Young Harrison Macdonald smiles with delight as he helps his family carry elongated hessian sacks onto a boat in Shark Bay, Western Australia.
"I've got big muscles," he remarks.
He is among Shark Bay community members working with Indigenous rangers in a pioneering trial to deploy 250 so-called seagrass snaggers along the ocean floor.
The snaggers are elongated hessian sacks filled with sand.
It is hoped the seagrass will cling to the snaggers on the sea floor of the UNESCO World Heritage Area to create a new home and feeding zone for a wide array of marine species, such as dugongs, fish and turtles.
Rachel Austin is a marine scientist from the University of Western Australia (UWA) and has helped drive the project in the bay.
"We've gone with the snagger shape to try and increase the surface area that they could possibly attach to," she said.
"Being quite a low, round shape, we're hoping it'll have minimal impact on the hydrodynamics along the bottom."
Tour boat operator Greg Ridgley said he was inspired to donate his boat and time to the project after seeing first-hand that a lack of seagrass was negatively affecting Shark Bay's marine habitat.
"We thought we'd give it a big push and organise everyone into action and provide our service and our vessel, and away we went," he said.
A diverse marine habitat
Spanning 2.2 million hectares, the Shark Bay World Heritage Area is home to 12 of the world's 72 species of seagrass.
This included the Posidonia australis, which was recently discovered as the world's largest plant.
Measuring more than 180 square kilometres as a seagrass meadow, it has grown over thousands of years by repeatedly cloning itself.
But the area is also the site of the single largest loss of dense seagrass, spanning 1,300 kilometres, attributed to climate change.
In the summer of 2010, almost 40 per cent of Shark Bay's seagrass meadows were damaged following a marine heat wave, which saw ocean temperatures climb 2 to 5 degrees Celsius warmer than average.
A vital tool against climate change
Seagrass captures carbon up to 35 times faster than tropical rainforests and, despite covering only 0.2 per cent of the sea floor globally, absorbs 10 per cent of the ocean's carbon each year.
Professor Gary Kendrick from UWA is considered one of the world's leading seagrass researchers.
"We lose approximately one soccer field of seagrasses every half an hour globally and it's not that different here," Professor Kendrick said.
"If we don't go out and help to maintain and restore our marine environments, they will disappear in the next 30 years."
Indigenous knowledge meets science
The project is considered a world-first trial by its proponents, but Malgana Land and Sea Management ranger Pat Oakley said it was also the first project since her people's Native Title determination over about 28,000 square kilometres of land and waters in the Shark Bay area during 2018.
She was keen to see more collaboration between Indigenous knowledge and science.
"When traditional ecological knowledge is combined with scientific data and research, I think we've got a far better chance of mitigating climate change," Mrs Oakley said.
If successful, the Malgana rangers hope to expand the seagrass snagger program across a larger area at the site.
