Research conducted in Bimini in The Bahamas spanning almost two decades shows that female lemon sharks that were born there returned 15 years later to give birth to their own young, confirming this behavior for the first time in sharks. The study began in 1995, and has resulted in the capture, tagging, and release of more than 2,000 baby sharks over the 19-year, ongoing project.
This article, published online on December 5 in the journal Molecular Ecology, entitled, "Two decades of genetic profiling yields first evidence of natal philopatry and long-term fidelity to parturition sites in sharks," was a collaborative effort involving scientists from The Field Museum, Bimini Biological Field Station Foundation, University of Miami and Stony Brook University (SBU). Results suggest that local and international efforts can make a big difference in the struggle to recover the world's coastal shark populations. Sharks have been heavily exploited to supply the Asian restaurants and banquet halls with shark fins, the main ingredient in a highly prized soup of great cultural significance but of no nutritive value.
"We used each shark's individual DNA fingerprint to construct a large family tree," explained Dr. Kevin Feldheim, the A. Watson Armour III Manager of the Pritzker Laboratory for Molecular Systematics and Evolution at The Field Museum and the lead author of the study.
"We found that newborn sharks captured in the mid-1990s left the safety of the islands when they were between five and eight years old. Yet, despite leaving and visiting many other islands in their travels, these sharks 'remember' where they were born after a decade of roving, and are able to find the island again when they are pregnant and ready to give birth," Dr. Feldheim added.
Many researchers had speculated that female sharks have this ability to home back to their birthplace to give birth, but it had never been proven because it is very
|Contact: Cindy Yeast|
The Institute for Ocean Conservation Science