Encouraging early result for seagrass restoration project

The first health check on a translocated population of endangered seagrass in Port Authority waters at Penryhn Estuary in Sydney’s Gamay Botany Bay, has received a green tick of approval from scientists from the University of New South Wales (UNSW). 

The researchers took to the water to inspect the plantation at close range, measuring survival and growth rates to assess how the transplanted seagrass fragments were adapting to their new environment.  

Port Authority of NSW Group Executive, People, Environment and Legal Amy Beaumont said the project with UNSW is bringing together scientific expertise and practical on-water capability to explore new approaches to restoring marine habitats.  

“Posidonia seagrass meadows are increasingly rare in Sydney’s and NSW waters but incredibly important as they serve as nursery habitats for juvenile fish and a wide variety of marine life including the likes of the endangered White’s seahorses,” Beaumont said.  

"It’s really encouraging to see the planted seagrass fragments, collected by the project team from local beaches, establishing in their new environment. Considering they were moved from the seagrass holding tank nursery just 3 months ago, their progress is certainly promising." 

UNSW postdoctoral fellow and research spokesperson Dr Giulia Ferretto said the importance of Posidonia to the marine environment can’t be overstated and the research team is buoyed by the strong collaboration driving the project forward.  

“Seagrasses, and Posidonia in particular, are incredibly important for supporting biodiversity, protecting the environment from coastal erosion, and capturing carbon. 

“Unfortunately, once disturbed or damaged, Posidonia meadows may never recover naturally, making the work being undertaken by this collaborative research project incredibly important.”    

Despite Sydney’s recent above-average rainfall, the planted Posidonia shoots have performed better than expected, surviving substantial freshwater inflows.

“Our aim is to develop and demonstrate methodologies for scalable restoration projects, including in heavily altered places like Gamay Botany Bay, while collaborating with Indigenous groups to document and restore cultural values.  

The team is also working on developing a genomic toolbox to optimise and future-proof restoration in the face of climate change.  

“Working with Port Authority has been key to making this happen. Their support helps us gather the data we need and turn research into action,” Dr Ferretto added. 

The collaborative research project involving UNSW, the La Perouse Local Aboriginal Land Council (Gamay Rangers) and Port Authority of NSW involved establishing an underwater restoration trial of the endangered seagrass Posidonia australis to explore the potential for advancing seagrass restoration techniques, which plays a crucial role in supporting biodiversity and improving water quality.  

The research project will continue for another few years with the next health check due to occur in two months. 

Posidonia also has deep cultural significance to local Aboriginal groups the Kamaygal Traditional Owners of Botany Bay, who have maintained a spiritual and cultural connection to the seagrass meadows for thousands of years. 

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