The restoration robot saving Cockburn Sound

A drone shipped in from the United States is sowing thousands of tiny seeds on the ocean floor between Fremantle and Rockingham in a bid to stop the underwater wipeout of a “mysterious” marine plant being damaged by industrialisation and climate change.

Seagrass – the only flowering plant that can live underwater – is used as an indicator of a healthy estuary, and can remove 35 times more carbon from the atmosphere than a rainforest.

The underwater restoration robot in action.

“We’re really lucky in Western Australia that we have the biggest and most diverse seagrass meadows in the world, and we should be really proud of that,” Seeds for Snapper program manager Steve Purcell said.

However, Professor Gary Kendrick from the School of Biological Sciences and UWA’s Oceans Institute said it was being destroyed at a rapid rate.

“The biggest challenge we face globally is that we’re losing seagrass at about one soccer field, or half a hectare, every 30 minutes,” Kendrick said.

“We need to be able to restore hundreds to thousands of hectares a year.”

Current restoration efforts have been carried out at the hands of volunteers, who throw seeds overboard like chicken feed, or by divers who manually plant them.

The labour-intensive methods make for slow progress, and can currently only sow one to two hectares – and there is a degree of luck.

A newly arrived underwater robot, or seed injection machine drone, would help improve that rate by allowing seeds to survive early life in, rather than on top of, the sediment.

The $230,000 trial has been funded by the state government’s $13.5m WAMSI Westport Marine Science Program, set up to support the environmental management of Cockburn Sound.

“This robot will be replanting seagrass in the Cockburn Sound, and we’re going to test how effective it is. What this does is actually embeds the seeds into the ocean floor,” Treasurer Rita Saffioti told 9News Perth.

“Currently it’s being done manually and some of the results haven’t been as great as we want. Seagrass is a key part of a healthy marine environment, and it supports a lot of other different creatures living in our oceans.”

Cockburn Sound is the site of the state’s biggest-ever infrastructure project; Labor’s $7.2 billion Westport dream.

“Westport has had a long-term goal of actually leaving Cockburn Sound better off than when we found it,” Chief executive Patrick Seares said.

“We can’t avoid having an impact when we develop the project, but we’re going to be there a long time afterwards.

“We need to build critical economic infrastructure for the future prosperity of the state, but we also need to do it really carefully.”

Researchers return to the site in March for a progress update. If successful, the robot would return next November to ramp up restoration efforts ahead of the planned Westport opening late next decade.

9News Perth