Female lemon sharks that were born in Bimini returned 15 years later to give birth to their own young, DNA analysis shows.
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.
"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," 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.
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.
Evidence that sharks utilize the same nursery areas across generations underscores the critical importance of preserving local nursery habitats and can provide strong input in designating inshore marine reserves that would protect sharks of future generations.
Many nations have awakened to the threats posed to sharks by unregulated fishing. The Bahamas recently enacted a law to fully protect all sharks in its waters, which will, among other benefits, sustain an annual $80 million shark tourism industry. “National efforts to reign in the shark fishing industry by many countries are likely to benefit homing shark species, like lemon sharks,” added Dr. Chapman, the study's co-author.