A Dubai Shark Tale, Dubai
29 December 2016
With shark populations in the wild at critical levels, Dubai Aquarium And Underwater Zoo is at the forefront of groundbreaking work to revive, not only numbers, but also a hard-bitten reputation.
You’ve seen Jurassic Park right?” asks Paul Hamilton, the general manager and curator at Dubai Aquarium And Underwater Zoo. “In Jurassic Park they had cryopreservation cylinders that kept all of the dinosaur DNA. Well, it wasn’t that far-fetched to be honest.”
The two of us are deep within Dubai Aquarium, far from the crowds that stream past the attraction’s 10-million-litre tank every day, largely unaware of what lies above and within. In front of us are two cryopreservation cylinders loaded with shark DNA.
Around us, and on the walls of the small rectangular laboratory in which we stand, are charts and the assorted paraphernalia of marine biology. Behind is a window through which the laboratory’s scientists can be viewed by visitors. It is, says Hamilton, part of a process of public outreach designed to help combat negativity surrounding sharks.
Within the cryopreservation cylinders themselves is the DNA of the sand tiger shark and 20 or so other species and endangered elasmobranch, frozen in liquid nitrogen at -196°C. It is, to all intents and purposes, a sperm bank.
“A lot of these shark species are becoming critically endangered in the wild and populations are diminishing to levels that give you little hope of a wild recovery,” says Hamilton. “For example, the sand tiger shark in Australia is down to 1,200 individuals. At that point you start to develop doubts as to whether there’s going to be any substantial change that would reverse that [decline] and see populations increase. You also start to wonder what’s happening to genetics when populations are getting so critically low.”
In an effort to confront the issue head on, Dubai Aquarium And Underwater Zoo is pioneering an assisted breeding programme designed to help protect the future of the sand tiger shark, which is found in the wild off the coasts of Australia, South Africa and America. Currently classified as ‘vulnerable’ on the IUCN’s (International Union For Conservation Of Nature) Red List Of Threatened Species, it could become extinct within a generation if firm action is not taken. What’s more, the sand tiger shark is far from alone. Amongst the numerous other species listed as vulnerable, endangered or critical include the scalloped hammerhead, the whale shark and the speartooth shark. Many Pelagic sharks continue to be caught for their fins at an unsustainable rate.
“Our immediate goal is to completely understand the cycling process of the sand tiger shark – when they produce sperm, when they produce eggs, when’s the right time for insemination,” says Hamilton. “Obviously the pup is the ultimate goal, and once we get the pup we can then package all of that [information and science] and make it public. The idea is to pioneer a technique that will be fed out to everyone who’s working on shark conservation.”
The groundwork for the programme, which was launched in Dubai last summer, was undertaken by Dr Jon Daly at Sea Life in Melbourne, Australia, alongside aquarium veterinarian Dr Rob Jones. Both regularly travel to Dubai to oversee and monitor the programme, which is led on a day-to-day basis by research veterinarian Nitwipa Ruangtrakool.
“The programme is an extension of the work that I did during my PhD in Australia and on the work that Rob Jones and I have done over the past few years,” says Daly, an elasmobranch reproduction consultant for his work with Dubai Aquarium And Underwater Zoo. “Last year I spent three months in Dubai working to set the programme up.
“At the moment we are still working to transfer some of what we know from other species to the sand tiger. We can collect sperm, observe ovaries by ultrasound, and monitor hormone cycles, and we are working on determining the optimum timing for artificial insemination. Much of what we have done so far has been centred on identifying reproductive cycles and determining which individuals to target for semen collection and artificial insemination.
“The next step is to apply what we have learned by attempting artificial insemination in selected females. If we are able to get to a stage with aquarium populations where we can reliably achieve successful artificial insemination, then perhaps there is a role for this kind of approach for helping to maintain genetic diversity in wild populations as well, although ideally this sort of intervention would not be required at all in the wild.”
The sand tiger shark, however, does not make life easy for itself or for the scientists. The females can only reproduce once every two years, while the males produce sperm for only a limited period of time during any given year. If that isn’t enough, the first thing an embryo develops is its teeth, with which it devours all of its brothers and sisters whilst still in the uterus. Only the strongest will be born. To complicate matters even further, there is a dominance hierarchy within males, which leads to a likely variation in reproductive output.
“They did do us one favour though, in that they made two uteri,” says Hamilton. “So we get two pups out of a breeding event. But essentially they struggle to replace themselves, and that low ability to do that in the wild is one of the big contributors to their decline, while the mass producers – the species that breed readily – tend to be the ones that are succeeding in the human age.”
“Mankind is 99 per cent responsible for what’s happened,” reveals Hamilton. “The shark fin trade decimated most species. In Australia – before anyone really understood sharks – it was also the case that if a shark attacked somebody, then people would look for the most toothy-looking creature and get rid of it. So these guys were getting culled when they had nothing to do with the attacks.”
Anyone familiar with Steven Spielberg’s Jaws will know what Hamilton refers to. A tiger shark, although a man-eater and rare for the waters around Long Island, was caught and erroneously blamed for the attacks around which the film was based. Only the oceanographer Matt Hooper (played by Richard Dreyfuss) raised a lonely voice of dissent.
“Jaws is also another big contributor to our lack of empathy for the species and our heightened state of fear around them,” adds Hamilton, himself a marine biologist.
“The public fear is definitely misplaced,” he continues. “There are certainly sharks out there that you can have a bad accident with, but the frequency of those incidents is just so low we should be prioritising it in our heads as minimum risk, but for some reason we put it at maximum. We seem to think that every time we get in the water the possibility of being attacked by a shark opens up in front of us. It’s not the case. More people are dying from toaster-related incidents. But you don’t tend to look at the toaster the same way.”
The sand tiger shark is also its own worst enemy. It looks ferocious and has three rows of long, jagged teeth that menacingly protrude from its mouth. In many ways it epitomises the human fear of the deep and has been chased and slaughtered simply because of its appearance, even if it is, in fact, a rather docile creature.
“You’re touching on the second arm of this project,” admits Hamilton. “As you can see there’s a window into the lab so the public can watch the scientists work. That is because without changing perception it’s hard to drum up support; it’s hard for people to understand why not to remove all sharks from the beach; it’s hard to get all those messages through. As such public outreach is just as important and this is a very public programme.”
The risks of failure are arguably incommensurable. The loss of any given shark species has a knock-on effect that impacts food-chains, habitats and species diversity. “The scary part about the shark is where it sits in the kingdom of things,” explains Hamilton. “If the shark is lost it takes other species with it, and that’s not something that we’re experiencing with, say, a frog. You may not care so much about the shark, but you may care about the hundreds of other species that will go with them.”
Hamilton uses the example of a frog for good reason. The Rabbs’ fringe-limbed treefrog, a native of Panama, became extinct in September and yet few people batted an eye-lid. Unfathomable numbers of diverse species are under threat, putting into context the work that Daly and Hamilton are doing.
“Jon’s also working on the cryopreservation of coral species; I mean they’re working on an ark more or less,” says Hamilton. “There’s an ark going on right now, where they’re going out and grabbing the last genetic materials of certain species and trying to store it.”
In the case of the sand tiger shark, the Dubai Aquarium And Underwater Zoo was chosen as the base for the assisted breeding programme because it has the largest group of sand tigers anywhere in the world, with both males and females of reproductive age. This gives the team all the genetic material they need. Before Dubai Aquarium there was no access to the species, with scientists working largely on theory and unable to practise technique. Dubai Aquarium made it possible for the science to come to the animal.
As part of the project, the team have created environmental cues in the tank, giving the sharks a spring, summer, autumn and winter, while the use of ultrasound enables the scientists to follow the ovary and follicle development of the females.
“For aquariums to have this role as advocates for conservation, they need to be able to manage their shark populations,” says Daly, emphasising the importance of the programme. “And the assisted reproduction helps with this goal by allowing the transfer of genetic material between different aquarium populations, the introduction of new genetic material from the wild without removal of animals, and long-term banking of genetic material so that individual animals can remain part of the genetic population beyond their own lifespan.”
“We’ve had success with other species,” says Hamilton, referring to the birth of a brown banded bamboo shark in 2014; the first ever shark to be born via artificial insemination in Australia. It was also the first shark pup to be born via live semen sample transported from one facility to another.
“Sand tigers are the most complicated species we could work with. So if we can crack the sand tiger then most of the other shark species in the world are going to be doable.”
He adds, “This is some very long-term thinking, although this is not the current opinion of the government in Australia. The general idea is to continue creating marine-protected areas and trying to prevent further loss of the species. However, the decline continues every year. Even recreational fishing is a big contributor to the shark loss. At some point – and it happens with all these species – everyone just drops their head and says, ‘We can’t save them in the wild’ – and that’s when this project comes into play.
“We’ll succeed,” says Hamilton without any shadow of a doubt. “We will get there. We are succeeding with other species and we’re already publishing papers and putting techniques out there, so there’s certainly information already available that can be used. But I think everyone’s waiting for some of these more critical species to be solved.
“People don’t realise how many species on planet Earth are in programmes like this because we have failed in the wild. It’s about being ready, but no-one’s doing it for sharks. You’ll never see this issue for panda because, well, it’s panda, right? We’ll do anything to stop losing them. But another shark species gone doesn’t really register with anybody. That’s why the project is two-pronged – it’s awareness plus science. Because without empathy for the species, you’re not going to progress. The science will go only so far.”
Words: Iain Akerman / Images: Masam Ali