It's a race against time for marine biologists as they look to rescue stacks of coral reef living underneath Government Cut.

They're receiving permission to conduct dive rescue operations to chip away at the habitat ahead of the planned dredging of Port Miami.

Colin Foord with Coral Morphologic says it's an extensive operation.

"We have to use a hammer and chisel," adds Foord, "It's a pretty invasive technique, but at the same time it's the only way to remove these corals to get them out of harms way from this dynamite."

Foord says they have two weeks before underwater blasting begins.

They've saved about 350 corals and are transporting them to an artificial reef a mile south of Government Cut.

(Photo: Getty Images )