Bob Gresswell, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 78
Population-scale movement of coastal cutthroat trout in a naturally isolated stream network Population-scale movement of coastal cutthroat trout in a naturally isolated stream network
To identify population‐scale patterns of movement, coastal cutthroat trout Oncorhynchus clarkii clarkii tagged and marked (35 radio‐tagged, 749 passive integrated transponder [PIT]‐tagged, and 3,025 fin‐clipped) were monitored from June 1999 to August 2000. The study watershed, located in western Oregon, was above a natural barrier to upstream movement. Emigration out of the watershed...
Authors
R. E. Gresswell, S.R. Hendricks
Effects of fire on salmonid persistence Effects of fire on salmonid persistence
No abstract available.
Authors
Robert E. Gresswell
Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders
Little information is available on the effects of implanting 23-mm passive integrated transponder (PIT) tags in salmonids less than 90 mm fork length (FL). Using juvenile steelhead Oncorhynchus mykiss (range, 73–97 mm FL), we compared instantaneous growth rates and survival among three experimental groups: control, surgery with no tag, and surgery with tag. Survival rate was lower for...
Authors
D.S. Bateman, R. E. Gresswell
A spatially explicit approach for evaluating relationships among coastal cutthroat trout, habitat, and disturbance in small Oregon streams A spatially explicit approach for evaluating relationships among coastal cutthroat trout, habitat, and disturbance in small Oregon streams
Abstract has not been submitted
Authors
R. E. Gresswell, C.E. Torgersen, D.S. Bateman, T.J. Guy, S.R. Hendricks, J. E. B. Wofford
Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management
A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington...
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
Forestry practices and aquatic biodiversity: Fish Forestry practices and aquatic biodiversity: Fish
In the Pacific Northwest, fish communities are found in a diverse array of aquatic habitats ranging from the large coastal rivers of the temperate rainforests, to the fragmented and sometimes ephemeral streams of the xeric interior basins, and high-elevation streams and lakes in the mountainous areas (Rieman et al. 2003). Only high-elevation lakes and streams isolated above barriers to...
Authors
Robert E. Gresswell
Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies
We examined the influence of riparian vegetation patterns on coastal cutthroat trout Oncorhynchus clarki clarki diet and prey from the summer of 2001 through the spring of 2002. Benthic and drifting invertebrates, allochthonous prey, and fish diet were collected from deciduous, conifer, and mixed sections of three Oregon coastal watersheds. The nine sites were best characterized as a...
Authors
N. Romero, R. E. Gresswell, J.L. Li
Evaluating single-pass catch as a tool for identifying spatial pattern in fish distribution Evaluating single-pass catch as a tool for identifying spatial pattern in fish distribution
We evaluate the efficacy of single-pass electrofishing without blocknets as a tool for collecting spatially continuous fish distribution data in headwater streams. We compare spatial patterns in abundance, sampling effort, and length-frequency distributions from single-pass sampling of coastal cutthroat trout (Oncorhynchus clarki clarki) to data obtained from a more precise multiple-pass...
Authors
Douglas S. Bateman, Robert E. Gresswell, Christian E. Torgersen
Describing spatial pattern in stream networks: A practical approach Describing spatial pattern in stream networks: A practical approach
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other...
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Factors influencing within-watershed genetic variation of coastal cutthroat trout Factors influencing within-watershed genetic variation of coastal cutthroat trout
No abstract available.
Authors
J. E. B. Wofford, R. E. Gresswell, M. A. Banks
A geostatistical approach for describing spatial pattern in stream networks A geostatistical approach for describing spatial pattern in stream networks
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other...
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Influence of barriers to movement on within-watershed genetic variation of coastal cutthroat trout Influence of barriers to movement on within-watershed genetic variation of coastal cutthroat trout
Because human land use activities often result in increased fragmentation of aquatic and terrestrial habitats, a better understanding of the effects of fragmentation on the genetic heterogeneity of animal populations may be useful for effective management. We used eight microsatellites to examine the genetic structure of coastal cutthroat trout (Oncorhynchus clarki clarki) in Camp Creek...
Authors
John E. B. Wofford, Robert E. Gresswell, Michael A. Banks
Science and Products
Filter Total Items: 78
Population-scale movement of coastal cutthroat trout in a naturally isolated stream network Population-scale movement of coastal cutthroat trout in a naturally isolated stream network
To identify population‐scale patterns of movement, coastal cutthroat trout Oncorhynchus clarkii clarkii tagged and marked (35 radio‐tagged, 749 passive integrated transponder [PIT]‐tagged, and 3,025 fin‐clipped) were monitored from June 1999 to August 2000. The study watershed, located in western Oregon, was above a natural barrier to upstream movement. Emigration out of the watershed...
Authors
R. E. Gresswell, S.R. Hendricks
Effects of fire on salmonid persistence Effects of fire on salmonid persistence
No abstract available.
Authors
Robert E. Gresswell
Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders
Little information is available on the effects of implanting 23-mm passive integrated transponder (PIT) tags in salmonids less than 90 mm fork length (FL). Using juvenile steelhead Oncorhynchus mykiss (range, 73–97 mm FL), we compared instantaneous growth rates and survival among three experimental groups: control, surgery with no tag, and surgery with tag. Survival rate was lower for...
Authors
D.S. Bateman, R. E. Gresswell
A spatially explicit approach for evaluating relationships among coastal cutthroat trout, habitat, and disturbance in small Oregon streams A spatially explicit approach for evaluating relationships among coastal cutthroat trout, habitat, and disturbance in small Oregon streams
Abstract has not been submitted
Authors
R. E. Gresswell, C.E. Torgersen, D.S. Bateman, T.J. Guy, S.R. Hendricks, J. E. B. Wofford
Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management
A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington...
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
Forestry practices and aquatic biodiversity: Fish Forestry practices and aquatic biodiversity: Fish
In the Pacific Northwest, fish communities are found in a diverse array of aquatic habitats ranging from the large coastal rivers of the temperate rainforests, to the fragmented and sometimes ephemeral streams of the xeric interior basins, and high-elevation streams and lakes in the mountainous areas (Rieman et al. 2003). Only high-elevation lakes and streams isolated above barriers to...
Authors
Robert E. Gresswell
Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies
We examined the influence of riparian vegetation patterns on coastal cutthroat trout Oncorhynchus clarki clarki diet and prey from the summer of 2001 through the spring of 2002. Benthic and drifting invertebrates, allochthonous prey, and fish diet were collected from deciduous, conifer, and mixed sections of three Oregon coastal watersheds. The nine sites were best characterized as a...
Authors
N. Romero, R. E. Gresswell, J.L. Li
Evaluating single-pass catch as a tool for identifying spatial pattern in fish distribution Evaluating single-pass catch as a tool for identifying spatial pattern in fish distribution
We evaluate the efficacy of single-pass electrofishing without blocknets as a tool for collecting spatially continuous fish distribution data in headwater streams. We compare spatial patterns in abundance, sampling effort, and length-frequency distributions from single-pass sampling of coastal cutthroat trout (Oncorhynchus clarki clarki) to data obtained from a more precise multiple-pass...
Authors
Douglas S. Bateman, Robert E. Gresswell, Christian E. Torgersen
Describing spatial pattern in stream networks: A practical approach Describing spatial pattern in stream networks: A practical approach
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other...
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Factors influencing within-watershed genetic variation of coastal cutthroat trout Factors influencing within-watershed genetic variation of coastal cutthroat trout
No abstract available.
Authors
J. E. B. Wofford, R. E. Gresswell, M. A. Banks
A geostatistical approach for describing spatial pattern in stream networks A geostatistical approach for describing spatial pattern in stream networks
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other...
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Influence of barriers to movement on within-watershed genetic variation of coastal cutthroat trout Influence of barriers to movement on within-watershed genetic variation of coastal cutthroat trout
Because human land use activities often result in increased fragmentation of aquatic and terrestrial habitats, a better understanding of the effects of fragmentation on the genetic heterogeneity of animal populations may be useful for effective management. We used eight microsatellites to examine the genetic structure of coastal cutthroat trout (Oncorhynchus clarki clarki) in Camp Creek...
Authors
John E. B. Wofford, Robert E. Gresswell, Michael A. Banks