Caltech Researcher Who Tracked COVID in Sewage Speaks at Free Marine Lab Series

Before the Omicron variant appeared in nasal swabs and PCR results, it was already flowing through the sewers — and Smruthi Karthikeyan found it there. 

Karthikeyan, a Caltech assistant professor whose wastewater surveillance work helped detect emerging COVID-19 variants more than two weeks before clinical testing caught up, will speak July 14 at Kerckhoff Marine Laboratory’s free Science Tuesdays series in Corona del Mar. The event is part of the lab’s summer lineup of weekly public lectures, tours, and hands-on activities at one of the oldest marine laboratories on the West Coast. The series launched in 2025 and returned this summer for a second season. 

The talk begins at 4:30 p.m. at the lab, located at 101 Dahlia Avenue in Corona del Mar. It is free, open to all ages, and RSVPs are available through Eventbrite at https://www.eventbrite.com/e/science-tuesdays-at-kml-tickets-1395407705009.

Karthikeyan holds the title of Gordon and Carol Treweek Assistant Professor of Environmental Science and Engineering and William H. Hurt Scholar in Caltech’s Division of Biology and Biological Engineering. She studies microbial communities in settings ranging from ocean sediments to the human gut, according to her Caltech faculty profile. She describes her work as focused on “harnessing the power of microbes for human and environmental health.” 

That focus took on new urgency during the pandemic. As a postdoctoral researcher at UC San Diego’s School of Medicine, Karthikeyan led the development of what her lab describes as one of the largest SARS-CoV-2 wastewater genomic surveillance programs. Her methods, published in the journal Nature in 2022, enabled researchers to spot emerging virus variants in sewage more than two weeks before those same strains appeared through standard patient testing, according to her Caltech faculty profile. The work also identified cases of virus spread that clinical surveillance had missed entirely. 

Science News named Karthikeyan one of its 10 Scientists to Watch in 2022. Her research has been covered by outlets including CBS’s “60 Minutes,” The New York Times, and CNN, according to Caltech’s Division of Engineering and Applied Science. 

Before the pandemic, Karthikeyan’s doctoral research at Georgia Institute of Technology focused on the microbial response to the 2010 Deepwater Horizon oil spill. She joined Caltech’s faculty in 2023.

Science Tuesdays runs every Tuesday from June 16 through August 18, with a different speaker each week. The lab offers tours upon request, and the public is welcome to walk around the facility on their own. A speaker presentation follows, with an activity afterward, according to the event listing. Each week, the speaker for the following week is announced on the KML website and the lab’s Instagram account. 

Kerckhoff Marine Laboratory, operated by Caltech since 1929, sits at the edge of China Cove in the Corona del Mar section of Newport Beach. Victoria Orphan, the James Irvine Professor of Environmental Science and Geobiology at Caltech, directs the lab. Stephen Ranson manages day-to-day operations. 

Science Tuesdays: Smruthi Karthikeyan takes place on Tuesday, July 14, 2026, from 4:30 p.m. to 6:00 p.m. at Kerckhoff Marine Laboratory, 101 Dahlia Avenue, Corona del Mar. Admission is free and all ages are welcome. There is no parking at the lab; guests should park along Ocean Boulevard and walk down the staircase to China Cove, then turn right and continue to the facility. Street parking is free. For more information, call 949-675-2159 or visit https://kml.caltech.edu/.