Polski
Science, Issue 3/2026
How does ship traffic affect ocean megafauna?
Mar
Increasing ship and boat traffic around the world is becoming a growing challenge for those who undertake conservation of large marine animals, or megafauna (including whales, manatees, sea turtles and large shark species). The authors of the study, the results of which were published in the journal npj Ocean Sustainability,conducted a global meta-analysis of the scientific literature to examine how vessels affect the behavior, physiology and functioning of these organisms.
The researchers looked at 204 publications from 1979-2022, most of which were published in the last decade. The research was conducted around the world, from the North Atlantic to the South China Sea, analyzing the impact of marine transportation on 261 species, primarily marine mammals, including cetaceans, pinnipeds and mermaids.
Distance from animals is crucial
A team of scientists led by Julia Saltzman of the University of Miami has shown that a key factor influencing the reactions of marine animals is their distance from the vessel.When ships get closer to animals, the likelihood of disrupting their natural behavior increases. These reactions can include changes in the way they move, avoidance of certain areas, and modification of acoustic signals used for communication.
For this reason, the authors emphasize the importance of regulations specifying the minimum distance of vessels from marine megafauna sites. Such regulations should cover all types of vessels, including tourist and recreational boats, which often approach animals for observation.
Speed limits reduce danger
Speed limits have proven to be a second important element in reducing the impact of ships on megafauna. Slower moving ships cause less disturbance to the environment while reducing the risk of collisions.
Speed limits can be particularly effective in key locations for many species, such as seagrass meadows used by manatees and sea turtles and cetacean migration corridors. Reducing vessel speeds in these sensitive areas can significantly reduce stress levels in animals and the likelihood of fatal collisions with vessels.
Ship noise – a smaller but still significant problem
Noise generated by vessels was also one of the factors analyzed in the study. The statistical models used by the authors showed that the impact of noise was usually smaller than the impact of the mere presence of the vessel or its distance from the animal. Nevertheless, the sound accompanying the operation of the engines elicited measurable responses in many marine species.
In the statistical analysis, noise was identified as a significant factor affecting changes in animal numbers. This means that even if it is not a major source of disturbance, it remains an important element of environmental pressure. The authors point out that the development of noise-reducing technologies, such as quieter engines, vibration dampening systems or new hull designs, could significantly reduce the negative impact of ship traffic on the marine environment. This would be particularly important in the nature tourism sector, where vessels often get close to animals without turning off their engines.
Technologies to protect animals from collisions
The study highlights the importance of technical solutions that can reduce direct risks to animals. Examples include propeller guards and engine modifications that will prevent serious injury if an animal comes into contact with a vessel. Such solutions are particularly important for large, slow-moving species, such as manatees and sea turtles.
Real-time animal detection systems are also a promising direction of development. These technologies use onboard sensors, acoustic monitoring or warning networks to inform ship operators of the presence of animals in the vicinity. This makes it possible to reduce speed or change course earlier. Currently, such systems are mainly used to protect marine mammals, but similar solutions could also prove effective for other large species, including whale and giant sharks or manta rays.
Management of ship traffic in time and space
The authors emphasize the importance of site- and season-specific management of vessel traffic. Restrictions can be implemented in areas of crucial habitat or during periods that are special to animals, such as when and where they are breeding or laying eggs. Such measures can reduce both disruption of reproductive behavior and mortality resulting from collisions.
Special attention has been paid to the concept of mobile marine protected areas. Unlike traditional versions, their boundaries can change as animals move. This solution allows protection to better adapt to dynamic changes in the environment, such as ocean currents, food availability and the effects of climate change.
Gaps in scientific knowledge
Despite the comprehensive scope of the analysis conducted, the authors emphasize that knowledge about the impact of ships on megafauna is still incomplete. Most studies focus on marine mammals, such as whales, dolphins and pinnipeds. Much less is known about other groups of animals.
Marine reptiles and cartilaginous and bony fish remain particularly poorly understood. Importantly, the available results suggest that marine reptiles may have a particularly strong behavioral response to the presence of ships. The analysis also notes that species at risk of extinction often respond more strongly to disturbances associated with vessel traffic, highlighting the need for further research on them.
Protection requires cooperation
The study’s authors stress that reducing the impact of ship traffic on marine megafauna requires a combination of different types of action. Regulations alone are not enough if they are not effectively enforced or if sea users are not aware of their importance. Vessel traffic monitoring, education of vessel operators and the development of technologies to reduce negative impacts are therefore crucial.
According to the researchers, effective protection of large marine animals requires the cooperation of scientists, policymakers and marine user communities. Only a comprehensive approach will reduce the pressure of increasing ship traffic and ensure the long-term protection of ocean megafauna.
pic. main: Peter_Lindenau/Pixabay
Source:
Saltzman, J., Yeager, E.A., Hlavin, J.F . et al. Charting the course for management: a global analysis of effects of vessels on marine megafauna. npj Ocean Sustain 5, 11 (2026). https://doi.org/10.1038/s44183-026-00182-5
