Biologist Petra Nevečeřalová on her life-long obsession with whales
Marine biologist Petra Nevečeřalová, who hails from the north-Bohemian town of Ústí nad Labem, has been obsessed with whales since early childhood. Today, she is part of an international team of scientists who study evolutionary genetics of the Southern Right Whale and spends a significant part of her time off the South African coast. When I caught up with her in Prague to discuss her work, I started by asking her what sparked her interest in the giant ocean mammals:
“I have no idea, honestly. I think I was born with that. One of the first memories I have is when I was a little girl and my mom bought me a blanket with a picture of a colourful seal playing with a ball. And I was always wandering: what kind of an animal is that?
“And then later in my life, my mom would buy me books about animals, because I loved animals. And one of the books was about marine mammals and there were seals on one page. I was really excited to see the seals, but then on the next page, there were dolphins, and on the next one, there were whales.
“So I quickly lost interest in seals and I fell in love with whales and dolphins. And then later, when I started to go to school, I always took notes from these books into a little notepad and I would carry that notepad everywhere, learning about whales and dolphins. So it was just in me.”
When did you first get a chance to encounter a live whale?
“It was one of the best days in my life. It was my 17th birthday, actually. We were in Mozambique, in the middle of nowhere, in an area called Jangamo. And that’s where I saw a humpback whale, a mom with a calf.
“We managed to get pretty close to them and it was an absolutely stunning, amazing experience. I took a picture of that mom with the calf and I have that picture right next to my bed. So every morning when I wake up I see my first whale!”
So was it at that moment that you decided that you wanted to study whales?
“I knew I wanted to work with whales since I was a little girl and I have never had a different dream.”
“I don't think so. I knew I wanted to work with whales since I was a little girl and I have never had a different dream. I knew my life would revolve around whales, so the first encounter was just a culmination of this dream.
“And then there was a film festival, and at the film festival, I managed to get in touch with some people who were working with humpback whales in Mozambique. So I talked to them about whales and I asked them about opportunities to get in touch with some research teams and one South African guy invited me to come to Mozambique.
“So I went home and I told my mom: I need to go to Mozambique to see whales. And she told me: But you're only 15, you cannot go to Mozambique. It is in the middle of nowhere, you can't go alone.
“But then she turned around and she said: You know what? I will go with you. So she packed me and she packed herself and we went to Mozambique. She was really brave!
“So two years later, when I was 17, I really got to see the whales. And that was the moment I managed to connect with all the local people and with some research teams. And once you have the connection, everything is much easier. So that’s how it all started.”
And then you went on to study biology at the Faculty of Life Sciences in Prague…
“Not at first, because whales are such an unusual topic in Czechia that Charles University wasn't really keen to accept me. So it was university at Ústí nad Labem that accepted me and they let me study whales, which I'm really grateful for.
“I was able to actually get in the field and that’s why my bachelor thesis and master thesis are both focused on southern right whales. And then, for my PhD, I managed to get to Charles University to the Faculty of Science.”
What does the research of whales look like for a person living in a landlocked country? How often do you get out in the field, in your case, to the sea?
“My PhD project is based on DNA research. It's a field of research called molecular ecology or conservation genetics, so I really needed to be in the field to collect samples for the DNA analysis.
“So for the PhD project, I spent every six months in South Africa, during the whale season. Because the whales aren’t present there the whole year around.
“They migrate to the south and then they come back to the north. So anytime they were present in South Africa, I was there.”
You said part of your research is collecting samples. What does that look like?
“That is actually really interesting. The golden standard among cetologists, people studying whales, are biopsies, which you do with a crossbow and special dart. And obviously you also need a research boat and an experienced crew, which is not that easy to find.
“Although there is no research showing any short or long term effect on these animals, it carries along a certain level of disturbance and I wasn't really happy with that. So in my project I focused on non-invasive sampling, which means collecting samples without any disturbance for the animals.
“When the southern right whales arrive in South Africa, they shed quite a lot of skin due to the change of UV light and the water composition. And I realized we can collect that with the net from the boat.
“So I started cooperating with local whale watching companies and I just trained the crew and I showed them how to collect those samples and suddenly we had hundreds and hundreds of samples collected from the whale watching boat without any level of disturbance for whales.
“And then later I also got the idea to collect an exhale sample from a whale and we actually managed to that that. So we are the first research team in the world who managed to isolate whale DNA from a blow sample and I'm very proud of that!”
Why did you focus your research on the Southern Right Whale? What makes it different from other whale species?
“Well, at first it was the opportunity. These whales are present around South Africa for six months of the year. But it's also the species itself. They are called right, because they were right to kill.
“They were given their name by whalers, because they're very slow moving animals, they're non aggressive and also, when you kill them, they float on the surface.
“But because they non aggressive and friendly, it also makes them right to study because it is quite easy to get close to them. And also, as I said, they shed a lot of skin, which makes the sample collection quite easy.
“So those were the reasons why I focused on these animals. And also, in South Africa, it is not such as well-known species. So this was also a reason why I focused on southern right whales.”
One of the things your research has focused on is the disappearance of krill, which I believe is the main source of food for these animals. How serious is this problem?
“We don't know, but it looks really serious. During the research we noticed there are two distinct time periods in the population. Before 2010, the population grew by about seven percent every year and the whales we saw were nice, fat and healthy.
“And then after 2010, you can see some of those whales becoming quite thin. Obviously, there is some problem with the population.
“And also during the genetic research, we saw suddenly there's a sharp peak in gene flow from South Africa to Australia and we couldn't really explain that. And then later, the research showed that they changed the migration route.
“We were confused, but then we realized that the Antarctic krill distribution moved to the South, probably because of the climate change. And suddenly the whales have to either swim much longer distances to find the prey, or they swim somewhere else to find different prey.
“So now they feed more on copepod, which is similar to krill, but it doesn't have the same nutrition value. That’s why the females are thinner and why they change the calving interval.
“Before 2010 they had one baby every three years and now it's every five years. And this might be a really huge problem for the population in the future.”
You said southern right whales are very friendly. Can you tell us about your most memorable encounters with these giant mammals?
“Every whale is different, so every whale has a unique temperament, but I must say I love them all.”
“There are so many of them! Every whale is different, so every whale has a unique temperament, but I must say I love them all. One of the most memorable whale was Daisy, which was a baby whale that was born in the bay where I lived, and she really loved our boat.
“Anytime we were on the boat, she came quite close to say hello. And they get really close. I would be able to touch her from the boat, but I have never done that, because you are not supposed to touch wild animals.
“One day there was a seal who joined us as well, and Daisy quickly lost interest in the boat, because she found the seal much more interesting. And at one moment she wanted to bite the seal, but of course whales don’t have teeth, they have baleens.
“So we just watched the Daisy trying to chew the seal, which was yelling, but obviously, nothing happened to it. She was she was a beautiful baby and I hope I will see her soon!”
Is it easy to distinguish one whale from another?
“Well, sometimes they have very unique white markings. But also, southern right whales are black, but they usually have something white on the head. These are called callosities, which is basically a patch of thick skin, and these patches are colonized by lice.
“They are small crustaceans and they eat the whale’s dead skin. So they don't harm them, but they create a very unique pattern for every single whale. It is basically like a fingerprint.
“So during the field work, you learn to recognize one whale from another. At first, they all look the same to you, but then during the work you start to distinguish them. And of course, we give them names, which is not really scientific, but it’s nice.”
How much of your research do you actually spend on the sea? And was it difficult at first to get used to spending so much time on a boat on a sea?
“Well, it was always six months of the whole year. So I spent six months in the field collecting samples and then, for another six months, I was in the lab analysing the DNA. So it was 50:50, which was really beautiful.
“The problem was that the whales are in South Africa during the winter. People think Africa is really hot, but it's not. South Africa is quite cold, especially in the winter. So the most difficult part for me was getting used to the cold.
“You also need to learn to work with the animals, but it doesn't really matter if you are from the landlocked country or from Australia. But perhaps the most difficult part of my project I must say was to get all the permits to make it legal according to the laws of EU, Czechia and South Africa. Honestly, that was the most difficult part!”
Is it important to cooperate with other universities, with people from other countries, who have the same focus of research?
“It is absolutely necessary. In science in general, especially nowadays, you cannot do your own project without cooperating with other scientists. So we cooperated with people from New Zealand, South African, South America, Argentina, Chile and other countries.
“It was absolutely essential for the project and also we made sure that our data set is comparable with other data sets. So we had to use the same primers during the analysis, to be sure that we can compare it and we can make a global output.
“And if you have a look on our latest publications, you will see there are often more than 20 co-authors, so it shows that cooperation is absolutely necessary.”
You are about to defend your final thesis at the Faculty of Science of Charles University. What are your plans for the future?
“Well, I will take a break after the PhD project. It lasted eight years and it was such a significant part of my life. I must say that I am a little sad that it's over now.
“So I must take a break and think about what to do next. There are quite a few options and possibilities in my head, but I need some time to think about it.”
But I guess your future will still be connected to whales….
“I hope so. I love them so much, I can't be without them!”
