Secrets of Whale Shark Migration Revealed:
for National Geographic
Published August 21, 2013
The world’s biggest fish are hungry migrators on a mission, according to a tracking study that mapped whale sharks’ long journeys around the Gulf of Mexico and Caribbean to a favorite feeding hot spot off the Yucatan Peninsula.
And one whale shark’s incredible 5,000-mile (7,200-kilometer) swim could even help solve the long-standing mystery of where whale sharks give birth—an event no scientist has ever seen.
[The data] could help answer a question that has plagued whale shark researchers for years: Where are all the females? Quintana Roo is more than 70 percent male, and other global aggregations show the same gender imbalance.
"You can’t have a stable population with that many males. You don’t see that in nature," Hueter said.
"The females have to be somewhere, and we hypothesize that mature, pregnant females undergo long migrations to the middle of the ocean, near seamounts or remote islands … and that’s where they give birth," Hueter explained. "In coastal zones where the feeding aggregations are, their young-which are less than two feet long at birth—might be subject to higher predation."
He added, “We feel good about the hypothesis, but it’s out there to be tested. So now we’ll have to see if it’s proven right in the years to come.”
Few very young whale sharks have been seen in nature. And discovering where the animals give birth, Maslanka said, is “the holy grail of whale shark biology.”