Global warming may heighten the risks that whale sharks face from large vessels, as indicated by a recent study.
According to a new research published in Nature Climate Change, global warming could elevate the dangers that large ships pose to whale sharks.
Scientists from the University of Southampton and the Marine Biological Association (MBA) anticipate that rising ocean temperatures will push this already threatened species into new areas that intersect with busy shipping lanes.
The findings of the study suggest that by the end of the century, the likelihood of whale sharks and large ships being in the same area could increase by as much as 15,000 times compared to current levels.
Lead author Dr. Freya Womersley, a Postdoctoral Research Scientist at the University of Southampton and MBA, stated: “These changes in whale shark habitats become most pronounced under high emission scenarios. A global reshuffle could result in significant habitat loss in certain regions, along with a rise in encounters with shipping traffic as oceans warm and other conditions shift.”
Whale sharks, recognized as the largest fish on the planet, are highly migratory and sensitive to temperature changes. Recent studies also show they are especially susceptible to vessel strikes—incidents where large marine creatures are injured, often fatally, by vast boats.
To examine potential changes in whale shark distribution, researchers analyzed satellite-tracking data alongside global climate models, evaluating three different future climate scenarios.
The models predict that under high emissions (where reliance on fossil fuels continues), more than 50% of their core habitats could be lost in certain national waters by 2100, particularly in Asia. However, under a sustainable development scenario, which aims to keep global warming below 2°C, some regions in Europe might actually see an increase in core habitats.
“The shifts we’re projecting are likely to be less severe if we can manage to decrease warming and alleviate climate change, showing that even complex challenges posed by climate change can be somewhat moderated through our actions,” explained Professor David Sims, co-author and Senior Research Fellow at the University of Southampton and MBA.
The researchers combined the habitat distribution maps with data on shipping traffic density to ascertain if the anticipated habitat shifts would lead whale sharks into busier areas, thereby raising the risk of vessel strikes.
They discovered that some newly suitable habitats coincided with heavily trafficked shipping routes, including regions like the US section of the North Pacific Ocean, the Japanese waters of the Eastern China Seas, and parts of the North Atlantic Ocean off Sierra Leone, among numerous others worldwide.
Conversely, some regions, such as the Gulf of Mexico near Mexico, experienced a reduction in overlap, as core habitats migrated towards more coastal areas, distancing themselves from the central Gulf’s busy shipping lanes.
Professor Sims remarked: “Overall, ship encounters are expected to rise under all future climate scenarios, even if shipping levels stay as they are now, rather than the projected growth of up to 1,200 percent by 2050.”
Womersley added: “Our research demonstrates that climate change could indirectly affect highly mobile marine species through the combined pressures from human activity and environmental changes. This underscores the necessity of incorporating climate change considerations into discussions about the management of endangered species.”
This research received backing from the UK Natural Environment Research Council (NERC) and the European Research Council (ERC) under the EU Horizon 2020 Programme.
