On the surface, Port Stephens appears to have largely recovered from the impacts of the extreme weather in March but a dive down into the depths of the blue water wonderland tells a far more devastating story.
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Flooding decimated fields of shallow kelp, in particular between Fly Point and Dutchie's Beach, and has further pushed the endangered soft coral Dendronephthya australis towards the brink of no return.
"In some areas, it is as if an underwater bushfire has ravaged all life," Port Stephens marine scientist Meryl Larkin said.
"A huge area of canopy-providing environments, which are home to many fishes, molluscs, and crustaceans, were severely affected during the flood event.
"It's not all bleak news, however, as the deeper habitats appear to be unscathed."
Ms Larkin, from Medowie, is the PhD researcher on a Southern Cross University and NSW Department of Primary Industries study exploring the decline in the purple, cauliflower-like coral.
Port Stephens is the only known location where the species is found in large, habitat-forming clusters.
Specimens of D. australis have been recorded from Port Stephens since the 1970s.
Colonies of the cauliflower coral provide shelter and support small crustacean communities, which are a key dietary component of many marine organisms.
Previous studies have shown that juveniles of the Australasian snapper Chrysophrys auratus and the endangered White's seahorse (Hippocampus whitei) strongly prefer the D. australis habitat.
Ms Larkin's study has so far found that the Port's clusters of D. australis, mapped by the research team in 2019, had declined by almost 70 per cent in eight years.
"Although environmental conditions are still conducive to the presence of the corals within Port Stephens, this species has continued to decline. Modelling has shown there is a correlation between the loss of coral colonies over the past decade and sand movements within the estuary," Ms Larkin said.
"While the models show that sand movement is likely to be a major contributing factor, many other factors can damage and kill colonies. Boat anchoring, moorings and fishing line have been observed impacting aggregations.
"There may also be other as-yet-undetermined factors at play, such as disease, pollution or other water quality issues contributing to their decline."
When researchers were able to enter the water again in April, they were shocked to find high that levels of run-off in the Karuah River catchment had caused even further devastation to the remaining coral population.
"To watch it decline so rapidly has been very upsetting. Hopefully this study helps highlight the urgent need to implement measures to protect this species," Ms Larkin said.
"We have started to investigate aquarium propagation followed by transplantation back to the natural environment to aid recovery. These early experiments have shown some promising results."
The population of D. australis in the Port Stephens-Great Lakes Marine Park was first mapped in 2011.
Due to the decline in its abundance and distribution, and its apparent geographic rarity, the NSW Fisheries Scientific Committee listed it as an endangered species in February 2021.
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