Susan Lynn Williams was a scientist who embodied the ethos of conducting original research and making that research relevant for the betterment of society. In a seminal work, Boyer (1990) defined scholarship in four categories: discovery, integration, application, and teaching. Susan Williams excelled in all four categories, each described in the following sections.
Susan actively conducted original research in both the laboratory and the field, and she was instrumental in making unique discoveries. Susan represented the generational shift to conducting much of her field research underwater; her predecessors were largely restricted to the intertidal zone or the laboratory. Susan did conduct intertidal and laboratory research, but she also was an accomplished SCUBA diver, and she spent endless hours underwater in all sorts of conditions. Susan’s underwater observations backed up with laboratory studies led her to challenge existing paradigms throughout her career.
Susan used radioisotopes in her Masters’ research to measure carbon uptake by seagrasses (Williams and McRoy 1982) and then used stable isotopes to track the uptake of sediment nutrients by coenocytic green algae (Williams 1984; Williams and Fisher 1985). Coenocytic green algae are giant single cells with multiple nuclei that move via cytoplasmic streaming. Susan’s PhD research upended the paradigm that algae absorbed water column nutrients exclusively. Early on, Susan recognized the importance of seagrass detritus in marine food webs (e.g., Suchanek et al. 1984) as well as the importance of tropical seagrass as a food source for megaherbivores (e.g., Thayer et al. 1984; Williams 1988a). During and immediately after her dissertation research, Susan studied the deepwater environments off St. Croix (e.g., Williams et al. 1985; Williams 1988b, 1990; Williams and Carpenter 1988), which required extensive SCUBA diving combined with experimental manipulations and state-of-the-art scientific techniques. Susan compared the circadian rhythms of a seagrass and a green alga using in situ light manipulations (Williams and Dennison 1990). Susan began and maintained a long and productive collaboration with Bob Carpenter, and they co-authored papers on coral reef algal turfs over several decades (e.g., Williams and Carpenter 1988, 1990; Carpenter and Williams 1993, 2007).
Moving to the west coast, Susan began looking at the genetic diversity and structure of seagrasses (e.g., Williams and Davis 1996; Williams and Orth 1998; Williams 2001). She was one of the first scientists to recognize the emergence of Ruppia in disturbed seagrass communities (e.g., Johnson et al. 2003). But then Susan’s research added a new component, studying the effects of introduced species, starting with studies of an Asian mussel in San Diego Bay (Reusch and Williams 1999), followed by studies of the invasion of a marine macroalga, Caulerpa, in southern California (e.g., Williams and Grosholz 2002; Williams and Schroeder 2004). Susan became an invasive species polymath, publishing over twenty papers on aspects of (a) invasive species and native seagrass interactions, (b) post-invasion management, (c) invasion vectors and their management, (d) invasions and climate change, and (e) synthesizing ecological aspects of invasive species (Williams and Smith, 2007).
Susan was a key member of the Seagrass Trajectories Working Group at the National Center for Ecological Analysis and Synthesis (NCEAS). In addition to Susan’s important individual contribution, as an advocate of women in science, she also recruited two young female University of California graduate students, Randall Hughes and Suzanne Olyarnik to join the working group. Several seminal papers resulted from this synthesis effort, including a Bioscience paper “A global crisis for seagrass ecosystems” (Orth et al. 2006) and a Proceedings of the National Academy of Sciences paper “Accelerating loss of seagrasses across the globe threatens coastal ecosystems” (Waycott et al. 2009). Each of these papers has received over 2000 citations and represent the most cited seagrass papers in the world. At the special session as a tribute to Susan Williams at the Coastal and Estuarine Research Federation conference in 2019, almost all of Susan’s co-authors from this NCEAS project attended, a testament to her lasting impact.
Susan did comprehensive reviews of various topics throughout her career, including the impact of invasive species (Lodge et al. 2006; Williams and Grosholz 2008; Ojaveer et al. 2018), the impact of invasive species on seagrasses (Williams 2007), trophic transfers from seagrasses (Heck Jr et al. 2008), and plastics in seafood (Rochman et al. 2015).
US Congressman Jared Huffman submitted a tribute to Susan to the Congressional Record that included the following statements:
Dr. Williams’ scientific research on coastal ecology and her activism surrounding the expansion of marine sanctuaries have left an indelible impact on the world. Throughout her career, Dr. Williams’ research underlined the connection between the health of oceans and the communities surrounding them. Her work on the ecology of nearshore marine ecosystems, seagrass, coral reefs, and invasive species helped illustrate the impact of warming oceans on coastal environments and yielded strategies for mitigating those impacts. Her work was heralded by the international scientific community, and provided the foundation for critical changes to state and federal policies addressing the management of coastal environments. Dr. Williams became a valued advisor for state and federal officials seeking to protect the California coast. Nowhere was this more apparent than through her work in significantly expanding two national marine sanctuaries off the coast of Northern California: the Cordell Bank National Marine Sanctuary, and the Gulf of the Farallones, now known as the Greater Farallones National Marine Sanctuary. Both sanctuary boundary expansions were proposed in legislation in 2005, and were ultimately expanded to more than twice their original size by the Obama administration in 2015. Throughout that ten-year process, Dr. Williams was the driving force that propelled the policy forward. (162 Cong. Rec. E737 2018)
Susan made multiple trips to Sacramento, CA, and Washington, D.C., to provide testimony or to brief congressional delegations. Susan worked tirelessly to provide the scientific basis for the expansion of marine sanctuaries and she often made these trips to Washington, D.C., at her own expense while juggling her many teaching, research and administrative duties. Susan also made the case for the inclusion of biodiversity in habitat restoration (Hughes et al. 2017) and she kept working to influence management and policy, even when she sometimes felt as though she was “Shouting into a hurricane”.
Susan’s latest research interests and science application efforts were in Indonesia, and she was deeply involved in a fruitful collaboration with Indonesian scientists and the Mars Incorporated’s coral reef restoration program. This experience in the Coral Triangle, a global biodiversity hot spot, caused Susan to reevaluate her priorities and shift her perspectives (e.g., Williams 2013). Susan made multiple trips to Indonesia, often taking graduate students along with her and conducting outreach (e.g., Sur et al. 2018) in addition to focusing on capacity building and research. Former student Holly Hanson Henderson said the following: “I carry the lessons and approach to science that I learned from Susan with me in my work every day. Susan was unwavering in her belief that science needs to be thoughtful and rigorous, and that it is our obligation as scientists to go out into the world to make a difference.” Susan wrote about how species richness accelerates marine ecosystem restoration in the coral triangle (Williams et al. 2017). Susan became the lead scientific advisor to Mars on a large-scale coral restoration project, documented in a paper published posthumously (Williams et al. 2019). She also helped design a second trial, which is still ongoing and is the world’s largest controlled coral reef restoration experiment, scheduled to finish in early 2021.
Susan’s former students were polled and they generated a word cloud to describe her. Words to describe Susan included the following: brilliant, sparkling, incisive, creative, trailblazer, generous, influential, passionate, direct, genuine, diplomatic, frank, tough, human, supportive, impactful, incredible, and honest (Fig. 3).
Bobby Espinoza said this about Susan’s mentorship: “All along, Susan supported me, as a person. Most other advisors would have abandoned me and my project soon after it morphed into something so distant from their own research interests. Not Susan. And she has continued to support me throughout my career.” Bengt Allen said the following: “As I look back over the past 20 years since I left her lab, I’ve more or less been successful by continuing to do all of the things she had me doing as a new graduate student.”
Amanda Newsom said this about Susan’s impact: “I don’t think I would have pursued or merited the work I do now without that shift Susan cultivated in me towards valuing myself and my truth. As a trailblazer for women in our field, Susan had to learn how to value herself in order to be the empowering presence she became. I think her influence was what finally made me understand my own worth as a professional. She demanded that I develop a thicker skin and a higher opinion of myself, which is a difficult thing to do, but I think she accomplished it with many of her students.”
Randall Hughes said that the Ralph Waldo Emerson quote fit Susan’s mentorship; “Our chief want in life is somebody who will make us do what we can.” In that vein, Susan was the advisor for the following graduate students: Lucina Hwang, Seth Yarish, and Eric Telemaque (Stony Brook Univ.); Mary Ruckelshaus (Univ. Washington); Michelle Chow, Tim Lu, Bobby Espinoza, Russ DiFioni, Chris Davis, Donna Ross, Patrick Ewanchuk, Amy Sewell, Alex Cheroske, Bengt Allen, Holly Hanson Henderson, Megan Cooper, and Carolyn Lieberman (San Diego State Univ.); and Laura Rodriguez, Heidi Weiskel, Cascade Sorte, Amanda Newsom, Amber Szoboszlai, Grace Ha, and Katie DuBois (Univ. California, Davis). But this list is far from complete—Susan was often a “drive-by” advisor who provided many more students and postdocs with input and career advice. Susan provided important input to Matthew Bracken, Jeffrey Wright, Christopher Harley, Raquel Muñiz-Salazar, Brendon Larson, Cynthia Hays, Randall Hughes, Jae Pasari, Laura Reynolds, and Brent Hughes (Univ. of California, Davis) and Florence Thomas, Thorsten Reusch, Jorge Terrados, and Terrie Klinger (San Diego State Univ.). Susan also provided K-12, undergraduate, and graduate mentoring to numerous students through programs like the Research Experiences for Undergraduates, National Science Foundation Graduate K-12 program (CAMEOS at University of California, Davis).
Susan taught a wide diversity of courses over her career, including Seagrass Biology and Ecology, Marine Ecology, Biological Invasions, Climate Change in the Nearshore Ocean, Marine Primary Producer Physiological Ecology, Life in the Sea, Principles of Ecology, Marine Environmental Issues, Phycology, Ecology and the Environment, Evolution and Ecology, Aquatic Ecology, Biogeochemistry of Coral Reefs, Algology, Estuarine Botany, Advanced Phycology, Ecology of Coral Reefs, and Tropical Coastal Marine Ecology. Susan developed numerous syllabi, lectures, and laboratories for individually designed courses. Susan even co-authored a paper that outlines ways for research scientists to more actively participate in K-12 education (e.g., Komoroske et al. 2015).