Since World War II, Sydneysiders have not had to worry about underwater intruders in their harbor.
But now marine conservationists are concerned about subtropical coral flocking to Sydney’s cooler waters with the potential to usurp local species.
University of Technology Sydney researcher Jen Matthews says global warming could spell trouble for the harbor city’s coral.
The waters around Sydney become home to the new subtropical species as they flee south of the Great Barrier Reef in search of cooler waters, thanks to the rise in sea temperatures.
They are likely to thrive in Sydney by being more resistant to rising water temperatures compared to the natives.
“While we found that these (upcoming) corals have the machinery to withstand large temperature swings, those temperatures could kill the existing corals in Sydney,” Dr Matthews said.
“This is incredibly important as we look to the future of Sydney’s precious ecosystems.
“Coastal Sydney falls in the temperate climate zone, so the establishment of subtropical coral populations raises some interesting questions.”
But there is debate among the Future Reefs program team as to whether the new corals are harmless fugitives or invading pests.
The new corals could provide benefits as they increase the biodiversity of Sydney’s marine environment and provide more refuges for fish, crabs and other corals.
Australia’s coral systems are negatively affected by climate change and the Great Barrier Reef on the east coast faces frequent bleaching events caused by high temperatures.
Likewise, conservationists on the west coast found evidence of a similar bleaching event at Ningaloo Marine Park in April.
