Seagrass - greenhouse gas fighter

Greenhouse Gas Fighter video transcript

Facilitator: Doctor Peter Macreadie, you're with the School of Environment at UTS, and I understand you're doing lots of interesting things. Firstly, tell me about your research with seagrass.

Interviewee: Well, the seagrasses have been identified as one of the most powerful natural systems for removing greenhouse gases. So when we're thinking about tackling climate change, these are pretty important systems. The seagrass community - there's been a number of publications identifying different [burial] rates or different carbon capture and storage rates, and they rank somewhere in the order between 30 and 50 times more powerful than tropical rainforests. So a lot of people identify with the Amazon as being so powerful in capturing and storing carbon, but seagrasses are much more powerful.

Facilitator: Why isn't this more widely known?

Interviewee: Well, I think if you go back a decade or so, there wasn't so much interest in carbon capture and storage. You know, the climate change issue has really come to light recently. So for the research that's come out recently to show that seagrass are one of the most powerful carbon sinks, that's why they've drawn a lot of attention recently.

Facilitator: Specifically, what is your research involving?

Interviewee: Well, one of the most recent studies we did, we took deep [cores] dating back over 6,000 years - so sediment cores - and we look at the carbon that's been stored, and we try and understand: throughout history, how has their carbon capture varied with what's been going on in the environment.

Now, if we look at the sediments recently, we see that since industrial revolution, these carbon sources have dwindled. We've see that seagrasses are no longer playing as effective a role in capturing and storing carbon. So, what are those industrial changes that have led to that weakening capacity of seagrasses to capture and store carbon, and how can we do something about that.

Facilitator: You also made a fake seagrass bed, I understand, that involved planting kilometres of artificial seagrass, is that right?

Interviewee: When you're doing seagrass research, you want to try and avoid destroying the system that you're trying to understand. But then you also have this complex problem of wanting to do studies on large enough scales, to make your research as meaningful as possible. So I had this study where I wanted to look at the effects of seagrass habitat fragmentation on fish populations. I soon realised I was going to need to use artificial seagrass if I wanted to base this on realistic scenarios. It involved hand tying over 250 kilometres of green Christmas ribbon to steel mesh to make the artificial seagrass. So there is a team of about 15 of us working around the clock for about three months, hand tying all this green ribbon to this steel mesh to make the artificial seagrass.

Facilitator: So it's not just boring lab work that you're doing?

Interviewee: No, I think there's a lot of - we often have to make things. We have to find solutions to approaching the science. There's no recipe given to us. That's where a lot of the innovation comes about. We've got this problem: how do we actually tackle this, what are the knowledge gaps, and then how do we actually do an experiment that will really just nail that hypothesis we're trying to test.

Facilitator: I've also been told that your research has gained you some notoriety in the scientific community. Tell me about the Eureka prizes?

Interviewee: So the Eureka Awards are often referred to as the Oscars of the science world, and for me, the prize, being a finalist, was an opportunity to promote awareness of the importance of seagrasses. It was going to be a challenge because we're talking about grass here, you know, up against spinal cord repair, cancer and other really important key issues. But I think the Australian people are now starting to appreciate seagrasses a little bit more after that campaign.

Back in my hometown in Victoria, throughout the 80s, they were bulldozing seagrass from up and down the peninsula. I mean people didn't like the feel of it underneath their feet, and as is the way government often works, they make decisions without really considering sometimes the environment. You know, you tick that box, you've made the locals happy, but what have you done for the environment. So to promote awareness about the importance of seagrasses through the Eureka Award was just a fantastic opportunity.

Facilitator: Can you see a day where Australians will be using seagrass to offset carbon emissions?

Interviewee: I think so. I mean if you try and understand how the government is working right now, they've just introduced the carbon farming initiative. This is a way that farmers can make some money by converting their farmland - this is farmland that used to be forest - they're converting it back into forest, and they can make money from that. So when we realise the value of seagrasses in terms of carbon capture and storage, we estimate their worth of about $45 billion dollars a year in terms of their carbon capture and storage ability. That's at $23 a tonne. As that price goes up, they're going to be worth even more. Once the government realises that, then I think they're going to be pretty keen to capitalise on Australian seagrasses.

Facilitator: Peter Macreadie, it sounds like you've got a lot of really important work ahead of you. Thanks very much for your time.

Interviewee: Thank you, Shannon.