Welcome to the inaugural edition of our EuroMarine OYSTER Young Researchers in the Spotlight series, where we engage in captivating conversations with early career scientists about their research, thoughts and current perspectives in marine sciences.

Today we welcome Nerea Piñeiro, one of our chairs from the OYSTER group. Nerea finished her PhD in 2021 and subsequently did a postdoc at the University of Aveiro. Nerea is currently working at the University of Vigo in Spain, where her research focuses on organic matter dynamics in coastal soils.

EuroMarine OYSTER: What sparked your interest in marine research for the first time?

I wasn't very interested in marine research at the beginning. I studied biology and I specialized in soil science, so I was very into soils and then I joined a lab where they were starting two projects in coastal soils. I wasn't looking forward to going to work in the sea at the beginning but then I joined these two projects and had to collect my samples diving, which was an amazing experience. Now I'm very happy I ended up working in a marine environment.

But yeah, usually when I talk with other postdocs in my lab they're like “oh yeah, when I was a kid, I loved the sea, so I wanted to work here” and in my case, it's like I never thought about that. I just like soils and then I ended up working in a marine environment, so I guess it’s not the answer you were looking for, but that's reality.

EuroMarine OYSTER: Could you briefly introduce your research topic and what you find most interesting or exciting about the research that you are doing right now?

I specialise in soil science and soil biogeochemistry, especially organic matter in coastal soils. I try to look at how organic matter degrades in these soils and why it doesn't always degrade as you would expect. After the organism that fixes this organic matter dies, this organic matter should degrade and go back to the atmosphere as CO2, but that's not always the case in soils, especially in coastal soils. What I want to know is why! It seems pretty straightforward - coastal soil, if there is water, there is less oxygen, so the degradation is slower.

But sometimes some part of the organic matter degrades, and then in a soil very nearby with similar environmental conditions, it doesn't. I'm trying to look into that; what are the conditions that make this particular type of organic matter degrade in this soil but not in the other one? How can we predict which type of organic matter is going to remain or which type of organic matter is going to be degraded? I just look at "which one and why", but the money to do this comes from blue carbon research.

Blue carbon research is something that is now a very hot topic because the idea is that if you have organic matter that doesn't degrade, you are actually taking CO2 from the atmosphere and stabilizing it as organic matter and this CO2 is not coming back to the atmosphere in the short term. Instead, you are taking part of this CO2 from the atmosphere to the soils. If you can make these soils take more CO2, what you are going to do is to lower the concentration of CO2 in the atmosphere. There is a lot of interest in this because we are trying to compensate for anthropic emissions to the atmosphere. It's not an excuse to keep emitting of course. It doesn't matter how much CO2 you can take out of the atmosphere if we just keep emitting more CO2, so it's more like a way to compensate for emissions, but we still need to cut those emissions. It's not magic, just to say. So, that's what I do! I'm very interested in the "why" and in the process but the money comes from climate change policy and emissions compensation.

EuroMarine OYSTER: You talked about different types of organic matter that degrade faster or that don't degrade at all in different types of soils in coastal areas. Could you desribe where this organic matter comes from?

The thing with coastal soils is like a buffer between land and sea, so it can come from everywhere. You will have all the organic matter that will arise from the rivers or floods, and then you will have the organic matter produced in situ, it could be by seagrass, salt marsh plants or algae. How much of each one of these sources is being accumulated is one of the main topics now. Who is producing this organic matter that is going to be stabilized? Is it algae? Is it the seagrass? Is it all organic matter? So, it depends on the area. You will have some areas that receive a lot of input from algae production because algae in that area are very predominant. You will have some places where you will have very productive seagrass meadows, or you will have areas where the river brings a lot of old organic matter from terrestrial areas. And, usually, you will expect organic matter from algae to degrade fast because the components of algae are very labile in comparison with organic matter from land or from seagrass where you have a lot of lignin and phenolic compounds that are more recalcitrant. But when we look at it sometimes it's not the case. So, on the one hand, it's very interesting. So, I'm super excited about this. On the other hand, it's a bit frustrating sometimes because it's like, come on. Would you please just work as you're supposed to work?

OYSTER: You mentioned that even if the environmental conditions are very similar, and locations are close to each other, things work differently. In one location, the organic matter is retained in the soil and in another location it isn't. So, it sounds like you have very small scale variability, and I was wondering, do you look at the macrofauna or the microfauna that lives at that sediment-seawater interface? And do you include bacteria in your research? Because I can imagine those would be very important for the remineralization of organic matter.

I have not specifically worked with macrofauna, but other researchers are doing that and I include this research in my discussion because it's quite important. I have seen that bioturbation of the soil increases the access of bacteria to oxygen and this can accelerate certain organic carbon degradation, but I have done some experiments with bacteria and the bacteria are very important to this. I don't look at which specific bacteria is there and what its eating, I just look at them at a community level.

When you have a lot of oxygen, you will have some bacteria that are going to take organic matter and they are going to degrade it fully. But, in an anaerobic environment, bacteria are not so efficient, so they are not able to degrade organic matter by themselves. They are going to work in a consortium, so it's not about which kind of bacteria we have here, but which kind of network they are building. But yeah, absolutely. Bacteria and the bioturbation is the key here.

EuroMarine OYSTER: I can imagine coastal areas are also very, very turbulent, so there's probably a lot of resuspension of material just from natural events like storm events because you're working in shallow areas, but also the amount of fishing, wouldn't that disturb the sea floor enough so that there's a lot of carbon that comes back into the water column?

Yes. So, the problem with soil is it takes hundreds and thousands of years to form. So, if you have an area that is very hydrodynamically active, they are not going to form in the first place. Because there is no time. When I talk about the coastal soils, what I refer to is those areas where plants are growing on top of them. So, we are talking about seagrass meadows or salt marshes. To have a very well-developed seagrass meadow, you need the area to not be hydrodynamically active. We are actually letting the ecosystem select where they are going to be able to accumulate more carbon, so to speak. But yes, it's true, we have human activities that disturb these soils. Fishing is one of them. If they are doing trawling, for example, the soil will be totally destroyed, or if they are harvesting shellfish, they usually also impact the meadows. The thing is, we have already destroyed so much that the areas where we still can find these meadows or these salt marshes are those areas not very interesting for fishermen.

The challenge now is if we want to improve the capacity of this ecosystem to sequester more CO2 from the atmosphere. Because they are already sequestering it. So, with the high amount of CO2 we are observing in the atmosphere, it's already counting on the CO2 that they are taking out. If we want to increase this taking out, we have to increase these ecosystems’ efficiency or we have to extend them. So, the idea is if you can restore areas where there used to be coastal wetlands, you will increase this capacity. So, the challenge now is working with local communities so they will see the value in restoring these areas. Right now there is some opportunity to do this because it's the United Nations decade for ecosystem restoration and the European Union has just passed one law on ecosystem restoration as well. We have all the things we can have to try to do this, we have the governmental approval, and we have money now. We have to go and work with the local communities because in the end they are going to be the ones living there and protecting or not protecting this ecosystem. It's up to them. So yeah, it's a challenge.

EuroMarine OYSTER: What was one of the things that you experienced while you were doing your research as a PhD student, or now as a postdoc that you really struggled with?

That's a very good question, One of the things I struggled more with, was how science works so fast. You are supposed to learn a lot of things and you are supposed to think about your research and what is happening and be creative in looking for answers and these kinds of things. But you don't have the time to do it. When you are a PhD student, your supervisor is not going to have the time to be with you and guide you because the supervisor is going to be doing so many things at the same time. And now that I'm a postdoc I realize that this is what the academia model is actually promoting. You have to apply for projects. You have to deal with the projects you already have. You have to do revisions. You don't have time to sit down, look at the data, read other researchers and think with that clear mental space about it. You are always going to have so many things in your head. When I was a PhD, I felt alone because the “grown-ups” didn't have time to guide me. And now that I'm all “grown up”, I realize oh there is no time. I think I struggled with how the scientific system right now requires for this quick path of production of new scientific knowledge.

EuroMarine OYSTER: How do you manage your work-life balance? Do you have any hobbies, do you do something to disconnect you from research or academia itself or work at all?

Yeah, I think I was very lucky again in this because when I started my PhD, I had a boyfriend who worked outside academia and he was an engineer. He was just working in a “normal” job, just to say, with his time off and he could not understand that I would be working outside working hours. So I had this outside perspective, which was good because if you work in academia, most of your friends are going to be from academia because you spend so much time there and sometimes you can just get into that thinking of “ohh I have to finish this and it's perfectly normal to stay working in the lab for a couple more hours because everybody is doing that”. But then I went home and my boyfriend would look at me like what are you doing? They are not paying you for the time! In the end, I was like you are right, this is not normal. If the only way I can finish my PhD is working 10-12 hours a day and then working on Sundays then, maybe I shouldn't finish this PhD, and that's fine.

I think it also helped that I didn't want to do a PhD at the beginning, it was a happy coincidence, so it's like if you are growing up thinking “ohh I want to be a scientist”, then you want to be a scientist and you are going to write to your PhD and you're like I'm going to put the work and the effort because this is what I want. In my case it was like, OK, I'm enjoying this. I think it’s super interesting, I think I can do it but if I cannot do this, I will look for another job. It's OK. So, at the end I decided to be very precise with my timing going to the lab at 9:00 and leaving at 5:00. And I do have hobbies, that's the question. I like sports, going to concerts and these kinds of things.

OYSTER: Do you have any piece of advice that you could give to people who want to pursue a PhD or after finishing the PhD?

I think that one of the main things about doing a PhD or a postdoc is not so much about the topic of your research, because when you look at things close enough, everything is super interesting. Like you start working on something and then you realize “ohh this is cool!” it doesn't matter what the topic is at the beginning. I do think it's very important what the atmosphere in the research group is like. If you have supporting colleagues, this is going to make such a huge difference in how you experience your PhD or your postdoc. If the atmosphere at your workplace is good, and if your supervisor is good - it's going to be good. If it's not, it's going to be a challenge, so I will recommend those students that are looking for a PhD that they will talk with other students from that lab and see how they are doing.

EuroMarine OYSTER: This year are co-chair of OYSTER, why did you decide to take on this role this year?

So last year they had a steering committee in Vigo and they asked if there were any volunteers to go to the steering committee, because usually, the two co-chairs go to the steering committee. But that year one of them was not able to go, and I was already living in Vigo, so it was like, OK, I can go and it's not going to be an extra expense for EuroMarine. I went to the steering committee and I found that it was super interesting to see how EuroMarine works from inside. I learned so much from that experience and I found it fascinating, and then when the time came to choose new co-chairs and we were trying to decide inside the group who would fill that role I volunteered. I really think being a chair is so interesting, you learn so much about how this scientific network works, how to manage the budget, how to manage the politics inside. And yeah, I'm very happy. I think it's all going to be only for a year because it's work, but It's a really good, good experience.

OYSTER: What do you think is one of the most important work that the EuroMarine OYSTER group does in this supporting network, or some of the best opportunities we offer?

For people who are OYSTER members, I would say the best thing is that you have the chance to be a reviewer for applications, you will be reviewing individual fellowships, you will be reviewing cooperation grants, etc. and this is something that as an early career researcher, you have the unique opportunity to do this and you will learn from this experience and you will see how it works Inside. Also, the atmosphere is super good. I love that about OYSTER. Everybody wants to contribute. Everybody wants to work, and everybody wants to do things and is super motivated.

If you are outside OYSTER (not a member), I will say that having the opportunity to ask for money to go for training courses is fantastic - for instance, to join a course to learn a specific technique you want to apply in your PhD. Researchers can ask OYSTER and in most cases, we are able to fund this. So, I think this is really, really good. We are impacting a lot of early career researchers with this call.