Tasmanian researchers are exploring the potential of using waste from invasive long-spined sea urchin processing as a soil amendment for agriculture.
Led by Dr Harriet Walker, the project is searching for a practical and profitable use for urchin waste, which is currently sent to landfill at a significant cost to the industry.
“Harvesting and processing urchins for high end restaurants and export markets is the most effective control measure for invasive sea urchins,” Dr Walker said.
“However, this results in a large amount of waste with 90% of the urchin diverted to landfill at a substantial cost to industry.”
“We wondered if the waste from urchin processing was actually a waste product, or if it was a product that we just hadn’t found a use for yet.”
IMAS researcher Dr. John Keane said long-spined sea urchins have rapidly expanded their range into Tasmania in recent years.
“With rapid population growth we now have over 20 million urchins on our east coast reefs, resulting in 15% of the reef area becoming unproductive urchin barrens,” he said.
“If we can turn the waste generated from urchin processing into something valuable like soil ameliorant, we can help address this environmental issue and increase the financial viability of the industry.”
Dr Walker said there is potential to transform the waste into a product that could be made commercially available to agricultural growers and home gardeners.
Early trials have been promising, showing that ground, dried urchin waste works well as a liming product while also supplying key micronutrients like boron and iron.
“It is very high in calcium which is an important nutrient for deacidifying soils,” she said.
To see how well it performs in real-world conditions, researchers have set up long-term field trials at a commercial vineyard, an organic apple orchard and a potato farm.
Harvests for apples and grapes are scheduled for April and May, with the potato trial set to be harvested in winter.
Walker and Keane are now working commercialise the product and are looking at ways to use waste from the entire seafood sector.
