Brenda Ballachey, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 73
Gene transcription in sea otters (Enhydra lutris); development of a diagnostic tool for sea otter and ecosystem health Gene transcription in sea otters (Enhydra lutris); development of a diagnostic tool for sea otter and ecosystem health
Gene transcription analysis for diagnosing or monitoring wildlife health requires the ability to distinguish pathophysiological change from natural variation. Herein, we describe methodology for the development of quantitative real-time polymerase chain reaction (qPCR) assays to measure differential transcript levels of multiple immune function genes in the sea otter (Enhydra lutris)...
Authors
Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William van Bonn, Lance Adams, James L. Bodkin, Brenda E. Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott
Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil
We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow’s goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/1997, and we found that areas did...
Authors
Daniel Esler, Brenda E. Ballachey, Kimberly A. Trust, Samuel A. Iverson, John A. Reed, A. Keith Miles, John D. Henderson, Bruce R. Woodin, John J. Stegeman, Malcolm McAdie, Daniel M. Mulcahy, Barry W. Wilson
Could residual oil from the Exxon Valdez spill create a long-term population "sink" for sea otters in Alaska? Could residual oil from the Exxon Valdez spill create a long-term population "sink" for sea otters in Alaska?
Over 20 years ago, the Exxon Valdez oil tanker spilled 42 million L of crude oil into the waters of Prince William Sound, Alaska, USA. At the time of the spill, the sea otter (Enhydra lutris) population inhabiting the spill area suffered substantial acute injuries and loss. Subsequent research has resulted in one of the best-studied species responses to an oil spill in history. However...
Authors
Daniel H. Monson, Daniel F. Doak, Brenda E. Ballachey, James L. Bodkin
Trends in sea otter population abundance in western Prince William Sound, Alaska: Progress toward recovery following the 1989 Exxon Valdez oil spill Trends in sea otter population abundance in western Prince William Sound, Alaska: Progress toward recovery following the 1989 Exxon Valdez oil spill
Sea otters in western Prince William Sound (WPWS) and elsewhere in the Gulf of Alaska suffered widespread mortality as a result of oiling following the 1989 T/V Exxon Valdez oil spill. Following the spill, extensive efforts have been directed toward identifying and understanding long-term consequences of the spill and the process of recovery. We conducted annual aerial surveys of sea...
Authors
James L. Bodkin, Brenda E. Ballachey, George G. Esslinger
Modeling the Effects of Mortality on Sea Otter Populations Modeling the Effects of Mortality on Sea Otter Populations
Conservation and management of sea otters can benefit from managing the magnitude and sex composition of human related mortality, including harvesting within sustainable levels. Using age and sex-specific reproduction and survival rates from field studies, we created matrix population models representing sea otter populations with growth rates of 1.005, 1.072, and 1.145, corresponding to...
Authors
James L. Bodkin, Brenda E. Ballachey
PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill
Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the...
Authors
Mark A. Ricca, A. Keith Miles, Brenda E. Ballachey, James L. Bodkin, Daniel Esler, Kimberly A. Trust
Science and Products
Filter Total Items: 73
Gene transcription in sea otters (Enhydra lutris); development of a diagnostic tool for sea otter and ecosystem health Gene transcription in sea otters (Enhydra lutris); development of a diagnostic tool for sea otter and ecosystem health
Gene transcription analysis for diagnosing or monitoring wildlife health requires the ability to distinguish pathophysiological change from natural variation. Herein, we describe methodology for the development of quantitative real-time polymerase chain reaction (qPCR) assays to measure differential transcript levels of multiple immune function genes in the sea otter (Enhydra lutris)...
Authors
Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William van Bonn, Lance Adams, James L. Bodkin, Brenda E. Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott
Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil
We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow’s goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/1997, and we found that areas did...
Authors
Daniel Esler, Brenda E. Ballachey, Kimberly A. Trust, Samuel A. Iverson, John A. Reed, A. Keith Miles, John D. Henderson, Bruce R. Woodin, John J. Stegeman, Malcolm McAdie, Daniel M. Mulcahy, Barry W. Wilson
Could residual oil from the Exxon Valdez spill create a long-term population "sink" for sea otters in Alaska? Could residual oil from the Exxon Valdez spill create a long-term population "sink" for sea otters in Alaska?
Over 20 years ago, the Exxon Valdez oil tanker spilled 42 million L of crude oil into the waters of Prince William Sound, Alaska, USA. At the time of the spill, the sea otter (Enhydra lutris) population inhabiting the spill area suffered substantial acute injuries and loss. Subsequent research has resulted in one of the best-studied species responses to an oil spill in history. However...
Authors
Daniel H. Monson, Daniel F. Doak, Brenda E. Ballachey, James L. Bodkin
Trends in sea otter population abundance in western Prince William Sound, Alaska: Progress toward recovery following the 1989 Exxon Valdez oil spill Trends in sea otter population abundance in western Prince William Sound, Alaska: Progress toward recovery following the 1989 Exxon Valdez oil spill
Sea otters in western Prince William Sound (WPWS) and elsewhere in the Gulf of Alaska suffered widespread mortality as a result of oiling following the 1989 T/V Exxon Valdez oil spill. Following the spill, extensive efforts have been directed toward identifying and understanding long-term consequences of the spill and the process of recovery. We conducted annual aerial surveys of sea...
Authors
James L. Bodkin, Brenda E. Ballachey, George G. Esslinger
Modeling the Effects of Mortality on Sea Otter Populations Modeling the Effects of Mortality on Sea Otter Populations
Conservation and management of sea otters can benefit from managing the magnitude and sex composition of human related mortality, including harvesting within sustainable levels. Using age and sex-specific reproduction and survival rates from field studies, we created matrix population models representing sea otter populations with growth rates of 1.005, 1.072, and 1.145, corresponding to...
Authors
James L. Bodkin, Brenda E. Ballachey
PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill
Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the...
Authors
Mark A. Ricca, A. Keith Miles, Brenda E. Ballachey, James L. Bodkin, Daniel Esler, Kimberly A. Trust
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government