Wednesday, July 26, 2017

Devil Sharks: Science Behind the Show

26 July 2017

With volcanologist Jess Phoenix at Ocean Entry
Scientists studying the active volcano of Kavachi in the southwest Pacific got a real surprise when they found sharks living inside the caldera a few years ago.

When you first think about sharks and volcanoes few would expect a special attraction — including me. But I was asked about exploring the links between the two, I was intrigued. For the last two years I’ve been part of the Global FinPrint project — a worldwide effort to survey shark and ray populations on coral reefs that is supported by Paul G. Allen and Vulcan, Inc. I realized that many of the coral reefs we’re working on, and where we see lots of sharks, have volcanic origins.

During the research and filming for Devil Sharks, which premieres at 10 p.m. tonight on Discovery Channel’s Shark Week, we had the opportunity to extend some of the lab's projects, meet and work with amazing scientists from around the world, and learn a lot about volcanoes. Special thanks to Volcanologist Jess Phoenix for showing us around the Big Island of Hawaii’s volcanoes — by both air and sea! 

So what do we know about the relationship between sharks and volcanoes?

A Nice Place to Call Home

Whitetip reef shark under a ledge.
At the most basic level, one thing that makes volcanoes important for sharks (and many other species) is that they create a comfortable habitat — maybe not for us, but certainly for sharks. Even before volcanic activity has created land that pushes above the surface of the ocean, seamounts form and are a place where all kinds of animals congregate. 

As islands form, so will many different habitats. In warm waters, coral reefs pop up to create shallow habitats near shore. For some sharks, the shallow waters and even old lava tubes of volcanoes can provide safety from predators. For many sharks, volcanoes provide food, and for others a convenient rest stop. Without question, volcanoes create secure environments in the middle of the ocean where sharks can thrive.

Different species of sharks at different life stages are found in each of these habitats. Because many volcanic islands have steep slopes, open ocean sharks can be found close to shore, providing researchers with great opportunities to study hard-to-find species. During our trip it was great to catch up with Dr. Melanie Hutchinson and see her work on the pelagic sharks you find close to shore off the Kona coast of the Big Island.

With Dr. Jeremy Kiszka (center) and Dr. Eric Clua (right)
Frances Farabaugh preparing to sample for Global FinPrint
Once volcanoes become dormant and islands start to erode away, the volcanoes are still great places for sharks. The shallow waters of lagoons are a perfect place for small sharks to grow up, keeping them safe from larger sharks that would like to eat them. 

Work we have done in the islands of French Polynesia, though, suggests that there might be a scramble for food in these nurseries. When baby blacktip reef sharks and baby sicklefin lemon sharks are found together, their diets change — probably because of competition.  

Throughout French Polynesia, FIU Ph.D. candidate Frances Farabaugh is sampling reef sharks as part of the Global FinPrint project with Dr. Jeremy Kiszka and Dr. Eric Clua. Some of their work is featured in Devil Sharks. We’re examining how the differences between islands impact the types and numbers of sharks present. We’re also collecting tissue samples to figure out where different species of sharks feed — along the reef, in the lagoon, or in the open ocean — and we are working with Eric to track silvertip sharks.

But wait, what about the heat?
When volcanoes are active and lava is flowing into the water, it creates patches of very warm water. Is warm water part of what attracts sharks to active volcanoes?

Unfortunately, we just don't know. But, we do know that lots of species of sharks and rays move between warm and cold waters (aka behavioral thermoregulation) to help with foraging, digestion and possibly reproduction. With warm waters available, it’s certainly possible that sharks use water around active volcanoes in the same way they use other pockets of warm water.

Magnetic attraction?

One question many scientists are interested in is how sharks navigate in what appears to be a completely featureless ocean. Shark tracking has shown that they can swim in nearly straight lines from one island to the next over huge distances. 

One possibility is that they use variations in the magnetic field. Work by Carl Meyer, Kim Holland, and James Anderson of the University of Hawaii tells us sharks have an impressive magnetic sense. Using trained baby sharks, they’re now conducting experiments that could help us understand just how small of a difference in magnetic fields they can detect. 

Lava pouring into the ocean off Hawaii.
Around volcanic islands and features, the strength of the magnetic field can change quite a lot. Here is a neat example from New Zealand. Could sharks use this variation to find their way to and from volcanic islands? Studies of sharks in the wild suggest that they could. Peter Klimley found that the hammerhead sharks he tagged off the coast of Mexico appeared to use variation in the magnetic field to move to and from seamounts.  

Do sharks use magnetic fields to navigate over large distances? Researchers are still working on it! Using satellite tags to track movements of many individual sharks — like we did off Saba Island in the Caribbean — is one way to find out.


Meyer CG, Holland KN, Papastamatiou YP. 2005. Sharks can detect changes in the geomagnetic field. Journal of the Royal Society Interface 2: 129–130.

I hope everyone enjoys the show! Thanks to Pangolin Pictures for the invitation to participate.  Also a huge thanks to all who worked on the documentary and those who have supported the research depicted in the film, especially Paul G. Allen, Pangolin Pictures, Divers Direct, Atomic Aquatics, and Exeye Ltd.


  1. Replies

      Good day, Out of my busy schedule just feel like to quickly share this because i know am going to save thousand of lives with this. A lot of persons will agree with me that fake loan lenders is no longer a news to us it has been trending for some months now and i was also victimized when i tried seeking for a loan for the invention of a new patent and invest on stock. After so many failed attempt to get a loan there was one company who proved themself to be different among the rest, They are trust worthy, straight forward, honest and reliable. I won't say much because as the saying goes "experience is the best teacher", I will candid advice anyone who need a loan of any amount to kindly contact this one and only true lenders UPSTART LOAN on their email address: ( ) Or you can as well text/call them on ( +1(574) 301-1639 ) . I remain my humble self Wesley Kurt Dwayne, I reside at Park Ave Richmond VA 23220. Say no more to be victim of scam enough is enough for the wise, Don't trust until you verified contact UPSTART LOAN now and be forever thankful for my advice.

      Hi everyone, i am Alexis Ohanian am so glade coming back to this great forum to testify about the help i received from Chester Brian. I was in desperate need of a loan in other to be free from debt and financial bondage that was place on me by my ex husband. It was really bad that i have to seek for help from Friends,family and even my bank but on one could assist me because my credit score was really bad. So i was browsing with my computer and saw some testimonies from people Chester Brian assisted with a loan, then i decided to contact him on his email, then i received a mail from them and i did all that was asked from me. To my greatest surprise they transferred to my account the loan i requested and now i am so happy clearing my debt and have also started a business with the remaining amount to take care of myself and family. If you need a loan do contact the best loan lender of all time Chester Brian on his email:

    3. Celebrate this Christmas season with joy and gladness in your heart...

      I would like to bring this to the notice of the public about how i met Funding Circle Loan PLC after i lost my job and been denied loan by my bank and other financial institution due to my credit score. I could not pay my children's fees. I was behind on bills, about to be thrown out of the house due to my inability to pay my rent, It was during this period my kids were taken from me by foster care. Then i set out to seek for funds online where i lost $3,670 that i borrowed from friends which i was rip off by two companies. Until i was referred to Funding Circle Plc by a very good friend, so if truly you are in need of a loan i advise you contact this Godsent lender via Email: OR Call/Text +14067326622 and be free from scam' Jennie Cortez by name from United State

  2. The challenge to risk online
    Royal1688It is the most popular site in Asia in the gaming community. Our online gambling website 69 has been open for more than 8 years, and also has a service in the category of international standards. The technology that comes into service. Regulation Different sounds are realistic. As if you were sitting in the middle of a real gambling world and our website also has satellite reception broadcast live from gambling casinos in Poipet. Cambodia Come to the screen of your mobile phone or computer screen. The more you get into the game, the more risk. You will also be able to invite your friends to participate in the game of gambling, live betting, too. Not only will you get the bonus of inviting your friends to join the game. Get the extra money to introduce 200 baht per foot. Unlimited number of indications. Do not wait too fast to join this amazing site at the same site. Goldclub Slot

  3. When I originally commented I clicked the -Notify me when new comments are added- checkbox and now each time a comment is added I get four emails with the same comment. Is there any way you can remove me from that service? Thanks!
    best dash cam - dash cam box

  4. Looking for business loans, personal loans, home loans, car loans, student loans, debt consolidation loans, unsecured loans, venture capital, etc. Or you've been denied credit from a bank or financial setting for one or more reasons. You well your credit solutions! I am a pastor, a private lender, loans to businesses and individuals at a low and affordable interest rate of 3%. Interest? Please contact us for processing credit transfer follow within 48 hours. CONTACT:
    Details of the application
    Marital status:
    Postal code:
    Purpose of loan status:
    Loan amount:
    The duration of the loan:
    Net monthly income.

    Please return as soon as possible with the information above for more information.
    We hope to hear from you.
    Thank you and God bless you,
    Mr. Osman