Revealed: how the Reef is really doing
Reports of the death of the Great Barrier Reef may have been exaggerated, with new research showing "encouraging" signs of coral growth in two-thirds of 86 monitored reefs.
The annual report of the health of the reef by the Australian Institute of Marine Science, published today, has been welcomed by tourism operators who say they are battling widespread perceptions the reef is already dead.
Today's report shows modest increases in coral coverage in the reef's central and southern zones, and a stabilisation in the north, after several years of hits from bleaching, cyclones and outbreaks of the crown-of-thorns starfish.
Head researcher Dr Mike Emslie said the survey, which is now in its 35th year, showed "the reef is resilient, but this resilience has limits".
Dr Emslie's team conducted their assessment between September 2019 and June 2020 at reefs scattered from below Rockhampton to the very tip of Cape York. The work is done by means of a "manta tow", in which a marine scientist is pulled along a section of the reef underwater for two minutes, and afterwards calculates the percentage of sea floor covered by coral.
While the signs of growth were "encouraging", Dr Emslie stressed that many reefs were coming from a low base.
"Out of the 86 reefs we surveyed this year, two thirds were low or moderate, with less than 30 per cent coral cover," he said. "There were 23 reefs that had high coral cover, which is 30 to 50 per cent, and only five had very high coral cover, over 50 per cent."
Comparing this year's results to previous years of coral coverage gives a different perspective on the health of the reef.
In the northern reef, coral coverage in 2020 was just half of what it was at its recorded peak, and in the southern reef it was at 60 per cent of its best-ever result. The peaks in both areas were recorded in 1988.
Coral coverage in the central part of the reef reached its highest level ever recorded in 2016, Dr Emslie said, but this year the coverage had fallen back to 61 per cent of that peak.
"The reef is taking repeated hits from coral bleaching, cyclones and crown-of-thorns outbreaks. While we have seen the Great Barrier Reef's ability to begin recovery from these pressures, the frequency and intensity of disturbances means less time for full recovery to take place," Dr Emslie said.
The full effect of last summer's mass bleaching event - the third in five years - would not be known for several months, he added.
"The 35-year data set we've got shows that the long term trajectory of hard coral cover is actually ratcheting down," Dr Emslie said.
"There are lot of good reefs still out there, but there's also lots of impacted reefs. People can still go out and see the Great Barrier Reef in all its glory but we really need to be aware of what the long term data is telling is."
Gareth Phillips, CEO of the Association of Marine Park Tour Operators and himself a reef scientist, said people who worked on the reef were seeing its recovery day to day, but negative publicity about the condition of the reef had been affecting visitor numbers prior to the coronavirus outbreak.
"The overwhelming message is 'Go now to see what's left, and what you will probably see is this stark white reef that's just on it's last legs'. It's just completely false," he said.
"Marine operators do not deny that the reef has gone through some substantial pressures but as this report has shown, the reef has ability to recover," Mr Phillips said. "It's exactly in line with what the operators have been trying to say - that the reef is not dead and it is a beautiful place."
Tourism operations on the reef were currently running at about 10-15 per cent of their pre-COVID capacity, Mr Phillips said, but he rejected popular suggestions this lack of activity could help the reef "heal".
"Tourism actually has a positive impact on the reef," he said. "With recent bleaching events, the tourism locations had very little impact because (operators) showed good stewardship. They monitor the reef. They're a critical part of its management."
The lack of commercial enterprise on the reef during the lockdown was also leading to an increase in illegal fishing in the area because the tourism boats provide surveillance, Mr Phillips said.
Cairns Tourism Industry Assocition president Kevin Byrne said operators were "continuously fighting against this over-egging of the decline of the Great Barrier Reef".
The perception that the reef was dying was "fuelled by the contest of academics to try and paint the most gloomy picture," he said. "The reef needs to be managed, it doesn't at the moment need to be saved."
According to the Great Barrier Reef Marine Park Authority, there were 2.1 million "visitor days" to the reef in 2019.
Originally published as Revealed: how the Reef is really doing