James Cook University scientists recently determined that some coastal areas are even more important to sharks than previously thought.
By tagging more than 100 sharks and tracking 28 with satellite tags over a period of two years, the scientists found that female blacktip reef sharks and their young stay close to shore for long periods of times. Adult males only show up during breeding season.
“Adult female sharks are supposed to come in seasonally to give birth, and then leave,” Dr. Andrew Chin, lead author from JCU, explained in a news release. “But these adult females seem to remain in these areas all year round, and give birth there. The young grow up in muddy coastal bays using seagrass beds and mangroves before migrating.”
This is the first study in the Pacific that shows young reef sharks grow up with breeding adult females in coastal habitats. While the breeding-age females are long-term residents, the young then move offshore in their teenage years.
The researchers also found that the sharks had a “mysterious attraction” to Cockle Bay near Townsville but haven’t yet been able to determine why they love that place so much.
They love it so much, in fact, that they stayed in the area “as a Category 5 cyclone approached while all the other sharks in the area left,” said Dr. Chin.
To learn more:
- Read the JCU news release: Shark research produces the unexpected
- Read the full study: Population organisation in reef sharks: new variations in coastal habitat use by mobile marine predators
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