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Associate Professor of Zoology
Associate Heritage Biologist, Oklahoma Biological Survey
Lab: (405)325-7071
Fax: (405)325-6202RM/Lab:SC134
Current Research Interests and Subject Areas Available for Graduate Research
I have broad interests in the ecology of freshwater macroinvertebrates and algae, particularly those inhabiting streams. My current research is focused in two areas: (1) the effects of biophysical disturbance on benthic stream organisms and (2) surveys of aquatic habitats and animals in Oklahoma.
Biophysical disturbances in streams include spates (freshets or floods), scraping by grazers during feeding, and effects of aerial exposure; all of which result in mortality of stream organisms. Most of my disturbance work is done with algae (especially diatom-dominated communities) and uses a combination of field and laboratory experiments. Diatoms have several advantages: their small size requires little research space, they are taxonomically and ecologically diverse, and they reproduce rapidly, so that short experiments can include several generations of diatoms.
Current research projects are:
1. Crevices as refuges. Depressions and cracks in streambed stones and crevices under the bark of submerged wood are examples of natural crevices found in streams. These crevices can protect organisms against abrasion associated with floods, being eaten by grazers or predators, and drying during brief periods of aerial exposure. I am studying the relationship of crevice size to the size and diversity of organisms protected within crevices, and how the texture of streambed substrates influences ecosystem productivity.
2. Response to aerial exposure of aquatic invertebrates and algae. I have begun experiments on desiccation tolerance of algae and on the behavior of exposed invertebrates.
3. Influence of disturbance on pre-existing patterns of community patchiness. Evidence from a flow tank study suggests that the spatial patchiness of benthic algae is maintained over a wide range of disturbance intensity, so that the community remaining after disturbance is also patchy. Patchiness is lost only when the disturbance is large enough to nearly obliterate the community.
In my work at the Oklahoma Biological Survey, I am involved in surveys of aquatic organisms in Oklahoma. I have two multi-year projects. The first is a survey of crayfish in the state, with the goals of ranking the conservation status of each Oklahoma species and of updating our knowledge of the distribution of crayfish species. The second project is a survey statewide survey of springs that includes both physical (e.g., habitat and water flow) and biological (macroinvertebrates, fish and plants) features. The original 50 springs in the study were sampled 20 years ago, providing an excellent opportunity for temporal comparisons. The survey is now expanding to include additional springs. The springs study has several objectives: searching for rare aquatic fauna, identifying springs with conservation value, and analyzing the distribution of spring biota in terms of water/migration source (aquifer versus watershed), water flow, and habitat type/modifications. I am interested in pursuing ecological spin-off projects from both the crayfish and springs surveys.
Graduate students in my laboratory choose their own projects that may or may not be related to my own research. Current examples include: the ecology of a rare Oklahoma-endemic crayfish, and the ecology of tropical tree-hole assemblages.
M.S., Colorado State University
B.S., University of Oklahoma
Selected publications:
- Bergey, E. A. and J. E. Weaver. 2004. The influence of crevice size on the protection of epilithic algae from grazers. Freshwater Biology 49: 1014-1025.
- Bergey, E. A. 2004. Crevice refuges as a source for algal colonists of disturbance-affected substrates. Archiv für Hydrobiologie 161: 235-243.
Taylor, C. A., S. N. Jones, and E. A. Bergey. 2004. The crayfishes of Oklahoma revisited: new state records and checklist. The Southwestern Naturalist 49: 250-255.
Suren, A., B. J. Biggs, M. Duncan, and L. Bergey. 2003. Benthic community dynamics during summer low flows in streams with contrasting enrichment: (2) Invertebrates. New Zealand Journal of Marine and Freshwater Research 37: 71-83.
Bergey, E. A. 1999. Crevices as refugia for stream diatoms: Effect of crevice size on abraded substrates. Limnology and Oceanography 44: 1522-1529.
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