A team of scientists, fishers and community leaders will pilot an innovative new method of harvesting sea urchins to help regenerate parts of the 8,000 km-long Great Southern Reef.
Instead of coral, Australia’s other globally significant reef features iconic kelp forests – incredibly important ecosystems, up to 16 times more productive than wheat fields.
They support hundreds of species including some of the most valuable fisheries in the world – rock lobster and abalone – and contribute more than A$10 billion each year to the nation’s economy.
But along the east coast of Australia long spined sea urchins have stripped kelp back to bare rock in many regions, creating “urchin barrens” which contain millions of urchins and minimal other sea life.
These barrens cover an estimated 50% of nearshore rocky reefs along the central and southern coastlines of New South Wales and are also a problem in Victoria and Tasmania.
Now a bold new project supported by the World Wide Fund for Nature-Australia will trial harvesting urchins in a way that regenerates kelp forests, enhances the urchin fishery, and boosts regional employment.
Wally Stewart, a Yuin Walbunja man, said important parts of his mob’s Sea Country – from Wollongong all the way down to Eden – have been destroyed.
“They were once healthy places with plenty of kelp, lobsters, fish and abalone. They were passed on for thousands of years. Now they’re sea urchin barrens. We’ve lost part of our culture,” Mr Stewart said.
Mr Stewart is on the steering committee for the urchin project as a representative of the NSW Aboriginal Fishing Rights Group.
The project is being led by Professor Adriana Verges and Emeritus Professor Peter Steinberg (both from UNSW Sydney), and also involves commercial fishers, NSW government representatives, and conservationists.
Inedible urchins from a barren will be turned into fertiliser; urchins beside restored kelp forest will fatten up & be harvestable © WWF-Australia / Grumpy Turtle Films
At a test site in southern NSW, not yet chosen, urchins from a barren will be removed and crushed up to be sold as agricultural fertiliser.
While healthy urchins are a lucrative seafood, the urchins in barrens are malnourished and inedible.
With the urchins removed, scientists believe kelp will naturally regenerate then urchins on the fringes will feed on some of the seaweed that regrows, breaks off and drifts within reach.
“The urchins that are nearby will start fattening up and creating a roe product that can then be sold. When that happens, you create a sustainable fishery that can be fished for decades to come,” said Professor Verges.
“Our unique program for harvesting urchins aims to create a mosaic of restored kelp forests alongside areas with a fair number of healthy urchins that can be harvested. If we get the balance right this approach could be rolled out across hundreds, or even thousands of kilometers of coast,” said Emeritus Professor Steinberg.
A UNSW Sydney project showed how quickly kelp can recover. White areas (left) indicate urchin barrens in 2018 at Kurnell. After 5000 urchins were removed, golden kelp and other seaweed started returning within months. The photograph on the right shows extensive recovery by 2021. © nearmap
WWF-Australia’s CEO Dermot O’Gorman said WWF’s Innovate to Regenerate program is mentoring a range of experimental projects, including this one, which aim to Regenerate Australia.
“We’re providing seed funding and access to experts who advise on business and marketing strategy. Many solutions might not have the opportunity to get off the ground if it wasn't for the support of a program like WWF’s Innovate to Regenerate.
“Everyone needs to work together to co-create a regenerative economy. That involves enabling experimentation and helping to scale up new and innovative community led regenerative solutions,” Mr O’Gorman said.
Commercial abalone diver Stephen Bunney, who is part of the urchin project, believes their approach is pioneering because so many groups have a voice.
“In the past projects were either done by industry or they were done by science. But this team includes scientists, the fishing industry, government, Indigenous leaders and conservationists all working together to understand the problem and what we might do about it,” Mr Bunney said.
Long-spined sea urchins are a native species in mainland Australia and scientists suspect historic overfishing of predators such as rock lobsters and blue gropers may have contributed to an increase in their numbers.
A blue groper eats a sea urchin © FoodForThought / A large lobster eats a sea urchin after flipping it over © Scott Ling/IMAS
Mr O’Gorman said the 14 projects supported in the first round of the Innovate to Regenerate program deal with issues such as energy generation, food production, tourism and waste removal.
“They tackle these concerns in ways that conserve land and marine environments, protect biodiversity, and drive wealth back into communities.
“Taken as a whole these projects symbolise what Regenerating Australia could look like in a future where we support projects and businesses with genuine environmental, social and economic benefits,” Mr O’Gorman said.