Most of my work at the Marine Megafauna Foundation focuses on Earth’s largest fish, the whale shark. Whale sharks are – in every sense of the word – awesome. They’re also seriously under threat. Whale sharks feed on zooplankton and small fish, and are totally harmless to people. Sadly, their gentle nature has been exploited through both targeted fisheries and high levels of accidental catch. They are now a globally threatened species, and without active conservation measures we could lose them forever. That would be a tragedy.
My whale shark research began in Mozambique in 2005. Not much scientific work on whale sharks had been published at the time, so my first task was to work out *how* to research them. Fortunately, every single whale shark has a distinctive pattern of white spots over their upper surfaces and, by taking photographs of each flank, we can reliably identify individual sharks over time. That means we can count how many sharks we see and track their movements and behaviours.
Whale sharks are really, really big. In practical terms, that makes it hard to get accurate measurements of how large they actually are. To get around this, we mounted green laser pointers on either side of the camera we use for photo-ID. That gives us a ‘scale bar’ on the resulting photo, and means that we can see who the shark is, and how long they are, with a single photograph. You can see this measuring system in the photo above. There’s more detail on the technique here.
Other researchers are using the same area of the sharks’ body for photo-ID, which has allowed us to start looking for regional movements between the known ‘feeding areas’ in the Western Indian Ocean. This has now become a global effort thanks to the Global Whale Shark Photo-ID Library. Over 6000 individual whale sharks have now been identified, from over 45 countries. Many of these identification photographs have been submitted by the interested public. This database represents a notable success for ‘citizen science’.
Whale shark are a very popular species with marine tourists, and there are several sites where sharks, particularly juvenile males for some reason, can be seen fairly reliably each year. I think that tourism has been largely positive for whale sharks, creating an economic incentive to ensure that they are managed well, but it has led to the need to evaluate the impacts of swimmers on the sharks. We have done considerable work on this, both in developing science-based codes of practice and monitoring protocols, and in conducting guide and skipper training in Mozambique and (with Sea Sense) in Tanzania.
‘Team Whale Shark’ at MMF
We have a great team in Mozambique, and now around the world. Pete Haskell completed his MSc (Distinction) on whale shark tourism in 2010. Dr Chris Rohner, my first PhD student, finished his doctoral thesis on Mozambican whale sharks in 2013 and has been leading our project at Mafia Island in Tanzania since 2012. Clare Prebble joined MMF as a Project Manager in 2011, has been running day-to-day operations in Mozambique since 2012, and is now also a PhD candidate at the National Oceanography Centre at the University of Southampton, UK. I’ve also had some fantastic long-term project assistants over the last few years, including Peter Bassett (who has now started Aquatic Alliance in Indonesia).
Dr Chris Rohner assessing the maturity of a male shark
Where do we work?
Our work in Mozambique has providing us with an excellent springboard for work in other countries. Between 2011 and 2013 I worked with the Utila Whale Shark Research Project based at Deep Blue Resort on Utila, a small island off mainland Honduras. Initially we focused on investigating the population structure of sharks visiting the island using photo-identification, and we are now examining whale shark populations more broadly in the Atlantic Ocean.
Somewhat unexpectedly, one of the largest whale shark feeding aggregations in the world takes place within the Al Shaheen Oil Field off the coast of Qatar. Since 2012 I have been assisting David Robinson from Sharkwatch Arabia and the Qatar Whale Shark Research Project team with their work in this fascinating area. See a blog post on our early work here.
In 2012 we also started a project at Mafia Island off Tanzania with the support of WWF Tanzania, and in partnership with King Abdullah University of Science and Technology from Saudi Arabia and the Tanzanian Fisheries Research Institute. I lead annual whale shark research expeditions to Mafia each November. It’s a beautiful place.
Whale shark off Mafia Island, Tanzania
Each year since 2013 I have been hosting Aqua-Firma groups to Isla Mujeres off the Yucatan coast of Mexico to work with Ch’ooj Ajauil AC. It’s an amazing spot! In 2015, we saw up to 180 whale sharks in a day. I wrote a blog post on the 2014 trip. (We’re heading there again in 2016.)
In 2014, I was (finally) able to visit the Galapagos Islands for the first time. That place. Wow. I also started work with the Large Marine Vertebrates Research Institute, Philippines, on multiple projects. Lots to do over there, it’s a great place to visit!
I’m presently working on a re-assessment of the global conservation status of whale sharks for the IUCN Red List. Following that, there’s lots to do! We still have a lot of work to do on the population ecology (and management implications thereof) of whale sharks in Mozambique, Tanzania and Qatar, and broader-scale population connectivity across all oceans.
Unfortunately, even though some of the largest fisheries for whale sharks have now closed – generally after running out of sharks to catch – there are still serious human threats to whale shark populations. We need to provide effective protection to their key habitats. We’re lucky in that whale sharks, with their huge size and placid natures, are very popular with marine tourists. We are working with the tourism industry to ensure that these activities are sustainable.
Want to join us?
If you’d like to participate in this work, we do public research expeditions each year (to Mexico and Tanzania in 2016) and in Mozambique we have partnered with Underwater Africa to provide a volunteer research opportunity. We also take on a very small number of long-term volunteers each year to work directly with the team. Those positions will normally be advertised on the MMF Facebook page.