An 8-meter whale shark named Milo has traveled over 54,000 km in a decade, setting a record and revealing new insights into the species.
Whale shark's long journey tracked
An animal disappears quietly, and no one really worries: this is the risk that silently threatens the whale sharks, an endangered species about which much remains unknown. However, a male named Milo has recently challenged this indifference. Milo's record-breaking travels
Tracked for ten years, Milo has traveled 54,700 kilometers between the Caribbean and the Gulf of Mexico, a record for a shark. Milo, a male whale shark measuring 8 meters, has been marked five times since 2017, a technical feat never before achieved. Milo's migration patterns
His journeys have taken him from Bermuda to Massachusetts and from the Gulf of Mexico to Mexico, but he always returns near the Yucatán, north of Cancún, where a census has already counted 420 whale sharks gathered over an area of 18 square kilometers due to the abundance of food. Ecosystem fragility highlighted
In 2025, observations were declining in this area before a recent resurgence of gatherings, a piece of data highlighting the fragility of this ecosystem for an endangered species. Tracking Milo's movements
Milo, the whale shark that breaks all distance records. It is impossible to talk about this ocean giant without giving the dizzying numbers. Milo, an 8-meter-long male, has been tracked by satellite for nearly a decade. Result: 54,700 kilometers, or approximately 34,000 miles, traveled between the Caribbean and the Gulf of Mexico. Technical challenges of tracking
This is simply the longest distance ever recorded for a shark tracked by scientists. This feat was made possible by a marking done five times on the same animal, a technical achievement in itself given how difficult these creatures are to locate and track over the long term. Milo's wide-ranging movements
Since 2017, researchers have been able to compile an unprecedented map of his movements. Milo freely crosses the waters surrounding the United States, Mexico, Cuba, Haiti, and Bermuda, as if maritime borders simply did not exist for him. Long-term tracking efforts
Ten years of scientific tracking to unravel the mystery of a solitary giant. Tracking an animal for a decade is a challenge, especially when it comes to a fish as discreet as the whale shark. Dr. Guy Harvey, a scientist and founder of the Guy Harvey Foundation at Nova Southeastern University, emphasizes the importance of this long-term work to better understand the full life history of these animals. Milo's varied migration patterns
Milo's journeys tell an unexpectedly varied story. In 2018, he ventured far into the Atlantic Ocean, well beyond Bermuda. Two years later, he headed north, passing off the coast of New York, until reaching the waters of Massachusetts. In other years, Milo preferred to stay in the Gulf of Mexico. Scientific identification method
In 2019, 2021, and 2022, he followed the coasts of Mississippi and Louisiana, crossed into Texas, then descended back to Mexico. A true loop, like an invisible thread that always brings him back to the same point. To ensure that it is indeed the same individual year after year, scientists rely on a simple yet effective detail: Milo's spots, unique like fingerprints. Sharks' migration flexibility
Dr. Mahmood Shivji, director of the Guy Harvey Research Institute, highlights the remarkable flexibility of these sharks, capable of migrating over long distances while being perfectly comfortable in small coastal areas for months. Milo's return to Yucatán
Milo's secret: an immutable meeting off the Yucatán. Despite these impressive travels, Milo inevitably returns to the same place: the Yucatán Peninsula, just north of Cancún. A near ritual meeting, even though whale sharks are known for being solitary animals. Yucatán's ecological significance
This area hosts one of the largest seasonal gatherings of whale sharks in the world. An aerial census had already counted 420 individuals gathered in an area of barely 18 square kilometers, proof of the exceptional attractiveness of this area for the species. Reason for Yucatán's attraction
The reason for this attraction lies in the abundance of food. Zooplankton, shrimp, copepods, and fish eggs concentrate there thanks to tropical water upwellings from the depths, which enrich coastal waters with nutrients. Manta rays, other peaceful ocean giants, often join the feast. Ecosystem resilience observed
This fragility of marine ecosystems is not just a theoretical concern. In 2025, the number of sharks observed in the area was significantly lower than normal, which alerted scientists. However, good news: the population seems to have rebounded, with a strong resurgence of gatherings observed this year. Milo's broader significance
Milo's story goes far beyond the simple distance record. It illustrates how these ocean giants remain largely unknown, oscillating between spectacular ocean migrations and an astonishing fidelity to certain territories. Conservation implications
Understanding these behaviors also provides the means to better protect a species currently classified as endangered.
