Marine Palaeontology: An interview with Dr. Leanne Melbourne
BY MARGAUX MONFARED
Numerous environmental changes have been observed in our oceans in recent years due to the increase in anthropogenic CO2 in the atmosphere. This in turn leads to ocean acidification and warming waters, phenomena that cause detrimental effects to marine organisms and their survival. Calcifying organisms are particularly at risk to these changes as it significantly reduces their ability to calcify, a vital process in which they create their hard shells or skeletons. Meet Dr Leanne Melbourne, a Marine Palaeontology lecturer at the University of Bristol whose research focuses on how these environmental changes affect the structural integrity of marine calcifiers through time. Dr Melbourne’s impressive research has led to the publication of over 6 papers, creating awareness of the importance of marine calcifiers such as coralline algae, particularly the beautiful habitats here on our doorstep in the U.K.
Not only is she an outstanding scientist, she is passionate about science communication and outreach and acts as a role model to promote diversity in STEM. She believes that ‘It’s okay to know what you don’t want to do…. as long as you are following your passions, you [will] end up where you want to be.’
Continue below to find out more about her work and experiences.
Hey! Tell us a bit about yourself.
Hi. So, my name is Leanne and I am originally from London, UK. I now live in Bristol in the UK. I am a lecturer in Marine palaeontology at the University of Bristol. Apart from my love of science I have always been interested in the arts. I used to do performing arts as a kid, singing, drama and dance, I love musicals and always wanted to be on a stage. I still love going to plays, musicals, and ballet, any kind of live performance really. Before lockdown you would probably find me in a museum. I have always loved going to museums and exhibitions and learning about history and culture. Natural history museums are obviously my favourite type of museum and I try to visit as many natural history museums as I can when I’m travelling.
You’ve built your life around the ocean. What drew you to it in the first place?
Both my parents are from Jamaica and I guess having two island parents have instilled a love and respect for the sea. So, I have always loved the water and been fascinated by marine creatures. I remember going to Jamaica as a child and standing in the water and seeing these sting rays swimming around and loving every minute of it. But growing up in London you don’t get to see the ocean that much. My favourite times were always the annual church trips to the beach, I don’t know if anybody else experienced that. My grandparents went to different churches and both churches had annual beach trips in the summer, which I used to always go on and they were the highlight of my summer. I think what I love about the water is how calming it is. When you are floating on your back and your ears are in the water and the sound is all muffled and the sun is beating down on you, it’s the place where I feel most peaceful.
Your research focuses on the impact of climate change on marine calcifiers. Can you describe the techniques you adopt to identify these changes?
What I love about my job is that I get to use a lot of different analytical methods and techniques to answer some really interesting questions. So I look at how climate change affects the internal structure, the mineral chemistry and also the material properties (so how hard the skeleton is) of marine calcifying organisms. I use Electron Microscopy to analyse changes in internal structure and mineral chemistry, nanoindenation to look at how hard the skeleton is and computed tomography scanning to assess overall shape changes. The exciting thing for me is using the different properties we have measured and then modelling that using finite element modelling to see how these changes affect overall structural integrity. So then this allows us to infer about the impact on form and function. For example does ocean warming and acidification cause marine calcifiers to form weaker skeletons and in the case of habitat formers weaken their ability to provide habitats.
An image to show how Dr Melbourne develops models based on the internal structure of coralline algae.
How does climate change affect the ability of these organisms to carry out their functional roles?
So for coralline algae, they are important habitat formers. Around the UK, the unattached forms known as rhodolith/maerl provide important nursery grounds for scallops and commercial species of fish. So if their 3D structure is altered or weakened it makes it harder for these organisms to provide that ecosystem service. Our research is showing that warming and acidification is leading to changes to the internal structure, which is causing weaker skeletons. We also modelled future stormier conditions as predictions suggested that the frequency and intensity of storm surges will increase. This is especially important for these organisms as they are mobile along the seafloor so stormier conditions will lead to them being more mobile, more likely to collide and break apart changing the nature of habitat they have formed. Our research suggests that future stormier conditions and changes to the internal structure are leading to these organisms being under more intense pressure.
Image of a maerl bed in Scotland, Loch Sween. Image taken by Elaine Azzopardi, Tritonia Scientific Ltd.
Do you notice the same impacts of climate change on marine calcifiers across a spatial and depth gradient?
So we looked at four different species from around the UK. What we found was that species in the north had more structurally sound skeletons compared to species in the south of the UK. The differences in structural integrity were larger than what we have seen over the last 100 years. So this means that some species may do worse under future climate conditions as they are already forming weaker skeletons. There is limited information on the importance of depth, anecdotally it seems that there is an effect of depth on internal structure, but this is something we would need to delve into and research in more detail.
You also work with benthic foraminifera, can you explain what these are and what type of environmental changes impact their shape and structure?
This is work I’m collaborating on with a colleague and a master’s student. Benthic foraminifera are tiny single celled organisms. They have these hard shells called tests that record information on the environment they live in. They are really good as palaeoenvironment indicators. We know that increasing temperature affects their morphology and overall shape. So, there is evidence of certain species dwarfing, becoming smaller in response to warming across large geological intervals such as the Palaeocene/ Eocene thermal maximum. What we are interested in is how these changes to the shape affect structural integrity and therefore their resistance to predation. We are in the early stages of the project currently developing the models to address these questions.
What does a day in your life look like?
I like that every day is different. One day you can be in the lab gathering data and another in the office analysing data, writing papers and preparing material. Some days I’m teaching or having meetings with students. I have tutor groups and I am supervising research students. Also there’s a lot of outreach, preparing content for schools and public events, as well as doing talks for other departments/ universities sharing knowledge and research. Sadly, there is not much fieldwork at the moment. With lockdown now as well, a lot of these activities are happening online rather than in person.
Dr Melbourne out in the field assessing coralline algal habitats.
How do you hope your voice and work will influence others?
I think the most important thing is to get people caring about these organisms and how our presence is impacting these organisms. I think most people are aware of corals and the great barrier reef and how warming is affecting them, but I think less people are aware of these beautiful coralline algal habitats that we have here in the UK. For me I had never heard of coralline algae before starting my PhD and I think they are fascinating now. So, I love talking to the public about coralline algae. From a policy perspective I hope that my research can help influence local and national management decisions in how we protect these organisms under future climate change.
What other endeavours/hobbies/dreams are you pursuing? (if any)
There isn’t the same job security in academia, unless affiliated with a university you are always working on short-term contracts. So I am currently trying to work out my next move, applying for jobs and writing fellowship grants. It’s exciting as it is allowing me to pursue other areas of research and focus on other organisms, but yes there isn’t that same security there. I guess also in the UK we have gone into a third lockdown so I am trying to stay healthy both mentally and physically. I’ve taken up running and I like a good jigsaw puzzle. I also learnt how to solve a rubik’s cube, which I’m really impressed about.
Whose work has influenced and inspired you?
Professor John Raven got me into this area of research. I went to a talk of his in my master’s year that focused on ocean acidification and I was instantly hooked and knew this was the area I wanted to be in. My master’s supervisor is the reason I did a PhD in the first place. I never considered doing one and he is the one who suggested it to me. So, if it wasn’t for him, I’m not sure I would have ever done a PhD in the first place. My PhD supervisors, as well, as they helped create the project and steered me in the direction I am today, but you pick up lots of different ideas and techniques from your colleagues, which is all part of being a researcher.
What is one thing you wish someone had told you/taught you a long time ago?
It’s okay to know what you don’t want to do and you don’t have to know what your career will be straight out of university. I had this idea growing up that I must know what career I would be going into after university and everything had to be set up straight away. I wish someone told me that as long as you are following your passions, you’d end up where you want to be. For me my career so far has been a lot of doing something and realising I didn’t actually enjoy that and then going back to the drawing board. Now I do something I love to do, but also it isn’t the end of the world if this doesn’t become my life long career. Circumstances change, different opportunities present themselves and I am open to the idea that in 10 years I may be doing something completely different and that is okay.
What has your experience as a woman in ocean science been like?
It has been really positive so far. I think I am fortunate that I had three amazing female PhD supervisors who are incredible role models that continue to mentor me now. There are a lot of inspirational women doing ocean research right now, which makes it so exciting. Like with many other scientific disciplines within the UK there are a lack of women and even more so with ethnic minorities so I hope that seeing me, a black girl from London doing what she loves, shows the younger generation that ocean science is a fascinating area and is open to them.
How has the recent COVID-19 Pandemic affected (or not) you and your research?
I’ve been fortunate that I have still been able to work. It’s given me the time to work on some papers that I’ve put off. Luckily modelling you just need a computer so I can work from home. Lab work and fieldwork definitely have been restricted. During the first lockdown I was converting the micropalaeontology course to an online course, which was challenging. It was quite daunting as I just started in my new role and had to navigate the role, the university from an academic side and to top it off being in an online role due to the pandemic.
Dr Melbourne creating her models.
Where do you go from here?
Short term, I am currently applying for jobs and funding, as my contract is temporary. But on a larger scale for me I really want to continue researching the impact of environmental change on different marine organisms. I want to get a deeper understanding of the wider ecosystem response to not only global climate change but to local stressors too like pollution, increased sedimentation and nutrient imbalances. Ultimately to understand the impact of the local environment and therefore have a greater understanding of what we can do on a local level to protect these important organisms in the future.