Lucie Bell ABC News 24 Jun 14;
Researchers from the CSIRO have just wrapped up their most recent visit to reef ecosystems along 300 kilometres of Pilbara coastline in Western Australia.
They've been collecting data on the health of corals, as part of a five year joint study with the University of Western Australia.
The Pilbara Marine Conservation Partnership is now coming to the end of its second year.
Initially researchers mapped the biodiversity in the region and studied the currents, to track how organisms flowed from place to place.
Senior research scientist Dr Russ Babcock, says the team's latest visits, which stretched from sites in the northern Ningaloo right through to the top of the Dampier Archipelago, have confirmed coral bleaching is ongoing and widespread.
"In our initial surveys we found coral bleaching, which seemed to have occurred over the past few years, and we saw more of that in this most recent survey.
"It's quite extensive and seems to be ongoing, even over the past summer.
"A lot of the coral has died and some of the giant corals, that we noticed at the end of last year, are again bleaching and have little patches of algae starting to grow on them."
The bleaching is believed to be due to a series of marine heatwaves, which affected much of the state.
Some of the corals in question are up to 400 years old and while the prognosis isn't good, Dr Babcock says there is a chance that they'll be able to repair themselves.
"We'll have to hope that they can recover naturally, but it's going to take a long time for other corals to grow to that size and replace them in the context of the whole reef."
The health of larger corals is being assessed using a coring method, according to Dr Babcock.
"These giant varieties are very interesting, in that they record their growth over the centuries, laying down rings similar to the way trees do.
"A team has been going out to bore down with a drill core into some of these corals to collect samples, which they'll analyse back in the lab to look at things like growth rate.
"They can even use ratios of chemicals in the coral core to determine the water temperature at the time the coral was growing."
The team will return to the Pilbara for more site assessments in around 12 months time.
Dr Babcock says the researchers' work will be made available to other government agencies, including the WA Department of Fisheries and the WA Department of Parks and Wildlife.
Ningaloo spared coral damage
Exmouth's major tourism drawcard, the Ningaloo Reef, seems to have been the exception to the widespread coral bleaching trend.
The CSIRO worked with local authorities to assess the reef, following April flooding which was described as a once-in-a-century event.
Dr Russ Babcock says the area was protected mainly due to the narrow continental shelf.
"It [the shelf] makes it easier for deep cool water to come up and mix with shallow warmer waters, keeping the reef at a more even temperature.
"The main part of the Ningaloo seems to have been pretty well protected from the bleaching, so it's a real sanctuary for corals in the region.
"You only have to go across the other side of the cape, to Bundegi at the top of the Exmouth Gulf, and the bleaching is really severe from there right across to the eastern side of the Gulf."
Local authorities from the Department of Parks and Wildlife will continue to monitor the Ningaloo Reef in coming months.
