Whales play a crucial role in marine ecosystems, serving as a vital component of ocean biodiversity. Despite their massive size and lack of natural predators, these majestic creatures face significant threats, primarily due to human activities. Pollution, climate change, and overfishing pose serious challenges, but perhaps the most pressing danger comes from the increasing number of cargo ships traversing global trade routes.
Each year, thousands of whales lose their lives due to collisions with these enormous vessels. These incidents are often difficult to detect and quantify, as whale carcasses quickly disappear into the depths of the ocean, frequently unnoticed by the ships themselves. Although the issue is recognized, monitoring and understanding the extent of the damage remains challenging.
Recently, a comprehensive study led by the University of Washington, in collaboration with Italy's Tethys Onlus, shed light on this critical problem. The research produced a detailed map highlighting collision risk areas between ships and whales, analyzing over 435,000 whale sightings from official monitoring, public reports, and satellite tagging studies.
By intersecting these data with the routes of approximately 176,000 cargo ships tracked from 2017 to 2022, researchers discovered a striking overlap between whale habitats and global shipping lanes. Alarmingly, the ranges of four of the most endangered species—the blue whale, fin whale, humpback whale, and sperm whale—overlap by 92% with major shipping routes.
The study identified numerous high-risk geographical areas, including the Mediterranean, North American Pacific coast, Panama, the Arabian Sea, Sri Lanka, the Canary Islands, and lesser-known regions such as the southern African coast, Brazil, Chile, Peru, Ecuador, the Azores, and the coasts of China, Japan, and South Korea. These areas are frequented by both whales and ships, creating a constant risk for these cetaceans.
Despite the risks, solutions to reduce ship-whale collisions are relatively straightforward. The authors of the study suggest protective measures such as slowing down ships in high-risk areas, which could significantly decrease the danger. Additionally, rerouting busy shipping lanes to deeper waters, away from whale habitats, could represent another viable solution. However, such measures have been implemented only in limited areas, such as the North American Pacific coast and the Mediterranean, covering merely 7% of high-risk zones, and even less for specific areas concerning blue and humpback whales.
Ironically, many of the most dangerous areas for whales lie within protected marine reserves, established mainly to combat illegal fishing and industrial pollution. However, these protected areas do not impose speed limits on ships, leaving species vulnerable to fatal collisions. As highlighted by researcher Anna Nisi from the University of Washington, introducing speed limits and other regulations would not only reduce risks for whales but also provide additional environmental benefits, such as decreased noise pollution, reduced greenhouse gas emissions, and improved air quality.
According to the study, covering an additional 2.6% of the oceans with protective measures like speed limits could safeguard all high-collision risk areas. Fortunately, most risk zones are located along coastlines within national exclusive economic zones, allowing countries to take concrete action in collaboration with the United Nations International Maritime Organization (IMO). While collaboration between industry and conservation is often challenging, this case presents a tangible opportunity to make a difference without incurring significant costs for the shipping industry, while simultaneously benefiting whale protection and the marine environment.