According to a forecast by a United States government agency, corals in large areas of the Great Barrier Reef could be affected by mass bleaching for just the fourth time in seven years.
Scientists hope that favorable weather, such as rain, cloud cover, or a cyclone could cool corals and ward off the threat.
According to the US National Oceanic and Atmospheric Administrations (Noaa), heat will accumulate in the northern and central parts, causing corals to begin bleaching by January.
Forecasting from the Bureau of Meteorology also shows heat building over the world-heritage-listed reef in January.
Dr David Wachenfeld of the Great Barrier Reef Marine Park Authority stated that water temperatures are above average almost everywhere and some areas are 2C warmer.
He stated that the current situation is not what we want but that it is not surprising in a changing world.
He said that neither the BoM nor Noaa forecasts were capable of predicting cyclones which can quickly lower temperatures. He said that he wished for rain and clouds.
The cyclone season in Australia runs from November to April. The eastern side of Australia, including the reef, experiences an average of four cyclones each year.
According to the Bureau of Meteorology, there is a very small chance of more than the average number of Cyclones this season.
A spokesperson for the bureaus stated that they Ocean outlookThe indicator is indicating an increase in thermal stress on Great Barrier Reef for the remainder and January 2022, decreasing in February.
According to Noaas forecastThe Coral Reef Watch service delivered the information via its Coral Reef Watch service. By the third week in January, sections of the reef will be bleached from south of Airlie Beach to Cape York, a distance of approximately 1,300 kilometres.
Mid-February shows that large areas from Cairns to Brisbane would be at Alert Level 2 which is the highest level heat stress where coral death is possible.
Australia’s climate is currently being affected by the La Nia weather pattern. Wachenfeld stated this would typically deliver more rain and clouds to the waters of the reefs.
We haven’t seen it yet this summer. We hope that La Nia conditions will prevail. The next few weeks will be crucial for weather events.
Coral bleaching is caused by heat stress. Corals are separated from special algae, which gives them their colour as well as many of their nutrients.
Corals can recover from milder bleaching but studies suggest that those that survive are weaker.
Although 2020 was the worst year for coral bleaching, Wachenfeld said that the heat levels were not as intense than previous events. Therefore, the reef was given many years to recover.
The Australian Institute of Marine ScienceThe latest reef condition report for 2021 showed that there was a decrease in disturbance and an increase of corals. However, this coral cover increase was dominated in part by weaker, faster-growing species that are more susceptible to bleaching.
Professor Peter Mumby from the University of Queensland said that the reef was in a critical phase for recovery. However, he was concerned about the Noaa forecast, especially because they tend to be very conservative.
He said that everyone is feeling a bit depressed about the possibility of another bleaching event.
Dr Selina Ward is the academic director of University of Queensland’s Heron Island research station. She said: I am always concerned when temperatures go up and stay high.
According to the Noaa forecast, we are likely to see a bleaching event earlier than we expected.
Professor Terry Hughes of James Cook University’s ARC Centre of Excellence for Coral Reef Studies is a coral bleaching expert who surveys and monitors the reef during bleaching events.
Five major bleaching events occurred in the Great Barrier Reef, including those in 1998, 2002, 2016, 2017, and 2020. All of these events were caused by rising ocean temperature due to global heating. Hughes conducted a November study and found that only 2% of the 2,300-kilometre-long reefs had survived bleaching since 1998.
Hughes said that the Noaa forecast was unusual as it predicted a rapid onset of bleaching in the north. However, he stated that the forecast also predicted a rapid drop in heat in early March, which would help corals to survive.
He stated that El Nio weather patterns, which are hotter and drier than La Nia, have historically caused bleaching.
It’s alarming to know that an El Nio is no longer necessary for a mass bleaching event. All we need is another heatwave, triggered by global heating.
The average sea temperature in the tropics during La Nia periods is higher than it was during El Nios 30 year ago.
He stated that the Bureau of Meteorology’s forecast was more benign for Noaas, however, temperatures across the reef were about a degree higher than average over the past month.
We hope that the reef will be able to withstand the bullet for another year with La Nia conditions increasing, he stated.
He stated that young corals that had begun to grow in recent decades would be at high risk if the reef’s northern areas were to bleach again.
Prof Tom Bridge, an ecologist and reef scientist at Museum of Tropical Queensland, said that the Noaa forecasts had not made him more or lesser concerned about the prospect of bleaching than any other year.
He said it’s getting hotter every year. This summer, we are facing this challenge where bleaching depends on the weather like rains, cyclones, and heatwaves.
Research from last month indicated that parts of the reef could be affected by temperatures high enough to kill corals in five years per decade by mid-century if global warming is kept below 2C.
Unesco’s science advisors had earlier suggested that the reef be added to a list of endangered world heritage sites. However, the Morrison government’s fierce lobbying has delayed a decision until June next year.
Coral reefs are one ecosystem that is most at risk from the climate crisis.
The Morrison government was asked to submit a progress report to Unesco by February 2019.
Unesco is yet not to schedule a monitoring mission on the reef. It is expected that this will be done in the first quarter of next year.
Three young Queenslanders were represented by lawyers who wrote Friday to the 21-country World Heritage Committee, urging them to place the reef on its in danger list at the next meeting in June in Russia.