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• 11. [Article] Critically endangered western gray whales migrate to the eastern North Pacific

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Author(s) and published by the Royal Society. It can be found at: http://r...

  Citation × Citation Citation Abstract Copy Title: Critically endangered western gray whales migrate to the eastern North Pacific Author: Bradford, Amanda L., Tsidulko, Grigory A., Irvine, Ladd M., Mate, Bruce R., Rozhnov, Vyacheslav V., Vertyankin, Vladimir V., Ilyashenko, Valentin Yu. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Author(s) and published by the Royal Society. It can be found at: http://rsbl.royalsocietypublishing.org/ Title: Critically endangered western gray whales migrate to the eastern North Pacific Author: Bradford, Amanda L., Tsidulko, Grigory A., Irvine, Ladd M., Mate, Bruce R., Rozhnov, Vyacheslav V., Vertyankin, Vladimir V., Ilyashenko, Valentin Yu. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Author(s) and published by the Royal Society. It can be found at: http://rsbl.royalsocietypublishing.org/ Close

• 12. [Article] Migratory behavior and passage of redband trout (Oncorhynchus mykiss) in the Donner und Blitzen River, Oregon

  Salmonids in arid high-elevation streams find themselves at the fringe of their tolerance range. Under the conditions they endure in such environments, long-distance migratory movements among widely dispersed ...

  Citation × Citation Citation Abstract Copy Title: Migratory behavior and passage of redband trout (Oncorhynchus mykiss) in the Donner und Blitzen River, Oregon Author: Anderson, Matthew C. Salmonids in arid high-elevation streams find themselves at the fringe of their tolerance range. Under the conditions they endure in such environments, long-distance migratory movements among widely dispersed habitats may be an important mechanism for some fish to persist, and even thrive. The Donner und Blitzen (Blitzen) River redband trout (Oncorhynchus mykiss gairdneri) population is known to have a migratory life-history component, but little is known about the timing, spatial patterns, or ecological context of the migration. I tracked trout movements and passage delays at diversion dams with radio telemetry and passive integrated transponder (PIT) tags from March 2007 to November 2008. PIT tag readers established at four locations (river km 1, 35, 48, and 76) recorded large-scale movements of trout. Three of the readers also recorded ladder entry time, ladder ascending time, and total passage time of each trout. My results indicated the existence of a life-history in which redband trout made long-distance migrations both as sub-adults and as adults. While adult trout migrated for reproductive purposes, movement of immature individuals appeared to be a response to seasonal stream temperature conditions. Trout migration rate was positively correlated with fork length and mean river discharge but was not associated with stream temperature, tagging method, or the number of dams passed. The upstream-most detection location for radio-tagged adults that reached potential spawning habitat was not different for trout from the lower river versus the middle river (t(42) = 1.07, p = .29); however, lower river trout reached spawning habitats an average of 20 days later (t(42) = 3.78, p < .001). Passage times at the dams were not affected by discharge, fork length, or tagging method. At a jump-pool ladder trout were 7.23 times more likely to pass during day than at night (2(1, N = 40) = 9.96, p = .002). At a Denil ladder, trout were 25.6% more likely to pass with each degree Celsius increase in stream temperature (2(1, N = 22) = 4.39, p = .036). At all three dams, a greater proportion of the total passage time involved trout finding and entering the ladder than ascending the ladder after initial entry. Trout passage times varied significantly between each of the dams. This study highlights the importance of landscape-scale distribution of habitats and refugia in determining life-history and movement patterns of trout. Migratory behavior was related to both life-stage and environmental conditions. Maintaining connectivity with efficient passage throughout the river is a critical element in managing migratory fish populations like the one in this study. The well-functioning fish ladders were those that provided adequate fish attraction, while those ladders with poor attraction delayed migrating trout for long periods. Title: Migratory behavior and passage of redband trout (Oncorhynchus mykiss) in the Donner und Blitzen River, Oregon Author: Anderson, Matthew C. Salmonids in arid high-elevation streams find themselves at the fringe of their tolerance range. Under the conditions they endure in such environments, long-distance migratory movements among widely dispersed habitats may be an important mechanism for some fish to persist, and even thrive. The Donner und Blitzen (Blitzen) River redband trout (Oncorhynchus mykiss gairdneri) population is known to have a migratory life-history component, but little is known about the timing, spatial patterns, or ecological context of the migration. I tracked trout movements and passage delays at diversion dams with radio telemetry and passive integrated transponder (PIT) tags from March 2007 to November 2008. PIT tag readers established at four locations (river km 1, 35, 48, and 76) recorded large-scale movements of trout. Three of the readers also recorded ladder entry time, ladder ascending time, and total passage time of each trout. My results indicated the existence of a life-history in which redband trout made long-distance migrations both as sub-adults and as adults. While adult trout migrated for reproductive purposes, movement of immature individuals appeared to be a response to seasonal stream temperature conditions. Trout migration rate was positively correlated with fork length and mean river discharge but was not associated with stream temperature, tagging method, or the number of dams passed. The upstream-most detection location for radio-tagged adults that reached potential spawning habitat was not different for trout from the lower river versus the middle river (t(42) = 1.07, p = .29); however, lower river trout reached spawning habitats an average of 20 days later (t(42) = 3.78, p < .001). Passage times at the dams were not affected by discharge, fork length, or tagging method. At a jump-pool ladder trout were 7.23 times more likely to pass during day than at night (2(1, N = 40) = 9.96, p = .002). At a Denil ladder, trout were 25.6% more likely to pass with each degree Celsius increase in stream temperature (2(1, N = 22) = 4.39, p = .036). At all three dams, a greater proportion of the total passage time involved trout finding and entering the ladder than ascending the ladder after initial entry. Trout passage times varied significantly between each of the dams. This study highlights the importance of landscape-scale distribution of habitats and refugia in determining life-history and movement patterns of trout. Migratory behavior was related to both life-stage and environmental conditions. Maintaining connectivity with efficient passage throughout the river is a critical element in managing migratory fish populations like the one in this study. The well-functioning fish ladders were those that provided adequate fish attraction, while those ladders with poor attraction delayed migrating trout for long periods. Close

• 13. [Article] Lakeview Newcomers: Mexican and Caucasian Perspectives

  Citation × Citation Citation Abstract Copy Title: Lakeview Newcomers: Mexican and Caucasian Perspectives Author: Johnson, Carly Title: Lakeview Newcomers: Mexican and Caucasian Perspectives Author: Johnson, Carly Close

• 14. [Article] IrvineLaddHMSCCriticallyEndangeredWesternGrayWhales.pdf

  Citation × Citation Citation Abstract Copy Title: IrvineLaddHMSCCriticallyEndangeredWesternGrayWhales.pdf Author: Vertyankin, Vladimir V., Tsidulko, Grigory A., Irvine, Ladd M., Ilyashenko, Valentin Yu., Rozhnov, Vyacheslav V., Bradford, Amanda L., Mate, Bruce R. Title: IrvineLaddHMSCCriticallyEndangeredWesternGrayWhales.pdf Author: Vertyankin, Vladimir V., Tsidulko, Grigory A., Irvine, Ladd M., Ilyashenko, Valentin Yu., Rozhnov, Vyacheslav V., Bradford, Amanda L., Mate, Bruce R. Close

• 15. [Article] Foraging ecology, diving behavior, and migration patterns of harbor seals (Phoca vitulina richardii) from a glacial fjord in Alaska in relation to prey availability and oceanographic features

  Understanding the movement behavior and foraging strategies of individuals across multiple spatial and temporal scales is essential not only for understanding the biological requirements of individuals ...

  Citation × Citation Citation Abstract Copy Title: Foraging ecology, diving behavior, and migration patterns of harbor seals (Phoca vitulina richardii) from a glacial fjord in Alaska in relation to prey availability and oceanographic features Author: Womble, Jamie Neil Understanding the movement behavior and foraging strategies of individuals across multiple spatial and temporal scales is essential not only for understanding the biological requirements of individuals but also for linking individual strategies to population level effects. Glacial fjords scattered throughout south-central and southeastern Alaska host some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world, and an estimated 15% of the harbor seal population in Alaska is found seasonally at these glacial ice sites. Over the last two decades, the number of harbor seals has declined at two of the primary glacial fjords, in Aialik Bay in south-central Alaska and in Glacier Bay in southeastern Alaska, thus raising concerns regarding the viability of seal populations in glacial fjord environments. From 2004-2009, the foraging ecology, diving behavior, and migration patterns of harbor seals from Glacier Bay National Park, Alaska were examined in relation to prey availability and oceanographic features in Glacier Bay and the surrounding regions of southeastern Alaska. Time-depth recorders, very high frequency transmitters, and satellite-linked transmitters were used to quantify the vertical and horizontal movement patterns of harbor seals in the marine environment. Specifically, (1) I characterized the diving behavior, foraging areas, and foraging strategies of female harbor seals from terrestrial and glacial ice sites relative to prey availability during the breeding season (May-June) in Glacier Bay, (2) I quantified the intra-population variation in at-sea post-breeding season (September-April) distribution and movement patterns of female harbor seals in relation to oceanographic features, (3) I quantified the post-breeding season migration patterns of female harbor seals relative to the boundaries of the marine protected area of Glacier Bay National Park, and (4) I characterized the use of the continental shelf region of the eastern Gulf of Alaska by female harbor seals from Glacier Bay, both as a foraging area and as a migratory corridor in relation to oceanographic features. During the breeding season, there was a substantial degree of intra-population variation in the diving behavior and foraging areas of juvenile and adult female seals from glacial ice and terrestrial sites in Glacier Bay. The presence of multiple diving strategies suggests that differences in the relative density and depth of prey fields in glacial ice and terrestrial habitats in addition to seal age and reproductive status may influence diving and foraging behavior of harbor seals. During the post-breeding season, juvenile and adult female harbor seals ranged extensively beyond the boundaries of the marine protected area of Glacier Bay National Park, throughout the northern inshore waters of southeastern Alaska and the continental shelf region of the eastern Gulf of Alaska between Cross Sound and Prince William Sound, Alaska (up to 900 kilometers away). Seals exhibited a relatively high degree of intra-population variation in their at-sea post-breeding season distribution patterns that may be a function of extrinsic factors such as oceanographic characteristics, which can influence prey availability as well as intrinsic factors including previous experience with foraging areas and seal condition and age. Use of the continental shelf region of the eastern Gulf of Alaska by harbor seals as a foraging area may be due to enhanced biological productivity which may be associated with ephemeral hydrographic and/or static bathymetric features. Despite extensive migrations of seals from Glacier Bay during the post-breeding season, there was a high degree of inter-annual site fidelity of seals to Glacier Bay the following breeding season after seals were captured. Title: Foraging ecology, diving behavior, and migration patterns of harbor seals (Phoca vitulina richardii) from a glacial fjord in Alaska in relation to prey availability and oceanographic features Author: Womble, Jamie Neil Understanding the movement behavior and foraging strategies of individuals across multiple spatial and temporal scales is essential not only for understanding the biological requirements of individuals but also for linking individual strategies to population level effects. Glacial fjords scattered throughout south-central and southeastern Alaska host some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world, and an estimated 15% of the harbor seal population in Alaska is found seasonally at these glacial ice sites. Over the last two decades, the number of harbor seals has declined at two of the primary glacial fjords, in Aialik Bay in south-central Alaska and in Glacier Bay in southeastern Alaska, thus raising concerns regarding the viability of seal populations in glacial fjord environments. From 2004-2009, the foraging ecology, diving behavior, and migration patterns of harbor seals from Glacier Bay National Park, Alaska were examined in relation to prey availability and oceanographic features in Glacier Bay and the surrounding regions of southeastern Alaska. Time-depth recorders, very high frequency transmitters, and satellite-linked transmitters were used to quantify the vertical and horizontal movement patterns of harbor seals in the marine environment. Specifically, (1) I characterized the diving behavior, foraging areas, and foraging strategies of female harbor seals from terrestrial and glacial ice sites relative to prey availability during the breeding season (May-June) in Glacier Bay, (2) I quantified the intra-population variation in at-sea post-breeding season (September-April) distribution and movement patterns of female harbor seals in relation to oceanographic features, (3) I quantified the post-breeding season migration patterns of female harbor seals relative to the boundaries of the marine protected area of Glacier Bay National Park, and (4) I characterized the use of the continental shelf region of the eastern Gulf of Alaska by female harbor seals from Glacier Bay, both as a foraging area and as a migratory corridor in relation to oceanographic features. During the breeding season, there was a substantial degree of intra-population variation in the diving behavior and foraging areas of juvenile and adult female seals from glacial ice and terrestrial sites in Glacier Bay. The presence of multiple diving strategies suggests that differences in the relative density and depth of prey fields in glacial ice and terrestrial habitats in addition to seal age and reproductive status may influence diving and foraging behavior of harbor seals. During the post-breeding season, juvenile and adult female harbor seals ranged extensively beyond the boundaries of the marine protected area of Glacier Bay National Park, throughout the northern inshore waters of southeastern Alaska and the continental shelf region of the eastern Gulf of Alaska between Cross Sound and Prince William Sound, Alaska (up to 900 kilometers away). Seals exhibited a relatively high degree of intra-population variation in their at-sea post-breeding season distribution patterns that may be a function of extrinsic factors such as oceanographic characteristics, which can influence prey availability as well as intrinsic factors including previous experience with foraging areas and seal condition and age. Use of the continental shelf region of the eastern Gulf of Alaska by harbor seals as a foraging area may be due to enhanced biological productivity which may be associated with ephemeral hydrographic and/or static bathymetric features. Despite extensive migrations of seals from Glacier Bay during the post-breeding season, there was a high degree of inter-annual site fidelity of seals to Glacier Bay the following breeding season after seals were captured. Close

• 16. [Article] IrvineLaddHMSCCriticallyEndangeredWesternGrayWhalesFigure1.jpg

  Citation × Citation Citation Abstract Copy Title: IrvineLaddHMSCCriticallyEndangeredWesternGrayWhalesFigure1.jpg Author: Bradford, Amanda L., Tsidulko, Grigory A., Irvine, Ladd M., Mate, Bruce R., Rozhnov, Vyacheslav V., Vertyankin, Vladimir V., Ilyashenko, Valentin Yu. Title: IrvineLaddHMSCCriticallyEndangeredWesternGrayWhalesFigure1.jpg Author: Bradford, Amanda L., Tsidulko, Grigory A., Irvine, Ladd M., Mate, Bruce R., Rozhnov, Vyacheslav V., Vertyankin, Vladimir V., Ilyashenko, Valentin Yu. Close

• 17. [Article] Juvenile coho salmon movement and migration through tide gates

  Tidal marshlands in the upper estuary ecotone provide essential habitat for juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to saltwater. Worldwide, tidal marshes have been ...

  Citation × Citation Citation Abstract Copy Title: Juvenile coho salmon movement and migration through tide gates Author: Bass, Arthur Langer Tidal marshlands in the upper estuary ecotone provide essential habitat for juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to saltwater. Worldwide, tidal marshes have been diked and drained to provide agricultural and residential land. Tide gates are one-way doors integrated into dike systems that prevent saltwater flooding and allow upland drainage to the estuary during low tide. By preventing tidal exchange, tide gates have significant upstream effects on water temperature and chemistry, plant and animal community structure, and geomorphology. Since they are closed most of the day and may be difficult to pass when open, tide gates may act as fish passage barriers for juvenile salmonids. They may also affect juvenile salmon migration timing by altering environmental variables that influence emigration rate in upstream habitats. We conducted our research in Coos Bay, one of the many Oregon estuaries with extensive use of tide gates. We studied three streams, one with a top-hinged tide gate, one with a side-hinged gate, and one without any tide gates that acted as our reference site. Our study species was coho salmon, Oncorhynchus kisutch, which may encounter tide gates both in the subyearling and smolt life stages in our study streams. Our objectives were to: 1) quantify upstream and downstream fish passage occurrence at all three sites, 2) determine whether juvenile coho salmon passage is associated with a specific range of gate conditions, and 3) identify any associations between coho smolt emigration rate and environmental variables that are influenced by tide gates. We installed stationary passive integrated transponder (PIT) antennae around both tide gates and a tidal channel in the non-gated stream to record the movement of PIT tagged juvenile coho salmon. Coho salmon smolts passed upstream most frequently at the non-gated channel (48% of all smolts detected at the array), next the side-hinged gate (28%), and lastly, the top-hinged gate (3%). Juvenile coho salmon passed more frequently at a specific range of gate angles and tailwater depths at both top hinged and side-hinged tide gates. Smolts passed downstream more frequently at greater gate angles and tailwater depths than available on average at both tide gates. Subyearlings passed upstream more frequently during small gate angles and a narrow range of tailwater depths at the top-hinged gate but did not pass more frequently under a particular range of conditions at the side-hinged gate. At the top-hinged gate, conditions favorable for subyearling upstream passage occurred towards the end of the gate open period and therefore subyearlings were severely limited in their opportunities for passage. At multiple sites, emigration rate was associated with environmental variables that may be altered by tide gates. Increases in water temperature were associated with an increasing likelihood of smolt emigration at multiple sites. At a tide gate that allowed upstream estuarine influence, increasing salinity was associated with a decreasing likelihood of emigration. Our results suggest that tide gates may interfere with salmonid movement and migration by creating physical barriers to fish passage and potentially influencing migratory timing by altering environmental variables. When installing or retrofitting tide gates, these factors should be taken into consideration since a tide gate's design may determine the severity of its effects on salmonids. Our work should be considered a case study and the findings should not be assumed to be transferable due to the great diversity of tide gate installations in use. We recommend further research, including a more in depth analysis of the affects of tide gates on subyearling coho salmon and an investigation of piscivorous predator exploitation of tide gates. Title: Juvenile coho salmon movement and migration through tide gates Author: Bass, Arthur Langer Tidal marshlands in the upper estuary ecotone provide essential habitat for juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to saltwater. Worldwide, tidal marshes have been diked and drained to provide agricultural and residential land. Tide gates are one-way doors integrated into dike systems that prevent saltwater flooding and allow upland drainage to the estuary during low tide. By preventing tidal exchange, tide gates have significant upstream effects on water temperature and chemistry, plant and animal community structure, and geomorphology. Since they are closed most of the day and may be difficult to pass when open, tide gates may act as fish passage barriers for juvenile salmonids. They may also affect juvenile salmon migration timing by altering environmental variables that influence emigration rate in upstream habitats. We conducted our research in Coos Bay, one of the many Oregon estuaries with extensive use of tide gates. We studied three streams, one with a top-hinged tide gate, one with a side-hinged gate, and one without any tide gates that acted as our reference site. Our study species was coho salmon, Oncorhynchus kisutch, which may encounter tide gates both in the subyearling and smolt life stages in our study streams. Our objectives were to: 1) quantify upstream and downstream fish passage occurrence at all three sites, 2) determine whether juvenile coho salmon passage is associated with a specific range of gate conditions, and 3) identify any associations between coho smolt emigration rate and environmental variables that are influenced by tide gates. We installed stationary passive integrated transponder (PIT) antennae around both tide gates and a tidal channel in the non-gated stream to record the movement of PIT tagged juvenile coho salmon. Coho salmon smolts passed upstream most frequently at the non-gated channel (48% of all smolts detected at the array), next the side-hinged gate (28%), and lastly, the top-hinged gate (3%). Juvenile coho salmon passed more frequently at a specific range of gate angles and tailwater depths at both top hinged and side-hinged tide gates. Smolts passed downstream more frequently at greater gate angles and tailwater depths than available on average at both tide gates. Subyearlings passed upstream more frequently during small gate angles and a narrow range of tailwater depths at the top-hinged gate but did not pass more frequently under a particular range of conditions at the side-hinged gate. At the top-hinged gate, conditions favorable for subyearling upstream passage occurred towards the end of the gate open period and therefore subyearlings were severely limited in their opportunities for passage. At multiple sites, emigration rate was associated with environmental variables that may be altered by tide gates. Increases in water temperature were associated with an increasing likelihood of smolt emigration at multiple sites. At a tide gate that allowed upstream estuarine influence, increasing salinity was associated with a decreasing likelihood of emigration. Our results suggest that tide gates may interfere with salmonid movement and migration by creating physical barriers to fish passage and potentially influencing migratory timing by altering environmental variables. When installing or retrofitting tide gates, these factors should be taken into consideration since a tide gate's design may determine the severity of its effects on salmonids. Our work should be considered a case study and the findings should not be assumed to be transferable due to the great diversity of tide gate installations in use. We recommend further research, including a more in depth analysis of the affects of tide gates on subyearling coho salmon and an investigation of piscivorous predator exploitation of tide gates. Close

• 18. [Article] Differential gene expression between fall- and spring-run Chinook salmon assessed by long serial analysis of gene expression

  Of all Pacific salmonids, Chinook salmon Oncorhynchus tshawytscha display the greatest variability in return times to freshwater. The molecular mechanisms of these differential return times have not been ...

  Citation × Citation Citation Abstract Copy Title: Differential gene expression between fall- and spring-run Chinook salmon assessed by long serial analysis of gene expression Author: Banks, Michael A., McArthur, Andrew G., Birkeland, Shanda R., Bernier, Jeremiah C., Cipriano, Michael J. Of all Pacific salmonids, Chinook salmon Oncorhynchus tshawytscha display the greatest variability in return times to freshwater. The molecular mechanisms of these differential return times have not been well described. Current methods, such as long serial analysis of gene expression (LongSAGE) and microarrays, allow gene expression to be analyzed for thousands of genes simultaneously. To investigate whether differential gene expression is observed between fall- and spring-run Chinook salmon from California's Central Valley, LongSAGE libraries were constructed. Three libraries containing between 25,512 and 29,372 sequenced tags (21 base pairs/tag) were generated using messenger RNA from the brains of adult Chinook salmon returning in fall and spring and from one ocean-caught Chinook salmon. Tags were annotated to genes using complementary DNA libraries from Atlantic salmon Salmo salar and rainbow trout O. mykiss. Differentially expressed genes, as estimated by differences in the number of sequence tags, were found in all pairwise comparisons of libraries (freshwater versus saltwater = 40 genes; fall versus spring = 11 genes; and spawning versus nonspawning = 51 genes). The gene for ependymin, an extracellular glycoprotein involved in behavioral plasticity in fish, exhibited the most differential expression among the three groupings. Reverse transcription polymerase chain reaction analysis verified the differential expression of ependymin between the fall- and spring-run samples. These LongSAGE libraries, the first reported for Chinook salmon, provide a window of the transcriptional changes during Chinook salmon return migration to freshwater and spawning and increase the amount of expressed sequence data. Title: Differential gene expression between fall- and spring-run Chinook salmon assessed by long serial analysis of gene expression Author: Banks, Michael A., McArthur, Andrew G., Birkeland, Shanda R., Bernier, Jeremiah C., Cipriano, Michael J. Of all Pacific salmonids, Chinook salmon Oncorhynchus tshawytscha display the greatest variability in return times to freshwater. The molecular mechanisms of these differential return times have not been well described. Current methods, such as long serial analysis of gene expression (LongSAGE) and microarrays, allow gene expression to be analyzed for thousands of genes simultaneously. To investigate whether differential gene expression is observed between fall- and spring-run Chinook salmon from California's Central Valley, LongSAGE libraries were constructed. Three libraries containing between 25,512 and 29,372 sequenced tags (21 base pairs/tag) were generated using messenger RNA from the brains of adult Chinook salmon returning in fall and spring and from one ocean-caught Chinook salmon. Tags were annotated to genes using complementary DNA libraries from Atlantic salmon Salmo salar and rainbow trout O. mykiss. Differentially expressed genes, as estimated by differences in the number of sequence tags, were found in all pairwise comparisons of libraries (freshwater versus saltwater = 40 genes; fall versus spring = 11 genes; and spawning versus nonspawning = 51 genes). The gene for ependymin, an extracellular glycoprotein involved in behavioral plasticity in fish, exhibited the most differential expression among the three groupings. Reverse transcription polymerase chain reaction analysis verified the differential expression of ependymin between the fall- and spring-run samples. These LongSAGE libraries, the first reported for Chinook salmon, provide a window of the transcriptional changes during Chinook salmon return migration to freshwater and spawning and increase the amount of expressed sequence data. Close

• 19. [Article] A topography of dams in China : impacts to agriculture, labor, and migration

  Dams are often promoted as a tool to reduce poverty and spur economic development. Dam construction worldwide, and particularly in China, which has built nearly half the world's large dams since 1949, ...

  Citation × Citation Citation Abstract Copy Title: A topography of dams in China : impacts to agriculture, labor, and migration Author: Foster-Moore, Eric Dams are often promoted as a tool to reduce poverty and spur economic development. Dam construction worldwide, and particularly in China, which has built nearly half the world's large dams since 1949, remains contentious due to the potential for negative environmental and socioeconomic impacts. Despite numerous case studies, there is little systematic empirical evidence about either the contribution of dams to human development or their negative impacts to humans and the environment. Identifying the impact of dams also presents a methodological challenge because dam placement is likely endogenous to socioeconomic outcomes. The topographic suitability of a landscape for dam construction provides a source of exogenous variation in dam siting, which, building on the work of previous scholars, I exploit to identify the effect of large dams on agriculture, population change, and labor allocation. My results suggest that dams have decreased grain production in the counties where they were built and have drawn labor into non-agricultural fields. Dams appear to impact population subgroups in predictable ways and create identifiable winners and losers. Title: A topography of dams in China : impacts to agriculture, labor, and migration Author: Foster-Moore, Eric Dams are often promoted as a tool to reduce poverty and spur economic development. Dam construction worldwide, and particularly in China, which has built nearly half the world's large dams since 1949, remains contentious due to the potential for negative environmental and socioeconomic impacts. Despite numerous case studies, there is little systematic empirical evidence about either the contribution of dams to human development or their negative impacts to humans and the environment. Identifying the impact of dams also presents a methodological challenge because dam placement is likely endogenous to socioeconomic outcomes. The topographic suitability of a landscape for dam construction provides a source of exogenous variation in dam siting, which, building on the work of previous scholars, I exploit to identify the effect of large dams on agriculture, population change, and labor allocation. My results suggest that dams have decreased grain production in the counties where they were built and have drawn labor into non-agricultural fields. Dams appear to impact population subgroups in predictable ways and create identifiable winners and losers. Close

• 20. [Article] Copper, chromium, and arsenic levels in soils surrounding posts treated with chromated copper arsenate (CCA)

  The levels of copper, chromium, and arsenic in soil surrounding CCA-treated posts and beneath CCA-treated stakes were investigated at a plot near Gainesville, Florida. Metal levels were elevated in soil ...

  Citation × Citation Citation Abstract Copy Title: Copper, chromium, and arsenic levels in soils surrounding posts treated with chromated copper arsenate (CCA) Author: Morrell, Jeffrey J., Huffman, Jacob The levels of copper, chromium, and arsenic in soil surrounding CCA-treated posts and beneath CCA-treated stakes were investigated at a plot near Gainesville, Florida. Metal levels were elevated in soil immediately adjacent to the treated wood, but decreased with distance away or depth. Mean extractable arsenic levels ranged from 1.74 to 8.19 ppm immediately adjacent to the posts, but declined to less than 1 ppm in samples 150 and 300 mm away, regardless of depth sampled. The results suggest that soil contamination due to the presence of CCA-treated wood for 45 years is minimal. Title: Copper, chromium, and arsenic levels in soils surrounding posts treated with chromated copper arsenate (CCA) Author: Morrell, Jeffrey J., Huffman, Jacob The levels of copper, chromium, and arsenic in soil surrounding CCA-treated posts and beneath CCA-treated stakes were investigated at a plot near Gainesville, Florida. Metal levels were elevated in soil immediately adjacent to the treated wood, but decreased with distance away or depth. Mean extractable arsenic levels ranged from 1.74 to 8.19 ppm immediately adjacent to the posts, but declined to less than 1 ppm in samples 150 and 300 mm away, regardless of depth sampled. The results suggest that soil contamination due to the presence of CCA-treated wood for 45 years is minimal. Close