Vessel traffic alters behavior, stress and population trends of marine megafauna

(Press-News.org) MIAMI — A new study provides a comprehensive global synthesis of how vessel traffic affects large marine wildlife, including whales, dolphins, seals, manatees, sea turtles, sharks and rays.

Drawing on over four decades of published scientific research, the meta-analysis combined findings from more than 200 peer-reviewed studies conducted around the world. In total, nearly 1,900 comparisons were compiled between scenarios with and without vessel presence, allowing for a robust assessment of how vessels impact marine wildlife.

The analysis examined documented responses to vessel activity across various species, geographic regions, and types of behavioral and physiological reactions. The results indicate that vessel traffic can alter animal behavior, disrupt communication, and affect stress physiology. Additionally, these disturbances may influence long-term population trends in marine megafauna.

Many species are especially vulnerable to vessel disturbance because they are long-lived, reproduce slowly and rely on coastal and surface waters where boat traffic is concentrated. By identifying consistent patterns across decades of research, the findings offer insights to inform conservation policy and marine management.

The researchers found that exposure to boats consistently alters how large marine animals behave and function.

“Even when vessels do not directly strike animals, their presence alone can disrupt feeding, movement, communication, and stress levels. These small, repeated disturbances can add up over time and affect populations,” said Julia Saltzman, the lead author of the study and a doctoral student in the Shark Research and Conservation Program at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science and the Department of Biology at the College of Arts and Sciences.

They also identified uneven research coverage among species groups.

“Some groups, particularly sea turtles, show stronger responses to vessel disturbance, while others, including large fishes, sharks and rays, remain relatively understudied despite frequent spatial overlap with vessel activity,” said Emily Yeager, co-author of the study and a doctoral candidate in the Department of Environmental Science and Policy at the Rosenstiel School and the Abess Center for Ecosystem Science and Policy.

The analysis found that species already listed as threatened or endangered may be more strongly affected by vessel disturbance. Animals at higher risk of extinction often exhibited larger or more consequential behavioral or biological responses, suggesting that vessel activity can intensify existing conservation threats.

“Because vessel activity and wildlife distributions shift across space and time, static management approaches are not always sufficient to protect species from disturbance,” said Catherine Macdonald, an associate professor in the Department of Environmental Science and Policy and director of the Shark Research and Conservation Program at the Rosenstiel School. “Dynamic management strategies, including seasonal speed restrictions, adaptive buffer distances and targeted closures of key habitats, can provide flexible, evidence-based tools to reduce vessel impacts while allowing continued human use of the ocean.”

The study, “Charting the Course for Management: A Global Analysis of Effects of Vessels on Marine Megafauna,” was published February 24, 2026, in npj Ocean Sustainability (Nature Partner Journals.)

The authors are Julia Saltzman¹ ² ³ ⁴ ⁵; Emily A. Yeager¹ ³ ⁴; John F. Hlavin¹ ³ ⁴; Mariana M. P. B. Fuentes⁵; Michelle Krumholtz⁵ ⁶; Camille Kynoch⁵ ⁷; Alexa R. Putillo-Wehry⁵; Kiersten Schweizer⁵; Remi Siegel-Ventura⁵; and Catherine Macdonald¹ ³ ⁴.

¹ Department of Environmental Science and Policy, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami. ² Department of Biology, College of Arts and Sciences, University of Miami. ³ John and Judy Schotte Center for Marine Conservation, Shark Research and Conservation Program, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami,⁴ Field School, Miami, ⁵ Department of Earth, Ocean and Atmospheric Science, Florida State University, ⁶ Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, ⁷ School of Biological Sciences, Monash University, Melbourne, Australia

 

About the University of Miami and Rosenstiel School of Marine, Atmospheric and Earth Science

 The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University’s vibrant academic community comprises 12 schools and colleges serving more than 19,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, and a commitment to tackling the challenges facing our world. The University of Miami is a member of the prestigious Association of American Universities (AAU).

 Founded in 1943, the Rosenstiel School of Marine, Atmospheric, and Earth Science is one of the world’s premier research institutions in the continental United States. The School’s basic and applied research programs seek to improve understanding and prediction of Earth’s geological, oceanic, and atmospheric systems by focusing on four key pillars:

*Saving lives through better forecasting of extreme weather and seismic events. 

*Feeding the world by developing sustainable wild fisheries and aquaculture programs. 

*Unlocking ocean secrets through research on climate, weather, energy and medicine. 

*Preserving marine species, including endangered sharks and other fish, as well as protecting and restoring threatened coral reefs. www.earth.miami.edu.

 

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