July 8, 2015
New Study Provides Insight into Tiger Sharks’ “Marathon Migration”
BY: Isabel Lankler
With Discovery’s thrilling week of shark-infested TV underway, it’s time to take a closer look at the magnificent world of sharks. Despite sharks being top predators in the marine food chain and playing a critical role in ecosystem stability, there is still much scientists don’t know about them. Recent discoveries, however, are beginning to shed light on these mysterious predators and their movement throughout the world’s oceans. Take a look below to learn more about studies surrounding an incredible new finding on tiger sharks:
It was previously believed that tiger sharks (Galeocerdo cuvier) remained in coastal areas, often in the deep waters that surround coral reefs. Therefore, researchers did not expect to see that some of their tagged tiger sharks were completing a 4,660 mile journey on a yearly basis. This eye-opening finding was made possible by data from satellite tags that monitored the movements of 24 tiger sharks for up to three years: a record-breaking length of time for tiger shark tracking. The sharks’ movement during these years revealed that they repeatedly enjoyed the Caribbean’s warm waters and coral reefs in the winter months, and then ventured into the North Atlantic’s open waters in the summer.
This “marathon migration” demonstrates the remarkable adaptability of the species, as it is a rarity for sharks to be able to alternate so comfortably between such vastly contrasting habitats. Experts are also impressed by this feat of navigation; tiger sharks can join the likes of the salmon shark and the great white as the only other known shark species with a similar long-distance migratory pattern.
The discovery of where these sharks spend the summer raises questions as to why they travel such great distances. The team speculates that Caribbean islands are a winter hot spot for mating, as this is where males and females tend to overlap the most. As for their solo summer tour of the open Atlantic, it’s possible that they are seeking to prey on juvenile sea turtles that are presumed to spend their so-called “lost years” there.
The research team anticipates that their findings about tiger sharks’ migratory behavior will be able to inform decisions when it comes to the preservation of these enigmatic and captivating creatures. They hope that effective conservation efforts and policy will allow these impressive hunters to continue maintaining the delicate marine ecosystems we depend on, and the health of our oceans for years to come.