A flotilla of tourist boats, tinnies and superyachts has completed a massive research operation on the Great Barrier Reef in a bid to capture a big-picture snapshot of its health.
Conservation group Citizens of the Great Barrier Reef recruited dozens of vessels to help survey more than 300 reefs from the tip of Queensland down to Lady Elliot Island over a 12-week period.
Snorkellers and recreational divers snapped more than 40,000 photographs for analysis.
Chief executive Andy Ridley said while it was the second Great Reef Census survey of its kind — the first was in 2020 — this year's census was significantly larger, with hundreds more reefs surveyed.
"It was a huge response from the community up and down the reef, with thousands of volunteer hours committed from scientists, dive crews, tourists and fishers who went out to the far edges of the reef to capture this critically important data," Mr Ridley said
He said the number of images submitted for analysis by citizen scientists this time round was well up from the 14,000 images collected in 2020.
Health of the reef
Katie Chartrand from James Cook University was involved in the survey and said early analysis showed some parts of the Great Barrier Reef had fared much better than others.
"The reefs that we have been looking at in this survey are varied in terms of their health," Dr Chartrand said.
"They have been smashed by cyclones, recent major bleaching events in 2016 and 2017, and others are starting to show really good signs of recovery — so we can see new recruits from this mass spawning event that are helping some of these areas.
"But it's really not enough time to say how that recovery is going."
The Great Barrier Reef comprises more than 4,000 individual reefs over a distance of 2,300 kilometres.
Following the mass bleaching events of 2016 and 2017, Mr Ridley, along with UQ marine ecology professor Peter Mumby and Great Barrier Reef Marine Park Authority director Roger Beeden, discussed how the gap in surveying the reef could be filled.
The idea for the Great Reef Census was born.
Professor Mumby said the survey had shown that coral bleaching continued to be a problem.
"There's nothing we can do to stop bleaching but hopefully we can help reefs recover between these bleaching events," Professor Mumby said.
"One of the pathways to helping recovery is to get large-scale reconnaissance like the survey, that tells us where the reefs are damaged right now, and where the reefs are that are in good shape.
Later this year, more citizen scientists will be required from around the world — this time to help analyse the 40,000 images collected from the 315 reefs surveyed on the Citizens of the Great Barrier Reef website.
