Professor Morgan Pratchett is a research fellow at the ARC Centre of Excellence for Coral Reef Studies, based at James Cook University, Townsville. He has broad interests in population and community ecology of coral reef organisms, especially corals and fishes. His current research focuses on major disturbances that impact coral reef ecosystems, with a view to understanding differential responses and vulnerabilities among coral reef organisms.
Morgan has written many papers describing direct and indirect effects of coral bleaching and outbreaks of Crown-of-thorns starfish, considering impacts on both coral assemblages and associated assemblages of coral reef fishes. He has also conducted extensive research on the biology and ecology of the coral reef butterfly fishes.
I recently interviewed him for No Fibs.
John Pratt: A recent study by Professor Terry Hughes has shown an 89 per cent crash in baby coral numbers, what can you tell me about the significance of this study?
Professor Pratchett: The National Coral Bleaching Task Force in Australia was raised prior to the coral bleaching in 2016. So what we have documented in the field, firstly, is there has been significant mass mortality of coral, mostly in the northern Great Barrier Reef; and then most recently, by studying the rates of coral recruitment, we’ve shown that the mass mortality of adult corals has led to a decline in the amount of coral recruitment.
Now what we mean by coral recruitment is the amount of new baby coral coming back and settling on the reef. So this is very important for the recovery of the Great Barrier Reef following the initial loss of those adult corals. Now it’s reassuring that we are seeing some level of coral recruitment even in areas that were worse affected by the bleaching, but given the rates of recruitment are so low it suggests that the time required for recovery back to what the reef was like prior to the 2016 bleaching is probably going to take decades. That’s a concern because with the ongoing carbon emissions and ongoing ocean warming, we could probably expect to see mass bleaching events that caused the widespread mortality on the Great Barrier Reef to occur well within that timeframe.
The combination of increasing frequency of disturbances and prolonged periods for recovery doesn’t bode well for the Great Barrier Reef and it is possible that unless we reign in our carbon emissions the reef will never recover.Professor Morgan Pratchett
John Pratt: I noticed in a report by Bill Leggat from Newcastle University that at Lord Howe Island some of the most southern coral on the planet suffered severe bleaching.
Professor Pratchett: That’s right, the important thing is that the bleaching that occurs on any given reef is dependant on how much the temperature is increasing above the normal temperatures for the corals at that location. So, even though the reefs in the south are much cooler it still means that if the temperature increases by more than a degree or two for a prolonged period of time, the corals will bleach.
I guess the thing is no reefs anywhere in the world are immune to coral bleaching really, and ongoing increases in ocean temperatures will increase the frequency and severity of coral bleaching around the world.
John Pratt: Already the IPCC, I think has given up on 1.5C warming and we are probably heading to 2C or more. Would you agree with that?
Professor Pratchett: I absolutely agree with that. Australia as much as any other country is not on-track to keep emissions below a level that will limit further increases in temperature below 1.5C. So what this really means is that some of the systems which are particularly vulnerable to ongoing increases in the global atmospheric and ocean temperatures are really going to be badly effected; but that’s not to say we should give up. If we can limit warming at any level it’s going to reduce the more devastating impacts of climate change along the way. So we need both an immediate and substantial effort to reduce emissions. Even if it goes above 1.5C the further below 2C we can keep it, the better it’s going to be for natural systems around the world.
John Pratt: I notice that in the United Kingdom, at the end of March, the shadow environmental secretary for the British Labour Party, Sue Hayman, declared a ‘climate emergency’, trying to get the UK on track; although the UK seems to be doing far better than Australia. Do you think it’s time for Australia to declare a climate emergency?
Professor Pratchett: I think we’re well past that point. So yes, we seem to lack what’s going to be needed to initiate the necessary changes, the federal government’s leadership on this issue. Maybe we should be doing that. The clear thing is that people around the world are trying to do their bit but what we need is the leadership to come from the governments of the day to really help promote the necessary changes in energy and transport policy, so we can make the necessary reductions in carbon emissions.
John Pratt: Have you heard about an organisation called the Extinction Rebellion?
Professor Pratchett: I haven’t, no, sorry.
John Pratt: They’re an organisation that took to the streets last October in London. Next Monday, on April 15, they are planning to sit down and disrupt traffic in London, a bit like the Occupy Movement did a few years ago. They are actually demanding climate action, saying we’re staying here until the government acts on climate change. They are calling for a ‘citizens assembly’ to make these decisions. Would you support people action to bring about change, bearing in mind the IPCC says we have ten years and the politics doesn’t look to be heading that way?
Professor Pratchett: Yes, we aren’t seeing any evidence that the governments of the day are taking this seriously. It’s sort of a relatively minor part of the current election campaign even. It does seem that only one party is really making any noises that they’re going to make the necessary changes, even then it’s probably not going to go far enough. So I think people around the world, certainly in Australia, need to show that this is an issue that they really care about. Hopefully they will vote accordingly. Things like the students strike have certainly helped raise the profile of the issue. Something needs to drastically change to make the current government, the coalition far more aware of this issue. I see today Melissa Price, the current environment minister, has just given the final go ahead to the Adani mine.
Taking more and more non-renewable resources like coal out of the ground is not consistent with our hopes to reduce further ocean and global warming.
John Pratt: I guess you’ve been in this battle for a long time, do you see any glimmer of hope?
Professor Pratchett: I think if we believe there’s going to be a change of government, Labor has at least put forward some strong words around trying to meet the Paris Agreement on climate change. I still think they are probably falling short of what is going to be required to stop us getting above 1.5C but at least there’s evidence they’re going to do something. How that policy will be played out and whether it’s going to be effective, we’ve still yet to see.
John Pratt: And finally do you think we’ll all be driving electric cars by 2030?
Professor Pratchett: I think that would be a big step forward. Obviously there is some question marks about how we’re going to power those electric vehicles. It needs to be sustainable not only for the transport system but also for the fundamental energy system. I think the sooner we move away from our reliance on fossil fuels — and the big one is driving petrol — the better.
John Pratt: Thank you very much Professor I really appreciate that.
Professor Pratchett: No problem at all.