Sherri Cooper (1956–2015)

Sherri Cooper in Dr Patrick's research office at the Academy of Natural Sciences of Philadelphia, 1990.

On 23 November 2015, paleoecologist and diatomist Dr Sherri Rumer Cooper passed away after a long battle with cancer. Sherri was born on 28 January 1956 in Ozark, Alabama and grew up in Buffalo, New York. She was the first of four daughters of Drs Ralph and Shirley Rumer. The family often spent summer vacations at Core Point, North Carolina on the south shore of the Pamlico River estuary, which later became one of Sherri's research sites.

Sherri received a Bachelor of Science degree in Botany in 1978 from Duke University, and a Master of Science degree in Marine Sciences from the University of Delaware in 1982. Following her graduation from Delaware, she worked at the United States Department of Agriculture, Beltsville, Maryland, at the Medical University of South Carolina in Charleston, and at the University of Maryland, College Park. In 1988 Sherri married her long-time friend David Cooper and started working on her Ph.D. at Johns Hopkins University under the supervision of palynologist Dr Grace Brush. For her doctorate Sherri analysed several long sediment cores collected in the Chesapeake Bay, the largest and most productive estuary in the United States, and a water body of a great economic importance. Famous for its seafood industry, the Chesapeake Bay has been experiencing considerable ecological decline because of nutrient and sediment pollution. To reconstruct the environmental history of the Bay, Sherri used such indicators as diatoms, pollen, and a variety of geochemical parameters.

To master diatom identification, Sherri applied for and was awarded a Jessup-McHenry Scholarship from the Academy of Natural Sciences of Philadelphia (ANSP). In 1990 she spent several months at the Academy's Diatom Herbarium studying diatom taxonomy under the supervision of Dr Ruth Patrick. Sherri used to recall the kindness with which Dr Patrick treated her, offering hospitality not only at the Academy but also at her own house. Diatoms obviously made a great impression on Sherri as they became her favourite tool for paleoecological reconstructions. A remarkable trend observed by Sherri in the Chesapeake Bay cores was the shift from the dominance of benthic diatoms towards the proliferation of small planktonic Cyclotella species, especially C. choktawatcheeana (Cooper 1993, 1995c), which began as early as the mid-1700s. Sherri and Grace Brush analysed historical maps in the Bay's watershed and demonstrated that this transition was perfectly correlated with the expansion of agricultural land by European settlers in the eighteenth century. The subsequent acceleration of the same trend, towards higher production of small planktonic diatoms, occurred in the mid-1850s when farmers started using inorganic fertilizers, and then again in the second half of the twentieth century, with industrialization and urbanization of the watershed. Sherri received her doctorate in 1993 and published the results of her Ph.D. study in Science (Cooper & Brush 1991), Estuaries (Cooper & Brush 1993), Ecological Applications (Cooper 1995a), and Diatom Research (Cooper 1995b).

Dr Grace Brush recollected that:

When Sherri began working on the Chesapeake paleoecology study at Johns Hopkins as a research assistant, she had no experience in paleoecology. She learned the methods quickly and decided she would like to work on diatoms. Later, when she entered the program as a graduate student, diatoms as an indicator of estuarine eutrophication became her main focus. I introduced Sherri to Dr. Ruth Patrick, as I had no experience with diatoms. She relied greatly on the generosity of Ruth for guidance in the fossil diatom studies and they remained friends long after Sherri completed her Ph.D. Sherri reached out to many others in the diatom community also. She was a great networker. I especially remember when we were looking at the results of the diatom and chemical studies in sediment cores from across the Bay, Sherri wondered whether or not we should try to publish the results in Science. We both thought ‘Well we have nothing to lose except some time.’ The manuscript was published – much of it due to Sherri’s carefully detailed research. Sherri was meticulous in her research and everything she did. She was a wonderfully kind and generous student and colleague, and a thoughtful teacher and mentor to the many undergraduates who worked in the paleoecology laboratory and a loyal member of the department’s graduate students. She was always my friend.

Following her graduation from Johns Hopkins, Sherri again worked at the University of Maryland, first as Assistant Director of the Mid-Atlantic Regional Marine Research Program and then as a postdoc at the Chesapeake Biological Lab in Solomons, Maryland. In 1995 she returned to her alma mater as a Research Professor at the Duke University Wetland Center. Initially, she was involved in a series of projects in coastal areas of southern Florida, including a project funded by the Everglades Agricultural Area Environmental Protection District. Sherri and co-authors constructed diatom and pollen calibration datasets with the goal of developing indicators of phosphorus enrichment of the Everglades' endangered wetlands (Cooper et al. 1999, 2008, Jensen et al. 1999, Willard et al. 2004). A paleoecological analysis of a core from Florida Bay funded by the US Geological Survey and Duke University demonstrated significant changes in the coastal ecosystem caused by various human activities (Pyle et al. 1998). She also conducted another paleoecological project in the Pamlico and Neuse River estuaries in North Carolina. The overall time trend, from the dominance of benthic towards planktonic species as a result of eutrophication, similar to that found in the Chesapeake Bay, was again observed in these North Carolina estuaries (Cooper 2000, Cooper et al. 2004). The dominant diatom species were, however, mostly different, reflecting quite dissimilar hydrological and salinity regimes. These paleoecological studies also demonstrated that, contrary to widespread opinion, cores of relatively undisturbed sediment, suitable for geochemical and microfossil analysis, may be obtained from estuaries. However, this required careful geomorphological investigation to determine depositional areas, and to ensure continuity of accumulated sediments (Cooper 1999).

In 1999 Sherri and David moved to suburban Philadelphia and Sherri became a faculty member at Bryn Athyn College, a small liberal arts institution that encourages moral and spiritual development alongside academic studies. She developed and taught courses in Botany, Environmental Sciences, Ecology, Marine and Estuarine Ecology, and Limnology, as well as many general biology courses. She quickly became director of the biology programme, and developed tracks in microbiology and ecology. A devoted educator, Sherri involved undergraduates in all of her research projects and brought a succession of students to the regional meetings of the Ecological Society of America and other conferences. She particularly enjoyed taking interested students through independent studies, internships, and field labs to help them understand the application of their science studies, and she included aspects of scientific writing and scientific public presentation throughout her courses.

Despite the heavy teaching load, Sherri continued her studies of estuarine sediment diatoms, and remained an adjunct professor at Duke until 2005. Her expertise in tracking down environmental changes leading to hypoxia and other water quality problems in coastal areas led to her involvement in a study on the West Coast of the United States. She analysed diatoms in sediment cores collected in the Puget Sound and Hood Canal, as part of the Coastal Hypoxia Research Program funded by the National Oceanic and Atmospheric Administration (NOAA). A sabbatical year of 2006–2007 was spent at the Coastal Studies Center of Bowdoin College, Maine, where Sherri contributed to the study of the ecology and environmental history of Merrymeeting Bay and the Lower Kennebec estuary (Cooper et al. 2010). The goal of another interesting project was to use sediment cores to reconstruct environmental changes in the Long Island Sound (Varekamp et al. 2010). After Sherri's passing, David donated her collection of 460 core sediment samples and 4000 slides, as well as her diatom library to the ANSP Diatom Herbarium, where these materials are available to all interested researchers.

Sherri and David raised their daughters, Zia and Anji, just a short walk from the College in Bryn Athyn, a picturesque and historic suburb of Philadelphia. Their neighbourhood borders the lands of the Pennypack Ecological Restoration Trust (PERT), which was not only Sherri's favourite green space for a weekend walk, but also a place where she initiated and carried out ecological restoration and environmental sustainability projects, conducted research with undergraduates, and taught some lab courses. Sherri served on the PERT Board of Directors, and developed joint research projects between PERT and the Bryn Athyn College that continue today. These projects involve faculty, students, and the larger community, and embody Sherri's vision of a harmony between people and nature as well as science and spirituality. As a testament to her influence, Bryn Athyn College has established a memorial research fund in Sherri's name, awarding grants to promising students to conduct undergraduate research.