Seagrass restoration under way at Useless Loop

03/04/2023 | 3 mins

Researchers from The University of Western Australia in collaboration with partner Shark Bay Resources have completed a 10,000 sq m seagrass restoration site at Useless Loop in the southern region of WA’s Shark Bay.

"It was a mammoth effort transplanting thousands of cuttings, so it was quite a relief to see over 85 per cent had survived in their new location so far"

Dr Elizabeth Sinclair

Led by Oceans Institute members Professor Gary Kendrick, Dr John Statton, Dr Elizabeth Sinclair, and Ms Rachel Austin from UWA’s School of Biological Sciences, the five-month project also involved Murdoch University researchers, the Tidal Moon Sea Cucumbers company, Malgana Aboriginal Corporation (MAC) Rangers, and the Useless Loop local community and volunteers.

The team harvested ribbon weed and wire weed cuttings, prepared and transplanted about 5000 cuttings and deployed more than 1500 seagrass ‘snaggers and wieners’ (sand-filled hessian socks).

Seagrass card 

MAC Ranger Richard Cross assisted with knowledge-sharing of Sea Country. New trainee rangers learned about different types of seagrass (known as Wirriya Jalyanu to the Malgana people), how to prepare ribbon weed and wire weed transplants for replanting and snorkelled among the seagrasses.

Those involved had a busy time filling seagrass snaggers and wieners, in addition to developing ways to turn coffee bags into a substrate for wire weed seedlings to attach.

“Two mornings of throwing snaggers and wieners off the boat made a welcome change from beach activities for the MAC Rangers,” Dr Elizabeth Sinclair said.

“It also permitted the rangers to view the restoration site, which is in approximately 4.5m of water, with visibility improving enough to see all the way to the sea floor.”

volunteers prepping seagrass transplants

Image: Dr Marion Cambridge showing MAC Rangers how to prepare seagrass transplants. Photo Elizabeth Sinclair

A visual record of the underwater restoration site, which used different planting and restoration methods, was created by the MAC Rangers. The creative and colourful record was used to share seagrass restoration knowledge with Useless Loop Primary School students.

With monitoring an important aspect of restoration, previous efforts were revisited to see how they had faired from last September when the project began.

The team checked to determine if the transplanted seagrasses survived and if seagrass snaggers and wieners had stabilised the sandy bottom.

"It was a mammoth effort transplanting thousands of cuttings, so it was quite a relief to see over 85 per cent had survived in their new location so far" reported Dr Elizabeth Sinclair. The transplants are look healthy, with some displaying new shoots.

The site will continue to be monitored annually to ensure the transplants are establishing and the new meadow is expanding.

seagrass meadow with fish

Image: A butterfish checking out the new highdensity transplants. Photo Giulia Ferretto

The new meadows are now increasing biodiversity within the restoration site. High-density seagrass plantings are especially popular, as they form an almost instant meadow. Plantings of different densities are being used as part of a trial to explore the interaction between seagrass and tidal flow.

Sea critters had moved into the site: mushroom corals, hermit crabs, cone snails, butterfish and many other fish species visited the newly establishing seagrass habitat. A squid was observed testing out its camouflage strategy of purple and white stripes next to newly planted wire weed with deep purple leaves.

Two sea snakes were also spotted, along with small warm-water (tropical) seagrasses (Halodule, Halophila and Cymodocea), seaweeds and mushroom corals already growing in amongst the snaggers, wieners and transplants. Biodiversity is returning to the open sandy environment.

Picture at top of page, credit: Rachel Austin

Share this

Related news


Browse by Topic

Cookies help us improve your website experience.
By using our website, you agree to our use of cookies.