Mary Freeman, Ph.D.
Mary Freeman is a research ecologist with the Eastern Ecological Science Center at Athens, GA.
She received a B.S. in biology (1979), a M.S. in entomology (1982) and a Ph.D. in forest resources (1990) from the University of Georgia. Before joining Patuxent, Mary conducted research for the U.S. Fish and Wildlife Service and the National Biological Service in Auburn, AL (1992-1996). Mary serves as affiliate faculty at the Odum School of Ecology, University of Georgia, and on the graduate faculties at the University of Georgia and Auburn University.
Science and Products
Filter Total Items: 108
Are large-scale flow experiments informing the science and management of freshwater ecosystems?
Greater scientific knowledge, changing societal values, and legislative mandates have emphasized the importance of implementing large-scale flow experiments (FEs) downstream of dams. We provide the first global assessment of FEs to evaluate their success in advancing science and informing management decisions. Systematic review of 113 FEs across 20 countries revealed that clear articulation of exp
Authors
Julian D. Olden, Christopher P. Konrad, Theodore S. Melis, Mark J. Kennard, Mary Freeman, Meryl C. Mims, Erin N. Bray, Keith B. Gido, Nina P. Hemphill, David A. Lytle, Laura E. McMullen, Mark Pyron, Christopher T. Robinson, John C. Schmidt, John G. Williams
Dealing with uncertainty when assessing fish passage through culvert road crossings
Assessing the passage of aquatic organisms through culvert road crossings has become increasingly common in efforts to restore stream habitat. Several federal and state agencies and local stakeholders have adopted assessment approaches based on literature-derived criteria for culvert impassability. However, criteria differ and are typically specific to larger-bodied fishes. In an analysis to prior
Authors
Gregory B. Anderson, Mary Freeman, Byron J. Freeman, Carrie A. Straight, Megan M. Hagler, James Peterson
Occupancy modeling and estimation of the holiday darter species complex within the Etowah River system
Documenting the status of rare fishes is a crucial step in effectively managing populations and implementing regulatory mechanisms of protection. In recent years, site occupancy has become an increasingly popular metric for assessing populations, but species distribution models that do not account for imperfect detection can underestimate the proportion of sites occupied and the strength of the re
Authors
Gregory B. Anderson, Mary Freeman, Megan M. Hagler, Byron J. Freeman
Use of recent and historical records to estimate status and trends of a rare and imperiled stream fish, Percina jenkinsi (Percidae)
Rarely encountered animals may be present but undetected, potentially leading to incorrect assumptions about the persistence of a local population or the conservation priority of a particular area. The federally endangered and narrowly endemic Conasauga logperch (Percina jenkinsi) is a good example of a rarely encountered fish species of conservation concern, for which basic population statistics
Authors
Megan M. Hagler, Mary Freeman, Seth J. Wenger, Byron J. Freeman, Patrick L. Rakes, J.R. Shute
Large-scale flow experiments for managing river systems
Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments hav
Authors
Christopher P. Konrad, Julian D. Olden, David A. Lytle, Theodore S. Melis, John C. Schmidt, Erin N. Bray, Mary Freeman, Keith B. Gido, Nina P. Hemphill, Mark J. Kennard, Laura E. McMullen, Meryl C. Mims, Mark Pyron, Christopher T. Robinson, John G. Williams
Assessment and management of ecological integrity: Chapter 12
Assessing and understanding the impacts of human activities on aquatic ecosystems has long been a focus of ecologists, water resources managers, and fisheries scientists. While traditional fisheries management focused on single-species approaches to enhance fish stocks, there is a growing emphasis on management approaches at community and ecosystem levels. Of course, as fisheries managers shift th
Authors
Thomas J. Kwak, Mary Freeman
Predictors of occurrence of the aquatic macrophyte Podostemum ceratophyllum in a southern Appalachian River
The aquatic macrophyte Podostemum ceratophyllum (Hornleaf Riverweed) commonly provides habitat for invertebrates and fishes in flowing-water portions of Piedmont and Appalachian streams in the eastern US. We quantified variation in percent cover by P. ceratophyllum in a 39-km reach of the Conasauga River, TN and GA, to test the hypothesis that cover decreased with increasing non-forest land use. W
Authors
Jane E. Argentina, Mary Freeman, Byron J. Freeman
Conservation planning for imperiled aquatic species in an urbanizing environment
As the global area devoted to urban uses grows, an increasing number of freshwater species will face imperilment due to urbanization effects. Management of these impacts on both private and public lands is necessary to ensure species persistence. Such management entails several hallenges: (1) development of a management policy appropriate to the stressors; (2) linking stressor levels to species po
Authors
Seth J. Wenger, Mary Freeman, Laurie A. Fowler, Byron J. Freeman, James Peterson
The response of stream fish to local and reach-scale variation in the occurrence of a benthic aquatic macrophyte
The aquatic macrophyte Podostemum ceratophyllum has been shown to increase stream productivity, abundance and biomass of benthic invertebrates, and local occurrences of some stream fishes. However, experimental evidence that fishes preferentially associate with Podostemum is lacking, and the value of Podostemum as a predictor of stream fish assemblage composition has not been studied. We conducted
Authors
J.E. Argentina, Mary C. Freeman, B. J. Freeman
Modeling the relations between flow regime components, species traits, and spawning success of fishes in warmwater streams
Modifications to stream hydrologic regimes can have a profound influence on the dynamics of their fish populations. Using hierarchical linear models, we examined the relations between flow regime and young-of-year fish density using fish sampling and discharge data from three different warmwater streams in Illinois, Alabama, and Georgia. We used an information theoretic approach to evaluate the re
Authors
S.W. Craven, J.T. Peterson, Mary C. Freeman, T.J. Kwak, E. Irwin
The ecological limits of hydrologic alteration (ELOHA): A new framework for developing regional environmental flow standards
The flow regime is a primary determinant of the structure and function of aquatic and riparian ecosystems for streams and rivers. Hydrologic alteration has impaired riverine ecosystems on a global scale, and the pace and intensity of human development greatly exceeds the ability of scientists to assess the effects on a river-by-river basis. Current scientific understanding of hydrologic controls o
Authors
N.L. Poff, B. D. Richter, A.H. Arthington, S.E. Bunn, R.J. Naiman, E. Kendy, M. Acreman, C. Apse, B.P. Bledsoe, Mary C. Freeman, J. Henriksen, R. B. Jacobson, J.G. Kennen, D.M. Merritt, J. H. O'Keeffe, J. D. Olden, K. Rogers, R.E. Tharme, A. Warner
Methods for assessing the conservation value of rivers
No abstract available.
Authors
P.J. Boon, Mary C. Freeman
Science and Products
Filter Total Items: 108
Are large-scale flow experiments informing the science and management of freshwater ecosystems?
Greater scientific knowledge, changing societal values, and legislative mandates have emphasized the importance of implementing large-scale flow experiments (FEs) downstream of dams. We provide the first global assessment of FEs to evaluate their success in advancing science and informing management decisions. Systematic review of 113 FEs across 20 countries revealed that clear articulation of exp
Authors
Julian D. Olden, Christopher P. Konrad, Theodore S. Melis, Mark J. Kennard, Mary Freeman, Meryl C. Mims, Erin N. Bray, Keith B. Gido, Nina P. Hemphill, David A. Lytle, Laura E. McMullen, Mark Pyron, Christopher T. Robinson, John C. Schmidt, John G. Williams
Dealing with uncertainty when assessing fish passage through culvert road crossings
Assessing the passage of aquatic organisms through culvert road crossings has become increasingly common in efforts to restore stream habitat. Several federal and state agencies and local stakeholders have adopted assessment approaches based on literature-derived criteria for culvert impassability. However, criteria differ and are typically specific to larger-bodied fishes. In an analysis to prior
Authors
Gregory B. Anderson, Mary Freeman, Byron J. Freeman, Carrie A. Straight, Megan M. Hagler, James Peterson
Occupancy modeling and estimation of the holiday darter species complex within the Etowah River system
Documenting the status of rare fishes is a crucial step in effectively managing populations and implementing regulatory mechanisms of protection. In recent years, site occupancy has become an increasingly popular metric for assessing populations, but species distribution models that do not account for imperfect detection can underestimate the proportion of sites occupied and the strength of the re
Authors
Gregory B. Anderson, Mary Freeman, Megan M. Hagler, Byron J. Freeman
Use of recent and historical records to estimate status and trends of a rare and imperiled stream fish, Percina jenkinsi (Percidae)
Rarely encountered animals may be present but undetected, potentially leading to incorrect assumptions about the persistence of a local population or the conservation priority of a particular area. The federally endangered and narrowly endemic Conasauga logperch (Percina jenkinsi) is a good example of a rarely encountered fish species of conservation concern, for which basic population statistics
Authors
Megan M. Hagler, Mary Freeman, Seth J. Wenger, Byron J. Freeman, Patrick L. Rakes, J.R. Shute
Large-scale flow experiments for managing river systems
Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments hav
Authors
Christopher P. Konrad, Julian D. Olden, David A. Lytle, Theodore S. Melis, John C. Schmidt, Erin N. Bray, Mary Freeman, Keith B. Gido, Nina P. Hemphill, Mark J. Kennard, Laura E. McMullen, Meryl C. Mims, Mark Pyron, Christopher T. Robinson, John G. Williams
Assessment and management of ecological integrity: Chapter 12
Assessing and understanding the impacts of human activities on aquatic ecosystems has long been a focus of ecologists, water resources managers, and fisheries scientists. While traditional fisheries management focused on single-species approaches to enhance fish stocks, there is a growing emphasis on management approaches at community and ecosystem levels. Of course, as fisheries managers shift th
Authors
Thomas J. Kwak, Mary Freeman
Predictors of occurrence of the aquatic macrophyte Podostemum ceratophyllum in a southern Appalachian River
The aquatic macrophyte Podostemum ceratophyllum (Hornleaf Riverweed) commonly provides habitat for invertebrates and fishes in flowing-water portions of Piedmont and Appalachian streams in the eastern US. We quantified variation in percent cover by P. ceratophyllum in a 39-km reach of the Conasauga River, TN and GA, to test the hypothesis that cover decreased with increasing non-forest land use. W
Authors
Jane E. Argentina, Mary Freeman, Byron J. Freeman
Conservation planning for imperiled aquatic species in an urbanizing environment
As the global area devoted to urban uses grows, an increasing number of freshwater species will face imperilment due to urbanization effects. Management of these impacts on both private and public lands is necessary to ensure species persistence. Such management entails several hallenges: (1) development of a management policy appropriate to the stressors; (2) linking stressor levels to species po
Authors
Seth J. Wenger, Mary Freeman, Laurie A. Fowler, Byron J. Freeman, James Peterson
The response of stream fish to local and reach-scale variation in the occurrence of a benthic aquatic macrophyte
The aquatic macrophyte Podostemum ceratophyllum has been shown to increase stream productivity, abundance and biomass of benthic invertebrates, and local occurrences of some stream fishes. However, experimental evidence that fishes preferentially associate with Podostemum is lacking, and the value of Podostemum as a predictor of stream fish assemblage composition has not been studied. We conducted
Authors
J.E. Argentina, Mary C. Freeman, B. J. Freeman
Modeling the relations between flow regime components, species traits, and spawning success of fishes in warmwater streams
Modifications to stream hydrologic regimes can have a profound influence on the dynamics of their fish populations. Using hierarchical linear models, we examined the relations between flow regime and young-of-year fish density using fish sampling and discharge data from three different warmwater streams in Illinois, Alabama, and Georgia. We used an information theoretic approach to evaluate the re
Authors
S.W. Craven, J.T. Peterson, Mary C. Freeman, T.J. Kwak, E. Irwin
The ecological limits of hydrologic alteration (ELOHA): A new framework for developing regional environmental flow standards
The flow regime is a primary determinant of the structure and function of aquatic and riparian ecosystems for streams and rivers. Hydrologic alteration has impaired riverine ecosystems on a global scale, and the pace and intensity of human development greatly exceeds the ability of scientists to assess the effects on a river-by-river basis. Current scientific understanding of hydrologic controls o
Authors
N.L. Poff, B. D. Richter, A.H. Arthington, S.E. Bunn, R.J. Naiman, E. Kendy, M. Acreman, C. Apse, B.P. Bledsoe, Mary C. Freeman, J. Henriksen, R. B. Jacobson, J.G. Kennen, D.M. Merritt, J. H. O'Keeffe, J. D. Olden, K. Rogers, R.E. Tharme, A. Warner
Methods for assessing the conservation value of rivers
No abstract available.
Authors
P.J. Boon, Mary C. Freeman