Mary Freeman, Ph.D.
Biography
Mary Freeman is a research ecologist with the Patuxent Wildlife Research Center and is stationed in 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
Assessing Faunal Recovery in a Headwater Stream
A catastrophic fish-kill in a small tributary stream of the Etowah River system (Dawson County, Georgia) has created the opportunity to assess faunal recovery, including recolonization by a federally-listed fish species (the Cherokee darter Etheostoma scotti). Fishes are expected to recolonize Flat Creek by moving upstream from downstream sources. In particular, Flat Creek flows...
Quantifying Restoration Benefits to Native Stream Fishes
This project is a collaboration of scientists from the USGS and University of Georgia to collect and analyze data describing how small-stream fishes use habitats created through stream restoration activities. The USFWS Region 4 requested this Science Support Partnership (SSP) project as a means to evaluate the effectiveness of stream restoration (primarily in north Georgia, and potentially in...
Synthesizing Multiple Long-Term Datasets to Test Flow Ecology Relationships for Fishes - Workshop
River ecosystems support a wide diversity of biota, including thousands of fish species, which are variously adapted to the dynamic environments provided by flowing-water habitats. One of the primary ways that human activities diminish the biological capacity of rivers is by altering the natural hydrologic variability of river systems through regulation and diversion of streamflow for other...
Quantifying Effects of Flow Variability on Riverine Biota
Stream and river biota around the world are imperiled by alterations to stream flow regimes that result from dams, land-use changes, water diversions and changing climate patterns. To manage and conserve stream-dependent species threatened by flow alterations, natural resource managers need quantitative information relating multiple aspects of ecological response to changes in a stream’s flow...
WaterSMART: Apalachicola/Chattahoochee/ Flint River (ACF) Basin
The Challenge: The DOI WaterSMART (Sustain and Manage America’s Resources for Tomorrow) initiative is developing data and tools to help water managers identify current and future water shortages, for humans and for freshwater ecosystems. Fishes, for example, can decline in diversity and abundance when streamflow becomes too low, for too long. However, ecologists find that effects of declining...
Southeast Regional Assessment Project (SERAP): Assessing Global Change Impacts on Natural and Human Systems in the Southeast
The Southeastern United States spans a broad range of physiographic settings and maintains exceptionally high levels of faunal diversity. Unfortunately, many of these ecosystems are increasingly under threat due to rapid human development, and management agencies are increasingly aware of the potential effects that climate change will have on these ecosystems. Natural resource managers and...
USGS-USFS Partnership to Help Managers Evaluate Conservation Strategies for Aquatic Ecosystems based on Future Climate Projections
The Southeastern U.S. spans broad ranges of physiographic settings and contains a wide variety of aquatic systems that provide habitat for hundreds of endemic aquatic species that pose interesting challenges and opportunities for managers of aquatic resources, particularly in the face of climate change. For example, the Southeast contains the southernmost populations of the eastern brook trout...
Annual survival, site fidelity, and longevity in the eastern population of the Painted Bunting (Passerina ciris)
Data comprise 6632 observations of individually banded Painted Buntings, captured and observed from 1999-2016 at 40 study locations on the southeastern Atlantic Coast (NC, SC, GA and FL, US).
Identifying life history traits that promote occurrence for four minnow (Leuciscidae) species in intermittent Gulf Coastal Plain streams
- Life history traits of stream fishes partly reflect adaptations to disturbance regimes, which in turn shape assemblage composition via environmental filters. In this study, we focused on life history traits of four morphologically similar leuciscid species in coastal plain streams of southwestern GA that are shifting from historically perennial...
Davis, Jessica L.; Freeman, Mary C.; Golladay, Stephen W. Water velocity regulates macro-consumer herbivory on the benthic macrophyte Podostemum ceratophyllum Michx.
1) Macrophytes influence aquatic ecosystems by increasing habitat complexity and providing trophic resources for aquatic fauna. While herbivory on freshwater macrophytes is widely documented in lakes, low-velocity riverine habitats, the influence of herbivory on macrophytes in higher-velocity habitats has rarely been examined. 2) We...
Wood, James L; Skaggs, Jon W; Conn, Caitlin C; Freeman, Mary C. Long-term (37 years) impacts of low-head dams on freshwater shrimp habitat connectivity in northeastern Puerto Rico
Freshwater migratory shrimp in Puerto Rico depend on watershed connectivity, from stream headwaters to the ocean, to complete their life cycle. Moreover, shrimp populations in different watersheds are known to be connected in an island-wide metapopulation. However, low-head dams paired with water intakes on streams draining the El Yunque National...
Chappell, Jessica; S. Kyle McKay; Freeman, Mary C.; Catherine M. Pringle
Adaptive management of flows from R.L. Harris Dam (Tallapoosa River, Alabama)—Stakeholder process and use of biological monitoring data for decision making
Adaptive management has been applied to problems with multiple conflicting objectives in various natural resources settings to learn how management actions affect divergent values regarding system response. Hydropower applications have only recently begun to emerge in the field, yet in the specific example reported herein, stakeholders invested in...
Irwin, Elise R.; Irwin, Elise R.; Freeman, Mary C.; Peterson, James; Kennedy, Kathryn D.M.; Lloyd, M. Clint; Ouellette Coffman, Kristie M.; Kosnicki, Ely; Hess, Tom Annual survival, site fidelity, and longevity in the eastern coastal population of the Painted Bunting (Passerina ciris) based on a 20-year mark-recapture/resighting study
A long-term study of annual survival, longevity, and site fidelity in the eastern coastal population of the Painted Bunting (Passerina ciris) during the breeding season was conducted from 1999 through 2018 in the outer coastal plain of the southeastern Atlantic coast of the United States. Painted Buntings were uniquely color-banded from 1999...
Sykes, Paul W. Jr; Freeman, Mary C.; Sykes, Joan J.; Seginak, John T.; M. David Oleyar; Egan, Joshua P. The missing dead: The lost role of animal remains in nutrient cycling in North American Rivers
While leaf litter, wood, and other plant remnants are known to play a central role in lotic ecosystems, animal remains (carcasses, bones, shells) have received less attention. We propose a simple classification scheme for animal remains in rivers based on origin (authochthonous vs. allochthonous) and frequency (pulsed vs continuous). We then...
Wengerd, Seth J.; Subalusky, Amanda L.; Freeman, Mary C. Stream fish colonization but not persistence varies regionally across a large North American river basin
Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus...
Wheeler, Kit; Wengerd, Seth J.; Walsh, Stephen J.; Martin, Zachary P.; Jelks, Howard L.; Freeman, Mary C. States and rates: Complementary approaches to developing flow‐ecology relationships
In recognition of the influence of flow on riverine habitats and organisms, stream ecologists have devoted considerable effort to the development of quantitative predictive relationships describing ecological responses to flow variability, i.e. flow‐ecology relationships.Methods used to generate flow‐ecology relationships can be thought of as a...
Wheeler, Kit; Wenger, Seth J.; Freeman, Mary C. Long-term monitoring data provide evidence of declining species richness in a river valued for biodiversity conservation
Free-flowing river segments provide refuges for many imperiled aquatic biota that have been extirpated elsewhere in their native ranges. These biodiversity refuges are also foci of conservation concerns because species persisting within isolated habitat fragments may be particularly vulnerable to local environmental change. We have analyzed long-...
Freeman, Mary C.; Hagler, Megan M.; Bumpers, Phillip M.; Wheeler, Kit; Wengerd, Seth J.; Freeman, Byron J. Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability
While previous studies have shown that evolutionary divergence alters ecological processes in small-scale experiments, a major challenge is to assess whether such evolutionary effects are important in natural ecosystems at larger spatial scales. At the landscape scale, across eight streams in the Caroni drainage, we found that the presence of...
Simon, Troy N.; Bassar, Ronald D.; Binderup, Andrew J.; Flecker, Alex S.; Freeman, Mary C.; Gilliam, James F.; Marshall, Michael C.; Thomas, Steve A.; Travis, Joseph; Reznick, David N.; Pringle, Catherine M. Ecology of the macrophyte Podostemum ceratophyllum Michx. (Hornleaf riverweed), a widespread foundation species of eastern North American rivers
Podostemum ceratophyllum, commonly called Hornleaf Riverweed, occurs in mid-order montane and piedmont rivers of eastern North America, where the plant grows submerged and attached to rocks and stable substrates in swift, aerated water. Multiple studies, mostly conducted in the southern portions of the plant’s range, have shown that Podostemum can...
Wood, James; Freeman, Mary C. Organic-matter retention and macroinvertebrate utilization of seasonally inundated bryophytes in a mid-order Piedmont River
There is increased understanding of the role of bryophytes in supporting invertebrate biomass and for their influence on nutrient cycling and carbon balance in aquatic systems, but the structural and functional role of bryophytes growing in seasonally inundated habitats is substantially less studied. We conducted a study on the Middle Oconee River...
Wood, James; Pattillo, Meryom; Freeman, Mary C.