Bob Gresswell, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 60
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 tagged fish
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
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
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, and to det
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
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 fish passag
Authors
Robert E. Gresswell
Factors influencing within-watershed genetic variation of coastal cutthroat trout
No abstract available.
Authors
J. E. B. Wofford, R. E. Gresswell, M. A. Banks
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 removal e
Authors
Douglas S. Bateman, Robert E. Gresswell, Christian E. Torgersen
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 continuum of
Authors
N. Romero, R. E. Gresswell, J.L. Li
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 hand, data
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Geospatial techniques for developing a sampling frame of watersheds across a region
Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investiga
Authors
Robert E. Gresswell, Douglas S. Bateman, George Lienkaemper, T.J. Guy
Effects of the wildfire on growth of cutthroat trout in Yellowstone Lake
This chapter discusses the effects of wildfire on the growth of cutthroat trout in Yellowstone Lake. Trends in year-to-year variation in growth for individual age groups and 25 mm length groups of cutthroat trout in Yellowstone Lake were examined in an attempt to detect shifts in growth patterns associated with the fires. Approximately 100,000 ha of the Yellowstone Lake watershed burned between ea
Authors
R. E. Gresswell
Spatial and temporal patterns of debris flow deposition in the Oregon Coast Range, USA
Patterns of debris-flow occurrence were investigated in 125 headwater basins in the Oregon Coast Range. Time since the previous debris-flows was established using dendrochronology, and recurrence interval estimates ranged from 98 to 357 years. Tributary basins with larger drainage areas had a greater abundance of potential landslide source areas and a greater frequency of scouring events compared
Authors
Christine L. May, Robert E. Gresswell
Science and Products
Filter Total Items: 60
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 tagged fish
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
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
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, and to det
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
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 fish passag
Authors
Robert E. Gresswell
Factors influencing within-watershed genetic variation of coastal cutthroat trout
No abstract available.
Authors
J. E. B. Wofford, R. E. Gresswell, M. A. Banks
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 removal e
Authors
Douglas S. Bateman, Robert E. Gresswell, Christian E. Torgersen
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 continuum of
Authors
N. Romero, R. E. Gresswell, J.L. Li
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 hand, data
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Geospatial techniques for developing a sampling frame of watersheds across a region
Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investiga
Authors
Robert E. Gresswell, Douglas S. Bateman, George Lienkaemper, T.J. Guy
Effects of the wildfire on growth of cutthroat trout in Yellowstone Lake
This chapter discusses the effects of wildfire on the growth of cutthroat trout in Yellowstone Lake. Trends in year-to-year variation in growth for individual age groups and 25 mm length groups of cutthroat trout in Yellowstone Lake were examined in an attempt to detect shifts in growth patterns associated with the fires. Approximately 100,000 ha of the Yellowstone Lake watershed burned between ea
Authors
R. E. Gresswell
Spatial and temporal patterns of debris flow deposition in the Oregon Coast Range, USA
Patterns of debris-flow occurrence were investigated in 125 headwater basins in the Oregon Coast Range. Time since the previous debris-flows was established using dendrochronology, and recurrence interval estimates ranged from 98 to 357 years. Tributary basins with larger drainage areas had a greater abundance of potential landslide source areas and a greater frequency of scouring events compared
Authors
Christine L. May, Robert E. Gresswell