A recent study published in *Nature Climate Change* forecasts that increasing ocean temperatures due to global warming will result in whale sharks being driven into new habitats that intersect heavily with shipping lanes. The likelihood of encounters between whale sharks and large vessels could rise 15,000 times by the end of this century. Researchers suggest proactive climate action could mitigate some of these risks, emphasizing the need for integrating climate change impacts into marine species management strategies.
Recent research indicates that the phenomenon of global warming may exacerbate the risks posed to whale sharks by maritime traffic. A notable study published in Nature Climate Change, titled “Climate-driven global redistribution of an ocean giant predicts increased threat from shipping,” conducted by researchers from the University of Southampton and the Marine Biological Association (MBA), forecasts that rising ocean temperatures will compel this endangered species into new habitats that intersect with busy shipping routes. The study estimates that the likelihood of whale sharks encountering large vessels could increase by 15,000 times by the year 2100, compared to current levels. Dr. Freya Womersley, the lead author and a postdoctoral research scientist at the University of Southampton and MBA, emphasized that the habitat shifts of whale sharks are expected to be most pronounced under scenarios of high carbon emissions. “These shifts in the whale sharks’ habitat were most extreme under high emission scenarios. A global reshuffling could lead to core habitat losses in some areas as well as increased co-occurrence with shipping traffic as oceans warm and other variables change,” she noted. As the world’s largest fish, whale sharks are particularly sensitive to temperature fluctuations and are already facing considerable threats from ship strikes, which can prove fatal. The research team utilized satellite-tracking data of whale sharks in conjunction with global climate models to project their future distribution under various climate scenarios, revealing potential habitat losses exceeding 50% in some national waters by 2100, especially in Asia. Conversely, under a sustainable development model aimed at limiting global warming to no more than 2°C, certain regions, such as Europe, may experience gains in whale shark habitats. Professor David Sims, a co-author and senior research fellow at the University of Southampton and MBA, remarked, “The shifts we predict are likely to be less extreme if we are able to slow warming and mitigate climate change, suggesting that even complex, multi-factor impacts of climate change can be somewhat alleviated by our actions.” The researchers combined their habitat distribution models with shipping traffic density data to analyze whether habitat shifts would result in whale sharks moving into more heavily trafficked areas, thereby increasing the risk of ship strikes. The findings indicate that many newly favorable habitats align with busy shipping routes across various regions, including parts of the North Pacific, the Eastern China Seas, and the North Atlantic Ocean. However, specific locations, such as the Gulf of Mexico, demonstrated a reduction in whale shark encounters with shipping traffic. Despite anticipated growth in shipping traffic—projected to expand by up to 1,200% by 2050—the overall likelihood of whale sharks co-occurring with vessels is expected to rise in all climate scenarios considered. Dr. Womersley asserted, “We show that climate change has the potential to indirectly impact highly mobile marine species through interacting pressures of humans and the environment. This highlights the importance of factoring climate change into discussions around endangered species management.”
The correlation between climate change and marine species movement is increasingly evident, particularly for vulnerable species such as whale sharks. As global temperatures rise, many marine animals are altering their habitats in search of suitable living conditions, which can inadvertently lead to increased interaction with human activities, particularly shipping. Whale sharks, which are already facing numerous threats, may be further endangered as they migrate into waters that conflict with major shipping lanes. Understanding this dynamic is crucial for developing strategies to protect these magnificent creatures from potential collisions with vessels, which can have fatal consequences given their size and mobility.
In conclusion, the study highlights the alarming potential for increased whale shark-ship collisions resulting from global warming and habitat redistribution. Researchers project a dramatic rise in the co-occurrence of these endangered fish with shipping lanes, particularly under high carbon emission scenarios. While habitat losses are significant, proactive measures to mitigate climate change could lessen these effects. The importance of integrating climate considerations into marine species management discussions is underscored, as evidenced by the intricate interplay between human activity and environmental changes affecting marine ecosystems.
Original Source: phys.org
