A joint team of researchers from Nova Southeastern University’s Save Our Seas Foundation Shark Research Center and Guy Harvey Research Institute, Fisher Finder Adventures, the University of Rhode Island and University of Oxford wanted to know more about the migration patterns of smooth hammerhead sharks (Sphyrna zygaena) in the western Atlantic Ocean.
The research team satellite tagged juvenile hammerhead sharks off the US Mid-Atlantic coast and then tracked the sharks for up to 15 months. The sharks were fitted with fin-mounted satellite tags that reported the sharks’ movements in near real time via a satellite link to the researchers.
“Getting long-term tracks was instrumental in identifying not only clear seasonal travel patterns, but importantly, also the times and areas where the sharks were resident in between their migrations,” said Ryan Logan, Ph.D. student at NSU’s GHRI and SOSF SRC, and first author of the newly published research. “This study provides the first high resolution, long term view of the movement behaviors and habitats used by smooth hammerhead sharks—key information for targeting specific areas and times for management action to help build back this depleted species.”
The researchers found that the sharks acted like snowbirds, migrating between two seasonally resident areas—in coastal waters off New York in the Summer and off North Carolina in the Winter. Their residency times in these two locations coincided with two environmental factors: warmer surface water temperatures and areas with high productivity—indicative of food rich areas.
“The high resolution movements data showed these focused wintering and summering habitats off North Carolina and New York, respectively, to be prime ocean “real estate” for these sharks and therefore important areas to protect for the survival of these near endangered animals,” said Mahmood Shivji, Ph.D., director of NSU’s GHRI and SOSF SRC, who oversaw the study.