Plan to pump cold water on to Barrier Reef to stop bleaching labelled 'band-aid'

A proposal to use $9m to pump cold water on to the Great Barrier Reef’s tourist hotspots to stave off coral bleaching has been described as a “band-aid” solution, which does little to address the fundamental threats to the world’s largest living structure.

The plan, proposed by the tourism industry and the Reef and Rainforest Research Centre, seeks to protect six reefs with high economic or environmental value near Cairns and Port Douglas.

It would involve using low-energy technology to push adjacent cold water from a depth of about 40 metres to the surface. The aim is to use the cooler waters to alleviate bleaching, which is caused by global warming-induced rises in sea surface temperatures.

The plan has been submitted to the federal government, and proponents say it is a measure that could prevent localised bleaching to valuable parts of the reef. “With the amount of bleaching that we currently have, the reef is going to change, that will affect the number of species that actually survive,” Reef and Rainforest Research Centre managing director, Sheriden Morris, told Guardian Australia.

“While this is highly localised, it may have the benefit of maintaining some complex communities in the face of some of the pressures that the reef is facing,” he said.

But others have warned the proposal would waste money and time to, at best, temporarily save small pockets of the reef, while vast swaths are lost to bleaching elsewhere.

A former Great Barrier Reef Marine Park Authority director Jon Day said the government should be trying everything it could, but the idea that such an approach would save the reef from bleaching was “ridiculous”.

Day, a protected area planner and manager, said solutions to the bleaching event must look at the entirety of the Great Barrier Reef system. “We should be taking broad-area results,” Day said.

“But instead we do these sort-of band-aid, small localised scale things, which in terms of trying to maintain tourism sites might actually work, but we’re going to actually lose the whole reef and spend a lot of money on these things.

“We probably need to be trying everything, but this idea that this is going to be the solution to the bleaching is just ridiculous, it might be something that helps in localised areas, but we’ve got to be looking at the whole of the GBR system.”

The University of Technology Sydney’s lead reef researcher, marine biologist David Suggett, said the proposal would probably be ineffective without strong action on climate change.

Suggett also raised concerns about potentially damaging effects to the reef. He said the colder water would be more acidic, and would contain more inorganic nitrogen and phosphate. Pumping it to the surface would probably cause just as much damage to the reef as warmer waters do.

“Cold water has lots of evils, as well as benefits,” Suggett said. “So we might be cooling them, but at the same time we’re probably manipulating them in ways that could be as detrimental.

“We have to remember that climate change is just a lot more than warming waters, we have ocean acidification, we have hypoxia, so a loss of oxygen. All of these factors, mean just cooling the reef itself is not the solution.”

Proponents say they are not planning to pump up waters from any great depths, meaning the risk of nitrogen or acidity are low.

James Cook University’s Jon Brodie, a professorial fellow at the ARC Centre of Excellence for Coral Reef Studies, was frank in his assessment of the proposal. He conceded the idea sounded silly but said it could work and was worth trying.

“It’s an absolutely silly idea when you read it, but we’re in silly times, so it looks like it could be a goer,” Brodie said.

He has been trying to save the reef for much of his career. He said the federal government had sat on its hands, and its current attempts to improve water quality were not working. “We’ve given up. It’s been my life managing water quality, we’ve failed,” he said.

Mass bleaching events have occurred in 1998, 2010, 2015-16, and this year.

• This article was amended on 10 April 2017 to correct a misheard quote from David Suggett. He said hypoxia was a a loss of oxygen, not a lot of oxygen.