October 28, 2019

Reef economics: Why losing coral to climate change could cost WA millions

News Source: The Age

Author(s): Marta Pascual Juanola

The death of Western Australia's coral reefs could cost our state's economy millions of dollars and tens of thousands of jobs, experts warn.

UNESCO predictions show 90 per cent of the state's coral reefs could be functionally dead in the next 30 years, but the scientists championing state-of-the-art research to restore and maintain them are struggling to make a dent in the gloomy predictions.

Despite being among the world's best preserved, WA reefs are not immune to coral bleaching, a phenomenon which arises when corals are exposed to higher temperatures and die.

Extending from Geraldton to the Kimberley and out to the remote Cocos Islands, reefs are showing their lowest coral cover on record, mostly due to severe heat stress and cyclone damage.

With WA identified by CSIRO as one of the world's hotspots for temperature increase, mass bleaching events are likely to happen more often, limiting chances for our reefs to recover.

Scientists are now warning the death of coral reefs wouldn't just be a biodiversity catastrophe; it could also cost our state's economy millions.

A battle of titans to save the canary in the coal mine

Despite playing a crucial role in protecting our coastlines during storms, ensuring fish stocks, and attracting tourism, there is no data on the overall value of WA's reefs.

Unlike in the eastern states – where Deloitte estimated the value of the Great Barrier Reef at $56 billion, supporting 64,000 jobs and contributing $6.4 billion to the national economy – there is no comprehensive data on the contribution of West Australian reefs.

However, Australian Institute of Marine Science reef ecologist Dr James Gilmour estimates the total could be in the millions, potentially even billions.

"When you start to add up in all the other secondary consequences, whether it'd be sea-level rise for example, or whether it's protection of the coast by coral reefs of the loss of resources and the migration of people ... when you put those in collectively the numbers and the value is astronomical, almost inconceivable," he said.

Coral reefs are vital to marine life, support the fishing and tourism industries and protecting the coastline during storms, which prevents erosion and damage to coastal infrastructure.

Dubbed the 'canary in the coal mine', they are good indicators of the overall state of the environment and potential impacts of climate change.

They are also nursery grounds for marine life and support critical food stocks for fisheries around the world, contributing an estimated $6.81 billion a year to Australia's 'blue economy'.

WA's recreational fishing alone contributes $2.8 billion a year to the state economy, and while not all recreational fishing occurs around the state's coral reefs, the health of the reefs impacts fish stocks elsewhere.

In the state's Coral Coast – from Cervantes up to Ningaloo, popular among snorkelling and diving enthusiasts – the tourism industry alone is worth $431 million, the equivalent to nearly 8 per cent of our state's economy, and employs nearly 6000 people, almost as many as the WA police force.

Dr Gilmour said the dire predictions for the reefs' future over the next three decades left scientists in a race against time.

"Are there any reefs that will escape bleaching? The general consensus is well, no, there isn't," he said.

"We are always facing this battle between appearing negative while at the same time trying to be pragmatic about what we are doing.

"There's a lot of people really struggling grappling with this and then trying to walk that line between saying 'well, we have to address the fundamental cause, whether it's pollution or overfishing or carbon in the atmosphere', while at the same time trying to save what we can."

Leading the charge at the University of WA's Ocean Institute, researcher Dr Verena Schoepf recently proved Kimberley's heat-resistant corals could be transplanted to colder areas, offering a glimmer of hope for reef restoration.

Through a series of lab experiments, Dr Schoepf observed tough Kimberley corals struggled to survive higher temperatures, but could adapt to colder water conditions in southern reefs such as Ningaloo.

"You would essentially take pieces of large colonies in the Kimberley ... and you would put these corals in containers with water, you would monitor the temperature really well, and then you would drive them or fly them to Ningaloo Reef and fix the coral to the ground at the new site," she said.

But Ms Schoepf said transplanting corals efficiently would require a significant labour and funding investment and several years of fieldwork, something Dr Gilmour said was a growing concern.

"The concern is that if you're going to do it, you have to do it at a scale where it's feasible," he said.

"Say we move tens of thousands of corals over five years, that would sound like a pretty incredible feat but at the rate of temperature increase and at the risk of a cyclone coming through and taking things out, it's actually a very small contribution.

"We recognise that if you really want to do this stuff it may not work but it has to be done in a massive scale and it has to be done now.

"What we are really tying to do with government assistance and also philanthropy assistance, and to some extent oil and gas assistance, is investing considerable amounts of money to scale those processes up, these restoration ideas, to test them with the knowledge that there's very little probability that they will work but we still have to give it a go.

"That's the battle we are facing; a race against time."

What is coral and how does it bleach?

Corals are invertebrates which live in colonies and produce protective skeletons made of calcium carbonate.

They organise in colonies and are home to extremely diverse ecosystems, which feed off and seek shelter in the colourful formations.

However, corals are extremely sensitive to temperature changes, acidification, overfishing and pollution, which can cause them to bleach.

Bleaching happens when temperatures are unusually high for several weeks. Heat stress forces the coral to expel the algae responsible for their impressive colours from their tissue, leaving the white calcium skeletons visible.

Under normal circumstances, most corals recover over a period of 10 to 15 years, but if temperatures continue to rise most reefs eventually die, crippling the local ecosystem.