Great Barrier Reef: record heatwave may cause another coral bleaching event
30 November 2018 | Mitigation
A record-breaking heatwave in north Queensland will further increase above-average marine temperatures, heightening the risk of another coral bleaching event on the Great Barrier Reef next year, scientists say.
Dozens of record November temperatures have been recorded in the region, most along the reef coastline, this week.
The most remarkable was at Cairns, where consecutive days reached temperatures of 42.6C and 40.9C. The maximum temperature on Tuesday broke a November record that has stood since 1900 by 5.4C.
Extreme weather fuelled more than 130 bushfires, which the premier Annastacia Palaszczuk said on Twitter was “not the kind of fire we have seen in Queensland before”.
“Heatwave records and fire weather is unprecedented,” Palaszczuk said.
A dust storm, brought by strong westerly winds, covered the southern inland parts of the state. In the north, thousands of native flying foxes died due to the high temperatures.
Reef scientist Terry Hughes, from the coral centre of excellence at James Cook University, said the summer heatwave was “terrifying” and lifted the chances of coral death on the Great Barrier Reef early next year.
The reef sustained successive marine heatwaves, in the early part of 2016 and 2017, which killed corals and badly damaged the northern and central sections.
Hughes said the bleaching forecasts were “trending upwards” but scientists would not have a clear picture until the end of January.
Coral ecophysiologist Dr Neal Cantin, from the Australian Institute of Marine Science, said ocean temperatures remained below those recorded at the same time in 2015 and 2016, but warmer than historical averages.
Cantin said the current heatwave would “add heat and warm up the ocean. It certainly adds heat to the system. We’ve seen record breaking land temperatures this week, which we expect to see into the future with climate change and everything heating up.
“We’re in a watch phase. There’s definitely the potential and how the local weather patterns pan out in January and February will really determine whether we get a large scale bleaching event or not.
“There are some signs we may avoid [bleaching] this summer. At this stage it’s less likely to be as bad as 2016, but we’ll be ready to respond [if bleaching occurs].”
Reality of climate change sinking in
“The hazard I worry most about is heatwaves,” Andrew Gissing, a disaster management expert from the firm Risk Frontiers, said.
“Australia needs to be better prepared for heatwaves, with climate change we are already predicting they will get more severe.”
Gissing told Guardian Australia people often respond to extreme weather events and natural disasters based on their previous experiences. But he said governments, businesses and individuals were often not prepared for the increasing severity and frequency of such events.
“We did a lot of work in Lismore after Cyclone Debbie. So many people sheltered in their homes because that’s what they always did when it flooded. They just didn’t realise this flood was that much bigger
“People really need to be attuned to what’s actually happening ... how the nature of climactic hazards is changing.”
Gissing said businesses needed to start investing in climate change mitigation and adaption measures.
“It’s going to be very hard to mitigate a lot of the [predicted climate] impacts, so adaptation for the future is going to be really important. Especially when you overlay climate change on a growing population base.
“The [number of people living on the Queensland coast] is likely to double by about 2030. Because of climate change, we’re looking at there being more exposure [to disaster risks] there as well.”
Source: The Guardian