Grace Brush and the Chesapeake Bay Ecosystem

Grace Brush, January 18, 1931-
1949 B.A., Economics, St. Xavier University
1951 M.S., Botany, University of Illinois (with Wilson Stewart)
1956 Ph.D. Paleobotany, Harvard University (with Elso Barghoorn)
Career Highlights
According to Dr. Brush’s 1988 letter to Dr. Jean Langenheim, her early career evolved through several fields:

“I graduated from college with a degree in Economics, which I liked alot; but the only job I could get after graduating was as a lab technician in a Geological Survey of Canada coal research laboratory. I did minor in Geology. The lab was very small—only a half dozen people. My job was to prepare polished sections of coal for petrographic study. But I became fascinated with the structure in the coal, and particularly with the spores. Because the laboratory was very small, it was possible for me to pursue this interest, which eventually led to my going to graduate school to become a paleobotanist. I studied first with Wilson Stewart at Illinois and eventually with Barghoorn. My interests have fluctuated between working on modern plant distributions and on the fossil distributions, so that my interests and work have gradually evolved into ecology and paleoecology. …
“My most important contribution to ecology so far [1988] has been the vegetation map of Maryland, which shows the close relationship between lithologies that are similar hydrologically and distributions of the natural forests. The work that my students and I are doing now on reconstructing estuarine history using the stratigraphic record is also providing interesting insights on the influence of man on the environment.” — Letter to J.H. Langenheim, 1988

Graduating from college (St. Francis Xavier University, Nova Scotia) at 18, Dr. Brush has now spent four decades studying the ecology of the Chesapeake Bay and its connections to the forests around it. During one college geology class, she recalls:

…”we went on a field trip to the Joggins Fossil Cliffs on the Bay of Fundy side of Nova Scotia. This is a very famous fossil site, where a 3-million-year-old forest is exposed. There were these huge trees that looked like ferns and other plants like nothing we had ever seen. I think that that is when I began to subconsciously wonder how this area got from being a tropical place to what it is now—a land of spruce trees, maples, aspens.”

From 1957 to 1973, Dr. Brush worked part-time at several universities before moving to the Johns Hopkins Department of Geography and Environmental Engineering as a research scientist. In 1981, she became a full professor in the department and continues her career there.
As a woman in the late 1950s, she encountered challenges starting her career, as she reported in a 2014 interview:

…”Elso Barghoorn, a professor in the Biology Department at Harvard,… accepted me as a student. I was very lucky because at that time professors were not anxious to take on women as students. They assumed that they would not do much with their education, especially if married. The few women who did pursue graduate work very often ended up as unpaid assistants for their husbands.
“We would go wherever Lucien got a job. He first worked for the U.S. Geological Survey, then the University of Iowa, later Princeton, and in 1969 came to JHU. I followed a husband.
“…The reality of someone being excluded from all aspects of learning based on sex alone at Princeton, one of the great universities in the country, just did not make any sense and impressed on me the terrible injustice of racial discrimination, which I had certainly read about but did not experience or actually see. I had never lived in a large city.”
— Johns Hopkins University Gazette

Chesapeake Bay was considered “dying” in the 1970s, with declines in catches of the fish and oysters that supported the local economy. Dr. Brush untangled the changing ecology using pollen and sediment from core samples taken with generations of students and colleagues. “Brush pieced together evidence of the relationships between failing fisheries, river sediment, the sudden disappearance of underwater grasses, and a bay with a serious chemical imbalance.” (Finkbeiner, 2017.)

“We were able to show that the recent disappearance of the grasses was unique, and that sedimentation increased from four- to tenfold since Europeans began to cut down the forests and plant crops, and that nitrogen and phosphorus inputs into the estuary corresponded with the use of fertilizer on the land. … These studies showed how sediment and fertilizers coming in from the land were smothering much of the rich benthic products. Previously, it was felt that the problems with the bay were due to industrial and sewage waste.”

Today, a host of institutions, researchers, and partners are working to restore Chesapeake Bay to improved ecological function. Grace Brush’s work has provided a strong foundation for their efforts.
Selected Research Contributions
Brush GS, Bain DJ (2016). Long Term Trends in Urban Forest Succession. In Science for the Sustainable City: Empirical Insights from the Baltimore School of Urban Ecology. Yale University Press.
Martin, M. D., Zimmer, E. A., Olsen, M. T., Foote, A. D., Gilbert, M. T., Brush, G. (2014). Herbarium specimens reveal a historical shift in phylogeographic structure of common ragweed during native range disturbance. Molecular Ecology. 23(7). 1701-1716.
Hilgartner, W., Brush, G. (2006). Prehistoric Habitat Stability and Post-Settlement Habitat Change In A Chesapeake Bay Freshwater Tidal Wetland, USA. Holocene. 16(4). 479-494.
Brush G (2001). Forests before and after the colonial encounter. In Discovering the Chesapeake: the history of an ecosystem. Johns Hopkins University Press. 40-59.Pasternack, G., Brush, G., Hilgartner, W. (2001). Impact of Historic Land-Use Change on Sediment Delivery to a Chesapeake Bay Subestuarine Delta. Earth Surface Processes and Landforms. 26(4). 409-427.
Brush G (1994). Human impact on estuarine ecosystems: an historical perspective. In Global Environmental Change: Geographical Perspectives. Blackwell. 397-416.Brush, G. (1986). Geology and Paleoecology of Chesapeake Bay: A Long-Term Monitoring Tool for Management. Journal of the Washington Academy of Sciences. 76(3). 146-160.
Brush, G. (1984). Patterns of Recent Sediment Accumulation in Chesapeake Bay (Virginia Maryland, USA) Tributaries. Chemical Geology. 44(1-3). 227-242.
Brush, G., Davis, F. (1984). Stratigraphic Evidence of Human Disturbance in an Estuary. Quaternary Research. 22(1). 91-108.
Brush, G., Defries, R. (1981). Spatial Distributions of Pollen in Surface Sediments of the Potomac Estuary. Limnology And Oceanography. 26(2). 295-309.
Brush, G., Lenk, C., Smith, J. (1980). The Natural Forests of Maryland – An Explanation of the Vegetation Map of Maryland. Ecological Monographs. 50(1). 77-&.
References and Links
1988. Brush, Grace S. Letter and curriculum vitae to Jean Langenheim, January 16, 1988.
N.D. Johns Hopkins website, faculty profile and publication list.
2017. Finkbeiner, Ann. The Scientist Who Reads a Lost History in the Mud, Hakai Magazine, November 2017.
2014. Rienzi, Greg. What I’ve Learned: Grace Brush, Johns Hopkins University Gazette interview, May-June 2014.