New research shows that endangered Kemp's ridley sea turtles are particularly attuned to the low-frequency sounds produced by ships and industrial activity in their coastal habitats. Scientists from Duke University, NOAA, and North Carolina State University measured the turtles' hearing and found peak sensitivity around 300 hertz, overlapping with common underwater noise sources. This discovery underscores potential vulnerabilities for the species amid busy shipping routes.
Kemp's ridley sea turtles, among the world's most endangered marine species, inhabit the bustling waters of North America's East Coast and Gulf Coast. These areas host major shipping lanes, exposing the turtles to constant human-generated noise alongside other dangers like fishing gear entanglements, vessel collisions, plastic ingestion, and habitat loss.
A study published in The Journal of the Acoustical Society of America reveals how these turtles perceive sound underwater. Researchers attached noninvasive sensors to the turtles' heads to capture electrical signals from their auditory nerves. They played tones from 50 hertz—near the bottom of human hearing—to 1,600 hertz. The turtles proved most responsive at around 300 hertz, with sensitivity dropping at higher pitches.
"Our findings indicate that the turtles are most sensitive in the same low-frequency band where much industrial and vessel noise occurs," said lead author Charles Muirhead. "This does not automatically mean that harmful effects are occurring, but it highlights where further monitoring and targeted impact studies should be focused."
The turtles rely on acoustic cues for navigation and environmental interaction, and low-frequency noises from ships can propagate far underwater, potentially interfering with these vital signals. As Muirhead noted, the species faces overlapping stressors in nearshore and shelf waters of the Gulf Coast and western North Atlantic, regions dense with human activity.
Looking ahead, the team aims to test turtle responses in natural ocean settings and link lab data to real physiological impacts. "These efforts will help refine our understanding of how human-caused noise interacts with sea turtle sensory systems," Muirhead added. "They will also support evidence-based management approaches aimed at minimizing unintended impacts while balancing human activities in coastal and offshore waters."
The research, detailed in a 2026 paper (DOI: 10.1121/10.0041867), emphasizes the need for noise mitigation to protect this fragile population.
