This is the first installment in a series of stories that span the boundary-defying people, cross-cutting research, and game changing collaborations that comprise the Pacific Marine Energy Center.
By Judy Twedt
Professor Shima Abadi, a PMEC researcher championing a new method for listening to ocean noise via fiber optic cables, began her career in engineering when she was just 6 years old. Now a professor of oceanography with an affiliate appointment in electrical and computer engineering at the University of Washington, Abadi is advancing techniques for ocean acoustical monitoring, and mentoring a new generation of engineers and scientists.
Abadi came to this work via a love of math and physics that was nurtured in her grade school years by her big sister, a high school math teacher. She would tag along and listen to her sister’s math lessons, thrilled when she understood a concept that was far ahead of her grade.
“I would get some concept, and I was so proud of myself that I could get high school math. And then I realized, ‘oh my gosh, this is very interesting! Math and physics became my focus all of my K-12 years.”
In Iran, high school students take a national exam to compete for coveted spots in the National University. Studying for the exam was like a race, and Abadi holds a record for studying 13 hours in one day.
Abadi aced the exam, and was admitted to the University of Tehran, the most prestigious university in the nation, where she studied Mechanical engineering.
When she finished her undergraduate studies — focusing on optimizations for internal combustion engines — she received a fellowship to study in the U.S. She chose the University of Michigan for practical reasons — it was close to General Motors. But she quickly moved into a different research path. Her fellowship allowed her to choose her line of inquiry, and when she learned about research in underwater acoustics, combining math, physics, and fluid dynamics, she realized, “Oh my God, this is what I love.”
At the beginning, she was the only graduate student in her program doing research in underwater acoustics. The University of Michigan wasn’t close to any large bodies of water for experimentation, so she collaborated with people from the University of Washington’s Applied Physics Lab and University of California- San Diego for ocean acoustic data. While a graduate student, she won an award for best student paper in underwater acoustics from the Acoustical Society of America.
Clarity about her career path came as she was finishing her PhD. The private sector did not call her, “I knew I wanted to become a faculty member and professor,” so she applied for postdocs, and was invited to work at Columbia University’s Lamont-Doherty Earth Observatory, on a research project in their oceanography department. Despite some initial hesitancy to work in a new field, she found the experience valuable, “it gave me new perspectives in oceanography and geoscience, and I developed skills in processing big data.”
Since joining the faculty at the University of Washington, Abadi rolled up her sleeves and dug into new hydrophone data from the Ocean Observatories Initiative, a science-driven ocean observing network. With 11 hydrophones — underwater microphones — recording at different depths along the continental shelf, she and her students have analyzed the data to characterize the ambient sounds in various underwater environments including the underwater Axial Seamount, and to investigate surface phenomena like the sounds of wind and rain propagating through the ocean.
Her work with PMEC is motivated by the need to understand noise from marine energy converters. In 2026 she and other PMEC researchers will conduct acoustic monitoring at PacWave, creating benchmark data to compare different systems for monitoring marine energy noise.
Understanding and characterizing the ocean acoustic environment is important for guiding marine energy developers and policymakers, as there are regulatory limits on ocean noise designed to protect marine life. Underwater animals exhibit a wide spectrum of hearing ranges – baleen whales, for instance, hear very low frequencies, as low as 7 Hz, while some porpoises and dolphins hear frequencies well above 100 kHz. Human hearing ranges, by comparison, from approximately 20 Hz to 20 kHz. Research that improves our understanding of the marine environment — including natural, ambient, and human-caused noise — is essential for the responsible development of marine energy.
Abadi is also among a small handful of researchers who are exploring the use of fiber optic cables to listen to sounds underwater. The technique is called Distributed Acoustic Sensing (DAS). Telecom fiber optic cable infrastructure is already available and carries the potential to greatly expand the area of the ocean which we can listen to. DAS is conducted with an instrument called an interrogator connected to the cable’s endpoint onshore. It sends laser pulses through the cable and records the backscatter, which is affected by sound waves that reach the cable through the water column. Each pulse interrogates the whole cable, so unlike the point-source recording of a hydrophone, this method enables enhanced spatial monitoring. And because it leverages existing fiber optic cables, there is no costly ship time or other instruments needed beyond the interrogator. Abadi and her colleagues have already demonstrated that this technique is capable of capturing fin whale calls and ship noises.
Now, like her sister, Abadi is teaching and mentoring, and her students are making their own waves in underwater acoustics. As our interview came to a close, I asked Abadi if there was anything else she wanted to share that hadn’t already come up in my questions. Her mind went right to the next generation of scientists and engineers.
“Previous generations of ocean acousticians,” she said, “had to do everything on their own— getting to the field, taking the measurements, then performing the analysis. But today there are so many networks of data, terabytes of data collected daily from multiple locations with high sampling rates.
These days, it’s easier for early careers to dive into research right away because the data is already there.”
To learn more about studying with PMEC, visit https://www.pmec.us/study-with-pmec