Welcome everyone to 100 Climate Conversations. Thank you so much for joining us. Today is number 33 of 100 conversations happening every Friday. The series presents 100 visionary Australians that are taking positive action to respond to the most critical issue of our time, the climate crisis. We are recording live today in the Boiler Hall of the Powerhouse museum. Now, before it was home to the museum it was the Ultimo Power Station. Built in 1899, it supplied coal powered electricity to Sydney’s tram system right into the 1960s. In the context of this architectural artefact, we shift our focus forward to the innovations of the net zero revolution.

Now it is particularly important to First Nations Peoples to preserve conversations like this, building on the oral histories and traditions of passing down our knowledges, sciences and innovations which we know allowed our Countries to thrive for tens of thousands of years. As always, I’d like to begin by acknowledging the Traditional Custodians of the ancestral homelands upon which the Powerhouse museums are situated. We respect their Elders, ancestors and recognise that their sovereignty was never ceded. To the Gadigal People whose land this talk is being recorded on, I acknowledge that the colonisation of this continent started here. I acknowledge your resistance and resilience and that despite violent attempts, your cultures, land and People are still here.

My name is Rachael Hocking, and I’m a Warlpiri woman from the Tanami desert, right in the heart of this country. I’m a very, very long way from home right now. I’ve lived and worked on Gadigal land for most of the past eight years, and as a visitor, I’m eternally grateful to the Traditional Owners for holding me in this space and for teaching me so much about the Country that I walk on every day. To lead this yarn with me, I’m joined by Wiradjuri woman, Dr Laura Parker. Laura is a marine scientist whose research aims to help futureproof natural oyster populations and the Australian oyster industry while restoring degraded oyster habitats that are of enormous importance to First Nations Peoples. She is an Indigenous Scientia senior lecturer and ARC DAATSIA fellow in the UNSW Faculty of Science, School of Biological, Earth and Environmental Sciences. We’re privileged and grateful to have her with us today. Please join me in welcoming Laura. Thank you for being here.

Thank you. It’s a real privilege and honour.

Absolutely, for me too. And I guess a really good place to start is where your love of the ocean came from, because I know that’s something for you that started pretty early on.

Yeah. I mean, I’ve always loved the ocean. We didn’t grow up close to the ocean. It was always a day trip to be able to go there. But it’s always the place that I’ve really felt like I’m at home and really myself. In terms of wanting to study marine science, that’s something that came a little later on in my life. I went to university and was doing biological sciences but really didn’t know exactly what I wanted to do. And then in my last year of university, I did a course called Aquatic Ecology, had a fantastic educator, and just really fell in love with it. And it was kind of at that moment that I decided this is where my passion is and this is what I want to do.

Where do oysters fit into that?

Oysters, again, came a little bit later. So, I started, after my undergraduate degree, I did an honours degree where I worked on the impacts that salinity and temperature have on barnacles. Barnacles are really important for our marine environment. They’re bio indicators. So, if things happen to them, it’s an indicator that it will happen to the rest of the environment. But when I finished my degree, the one thing I really remember is that any time I spoke to anyone about it, the first question I got was, what is a barnacle? So that really was something that was a bit concerning. And it kind of led me to when I started my PhD to want to work on an organism that was equally as important for the environment, but that people also cared about. So that kind of led me in the direction of oysters.

You’re right, people do care about oysters for many different reasons. As we know, they’re a great food source for humans and animals. But obviously in your research you’ve learnt so much about the services to the ecosystem and to us as Indigenous peoples. What have you learnt about what they provide for us and our environment?

For the ecosystem they’re really just so important. They provide essential services such as providing the habitat and nursery ground and a food source for a whole range of other marine organisms as well as birds. They’re important at protecting the shoreline. So, we see now with – we’ve got a lot of storm events that are increasing in intensity and frequency, and they really provide a really important role of protecting the shoreline from erosion. And another major kind of ecosystem service is that they filter the surrounding seawater, so an adult oyster can filter up to a bathtub full of water each day. So they’re really important at maintaining water quality in our coastal environments.

From kind of the economic perspectives, they form large aquaculture industries here in Australia as well as across the globe worth around $7 billion each year. And something that’s close to my heart is that they have a really enormous cultural importance. They’ve been a source of food and trade as well as provided that connection to Country for First Nations Australians for thousands of years.

Yeah, we’ll dig into some of that connection a little bit into the conversation, but I guess it’s important to understand just how different oysters are today than they were pre-colonisation to our First Nations Peoples. In 2011, a group of researchers conducted a global survey of oyster reefs and they found that essentially all of Australia’s oyster reefs were functionally extinct. I just wanted to know if you could explain what exactly an oyster reef is, because it’s not a term I’d come across before. And what has contributed to their decimation along the New South Wales coastline?

Yes. So, oyster reefs are areas where you get kind of dense aggregations of oysters where they settle on top of one another over many years. So, you’ve got this big kind of almost rock like structure that forms a reef and it’s a really important location where you have a lot of those ecosystem services that I was talking to you about that these used to be abundant all along the east coast of Australia and much of the south coast as well. But unfortunately, things such as overharvesting of the oysters for food as well as their shells to burn and create lime that went into the cement for early buildings. Also, things such as pollution, disease and increased sedimentation. So, more sediment running into our waterways has led to their decimation over the last couple of hundred years. So, we’re at the point now where, as you have already mentioned, they’re classed as being functionally extinct. So, we’ve got less than 1 per cent of the original oyster reefs actually remaining.

And when we look at the map of Australia that they included in that study, it’s not just Australia that’s been hit hard by that. Oyster reefs are disappearing across the globe. Is there any sort of understanding at the moment that oyster reefs, especially in Australia, can come back from being functionally extinct?

Yeah, I mean that was a great study that you highlighted that really focused on just how bad things were. And from there we’ve really seen a push in Australia, as well as globally, of research efforts trying to bring back these oyster reefs. So, one of the major things that they do in these projects is to replace the lost substrate so that the oysters actually have somewhere that they can settle on and start forming those reefs. So, they’ll put rocks or oyster shells, things that are hard into the water at a specific location so that the oysters can actually recruit there and start forming those reefs. So, yeah, there’s a lot of research underway at the moment with some really positive results so far that show that we can start to restore these reefs.

I want to go to your PhD, which I’m sure is not a fun time to revisit for most people. But you actually completed it more than a decade ago, before these global surveys of oyster reefs had even been conducted. Back then, how did predictions of ocean warming and acidification start to change your understanding of the challenges oysters and industries will face in the future?

When I started, my PhD, particularly, the field of ocean acidification, was really in its infancy, so we didn’t know a lot about it. I’d read about the fact that the PH of the ocean was dropping, which is what happens with ocean acidification. So, the ocean absorbs a lot of the carbon dioxide that we released into the atmosphere. When it’s absorbed, it reacts with seawater and it changes the chemistry of the ocean and we get this drop in the PH of the ocean.

So, I had read not even a handful of studies that have been done at the time that kind of said, you know, this might be bad for organisms such as oysters, corals, anything that kind of grows a calcium carbonate shell or structure. So that kind of led us to thinking, okay, let’s have a look at where the oysters will be impacted. So, we looked at ocean acidification combined with ocean warming because both of them will be happening together over this century. And we found, unfortunately, some really disturbing results. Oysters were highly vulnerable. They found it very hard to grow their shell. Those that did grow a shell had abnormalities in their shell that made them more vulnerable to predation and disease and just a whole range of changes to their physiology that were really concerning and causing a reduction in their survival. Also, what happens is that inside their body, in their blood, that reduction in PH actually drops the PH of the blood inside the oysters. And that has all flow on consequences for other processes inside of them.

So, it kind of got to the end of my PhD where I felt quite hopeless. You know, I completed the PhD, which I was really proud of. But I was at the point where I thought, well, that’s great that I got the PhD, but look at these terrible results, and what does that mean for the future?

So you’re now working towards building climate resilient oyster populations and communities to combat these predicted impacts in the ocean. What is selective breeding of oysters and which avenues of breeding have you explored?

So selective breeding has been used by oyster aquaculture for many years now, and in terms of that kind of traditional aquaculture sense, they use it to have benefits for aquaculture industries. So here in Australia, for the species I work on, which is the Sydney rock oyster, they’ve been able to breed Sydney rock oysters that have resistance against diseases that impact the industry as well as Sydney rock oysters that can grow faster. So, this is a benefit because they reach market size sooner so they can be sold sooner.

So, for us, we’re employing this now to also try and breed for climate change resilience and we’re using two different methods. So, the first is a method that’s currently being employed by the Sydney rock oyster industry, and that’s known as pair mated breeding. So, what that involves is getting a single male and a single female and we breed those together to create what’s known as a pair mated family line. So, I’m working in collaboration with the New South Wales Department of Primary Industries and currently they’ve got hundreds of these pair mated family lines that exist within their breeding program. Now for us they’re really unique because each of them has different genetics from one another, so they represent the wild population, but they’re little snips of different genes that are within that population. So, we can go through now and test a range of the families and see whether there are already some genetics within the population that are more resilient to climate change. So that’s one avenue that we’re going down.

Have you found any genes that are more resilient at the moment?

We’ve been able to identify families so far that are more resilient. So, we’ve tested about 50 families so far, and the large majority of those are highly vulnerable and respond quite similarly to the wild population. But we’ve been able to identify so far around 13 of them that showed that increased resilience so they’re able to grow better. That PH that I talked about of their blood, they’re able to keep that at a normal level and the abnormalities in their shell are no longer present. So yeah, those kind of 13 families who we’ve identified so far, we’re now looking into those more breeding from those families and then also trying to identify more that we can continue to breed with.

And so you have another breeding technique that is called transgenerational plasticity. Can you explain what that is and why it’s become a sort of a leading tool in the global research on marine life?

Yes, a transgenerational plasticity involves exposing adult oysters to climate change stressors at the time when they’re growing their eggs and their sperm. And the reason we do this is we want to see whether the adults pass on any beneficial carryover effects to their offspring that then allow their offspring to do better. So, this type of method is really quick. You know, we can do this quite quickly to adapt our populations. So, it’s one reason why it is quite a popular method and it’s also something we can look at to get a better understanding of whether the wild population may have the capacity to adapt.

So you have these two breeding techniques. Are you doing just one at the moment? Do you combine the both? How do they work in the hatcheries that you work in?

So in the hatchery, we are combining the two of them at the moment. So, we work on our pair mated breeding sometimes in isolation, but then we also at times combine the transgenerational plasticity on our pair mated breeding oysters to see whether we can actually really increase their resilience even further.

So what challenges have started emerging in the early stages of this breeding? I know that you were introducing the impacts of ocean acidification. What happens when you start introducing other stressors like salinity?

Yeah, so really early on when we were breeding for resilience, we were focusing only on ocean acidification, and we found some really fantastic results. We were able to, as I mentioned before, really improve the growth of our oysters, under ocean acidification. We all but got rid of that impact on their abnormality so that was no longer present.

But a really major challenge that we found and something we didn’t realise was a challenge at first, was that to do this they had been using much more energy, so they were growing better, they didn’t have that abnormality, but it was costing them a lot of energy to be able to do this. And what we later found is that when we exposed these oysters to ocean acidification, along with other stressors that they’d naturally experienced in the environment, so that warmer environment, salinity changes, so the salt content changing, or if they didn’t have optimal foods, so if they had less food than they would normally want, which can happen in the environment, those oysters did far worse than our wild population. They actually couldn’t survive anymore because they just didn’t have that energy available. They’d use too much to do well under ocean acidification, and there was just no energy left over when they’re exposed to those other stressors. So, this was something that was really concerning because obviously that reflects the real world scenario more accurately.

So how did you address that problem? How did you shift your research focus?

So at that point, we really went back to the drawing board. We kind of knew why it was happening. So that was really good because it gave us a place to start. So, our research really focused from then and that’s where we’re at now at really breeding for resilience but focusing on that energy budgets and making sure that they have that resilience, but it’s not costing them more energy to do that.

Now, when we talk about this transgenerational plasticity tool, which I find really interesting, you’ve talked about it being a leading research tool, and it’s been used globally by other researchers. But there are gaps in what we know about its usefulness at the moment. What are those gaps?

So one of the gaps is that we don’t know why it’s occurring. We know that the offspring are doing better, that the adults are passing something onto them. We’ve got no idea what that is. So, we first thought that it might be that the mothers were passing more energy into their eggs and that that helped the offspring to do better. But we tested them and found out that that wasn’t what was happening. So yeah, a big area of our research now is really to understand what that is that’s allowing them to do better.

The other major kind of unknown is how long it lasts for. So, a lot of the research done in our lab and in labs across the globe really is on that first few weeks to months of the offspring’s development. And we know they do better over that short period of time, but we really don’t know how long it persists for and whether it is actually passed on to the next generation. So, we really need to know that to have an understanding of how beneficial it’s going to be for those offspring over time. So that’s something that we’re really focused on now as well, is really identifying what it is that’s allowing it to happen and how long those beneficial effects actually last.

So how many generations of oyster family lines have you been able to test this on?

So at the moment we’ve just begun our experiment where we’re testing it on those parents. We take that next generation through all the way until they’re ready to reproduce and then we test the next generation. So yeah, we’ll be having a look over multiple generations in the coming two years to see. That’s around the amount of time that it’ll take to get through those generations.

Is that the first time anyone’s attempted to try multiple generations?

On oysters, yes. There has been some work done on organisms that have shorter generation times, but as you can imagine, something that takes over a year to get to the point where they’re at adulthood and can reproduce, it’s really hard to kind of keep them in a hatchery setting for that period of time. So yeah, there has been some work done, but it’s really kind of one of the first times we’re able to do this at a large scale on an organism that has that long generation time.

Anything you’ve noticed so far that you haven’t mentioned about their offspring and the adults that you’re currently looking at?

The interesting thing is that we were very worried at the start that this kind of energy budget trade-off that we’re seeing that that was something that we wouldn’t be able to overcome. But one thing that we have noticed by working with these family lines and those kind of different genetics is that they just have this enormous capacity within them. There are some of our more resilient oysters that have that same energy profile that our previous ones did. So, it costs them a lot of energy. But, you know, obviously, to our excitement, we’ve been able to identify family lines that are just doing wonderfully without that energetic cost. So, we’re hoping that those ones really do have that capacity to survive in that real world environment.

And so that’s the next step, right? Because these oysters have not been at any point introduced into the natural environment. Now, you’ve spoken about this at length, but future proofing oyster populations, it’s obviously not straightforward and it has to rely on multiple areas of research and relationships with multiple different groups. So, can you explain the relationship between reef restoration and selective breeding research and how they complement one another?

Yeah, well, I mentioned before there’s some great research underway in terms of the reef restoration area. But one thing that I’ve always been mindful of is that reef restoration is occurring in the face of climate change. So, while we can restore these reefs now, we need to really be proactive and protect them into the future and be ready to have oysters that can survive into the future as our oceans become warmer and more acidic. So that’s kind of the area that my research kind of compliments reef restoration that’s occurring at the moment, because we’re going to have the capacity to be able to see those reefs with oysters that are more resilient so that we can protect them into the future.

So let’s talk about one location of oyster reefs in particular. How did your relationship with the Gubbi Gubbi Traditional Owners in south-east Queensland begin?

Yeah, this is a really wonderful partnership that we began, I think, back in 2018. We were designing a project at the time. We knew we wanted to put our oysters out into the field somewhere and we started speaking to some of the Traditional Owners of the Pumicestone Passage region. And something that we realised quite quickly is that we had this common goal of wanting to restore oyster reefs. For the community there, oyster reefs had been so important in their history. But in that region, I think they’ve lost 97 per cent of the vertical zonation of oysters due to some of the issues that we were talking about previously. So, it was a real aspiration of the community there to restore oyster reefs back to what they once were and really restore that connection to Country.

So, for us, we quickly worked out that that could be a really great partnership and a great location for us to test our climate change resilient oysters. Because we’re breeding for resilience on the southeast coast of New South Wales, where temperatures in summer are around 24 degrees Celsius. At the same time, in the Pumicestone Passage their around 28 degrees Celsius. So, it creates this great opportunity to really test that future warming scenario, but also work with the Traditional Owners to try and see whether we have oysters that can survive better in that region. So, we’ve been working together on that, and the next step in our research is to start deploying some of our resilient oysters up into the Pumicestone Passage with the hopes that they’re going to do better up there.

Absolutely. You would know better than anyone that as blackfellas, our knowledge of our Country is so vital in all of these climate conversations. I wanted to know if you could break down how you have attempted to centre Gubbi Gubbi Traditional Owners’ aspirations for their own Country throughout this process.

So look, it’s been all about, you know, having that yarn, talking about the aspirations every step of the way. It’s been wonderful for me because I think from a Western science point of view, you get kind of the overview of things. We know that oyster reefs were abundant. We know that they’re declining. But when you’re talking to Traditional Owners, you get that really localised view of the area. You know what was there, what it meant to the community, what happened in that specific region that has led to that decimation. So, you just get this wealth of information that you really wouldn’t have had if you weren’t speaking to the Traditional Owners. So that’s been really wonderful for me. And then also to, you know, I want to restore oyster reefs in that region, but where is it most important to do that for the community? And I think that’s something that’s really important in my research, and I hope that it starts to become important in research of all of our marine scientists that, you know, that there’s another aspect there that we should be considering. It’s really important to do so.

Is there anything that you didn’t know before working with Gubbi Gubbi People that you’ve now learnt through working together?

Look, I think with our yarns it’s really just, you know, I talk about from the science point of view, the importance of oysters, but really hearing it through their lens, it really drives me to do what I do more, it’s that added drive to want to do good and want to be able to be successful because I know how important it is. And just like I was mentioning before, hearing about their traditions that were used previously, you know, a lot of a lot of the Traditional Owners did have something to do with oyster farming, so to speak, and hearing their journey and what they used to do and the locations that they used to farm. You know, it’s really great to just learn, to listen and learn.

Sustainable practices for thousands of years, right?

That’s exactly right.

So in terms of your own journey throughout nearly 20 years of research coming up in a couple of years. As a Wiradjuri woman, how do your own principles and your own responsibility to Country guide you in all of the work that you do?

Look, I think that you’ve always got that need – importance to care for Country. And that really drives me in everything that I do. And I think also now having the capacity to help First Nations Australians achieve their aspirations, that drives me a lot now as well, to be able to combine the two caring for Country and that need to help communities achieve their aspirations. Yeah, it’s hard to describe but it’s just something that yeah, it’s kind of the need to do.

So we talk about the importance of Indigenous knowledges working alongside Western sciences. Obviously, it’s really great to have these partnerships with marine scientists and with Traditional Owners, but I think what I’m seeing is that it’s super beneficial to have a black woman or a black person working in the western science side of things as well. What does it look like at the moment in the industry? Do we have many blackfellas working in marine science?

Unfortunately, no. You know, I would love to see greater representation in marine science, and that’s something that I think everyone is realising the benefit of. And there’s a real push to try and help in areas like I really hope in my career that I’ll be able to change that so that we do have more Indigenous scientists, marine scientists, because it’s so important.

If you could encourage anybody listening to this to take a leap, what would you say to encourage them?

I feel so passionate about what I do every day. I feel like I’m doing something that is very important for myself, for the environment, for my children and the future of our waterways in Australia. I would just encourage anyone who kind of wants to feel passionate about what they do every day to really take that leap and work in this space.

And anyone from saltwater Country, you probably already know half of this anyways, go check it out. We do need to talk about the most exciting part of all of this, which is when the selectively bred oysters will be reintroduced into Pumicestone Passage, when?

So we’re just breeding some oysters now. They will be spawned towards the end of this year. And then once they get big enough, which is when they are about three or four months old, we will then start deploying them. So yeah, kind of early to mid-next year we’ll start doing our first deployment, which is really exciting.

How long has that been coming?

It feels like forever. So, we started this project in 2020. So realistically it’s not that long. But because this is a culmination of our research for so many years now, it’s really exciting to get to this point where we can ground truth and test whether what we’re doing in the hatchery is going to do what we hope in the environment. So that’s great.

How does it work once they’re in there? How are you going to be able to study them in the natural environment?

So we deploy them across a range of different sites in the Pumicestone Passage as well as other estuaries. And then we leave them out there for a course of a year. But during that time, we go back. So first we’ll be going back monthly, for the first few months, and we look at things such as the survival and the growth of the oysters. What’s recruiting in amongst the oysters, as I talked about them being that important habitat. And then we’ll go back at six, nine and 12 months. So, yeah, just assessing them along the way and seeing if they do better. So, we’ll be putting out our resilient oysters as well as our non-resilient oysters. And so, what we’ll be looking for is really that our resilient oysters are performing better with their growth, with their survival than our non-resilient oysters.

It’s really exciting. Has this reintroduction happened anywhere else in the world and have we learnt anything from that?

No. This will be the first time that we’re here that we’re doing this. So, it’s pretty exciting.

All eyes on you then eh? In terms of natural, wild oysters that may already be in the water, are there any benefits we can expect to flow on to them, or do you have any expectations on how this will impact them?

We don’t know a lot yet about the gene flow between our selected oysters and the wild population and just whether – I know from aquaculture that there isn’t a lot of evidence to show that they go from an aquaculture setting into the wild population. But I do hope that by seeding in oyster reefs potentially in the future, that that’s going to have the benefit for the world population there. I mean, very interestingly from our research is that, you know, our selected oysters have originally come from the wild population. So those genetics are there. The only thing is whether – how widespread they are and whether they have the capacity to adapt quick enough, which I think is a challenge for all our marine environment, I think our marine environment is very good at adapting, but we’re throwing a lot of stress at them at the moment, all at once and very rapidly. So, it’s just whether they have that capacity to keep up.

Ahead of the reintroduction, do you have any predictions and how are you feeling?

Look, my main feeling is excitement. Obviously nervous to know whether, you know, what we have worked on for so many years now is going to work. I think in science, I’m always very scared to say ‘I think it’s definitely going to work’, but I’m really hopeful. I think from what we’re seeing in the hatchery, it’s really exciting and I can’t wait to see the results.

Me neither. I want to take you out at the end of this conversation back to the beginning, and that feeling of I suppose sort of despair that you had at the end of your PhD How do you hold onto hope? You know, it’s been more than a decade after publishing those findings on ocean warming and acidification, the impacts on oysters, you’re still sticking out at it. How do you hold on to hope?

You know, there’s two reasons. The first is not just my research on oysters, but you see research here in Australia and across the globe where there’s just such wonderful efforts underway to improve the resilience of our ecosystems now, to try and give them the best chance of success in the future and seeing the gains that people have made, you know, that really gives me hope. And the second is something that I’ve seen a shift in certainly since I started my journey in climate change research. And it’s really just that you see kind of everyone getting on board now from, you know, the general public right up through to our leaders and really wanting to make the change and do the things necessary. And I think with a challenge as big as climate change, we need everyone. So, the fact that we are seeing that change now and so many voices come to the table and really try and stand up for this and for us to do something about it that gives me hope for the future.

I love that. Thank you so much for your time, Laura. I’ve learnt a lot from you. Just reading in preparation for this but also in this conversation. So, thank you for your work.

Thank you so much.

To follow the program online you can subscribe wherever you get your podcasts and to visit the 100 Climate Conversations exhibition or to join us for a live recording, please go to 100climateconversations.com. To follow the program online, you can subscribe wherever you get your podcasts and to visit the 100 Climate Conversations exhibition or join us for a live recording like this one. You can go to 100climateconversations.com and just search for 100 Climate Conversations in your pod catcher of choice.

This is a significant new project for the museum and the records of these conversations will form a new climate change archive preserved for future generations in the Powerhouse collection of over 500,000 objects that tell the stories of our time. It is particularly important to First Nations peoples to preserve conversations like this, building on the oral histories and traditions of passing down our knowledges, sciences and innovations which we know allowed our Countries to thrive for tens of thousands of years.