Mary Freeman, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 110
A new species of Percina (Perciformes: Percidae) from the Apalachicola River drainage, southeastern United States A new species of Percina (Perciformes: Percidae) from the Apalachicola River drainage, southeastern United States
Percina crypta, the Halloween Darter, is described as a new species endemic to the Chattahoochee and Flint River systems in Georgia and Alabama. Percina crypta differs from sympatric Percina nigrofasciata in having narrowly separated dorsal saddles (inter-saddle spaces typically less than or equal to saddle width, compared to frequently wider than saddle width in P. nigrofasciata), in...
Authors
Mary C. Freeman, B. J. Freeman, N.M. Burkhead, C.A. Straight
Estimating species occurrence, abundance, and detection probability using zero-inflated distributions Estimating species occurrence, abundance, and detection probability using zero-inflated distributions
Researchers have developed methods to account for imperfect detection of species with either occupancy (presence-absence) or count data using replicated sampling. We show how these approaches can be combined to simultaneously estimate occurrence, abundance, and detection probability by specifying a zero-inflated distribution for abundance. This approach may be particularly appropriate...
Authors
S.J. Wenger, Mary C. Freeman
Riparian influences on stream fish assemblage structure in urbanizing streams Riparian influences on stream fish assemblage structure in urbanizing streams
We assessed the influence of land cover at multiple spatial extents on fish assemblage integrity, and the degree to which riparian forests can mitigate the negative effects of catchment urbanization on stream fish assemblages. Riparian cover (urban, forest, and agriculture) was determined within 30 m buffers at longitudinal distances of 200 m, 1 km, and the entire network upstream of 59...
Authors
A.H. Roy, B. J. Freeman, Mary C. Freeman
Hydrologic connectivity and the contribution of stream headwaters to ecological integrity at regional scales Hydrologic connectivity and the contribution of stream headwaters to ecological integrity at regional scales
Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water-mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two-thirds of total stream length in a typical river drainage and directly connect the upland...
Authors
Mary C. Freeman, C. M. Pringle, C.R. Jackson
Chemical and Ecological Health of White Sucker (Catostomus Commersoni) in Rock Creek Park, Washington, D.C., 2003-04 Chemical and Ecological Health of White Sucker (Catostomus Commersoni) in Rock Creek Park, Washington, D.C., 2003-04
Several classes of chemicals that are known or suspected contaminants were found in bed sediment in Rock Creek, including polyaromatic hydrocarbons (PAHs), phthalate esters, organochlorine pesticides, dioxins and furans, trace metals and metalloids (mercury, arsenic, cadmium, chromium, cobalt, copper, lead, nickel, silver, and zinc), and polychlorinated biphenyls (total PCBs and selected...
Authors
Cherie V. Miller, Holly S. Weyers, Vicki Blazer, Mary E. Freeman
Water Availability for Ecological Needs in the Upper Flint River Basin, Georgia Water Availability for Ecological Needs in the Upper Flint River Basin, Georgia
No abstract available.
Authors
M. Brian Gregory, Mary Freeman, W. Brian Hughes
Science and Products
Filter Total Items: 110
A new species of Percina (Perciformes: Percidae) from the Apalachicola River drainage, southeastern United States A new species of Percina (Perciformes: Percidae) from the Apalachicola River drainage, southeastern United States
Percina crypta, the Halloween Darter, is described as a new species endemic to the Chattahoochee and Flint River systems in Georgia and Alabama. Percina crypta differs from sympatric Percina nigrofasciata in having narrowly separated dorsal saddles (inter-saddle spaces typically less than or equal to saddle width, compared to frequently wider than saddle width in P. nigrofasciata), in...
Authors
Mary C. Freeman, B. J. Freeman, N.M. Burkhead, C.A. Straight
Estimating species occurrence, abundance, and detection probability using zero-inflated distributions Estimating species occurrence, abundance, and detection probability using zero-inflated distributions
Researchers have developed methods to account for imperfect detection of species with either occupancy (presence-absence) or count data using replicated sampling. We show how these approaches can be combined to simultaneously estimate occurrence, abundance, and detection probability by specifying a zero-inflated distribution for abundance. This approach may be particularly appropriate...
Authors
S.J. Wenger, Mary C. Freeman
Riparian influences on stream fish assemblage structure in urbanizing streams Riparian influences on stream fish assemblage structure in urbanizing streams
We assessed the influence of land cover at multiple spatial extents on fish assemblage integrity, and the degree to which riparian forests can mitigate the negative effects of catchment urbanization on stream fish assemblages. Riparian cover (urban, forest, and agriculture) was determined within 30 m buffers at longitudinal distances of 200 m, 1 km, and the entire network upstream of 59...
Authors
A.H. Roy, B. J. Freeman, Mary C. Freeman
Hydrologic connectivity and the contribution of stream headwaters to ecological integrity at regional scales Hydrologic connectivity and the contribution of stream headwaters to ecological integrity at regional scales
Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water-mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two-thirds of total stream length in a typical river drainage and directly connect the upland...
Authors
Mary C. Freeman, C. M. Pringle, C.R. Jackson
Chemical and Ecological Health of White Sucker (Catostomus Commersoni) in Rock Creek Park, Washington, D.C., 2003-04 Chemical and Ecological Health of White Sucker (Catostomus Commersoni) in Rock Creek Park, Washington, D.C., 2003-04
Several classes of chemicals that are known or suspected contaminants were found in bed sediment in Rock Creek, including polyaromatic hydrocarbons (PAHs), phthalate esters, organochlorine pesticides, dioxins and furans, trace metals and metalloids (mercury, arsenic, cadmium, chromium, cobalt, copper, lead, nickel, silver, and zinc), and polychlorinated biphenyls (total PCBs and selected...
Authors
Cherie V. Miller, Holly S. Weyers, Vicki Blazer, Mary E. Freeman
Water Availability for Ecological Needs in the Upper Flint River Basin, Georgia Water Availability for Ecological Needs in the Upper Flint River Basin, Georgia
No abstract available.
Authors
M. Brian Gregory, Mary Freeman, W. Brian Hughes