as the financial crisis, exchange rates, quota restriction and policy implications. Title: Trends in Fish Price Volatility: Icelandic Whitefish Author: Asche, Frank, Jonsson, Erlendur, Dahl, Roy Endré For centuries, the Icelandic people has relied on its abundance of natural resources and fisheries in particular. In today’s volatile and homogenous economy of Iceland, fisheries is one of its main export industries, together with power-intensive manufacturing and tourism. Consequently, movements in fish prices have a significant effect on the economy as a whole, making the small nation of Iceland vulnerable to fish price volatility.  In this study, we investigate market price uncertainty of exported whitefish in Iceland. Among whitefish, cod is the most important fish species for the Icelandic fisheres, with haddock and pollack following. We model the price volatility for a set of whitefish speiees and establish empirically that price volatility is stable or in a downward trend. Contributing factors such as the food price trends and trends in world whitefish markets are discussed. In addition, we account for other contributing factors to volatility such as the financial crisis, exchange rates, quota restriction and policy implications. Close

• 27. [Article] Analysis of Greater Sage-grouse Lek Data: Trends in Peak Male Counts 1965-2015

  Trends in greater sage-grouse breeding populations are typically indexed by determining the peak number of males attending a lek in a lekking season. Numerous studies have estimated negative trends in ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Greater Sage-grouse Lek Data: Trends in Peak Male Counts 1965-2015 Author: Nielson, Ryan M. Trends in greater sage-grouse breeding populations are typically indexed by determining the peak number of males attending a lek in a lekking season. Numerous studies have estimated negative trends in sage-grouse breeding populations over time via data collected for the last 50 years. However, the inherent bias in data collection and unknown relationship between lek counts and population size limits the utility of using counts to evaluate range-wide population trends. This study estimated trends in the male segment of greater sage-grouse breeding populations within core and periphery areas in seven habitat management zones during two time periods, 1965-2015 and 2005-2015. In addition, we compared analysis methods used in this study to previous studies, and provided recommendations on future data collection. We developed a hierarchical model that followed individual leks through time and allowed trends at individual leks to inform estimates of regional trends. We fit overdispersed Poisson models using a Bayesian hierarchical framework and Markov-chain Monte Carlo (MCMC) methods. The average range-wide decline, weighted across management zones, was 2.10% per year, for an average total decline of 66% from 1965-2015. Estimates of trend over 2005-2015 for individual management zones, in both core and periphery areas, indicated that recent annual declines were more severe compared to the average declines over the entire analysis period 1965-2015. The declines estimated in this study were similar to other studies; however, review of the literature reveals numerous issues surrounding the historical data, the on-going monitoring and sampling scheme, and utilization of various statistical methods, all of which limit our inference on population trends. We believe the overdispersed Poisson regression model is the most appropriate analysis method for these and future data, regardless of whether the focus remains on peak male counts or total counts of observed sage-grouse based on a more spatially balanced sample of monitoring sites that are randomly selected. Title: Analysis of Greater Sage-grouse Lek Data: Trends in Peak Male Counts 1965-2015 Author: Nielson, Ryan M. Trends in greater sage-grouse breeding populations are typically indexed by determining the peak number of males attending a lek in a lekking season. Numerous studies have estimated negative trends in sage-grouse breeding populations over time via data collected for the last 50 years. However, the inherent bias in data collection and unknown relationship between lek counts and population size limits the utility of using counts to evaluate range-wide population trends. This study estimated trends in the male segment of greater sage-grouse breeding populations within core and periphery areas in seven habitat management zones during two time periods, 1965-2015 and 2005-2015. In addition, we compared analysis methods used in this study to previous studies, and provided recommendations on future data collection. We developed a hierarchical model that followed individual leks through time and allowed trends at individual leks to inform estimates of regional trends. We fit overdispersed Poisson models using a Bayesian hierarchical framework and Markov-chain Monte Carlo (MCMC) methods. The average range-wide decline, weighted across management zones, was 2.10% per year, for an average total decline of 66% from 1965-2015. Estimates of trend over 2005-2015 for individual management zones, in both core and periphery areas, indicated that recent annual declines were more severe compared to the average declines over the entire analysis period 1965-2015. The declines estimated in this study were similar to other studies; however, review of the literature reveals numerous issues surrounding the historical data, the on-going monitoring and sampling scheme, and utilization of various statistical methods, all of which limit our inference on population trends. We believe the overdispersed Poisson regression model is the most appropriate analysis method for these and future data, regardless of whether the focus remains on peak male counts or total counts of observed sage-grouse based on a more spatially balanced sample of monitoring sites that are randomly selected. Close

• 28. [Article] Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 to 2010: a new look at an old problem

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10533.

  Citation × Citation Citation Abstract Copy Title: Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 to 2010: a new look at an old problem Author: Lajtha, Kate, Jones, Julia This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10533. Title: Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 to 2010: a new look at an old problem Author: Lajtha, Kate, Jones, Julia This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10533. Close

• 29. [Article] Shear development and overprinting in a back-arc basin, Klamath Falls, Oregon

  Celebration of Undergraduate Excellence (2013)

  Citation × Citation Citation Abstract Copy Title: Shear development and overprinting in a back-arc basin, Klamath Falls, Oregon Author: Meigs, Andrew, Waldien, Trevor Celebration of Undergraduate Excellence (2013) Title: Shear development and overprinting in a back-arc basin, Klamath Falls, Oregon Author: Meigs, Andrew, Waldien, Trevor Celebration of Undergraduate Excellence (2013) Close

• 30. [Article] Oregon's long-term trends in agriculture (1925-1929 to 1945-1949)

  Published November 1951. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/cata...

  Citation × Citation Citation Abstract Copy Title: Oregon's long-term trends in agriculture (1925-1929 to 1945-1949) Author: Oregon State College. Federal Cooperative Extension Service Published November 1951. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Oregon's long-term trends in agriculture (1925-1929 to 1945-1949) Author: Oregon State College. Federal Cooperative Extension Service Published November 1951. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close