There are fears a mussel farm on the New South Wales south coast could be leading to an infestation of endemic, but invasive mussels in an area of high conservation.
Key points:
- Residents fear a Jervis Bay mussel farm could pose a threat to the marine environment
- The NSW DPI says the Jervis Bay mussel farm is farming endemic species
- Researchers say it’s too soon to determine if the farming of mussels are a threat to biodiversity
Jervis Bay boat owners have reported a previously unseen amount of mussel growth of up to 3 inches long on their hulls at Currambene Creek and Nelsons Beach, prompting debate around whether a new mussel farm within the marine park at Callala Bay is to blame.
Jervis Bay Marine Park is one of six NSW marine conservation sites, covering 215 square kilometres of ocean with over 230 types of algae and more than 210 species of reef fish, sharks, and rays.
Dane Willmot is the president of the south coast Nature Coast Marine Group and said any concerns relating to marine biosecurity should be taken seriously, especially in an area protected for conservation.
“Introduced species have a long history of causing imbalances in ecosystems and if that’s the case here we have some genuine concerns around it,” Mr Willmot said.
“There are countless examples of where we’ve intensified agriculture and instilled monocultural systems that have led to a myriad of issues.
“The marine space is the same.”
South Coast Mariculture (SCM) applied for the first ever commercial aquaculture licence in a protected marine park eight years ago, and had their first commercial mussel harvest in Jervis Bay in 2021.
SCM managing director Sam Gordon has rejected claims that the species he farms, Mytilus galloprovincialis, also known as the blue mussel, are introduced and not endemic to the bay.
“That’s the species endemic to the waters so we have to farm those species,” Mr Gordon said.
He does not believe his farm is the cause of any reported issues in mussel growth across the area, but agreed a deeper look into the issue would be beneficial.
Concerned residents are calling for further scientific study to understand whether the species farmed at Jervis Bay is becoming, or could become, a threat.
More work to be done
The NSW Department of Primary Industries (DPI) said the mussel Mytilus galloprovincialis has been farmed in Jervis Bay since the early 1970s and is considered endemic.
The department said there is no evidence that mussels are out of control in Jervis Bay, and that bivalve mussels and scallops follow a “boom-bust cycle”.
“This is the case in Jervis Bay where there is a long history of mussels being present in large numbers and then absent,” a DPI spokesperson said.
Cynthia Riginos, a professor at the University of Queensland’s School of Environment, has been using genetics to understand the history of wild blue mussels in Australia.
She said the history is incredibly confusing because introduced and native mussels look identical, and we do not know how and when Mytilus galloprovincialis arrived in Australia.
“There’s more work to do to understand whether farmed mussels act differently from native mussels in the environment” she said.
South Coast Mariculture is seeking approval from the NSW government to extend its mussel farm leases from 50 to 70 hectares within the marine park.
Its development application on the NSW Planning website is currently open to community submissions.
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