Changing Planet

Mozambique Expedition: Tracking Nonstop Swimmers

For the month of April 2014, National Geographic Pristine Seas expedition leader Paul Rose will lead a group of key scientists and filmmakers, together with National Geographic Emerging Explorer Andrea Marshall and the Marine Megafauna Foundation, to explore, survey, and record what they expect to be some of the healthiest reefs in East Africa, home to ocean giants like manta rays, dugongs, and more.

By Andrea Marshall, NG Emerging Explorer

Giant manta ray (Manta birostris) at Zavora, Mozambique (Photo by Andrea Marshall)
Giant manta ray (Manta birostris) at Zavora, Mozambique. (Photo by Andrea Marshall)

There are so many mysteries yet to be unraveled when it comes to the ocean. One of them that’s close to my own heart is the secretive life of the manta ray, one of the world’s largest and most majestic fish. I’ve spent the past decade trying to learn more about this elusive animal, but it’s proven quite a challenge. They’re a highly mobile species that never stops swimming—so how on Earth do you learn more about their lifestyle and habits? Luckily for me, I have technology on my side, a huge advantage for field researchers in this day and age.

One of the tools we currently use to track these giant rays is acoustic telemetry, a system that works by attaching small acoustic transmitters to their backs. These small pinger tags are picked up by receiving stations placed down on our inshore reefs. In Mozambique we’ve been using this technology for years, and slowly we’re piecing together the story of their lives along the country’s southern coast.

The reef manta ray, which I differentiated from the giant manta ray back in 2009, appears to be resident to our coastline. This magnificent ray, which swims like a giant underwater bird, has a distinct rhythm to its life. In the mornings it comes close inshore, where it visits cleaning stations to get attended to by small fish. Because they never stop swimming, they’re constantly moving along the great highways of the ocean, migrating from one good feeding area to the next in search of rich patches of zooplankton, the tiny suspended animals in the water column that they feed on. Making a pit stop at a cleaning station is like stopping into a car wash and represents an important daily activity for their health. Tiny fish remove algal buildup and parasites from their skin and help to heal any injuries they may have (e.g. from shark bites).

In the twilight hours most manta rays seems to depart the inshore area and make their way to deeper waters to feed. Today, with the Pristine Seas team, I placed my 50th acoustic tag in Mozambique. I hope that our continued efforts along this coastline will provide a greater understanding of this gentle giant so that we can better manage one of the most important populations for this species in the world—and safeguard one of their last strongholds in Africa.

The Pristine Seas Mozambique expedition is sponsored by Blancpain and Davidoff Cool Water.
Paul Rose is an ardent explorer, television presenter, journalist, author, and Vice President of the Royal Geographical Society, and an Expedition Leader on the Pristine Seas team.
  • Dipanjan Mitra

    75% of earth is water. i really wonder how much we human beings have been able to unravel the water world. Would like to know the ratio compared to land.

  • patrick John hanway

    fantastic stuff,dream of mine that kind of work….amazing.

  • John

    Would do anything to work with these guys. . 🙂

  • Jeanette Marcus

    My husband is Stuart Marcus, wildlife on seven countients .did Alaskans brown bear. Harbor seal. Studies. His works hang in Juneau airport
    Since stroke he doesn’t take many pictures so talented speaker educational talk researched everything..still can do it all can dive has equipment and free time..rangervp 417 6336.

  • Sergio Mendoza Hochmann

    Thanks for this well-written article and for your continued efforts on the matter of the tracking of these beautiful animals. And also, great photograph, Andrea!

  • Edwin Aleman

    I just discover this site today. I really admire your capabilities and the supporters that stand by you. This is very informative and helpful. People will know about the ocean and the living creatures that ordinarily would never have been discovered if efforts like yours were not initiated. Thank you so much. Keep up this noble work. I will constantly follow you.

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