Using satellite tag technology, research assistant professor Neil Hammerschlag and his colleagues have tracked a hammerhead shark during 62 days, as it journeyed from the southern coast of Florida to the middle of the Atlantic off the coast of New Jersey.
The straight line point-to-point distance turned out to be 1 200 kilometers (745 miles).
“This animal made an extraordinary large movement in a short amount of time,” says Hammerschlag, director of the R.J. Dunlap Marine Conservation Program at the University of Miami Rosenstiel School of Marine & Atmospheric Science. “This single observation is a starting point, it shows we need to expand our efforts to learn more about them.”
The hammerhead is believed to have been following prey fish off the continental slope, and it was probably prey that caused it to enter the Gulf Stream current and open-ocean waters of the northwestern Atlantic.
The study headed by Hammerschlag is a part of a larger effort to satellite track tropical sharks to find out if any areas are especially important for their hunting, mating and rearing of young. Hammerschlag also wish to document their migration routes.
“This study provides evidence that great hammerheads can migrate into international waters, where these sharks are vulnerable to illegal fishing,” says Hammerschlag. “By knowing the areas where they are vulnerable to exploitation we can help generate information useful for conservation and management of this species.”
More information can be found in the paper “Range extension of the Endangered great hammerhead shark Sphyrna mokarran in the Northwest Atlantic: preliminary data and significance for conservation“, published in the current issue of Endangered Species Research. The paper’s co-authors include Hammerschlag, Austin J. Gallagher and Dominique M. Lazarre of the University of Miami and Curt Slonim of Curt-A-Sea Fishing Charters.