There is a presence to tiger sharks. It’s not just their often imposing figure, as they tend to be quite big sharks when one is seen for the first time by the general public. But they have this sort of confidence in the way they move through the water, slicing through it effortlessly and without backing down from anything ( unless it’s a triggerfish in the Maldives ). And while most only get a fleeting encounter with this predator, many dream of following that same animal, not for minutes or hours, but for months, across entire ocean basins. What would they see? Where would they go? Off the coast of Cabo Verde, also known as Cape Verde, a small island nation in the eastern Atlantic, scientists set out to answer exactly that .

The Eastern Central Atlantic (ECA) has long been considered data-poor when it comes to sharks and rays, although substantial shark fisheries have been operating in West Africa for decades and there is mounting evidence that fishing pressure is reshaping marine ecosystems there. Over several years, researchers tagged tiger sharks ( Galeocerdo cuvier ) to understand where they go, how they use the habitat, and what that might mean for their survival. They found that some tiger sharks stayed close to home; out of the individuals tracked, most remained within Cabo Verde’s waters, frequenting the same coastal areas near islands like Boavista, Sal, and Maio. And the level of residency shown by these tagged individuals suggests these islands are not just pitstops in some sort of long roadtrip, but habitats that are used repeatedly over time by all lifestages — juveniles, subadults, and adults were all present.

But that’s where the similarities stopped. Some individuals traveled far beyond the archipelago with one female, in particular, crossing the Atlantic Ocean to Brazil, spending time in coastal waters near Salvador before turning around and making the journey back. Having been initially tagged in near Boavista, her track covered nearly 11,185 miles (18,000 kilometers) in total. It is the second-longest movement ever recorded for a tiger shark and the first documented round-trip trans-Atlantic journey for the species.

So, why would a shark make such a long trek, linking two continents? The study did not reveal any concrete answers, so nothing can be said for certain. But there are theories! For example, this journey could be tied to feeding opportunities, mating behavior, or shifts in prey availability. After all, coastal Brazil hosts both abundant prey, like sea turtles, and known tiger shark mating grounds. But there’s a catch to this… similar resources exist in Cabo Verde. Why would one individual think what’s local is enough while another crosses an ocean? While as a species they may fall under the label of “tiger shark,” that doesn’t mean they are interchangeable units. Each one is an individual making different decisions, potentially based on past experience, environmental cues, or physiological needs. Variation between individuals, even within the same species, is increasingly recognized as a key part of how animals interact with their environment.

Of course, this has implications for the conservation of the species. We cannot assume that protecting one place will protect this species, as their wide-ranging movements expose them to threats that do not respect boundaries. Even within Cabo Verde, risks are present; both small-scale and industrial fishing operations overlap with areas where sharks spend significant time. As fishing pressure increases, the likelihood of encounters rises. The study documented sharks caught in fisheries, including one individual that had been finned while still alive. And for the long-distance travelers? The danger multiplies as protection ebbs and flows depending where in the world they are.

Tiger sharks are apex predators. They help regulate prey populations and influence the behavior of other species, which in turn shapes entire ecosystems. And if tiger sharks are moving between the eastern and western Atlantic, then not only are populations more linked than we thought but possibly environments. If so, that might mean that declines in one region could ripple across the ocean. Both for the tiger shark population but also the health of the habitats they frequent and call home. It seems that Cabo Verde may function as a hub, a place where sharks feed, grow, and perhaps reproduce before dispersing. Protecting such hubs could have effects far beyond their geographic boundaries. But that only works if we recognize them in time.

So much remains unknown. Only a dozen sharks were tracked with satellite tags and several provided limited data. And yet, even within this small sample, the range of behaviors was immense. It makes you wonder what we are still missing! More than one-third of shark and ray species are currently threatened with extinction. For highly migratory species like tiger sharks, the challenge is not just reducing fishing pressure in one place but coordinating conservation across entire regions.