Tom Norris, Marine Mammal Acoustician, Dies at 55

Originally from San Diego, Norris received a bachelor’s degree in zoology from the University of California, Santa Barbara, in 1987 before moving north to attend graduate school at Moss Landing Marine Laboratories. His research there focused on the acoustics of whales off the coast of Kauai, and he returned to Hawaii at least two dozen times over his 30-year career, according to a 2011 article profiling his work.

Norris’s master’s thesis focused specifically on how boat noise affects the singing of humpback whales. By analyzing the calls of whales before and during the time when boats were passing nearby, he was able to show that humpbacks modified the rhythm of their song, decreasing the length of their notes and increasing their tempo. His results led him to suggest that in addition to the notes themselves, the pauses between might also be important in relaying information.

“Everyone thinks that the notes and the frequencies are what matters, but Tom was one of the first to propose that it was the space between the notes that communicated content,” Ann Zoidis, the founder of the non-profit Cetos Research Organization, tells The Scientist. “It just showed Tom’s unique way of thinking.”

Even before graduating in 1995, Norris began working as an independent acoustician, and was one of several involved in the world’s first large-scale marine climate study, the Acoustic Thermometry of Ocean Climate (ATOC) program. Between 1996 and 2006, researchers used acoustic sources located off central California and Hawaii to study temperature throughout the North Pacific, showing that sound was a viable way of modeling climate. Norris worked on the marine mammal research team that studied whether the technology was harmful to animals; while it remained a contentious issue, scientists on the team largely concluded the technology was safe.

Tom Norris and Ann Zoidis studying humpback whales off the coast of Kauai in 1992

DANIEL SHAPIRO

In the early 2000s, Norris began experimenting with designing his own hydrophone arrays, which are towed on long lines behind ships. He returned to San Diego to launch Bio-Waves in 2006, and it remains one of the only companies in the world developing customized hydrophone arrays for the study of marine mammal acoustics. Much of his work with NOAA and the Navy focused on minimizing the effects of noise pollution on marine mammals.

Information about the presence and abundance of marine mammals in certain areas is useful to federal agencies looking to comply with the Marine Mammal Protection Act, which protects animals from harassment, including the use of sonar and other sound-based tools. “We are providing basic information like how many mammals there are so [agencies like] the Navy can make appropriate management and policy decisions based on scientifically based information,” Norris said in a 2016 interview. 

In addition to his ongoing development of new hardware technology, Norris frequently traveled with other Bio-Waves employees to carry out contracted research surveys, including work in Vietnam, Canada, Brazil, and Mexico. Over three decades, Norris studied killer whales, sperm whales, minke whales, humpbacks, and many species of dolphin, among other marine mammals.

More recently, Bio-Waves harnessed the power of machine learning to create a software called ROCCA that automatically extracts suspected toothed whale calls from raw sound data. The program can accurately identify more than a dozen different species of whale and dolphin.

Even as the technology advanced, “Tom was really grounded with respect to his use of the equipment, his interpretation of data, and relating to others where bias might enter the situation,” Elizabeth Ferguson, the founder of the software company Ocean Science Analytics and a previous Bio-Waves employee, tells The Scientist. “I’ve never known anybody to put so much thought into how we covered all our bases.”

Norris is survived by his wife Danielle, his older brother Peter, and parents Marlies and Patrick. Moss Landing Marine Laboratories will be establishing a student scholarship in his honor to support emerging marine mammal scientists who embrace creative methods in their research.