The whale shark is the biggest fish in the ocean, but one of the hardest to spot and least understood. Research at Georgia Aquarium is changing that.
Dr. Alistair Dove, a leading marine biologist and Georgia Aquarium’s director of research and conservation, spoke with MNN and explained the aquarium’s current whale shark research efforts, showing the connection to both human health and marine conservation.
MNN: Why is the whale shark research at Georgia Aquarium considered so significant?
Dr. Dove: I think it’s incredible that we know so little about the largest fish in the world. In 2015, we can fly by Pluto, but we don’t know where whale sharks mate or where they give birth. It’s never been seen. The chance to answer these questions in the course of what we do here at Georgia Aquarium is tremendously exciting to me.
I’m also excited about the ability to translate what we learn into conservation measures. I love turning research into strategies that change the plight of animals in their natural setting. For example, we’ve worked with the Mexican federal government to set up a marine protected area for whale sharks, and we’re currently working with the cruise ship industry to get them to modify practices so whale sharks are protected from the risks of ship strike.
MNN: What are the benefits of having whale sharks in the aquarium setting?
Dr. Dove: There are certain types of research you can only do in the field, and there are certain types of research that you can only do in the aquarium. It’s been really wonderful to pursue both lines of inquiry at the same time. That’s where the magic really happens.
For example, we’ve never been able to take a blood sample from a wild whale shark. But we have learned how to take blood from the whale sharks at Georgia Aquarium. That’s allowed us to better understand them and publish studies of their hematology, or blood cells, as well as their biochemistry. That’s not possible with wild animals.
There are things that we can do at Georgia Aquarium that have really been bonanzas for some of our research partners from all sorts of universities. When they receive access to the collection, it’s like watching kids in a candy store.
We also get to share the whale shark experience with all of the guests who visit every day and create a tangible connection. They go away, and they’ll never forget seeing the whale sharks in person. Maybe they even go away with a new appreciation of our oceans and how their own behavior affects the ocean’s biology in terms of creating waste and pollution.
MNN: What is the whale shark genome research project, and why is it so groundbreaking?
Dr. Dove: In partnership with Emory University, we recently published the complete genome of the whale shark, the first shark of any kind to have its complete genome sequenced. It gives us an enormous starter set of genetic information about the whale shark that allows us to ask all kinds of questions about the origins of the species—why it is the way it is and how the biology of whale sharks relates to our own human biology.
Some of the questions we’re most interested in relate to the immune system. Sharks were the first group of animals to evolve an adaptive immune system, so they were the first to have antibodies in their blood to fight specific diseases. If you look at more primitive fish, they don’t have antibodies. We ourselves use antibodies when our bodies fight off disease. So if you want to understand where our immune system came from, looking at the genes of whale sharks is a great place to start.
Publishing the complete genome has taken about five years of continued sequencing efforts. What you’re trying to do is understand the genetic blueprint of the whole animal. Rather than looking at individual genes, you’re looking at all the DNA from the beginning to the end of every chromosome. In the case of whale sharks, the genome is about seven billion letters long—the size of multiple encyclopedias.
MNN: What does the behavioral observation research program at the aquarium entail?
Dr. Dove: Our behavioral observation research has been ongoing for almost six years now. We work with researchers from Georgia State University and a number of dedicated volunteers to understand the behavior of the whale sharks that are in our care. A lot of dedicated volunteers spend a lot of hours watching the whale sharks and writing down everything that they do.
MNN: What is the conservation status of the whale shark?
Dr. Dove: The International Union for Conservation of Nature (IUCN) lists the whale shark as vulnerable, that’s one step up from endangered. It’s also what we’d call “data deficient;” we simply don’t know how many whale sharks there are out there. There is no global estimate of the whale shark population.
We hope it doesn’t progress from vulnerable to endangered. If it does, one of the big problems they will face is they live a long time and take a long time to mature, so the population is not very resilient. If you knock them back, it’s going to take decades to recover.
MNN: What are the biggest challenges and the biggest rewards of your whale shark research?
Dr. Dove: It varies whether we’re in the field or in an aquarium setting. In terms of what we do in the field, the most challenging aspect is the remoteness of the oceans. If you want to see whale sharks, you have to go to far-flung locations like the Galapagos, the Azores, St. Helena, the Philippines and the Maldives. These are all difficult, remote locations to get to. It’s also the most gratifying part because you get to go to the Galapagos, the Azores, St. Helena, the Philippines and the Maldives. These are wonderful places to experience biology in some of the most untouched parts of the world.
In terms of the aquarium setting, the biggest challenges relate to the sheer size of the animals. We really don’t want to interfere with them. We try to do our research as part of the preventive medical care and the husbandry care that we provide. We don’t do manipulative research with the animals for its own sake.
MNN: What is the ultimate goal of the research?
Dr. Dove: What we’d really like to do is develop the whale shark into an ambassador for the oceans, in part because of its size and charisma. Whale sharks help people start to learn and understand what happens in the open ocean, an ecosystem that is really important to all of our lives. Half of the oxygen that we breathe comes from the ocean. The ocean is also currently absorbing about 90% of the trapped heat from the greenhouse effect. Climate change would be a whole lot worse if the ocean weren’t soaking up all that heat for us.
The ocean has also become the recipient for the end products of our modern consumer lifestyle—plastics, carbon dioxide, pollution and fertilizers. These all end up in the ocean, and they affect the lives of animals like the whale shark.
Interested in learning more? See the latest posts from Dr. Dove and whale shark research on the Georgia Aquarium Blog. And, check out Georgia Aquarium's webcam to see the whale sharks in Ocean Voyager.