The Great Barrier Reef is "en route for a difficult ride"

During the summer of 2017, much of the Australian Great Barrier Reef – usually a riot of electric oranges, reds and other colors – has become pale and ghostly.

Unusually warm water temperatures, in part due to global warming, have caused corals to expel symbiotic algae from their tissues, providing them with food and giving them vibrant hues. It was the second mass-bleaching event to hit the reef in as many years. Together, back-to-back events touched two-thirds of the reef.

While the Australian summer of 2019 is about to begin, scientists in the atmosphere predict an El Niño, a recurring period marked by milder temperatures in the tropical Pacific Ocean. This high temperature potential is again a threat to the Great Barrier Reef, which will be monitored by marine biologist Terry Hughes – a leading advocate of coral reef protection – for signs of further damage to protect him.

Hughes believes that valid mitigation efforts need to be explored, such as reforestation of watersheds that dump into the reef to avoid polluting runoff. But at the end of the day, he thinks that the preservation of corals lies in reducing the greenhouse gas emissions that fuel global warming.

Hughes' efforts to raise awareness of this 2,300-kilometer long coral reef – the largest in the world and home to thousands of marine species – have put it in conflict with commercial and political interests. Last month, it appeared that the Australian Research Council (ARC) would drop funding from the Hughes Institute for Coral Reefs led by James Cook University in Queensland, a decision decried by scientists from the ocean, around the world. (The ARC and the current Australian Conservative government have said the decision was not politicized, according to reports.) Last week, Hughes received the John Maddox Award for defending scientific evidence facing hostility. American scientist caught up with him at the Falling Walls annual scientific conference in Berlin earlier this month and talked about the future of the Great Barrier Reef.

What are your prospects for the Great Barrier Reef in the coming months?

NOAA [the U.S. National Oceanic and Atmospheric Administration] and the Australian Bureau of Meteorology both predict a high probability that an El Niño event will form later this year. If this happens, the probability of bleaching when the summer sea temperature peaks next March will be very high, but we will not know until January. A cyclone at the right time could cool the water despite long-term forecasts. But you must pay attention to what you want. In 2016, the southern third of the Great Barrier Reef was saved by a cyclone that caused the [water] low temperature of about 2 to 3 degrees Celsius. But with Hurricane Debbie in 2017, the bleaching had already taken place and the storm was in Category 4 when she hit the coast – so it was very damaging and destructive. [to the reef].

How do you monitor a whitening event?

Our aerial surveys, which we adapt to satellite temperature data, cover the entire reef. It takes us seven or eight days to crisscross the Great Barrier Reef in a small plane flying up to eight hours a day. It's quite challenging, but it's the best way to get a complete picture. We base the truth all this [data] submarine [during dives]. Every event we study has a different geography. The 2016 event was really a northern affair. The whitening cards for 2017 will show that the hottest part of the reef – the most laundered part – was in the center.

Is there an area of ​​the reef that is of particular concern to you?

My worst nightmare is that the bottom [southern] one-third of the Great Barrier Reef, which has escaped the last two events, will be laundered. It's just the luck that prevented it from bleaching in 2016 and 2017. These reefs have a very large number of branched corals that are most susceptible to bleaching. So, if it is very hot in the summer or next summer, the death rate will be high. This would mean that all areas of the reef will have been affected in a few years.

How did the Australian government react to the bleaching events?

The history of the Great Barrier Reef in Australia, after the unprecedented whitening that followed, is very controversial politically. One might think that an appropriate response from the government would be to say, for example, that it would not proceed with the world's largest coal mine. [with a coal shipping terminal near the reef] or that it would increase its renewable energy goals. Neither has occurred. The government has spent a lot of money investigating different interventions. Some are downright stupid – the [underwater cooling] fans, floating sunscreen. There is a campaign to ban plastic straws. If you were cynical, you'd say it was more about giving the appearance of helping the reefs when the elephant in the room is still subject to climate change. There is also money to improve the quality of the water. Sediment and nutrient runoff from agriculture to the Great Barrier Reef is a significant problem, but the amount of money spent is not sufficient to meet government objectives . As the responsible country for the Great Barrier Reef World Heritage Area, Australia should lead international efforts to reduce emissions, especially after the latest IPCC report. [Intergovernmental Panel on Climate Change] report. Our current Commonwealth Government officially adhered to the target of 1.5 degrees C [for limiting global temperature rise] of the Paris Agreement, but Australia's emissions are increasing.

How will the loss of funding from the Australian Research Council affect your work?

That's about a quarter of our funding, and it will only come into effect in two or three years. So we have the time to maintain our current level of activity and to modify our funding model in a moderate way to compensate for this loss. This is not good news, certainly. But we will continue to do the research we do, especially if we see a bleaching next year.

What do people misunderstand about the Great Barrier Reef?

There are still about 10 billion live and healthy corals. We have just experienced a sacred process of natural selection in which the so-called losers – heat-sensitive species – have been severely depleted. The mixture of species has changed. The genetic makeup of coral populations is changing. I think this is just the beginning of a transition that, hopefully, will make the Great Barrier Reef more difficult for inevitable future events. Things will generally get worse before you improve. Until CO2 emissions and temperatures stabilize, corals will be put to the test. Since corals have large, geographically dispersed populations, there is light at the end of the tunnel – but this is totally dependent on the ability to keep temperatures at a target of 1.5 ° C.