After dedicating 35+ years to higher education, Professor Deneb Karentz is retiring from USF and looking forward to what life (and the Antarctic) have yet to offer. Before she leaves, though, MSEM sat down to hear her take on her amazing career in science and how that has shaped her today!
“Going to Antarctica was something that I would never ever have planned on and that first trip changed my whole trajectory. I think that was a really big marker for what happened for me afterwards.” -Deneb Karentz
What courses have you taught at USF?
Dr. Karentz has been a professor for the Biology and Environmental Science Departments at USF – she was the first hired in the Environmental Science Program when it was still up and coming. She has taught classes like Introduction to Environmental Science, General Biology, Marine Environments, Cell Physiology, Oceanography, and Evolution; as well as teaching Climate Science and Master’s Project for MSEM; but really enjoyed the Oceanography class – weekly field trips and the opportunities along the SF Bay were a highlight. But all of her classes were a joy to teach. Because of her research interests in phytoplankton ecology, ultraviolet photobiology, and Antarctic biology (ozone depletion), Dr. Karentz has trained several students in her research lab, as they studied phytoplankton species succession in the Bay, or as they quantified ocean microplastic. When asked what advice she has for incoming and current MSEM students, she let us know what she likes to tell her undergraduate students as well: “Do something you really like. Another big one is that you really need to be aware that opportunities do pop up and you just need to take them. Be flexible and open to new things!”
What was your educational journey when you were getting started in science?
Dr. Karentz’s educational journey began with a Bachelor’s of Science in Biology from the University of Rhode Island, where her fascination with algae started. After having a brief senior project on phytoplankton, her interests continued in this field when she attended Oregon State University, receiving her Master’s of Science in Botany and Plant Pathology. When pursuing her PhD in Biology, she attended the University of Rhode Island, where she worked on phytoplankton succession research. Her dissertation focused on the physiology and cell cycles of dinoflagellates and their unique circadian rhythm. She did her post-doctoral research at the University of California, San Francisco (UCSF).
How did your research interest in phytoplankton start?
When Dr. Karentz returned to the East Coast as a PhD student, she was told of there being 22 years of data from weekly collections of phytoplankton at the University of Rhode Island; that long-term dataset became the basis for her research project. In the 1970s, she dove into how DNA synthesis relates to phytoplankton cell cycles. She really wanted to learn more about molecular biology, so when she was finishing her PhD in search of a postdoc opportunity, she wanted to be a part of a lab where she would get that experience. In the early 1980s, UCSF on the West coast was that chance. An NIH fellowship allowed her the opportunity to study molecular genetics regarding skin damage and repair for an inherited human disease that does not have repairing capabilities. During that time, marine biology was still very important to her, so when she attended a conference and heard from a PhD cohort member needing another member for their Antarctica project, she volunteered.
Where has your career led you?
The opportunity to travel to Antarctica really moved Dr. Karentz’s career trajectory on to her own funding for Antarctic research on ultraviolet photobiology in phytoplankton in relation to plankton ecology and Antarctic ozone depletion. Throughout the years that followed, she did a rotation with the U.S. National Science Foundation (NSF) as an associate program manager. To this date, she is the US Delegate to the Scientific Committee on Antarctic Research (SCAR) and recently served as the SCAR Vice President for Science. She has also been the co-director of the NSF International Antarctic Biology Training Program, where she worked with early career scientists who were interested in polar research.
Dr. Karentz also serves as a science advisor for the US delegation to the Antarctic Treaty and has learned firsthand how science is translated into environmental policy and conservation management at the international level. Last year she had a chance to be an observer on a new tourist cruise ship to Antarctica – evaluating and providing guidance on how interested parties are abiding by the Antarctic Treaty. With 120,000 tourists visiting Antarctica every year, honoring the rules set forth to protect the environment and ecosystems is crucial. Dr Karentz mentioned how the penguins have seemingly adapted to humans walking near them in their colonies, having no threats or predators on land; but are very much affected by lack of prey, unstable ice conditions, and more and more frequent pollution, be it oil spills or microplastics.
Can you give us some insight on what your latest research has been and were there any unexpected discoveries in any of your research endeavors?
In the 1990s there was not much research on UV effects on phytoplankton. One notable discovery of Dr. Karentz’s research team was that DNA damage mechanisms used in phytoplankton are similar to human cell damage under ultraviolet exposure. Still, the team discovered that some phytoplankton species react differently from each other, where the larger the cell is, the more tolerant they are of UV exposure. Specifically, they found that the size spectrum of phytoplankton could shift over time to larger cell sizes, something that could then interfere with the transfer of energy within the food web. Dr. Karentz’s most recent publication in the journal Frontiers of Science describes the environmental implications of geoengineering in polar regions. The study is available in pre-print at the following link: Safeguarding the polar regions from dangerous geoengineering.
Thank you, Dr. Karentz, for your dedication and scientific contributions to climate science, marine biology and the management and protection of the Antarctic. Your academic path and knowledge have been shared with so many students, scientists and leaders around the world and the USF community and MSEM have been fortunate to have had a part in that. Dr. Karentz plans to continue to serve within SCAR after her retirement from USF, but will also get to many of her personal research to-do lists. She looks forward to any adventure that may come up in Antarctica. We will surely miss her, her classes and her wonderful baked goods.
Want to learn more? Below is a list of publications related to the topics Dr. Karentz mentioned during her interview with us:
Kordon, M. M., S. Arron, J. E. Cleaver, V. Bezrookove, D. Karentz, B. Lu, E. Perr, D. Chang, and T. Pederson, 2022: The UVSSA protein is part of a genome integrity homeostasis network with links to transcription-coupled DNA repair and ATM signaling. Proceedings of the National Academy of Sciences 119: 1-8.
Karentz, D. 2014. Beyond xeroderma pigmentosum: DNA damage and repair in an ecological context. A tribute to James E. Cleaver. Photochemistry and Photobiology 91: 460-474.
Karentz, D., I. Bosch, D.M. Mitchell. 2004. Limited effects of Antarctic ozone depletion on sea urchin development. Marine Biology 145: 277–292.
Karentz, D. 2001. Chemical defenses of marine organisms against solar radiation exposure: UV-absorbing mycosporine-like amino acids and scytonemin. pp. 481-520. In J. McClintock and W. Baker, eds., Marine Chemical Ecology. CRC Press, Inc. Boca Raton, Florida.
Karentz, D., J.E. Cleaver and D.M. Mitchell. 1991. Cell survival characteristics and molecular responses of Antarctic phytoplankton to ultraviolet-B radiation exposure. Journal of Phycology 27: 326-341.
