Behind the Fins: DR Johann Mourier

If you watched "700 sharks" on National Geographic's Shark Fest​ this year, you know Dr. Mourier's work well. Dive in with us as we talk about his work!

The Fins United Initiative: First off, why did you decide to study the ocean and its marine creatures?
Johann Mourier: Hard to say, although I am originated from an inland city in France (Lyon), since my young age my parents took me on holiday in the south of France. They put me a mask on as soon as I was able to wear one and swim and my father often captured some sea creatures like octopus or cuttlefish and put it in a bucket to show me. I visited also many aquariums and I think this is where I’ve become intrigued by sharks. The sea life started to attract me and I quickly wanted to dedicate my life in contributing to improve our knowledge on marine animal and especially on sharks which appeared so mysterious to me.

TFUI: Can you tell us a little bit about the work you are currently doing?
JM: I am currently studying the behavioural ecology of sharks and particularly how the behaviour at the individual level influences the structure and ecology of the population.

TFUI: For those who don't know what that means, can you elaborate?
JM: For example, I am interested in understanding how sociality evolves in sharks and what factors influence their social network but also how it will influence the ecology of the species. Currently, I am working on understanding the ecology and behaviour of the largest aggregation of grey reef shark ever reported, trying to understand how associations between sharks evolve during resting time in large polarized schools during the day but also at night when they hunt in large packs. I am trying to understand the social structure of pack hunting in sharks. In this project, I am also revisiting the trophic ecology of sharks as we are the first to document the natural hunting of reef sharks at night and are able to determine their diet as well as their hunting tactics, as opposed to the common methods involving stomach content analysis or stable isotope analyses which are informative but only provide an incomplete picture of the feeding ecology of sharks.

TFUI: Why is your research important? 
JM: My research provides important missing data on the ecology of vulnerable animals like sharks. A better understanding of their ecology and the functioning of populations is important to improve conservation management and protect these species. I hope it also helps changing the image sharks have by showing to the public the unknown facets of sharks and demonstrate that they deserve more respect than just being considered as predators.

TFUI: We definitely like that!
​JM: Through outreach and documentaries I hope to show sharks in their natural behaviour and not within a sensationalism way.

TFUI: You had a postdoc in Sydney, Australia- very different from France! Why did you ultimately choose Australia and what did you learn during your time there? 
JM: Well it was a funny story. I found this postdoc on twitter!

TFUI: No way!!
JM: Yes, I have seen a tweet from Prof Culum Brown who was looking for someone to work on Port-Jackson sharks. As I was following his work and was really interested, especially on the social behaviour in PJs, I quickly contacted him to see if he would be interested in my profile. And that worked. I was really excited to work in Australia and Macquarie University in Sydney was a great opportunity to conduct my research, continuing working on research questions I developed around tropical reef sharks and apply it in temperate famous PJ sharks! I really liked Culum’s lab and all the highly friendly and motivated team of young researchers and student there. It was really interesting for me to work with different researchers and I really liked the field work season, discovering the nice underwater world of Jervis Bay and Sydney Harbour and work with friendly Port-Jackson sharks. For someone who has mostly worked on active reef sharks, it was so surprising for me how easy it was to catch a PJ that generally does not even react and stay still.

TFUI: Haha, I bet.
JM: Also I was so impressed to see how these little sharks are interesting ecologically and ethologically. Indeed, thinking that these little benthic sharks were able to migrate more than 1,000 km and come back every year to the same reef to socialise with partners was impressive. Outside the research sphere, I really liked the Aussie way of life and all the Sydney region. Spending a year there will always represent a really great moment of my personal and professional life.

TFUI: Have you found speaking multiple languages helps you when discussing science (i.e. do you find you have a larger network because you speak multiple languages)? 
JM: For sure, speaking English is a necessity in science and spending a year in Australia was important for me to improve and practice my English. Speaking English is important in science for multiple reasons.

TFUI: Do you think speaking multiple languages helps with your science outreach efforts at all?
JM: First, most scientific publications are written in English and as a non-native English speaker it is usually more difficult to write than a native English speaker. Then, English is important for networking with other researchers on social medias or conferences. Finally, English is important to share your science for outreach via medias, documentaries or schools…

TFUI: Do you think people in your current country (France) have a good relationship with the ocean environment? If not, what can be done to better it?
JM: In France, there is a general long-term relationship with the ocean because the country is surrounded by the Atlantic ocean and the Mediterranean sea and because diving and ocean expeditions have a long story in France for example with Cousteau in the previous century. Sailing has also a long story in France. However, there is also some negative interactions with the ocean as France is one of the biggest fishing country in Europe with some non-negligible effects on the ocean. On the other hand, France has been one of the first country to ban plastic bags which is a huge threat to ocean life through pollution. I think that the numbers of MPAs or other reserves/sanctuaries could be improved in France because these are well represented in overseas territories but they are under-represented in France’s coasts.

TFUI: Do you see a difference in attitude towards the ocean in France and Australia? 
​JM: Australia has also a strong relationship with the ocean. This may be certainly due to the fact that most of Australian people live along the coastlines of the country. Coming from French Polynesia where sharks are protected in the largest shark sanctuary in the world, it was hard at first to see how sharks were exploited in Australia, but on the other hand Australian marine research is really active which is a good sign. What shocked me however was the use of plastic bags in supermarkets where you are given a plastic bag for 4-5 items only.

TFUI: That's not healthy at all! Thankfully it seems grocery stores in Australia are banning plastic bags.

TFUI: What has been your most exciting discovery/trip?
JM: My most exciting discovery was that sharks could be more social than previously expected. By conducting underwater surveys (>200 dives) during my PhD, I was able to identify more than 300 individual blacktip reef sharks based on coloration patterns of their dorsal fin. This allowed me to notice that I was observing the same individuals together which pushed me to test for preferred associations between the individuals I monitored. Therefore using network theory, I was able to demonstrate that sharks were forming not only non-random associations but that these preferred associations were structure in social communities. My best research trip was a 4-month expedition I coordinated in Marquesas Island in North of French Polynesia, spending this time on a ship to report the biodiversity of underwater life from this archipelago and diving in really remote, never before dived locations (>100 dives in 4 months). This was a very exciting and constructing experience. But I can’t avoid speaking about my big project in Fakarava where I study the behavioural and trophic ecology of what is currently the largest aggregation of grey reef sharks reported so far, diving at night with up to 700 sharks hunting in group in a feeding frenzy; maybe the experience of a life! 

TFUI: Oh man, that sounds fantastic. So what was some advice you wish you had gotten at the beginning of your marine science career?
JM: I already knew that but this is something that I continue to tell students: marine science is a hard field because there are very few jobs but having this in mind, if you are really motivated and not afraid of working hard and being patient, follow your dreams, it is worth it.

TFUI: What's next for you?
​JM: Well, the next step will be to secure a full-term job allowing me to fully concentrate on my research as well as supervising more students. I will see where the future will bring me, but for sure not far from sharks…

THE FINS UNITED INITIATIVE WOULD LIKE TO THANK johann FOR His TIME AND 
WE WISH Him WELL ON His CURRENT/FUTURE PROJECTS! 

SAY HELLO!

YOU MAY ALSO LIKE:

TOM VIERUS

SKYLAAR AMANN

LILY WILLIAMS