Questions have been raised over whether Brisbane would be an appropriate location for a nuclear submarine base, with scientists saying Moreton Bay can be heavily populated with swarms of catostylus mosaicus jellies.

If were Brisbane were off the table it would substantially increase Port Kembla's chances of being selected for the base, along with Newcastle.

Read more: Wollongong advocates 'shout from rooftops' for subs base

Jellyfish can pose problems for nuclear-powered vessels if large amounts of the blubbery critters are taken into cooling pipes. Most famously, in 2006 the pride of the US Navy, aircraft carrier USS Ronald Reagan, had to shut down while visiting Brisbane because of a mass jellyfish intake.

But asked whether Brisbane was now out of the running, the Defence Department told the Mercury its vessels would be adequately protected against the unwanted marine stowaways.

"Nuclear-powered submarines have systems in place to prevent the disruption of functionality from foreign matter being sucked into cooling systems," a spokesperson said.

"The Commonwealth will write formally to the respective state governments to seek their engagement with feasibility activity, including formal community engagement."

Jellyfish expert Jonathan Lawley of Queensland's Griffith University said the seasonal nature of the jellyfish blooms in Moreton Bay may allow successful mitigation strategies.

"This is nothing new - this occurs throughout the world," he said. "This has been a problem for a long time, especially for nuclear plants.

"I know a few researchers in Scotland who are working with nuclear plants to try and solve this problem. One of the things they do is try and monitor the occurrence of these jellies, using drones to monitor how massive these blooms are.

"They use this monitoring program [to] advise the plants whether they have to close or not.

"I suspect this could be something that you could do here in Brisbane.

"Because we have this consistent seasonal occurrence, there could be some mitigation strategies around ... these jellies. You could have a monitoring program to see if the jellyfish numbers are too high for the submarines to be travelling around."

There have been numerous and well-documented instances of jellyfish shutting down nuclear reactors, including in Sweden in 2013, and Japan, Scotland and Israel in 2011.

The Washington Post even dubbed them the "ultimate guerrilla protesters" against nuclear power plants.

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