Shark Side of the Moon | SharkFest | National Geographic

The full moon emerges as if on cue. Sharks take off. Palaio and the team track their movements in near real time.

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Swimming 30 miles a day.

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So now we are big brother. Living as we sit here, I'm receiving messages saying that 11 out of the 13 satellite tags that we deployed on the pregnant females are already transmitting. So we're going to have a lot of data points that before we didn't have. It's a successful start to the study, but the journey for these mothers has only just begun.

To navigate, they rely on a supersensory organ called the ampullae of Lorenzini. This organic GPS will allow them to sense electromagnetic fields emanating from a chain of undersea volcanic mountain ranges known as the Cocos Ridge.

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But the open ocean is a gauntlet for the mothers.

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[Applause]

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And there are harsh reminders of the dangers sharks face, even here in protected waters. So any shade in the ocean attracts a smaller fish, and then a smaller fish attracts a bigger fish. This is a fish aggregating device, or FAD.

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Equipment used by fishermen to attract and catch fish in the open ocean.

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All too often, passing scalloped hammerheads end up ensnared, injured, or worse. Overfishing and illegal fishing practices are the biggest threat to the conservation of the scallop hammerhead shark, and this is why they are critically endangered.

The moment they leave Darwin, the moment they cross the boundary of the Galapagos Marine Reserve, they are completely vulnerable. Beyond the Galapagos, 40 miles of protected waters, the open ocean is full of lethal obstacles. There are curtains of hooks, there are fishing nets everywhere, and they have to take these migrations to mangroves through unprotected waters and survive the journey.

So with our data, we hope to achieve knowledge that is necessary to tell the decision makers, you need to establish, you know, like a fishing ban during this time of the year, or you have to protect these biological corridors so we can protect hammerheads across the entire life cycle.

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With the future of the species on the line, groundbreaking studies like this are critical. If Palaio can tie the moon phases to scalloped hammerhead migrations, it could unlock the secrets of what triggers the movements of other migratory sharks and help protect the shark superhighways.

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That are key to survival.

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