February 1, 2021

Dear Members of Our Campus Community,

I am deeply saddened to share with you the news that Professor Emerita Barbara Prézelin of our Department of Ecology, Evolution, and Marine Biology passed away on January 22, surrounded by her loved ones. Our hearts go out to her daughter, Christine, and family, as well as to her wide circle of colleagues, former students, and friends around the world. Our campus flag will be lowered in her honor on February 3, 2021.

Professor Prézelin was an admired colleague, a pioneering researcher, an inspiring teacher, and a deeply devoted mentor to generations of students, as attested to by her 2002 Chancellor’s Faculty Award for Undergraduate Research Mentoring. Among her many leadership roles on our campus over four decades, she served as my Faculty Assistant for nine years, providing sage advice and participating in numerous committees to advance our mission and support our campus community. We are forever grateful for her tremendous contributions to our university, to marine science, and to our society.

I am honored to share the following tribute from Professors Alice Alldredge and Craig Carlson and our Department of Ecology, Evolution, and Marine Biology.

Barbara B. Prézelin (1948-2021)

Dr. Barbara Prézelin, long-time UCSB Professor in the Department of Ecology, Evolution, and Marine Biology, passed away peacefully on January 22, 2021, due to complications from brain surgery. Professor Prézelin graduated from the University of Oregon in Molecular Biology in 1970 and received her Ph. D. in Marine Biology from Scripps Institution of Oceanography in 1975. She came to UCSB as a post doc to work with Biology Professor Beazy Sweeney and was then hired as an Assistant Professor in the Department of Biological Sciences in 1977. She retired in 2012.

Dr. Prézelin is internationally recognized as a leading researcher in studies of marine phytoplankton photosynthesis, photobiology, and the effects of ultraviolet radiation on phytoplankton primary production. Her early work pioneered our understanding of how chlorophyll can be organized in various marine algae and how algal growth is regulated by biological clocks. She expanded this work to investigate photo adaptation in phytoplankton, and her work was instrumental in developing more accurate bio-optical models of primary production in the ocean that included changes in the day-night cycle and the spectral light field. Her later work centered around Antarctica, where she demonstrated significant declines in the primary production of the Southern Ocean due to increased ultraviolet radiation resulting from ozone depletion and expansion of the Antarctic ozone hole. Her further work on UV impacts and on ecological time series in the coastal waters of Antarctica considerably advanced our understanding of this important ecosystem. She was an ISI highly cited researcher in Animal and Plant Science, placing her in the top 1% of researchers in the field.

Professor Prézelin played a key role in the success of the Aquatic Biology Major at UCSB. She offered several upper-division courses in that major throughout her career. She mentored more than 100 undergraduate researchers at UCSB and took most to sea on research cruises. She was known as an engaged, rigorous, and inspiring mentor. Having been mentored as an undergraduate herself, Professor Prézelin strongly believed that undergraduate research opportunities changed students’ lives for the better and put them on the road to accomplishing their own dreams. She was highly successful at mentoring graduate students and post docs as well, many of whom went on to highly successful careers as professors and research scientists.

Professor Prézelin was very active at the local, national, and international level. Examples include serving as an editor for the Journal of Phycology, chairing Gordon Research Conferences, offering many keynote addresses at scientific meetings, and serving on NSF Panels. She played prominent roles as a board member of the US Joint Global Ocean Flux Study, the University-National Oceanographic Laboratory System, and the American Association of Limnology and Oceanography. She was the UC Education Abroad Study Director in France for two years, Chair of UCSB’s Committee on Committees, served on search committees for a number of Deans and Vice Chancellors, and on numerous administrative committees at UCSB including the Regents Scholarship Selection Committee, Athletics Committee, Student Fee Advisory Committee, and many others. For a decade Professor Prézelin served as the Faculty Assistant to Chancellor Yang.  

It is hard to capture a long and distinguished career in a few paragraphs and even harder to characterize the actual person. Barbara Prézelin was a warm-hearted, caring, energetic, thoughtful, passionate, and outgoing person who was deeply committed to high quality research, science education, and the mission of the University of California. She touched many lives in her long career here and many of her contributions were behind the scenes, accomplished with quiet proficiency and dedication. She is succeeded by her daughter, Christine Sieburg, and grandson, Chase. She will be sorely missed by her family, students, and colleagues alike.


Henry T. Yang