BOCA RATON (USA)- How do you stay safe from big hammerhead sharks? You run into the shallows. Sounds so logical, but it was never proven before. Researchers of the Florida Atlantic University show with drone footage that adult Blacktip Sharks (Carcharhinus limbatus) along the coast of Southeastern Florida use shallow water adjacent to the beach when confronted with or chased by a predatory Great Hammerhead Shark (Sphyrna mokarran).
Several juvenile shark species use shallow water as nursery sites so their young can grow, reducing their risk of attacks from predators. However, prior to this study, there was no documentation that showed large adult sharks also swim in shallow waters to avoid predators. To the researchers knowledge, this is the first evidence of adult Blacktip Sharks using shallow waters as a refuge.
See video footage of a large hammerhead chasing Blacktip Sharks: jfb14342-sup-0001-videos1.
Unmanned aerial vehicles
The use of unmanned aerial vehicles (UAVs) enabled FAU scientists to unobtrusively observe and allow natural behaviors to be documented in the wild, providing insight into seldom-seen predator-prey interactions. Results of the study are published in the Journal Fish Biology.
Blacktip Sharks
Every year large schools of sharks, such as Blacktip Sharks gather for migration in the clear, shallow waters close to the beach in Palm Beach County, Florida. This makes the research with unmanned aerial vehicles perfect. The Blacktip Shark is both an agile predator of teleost fishes, cephalopods and crustaceans and a prey for larger sharks, such as the Great Hammerhead, which can get as big as 18 feet long.
Despite their large size, hammerheads are often found in relatively shallow waters that are likely an important area for their feeding. Their prey typically includes stingrays, bony fishes and other sharks, so it is no surprise that they have been spotted in and around the Blacktip Shark aggregations, which provide an abundance of possible prey.
The results of the study were published in the Journal Fish Biology.
