Hidden beneath the tranquil waters of Cockburn Sound (Derbal Nara), located to the south of Perth, countless small marine organisms are diligently working to improve the ecosystem.
A new initiative is tapping into the extraordinary capabilities of mussels to aid in the restoration of the health of this aquatic environment.
Once a bustling hub for mussel farming, Cockburn Sound employed aquaculturalist Glenn Dibbin for nearly forty years, during which he observed significant fluctuations in the seafood and fish populations.
As the commercial mussel farming industry waned, many operators either shut down or relocated, leaving behind a significant amount of unused infrastructure.
Presently, some of this abandoned infrastructure is being repurposed by the Byssal project, which innovatively approaches mussel farming with a focus on ecological restoration rather than seafood production.
The Byssal initiative was established by Mr. Dibbin in collaboration with Recfishwest, which advocates for Western Australian recreational fishers, alongside partners Indo-Pacific Environmental and Commercial Maritime.
Mussels, like other bivalves, serve as natural water filters by drawing water through their gills and capturing microscopic food particles, which enhances water clarity.
“An adult mussel can filter as much as three liters of water every hour,” Mr. Dibbin noted. “When we consider 1,000 tonnes of mussels, the impact is immense—it’s staggering.”
Recfishwest highlights that nearly 80% of the seagrass meadows in Cockburn Sound have disappeared since the 1960s. These meadows are crucial not only for providing essential habitats but also for stabilizing sediments and sequestering significant amounts of atmospheric carbon.
Mr. Dibbin explained that murky waters significantly contribute to the decline of seagrass in the area. “The lack of sunlight penetration into deeper waters due to surface activity hampers seagrass recovery. By filtering the water, mussels play a vital role in improving clarity, thus fostering potential recovery of seagrass,” he stated.
In addition to their filtering capabilities, mussel farms create habitats and food sources for numerous marine species. The Byssal project features a straightforward setup involving robust 10-meter lengths of hairy rope suspended just beneath the water’s surface.
Young mussels, or spat, that are present in Cockburn Sound naturally adhere to the ropes, gradually forming dense clusters that resemble reef structures as they mature.
As these mussels grow, they lay the groundwork for a more intricate ecosystem. Seaweeds begin to inhabit their shells, creating habitats for juvenile crabs, prawns, and shrimp, which in turn attract larger predators like squid and fish. “Ultimately, this area becomes a significant nursery for marine life,” Mr. Dibbin remarked.
Cockburn Sound is also recognized for hosting the largest spawning aggregations of pink snapper in Western Australia. Mr. Dibbin noted that for many years, these fish had been a nuisance to mussel farming, consuming large quantities of mussels during spawning seasons—up to 25 tonnes nightly.
However, Mr. Dibbin now views these snapper as an asset to the project’s success, hoping to see them thrive in the area once again.
Andrew Rowland, CEO of Recfishwest, expressed that the successful implementation of the Byssal project could lead to improved fishing outcomes. “We need to support environmental health and productivity, which are essential for sustaining robust fish stocks. Everything begins with foundational productivity,” he stated.
He also highlighted the critical role of community involvement in ensuring the project’s success. “Initiatives like this thrive when the community rallies behind them, sharing the benefits and discussing them in local fishing clubs, with politicians, or even at social gatherings,” he emphasized.
The next phase involves scaling the operation, with aspirations to produce 1,000 tonnes of mussels each year to build on the project’s initial successes.
The Byssal project is also working on establishing mussel populations in additional locations through a technique called greenwalling. This method involves transferring mussels of appropriate size from the ropes to nearby rock walls.
In partnership with the Fremantle Ports Authority (FPA) and DevelopmentWA, Byssal recently completed its first mussel reseeding along limestone walls within the Australian Marine Complex located in Henderson.
Rebecca James, the FPA’s environment manager, described the project as “a nature-based solution for sustainable port operations.” She noted that utilizing existing infrastructure can support the health of surrounding ecosystems, which is mutually beneficial.
Ms. James added that initiatives like Byssal contribute to enhancing environmental resilience. “When disturbances such as heat waves occur, these marine ecosystems are more likely to withstand them without severe damage. It is in everyone’s best interest to pursue and engage with these solutions,” she concluded.
