Have We Met? Secrets to Marine Megafauna ID

Ever had the great fortune to see a couple of mantas or whale sharks in the course of a dive trip, and been left wondering if you’ve encountered the same individual before?  Can we ever tell marine megafauna apart, and confidently say hello to old underwater buddies?  Read on and find out!

ID Secrets

It’s always a super thrill to see marine megafauna in their natural environment – whales breaching out of the water, sharks patrolling the edge of a drop off, mantas swooping over to check us out on a dive!  Just the thought of these encounters is enough to put a massive smile on my face, and start plotting my next dive trip!  But sometimes, I end up wondering if I’ve met that whale, or shark, or manta before – maybe earlier in the week, or even on a previous trip.  Is this likely to happen?  How can I tell if we’ve met before?  Let’s find out!  

Diving with great hammerheads in Bimini, The Bahamas. Photo by Jay Clue, Dive Ninja Expeditions
Diving in Tonga with humpback whales. Photo by Jay Clue, for Dive Ninja Expeditions

Whale Tails

Whales are one of the biggest animals around – with the blue whale holding the record as the largest animal that has ever lived!!  So how can we tell if our big buddies are new or old friends?  Well, we do this by paying close attention to their rear ends – looking out for the fluke, or tails.  The colouration and pattern on the fluke of a whale, the shape of its edges, and scarring patterns, are all unique to an individual whale.  Their tails are whale ID!  Whales are big migrators too, undergoing long seasonal voyages – so it’s entirely possible to whale watch in Alaska and Cabo, and see the same whale – wouldn’t that be awesome!  You can even log your whale fluke photos with HappyWhale, and find out where your whale buddy has been!  Want to find out more about whale ID and why they move around so much?  Sign up for a Ninja Whale Conservation Course!

Spot the Whale Shark

Next up, let’s take a look at the biggest fish in the ocean – the whale shark!  These big spotty gentle giants also undertake long migrations – so there’s a chance that you might see the same whale shark at different aggregation sites around the world!  Each whale shark has a unique pattern of spots – their version of fingerprints.  Researchers focus on the pattern around the left pectoral fin to assign a unique “bodyprint”. You can check out the database at Wildbook for Whale Sharks to see where your whale shark friend has been up to!  Want to find out more, and learn how a NASA algorithm for mapping star fields was modified to help with whale shark ID?  Sign up for a Whale Shark Conservation Project AWARE Course!

Swimming with whale sharks - close up encounters in the Sea of Cortez with Dive Ninjas
Jitterbug the Tiger Shark, on expedition with Dive Ninjas
Shark diving in The Bahamas with Dive Ninja Expeditions

Big Sharks

So, for all ninja shark lovers, how can we tell which shark is who?  It’s a little easier with bigger shark species, such as great whites, tiger sharks and great hammerheads.  The keen shark lover needs to keep an eye out for identifying features such as size and shape of scars, notches or curls in the dorsal fins, and any other distinctive marks.  For example, tiger shark Jitterbug in the Bahamas has a heart shaped face, Emma is a big tiger shark with a curled dorsal fin, and Scylla is a great hammerhead with a distinctive tear in her dorsal fin. Sharks also have their own personalities, so if you’re lucky enough to spend lots of in water time with them, you can start to notice the shy versus forward shark.  Bigger sharks tend to have seasonal migrations – so you can look out for your great white buddies in both Guadalupe and Hawaii, for example! 

Not So Big Sharks

It’s a little bit more difficult with smaller sharks, such as the scalloped hammerheads, silvertips, lemons, grey reef sharks etc.  You can still look for identifying scars and dorsal features, of course.  However these sharks tend to be more cautious, and divers don’t always get the time for a super close look at them.  Scientists rely on tagging sharks – using internal or external tags, to be able to definitively identify individuals and figure out their movements.  The good news with not so big sharks is that they tend to be resident within their home range, so if you dive a site or area repeatedly, you’ve got a good chance of saying hello to a shark you’ve met earlier!

Want to learn more about sharks and sharkie behaviour?  Sign up for a Project AWARE Shark Conservation Course!

Manta Rays

Now let’s take a look at mantas, my favourite flat shark!  Mantas have distinct colouration patterns on their belly, which allows us to uniquely identify them.  It’s an awesome feature, particularly as these intelligent, super curious fish have a habit of swooping in to check out us bubbly divers, showing off their bellies as they do so!  Researchers have established databases of hundreds of manta photo IDs – and if you take an ID shot of a new manta, you even get to name him/her!  Which is how Ninja El Guardian in the Revillagigedos got named in January 2019!

Diving with mantas in Socorro liveaboard
Snorkeling with wild dolphins in Bimini with Dive Ninja Expeditions

Dolphins and Orcas

And what about our favourite squeaky marine mammals – dolphins and orcas?  Here, you’ll need to look out for their dorsal fin, which they helpfully show off when they come to the surface to breathe.  No two dorsal fins are alike – look out for its shape, height, thickness, markings and notches.  It may be challenging to get a good look though, as dolphins and orcas move fast – so keep your eyes peeled!  Dolphin and orcas do tend to stay within their home territories, so if you’re in the area for a few days, you may get to see your squeaky buddies again!

Can’t wait to get into the water to find new friends?  Team Ninja has special trips all around the world, looking for those amazing encounters!  Contact us today to find out more, or sign up!

Diving in Xcalak Mexico with Dive Ninja Expeditions & Girls That Scuba

Ninja Family Guest Writer:

Sze Wei

Lover of all marine animals big and small – and ok, yes, I like diving a lot!  When not underwater, I can be found in London with my goldfish.
Follow Sze Wei on Instagram

Seahorse hanging on fast to coral - come find them with Dive Ninjas!