Rescuing the reef

Rescuing the reef

Coventry may be the other side of the world to the Great Barrier Reef – but research carried out by a university academic is helping to preserve the natural icon.

It’s a world-famous natural wonder that’s home to colourful corals, unique biodiversity and endangered species, from ancient sea turtles to dazzling tropical fish.

But over recent years, the devastating toll that global warming has had on Australia’s stunning Great Barrier Reef has been widely reported around the globe. It’s a story of severe coral bleaching caused by warmer than usual seawater that has affected over half the reef in each of the past two years.

However, there’s another threat to this iconic ecosystem – the nutrients and contaminants that flow into the ocean from in state of Queensland’s rivers. And this is an area where scientists are making progress in changing policy and attitudes to try to protect this incredible natural resource.

Politicians have noticed this too. In April this year, the Australian government pledged A$500 million  - that’s the equivalent of £275m to protect the World Heritage-listed Great Barrier Reef, some of which will go to improve water quality and reduce the runoff from pesticides.

For once, there’s good news for the embattled reef. And even though Coventry University and its Centre for Agroecology, Water and Resilience is 9,500 miles from the coast of northeastern Australia, its Professor Michael Warne is one of the team making a difference in the fight to save the Great Barrier Reef.

“We know that Australia can’t control global climate change,” he said. “Even if the country became carbon neutral, there are other countries with huge populations and massive industry that will continue to contribute to climate change.

“What we can do is to minimise the contaminants coming off the land. We can have a positive impact on the future of the reef by looking at this one area. This is where we can make a difference.

“The extra funding is very welcome,” he adds, speaking about the Government’s recent pledge. “There’s still more investment needed, and it will be a while before we can see exactly how this extra money will help.

Over the past few years, his work has involved monitoring pesticides, nutrients and what are known as ‘total suspended solids’, such as eroded soils. This has given scientists a greater understanding of the amount and concentration of contaminants being transported to the reef – and the damage they are doing.

“It was important to measure these contaminants. We had to understand this to realise how bad the situation was,” explains Professor Warne.

The Australian and Queensland governments had set targets to reduce the amount of contaminants being transported by rivers to the reef.

But Professor Warne and his team discovered several limitations in these targets – and their work has helped create new better targets and water quality guidelines for pesticides, to try to control the level of pesticides within the reef.

“The governments wanted to decrease the load (total amount) of these contaminants being transported to the reef. That’s ok if you are measuring particulate nutrients or suspended solids in the water.

“But for pesticides you really need to look at the concentration at which they are in the water. That’s the key to understanding what’s happening and doing something about it.”

Another limitation of the earlier work to protect the Great Barrier Reef, was the idea that these targets would be the same across the whole coastal area.

“The Great Barrier Reef stretches for 2,500km,” explained Professor Warne. “A one size fits all approach really doesn’t make sense. There are rivers flowing into the ocean that run through national parks, others that run through mainly agricultural areas. Some of this farmland is for cattle grazing, others for sugar cane and other forms of horticulture.

“It was not a sensible approach to treat all these rivers the same,” he said. “Money could be spent trying to carry out work where it was not needed or the potential benefits would be quite small. You may not be getting the greatest bang for your buck”

Professor Warne and colleague’s work has been key to getting it realised that each river needs its own targets – and that these are appropriate for the type of land the river runs through.

The Australian and Queensland governments have taken this on board and recently released a draft reef long term sustainability plan, covering up to 2050, for public consultation.

It features the individual river catchment targets and the pesticide targets are based on the new water quality guidelines, developed by Professor Warne and his colleagues. Crucially these targets could influence the level of investment by the governments to tackle the pollutant problem in each region.

“Before the money was divided equally between each region, irrespective of how much it was needed. Understanding the differences between these river catchments will help direct the money to the places that need it most, where the biggest problems lie.”

The key now is to show people living and working in these particular river catchments that what they do and how they act can make a difference to reducing the contaminants flowing out of the rivers and damaging the reef.

Professor Warne and his team have monitored environmental DNA, algae, pesticides, nutrients and total suspended sediment levels in the rivers to build up an evidence base of what impact they have – and also what happens if they are reduced.

One way they’ve done this is by working on a much smaller scale, down to individual river sub-catchments rather than Great Barrier Reef-wide.

“We have these new water quality guidelines which are used to estimate the risk that the pesticides pose to aquatic environments. But some critics tell us all this is based on tests in the lab. They don’t believe it applies to the real world.

“We’re doing all this work in the rivers so that we can provide multiple lines of evidence, so that we can show the effects that are happening in their rivers. We want to make our argument completely solid,” he says.

“There are farmers that want to change. But some believe that the contaminants are coming from other farms, not their own. They don’t believe it’s their chemicals that are causing the problem. Giving them more local proof helps overcome this attitude.”

There’s one anecdote that Professor Warne likes to tell which highlighted to farmers along one particular river how much impact one person’s actions could have.

“One of the farmers in a sub-catchment we were monitoring put some pesticides on his fields. He’d done the right thing and checked the weather forecast, but it unexpectedly rained. We were able to show exactly what effect those pesticides had on water quality, not just in his particular sub-catchment but in the whole catchment downstream of his farm.

“All the farmers in the area were shocked when they saw how the pesticides moved down the creek. It was very successful in showing how just one person’s actions can have a measureable impact.”

To see that his work is making a difference and that regulators are adopting findings from he and his colleagues work to help save the Great Barrier Reef is a huge positive for Professor Warne.

“The Great Barrier Reef is one of the most iconic natural phenomena in the world. It’s absolutely awesome. To be involved in working to protect this scenic and natural wonder ... let’s just say I don’t have any problems getting motivated for work.”

For more information on Coventry University’s research, visit www.coventry.ac.uk/research.