The US Navy announced that "in coordination with the Australian Defence Force, U.S. Seventh Fleet will take the lead in the safe retrieval and disposal of four bombs which were jettisoned off the coast of Queensland, Australia by two AV-8B Harrier aircraft in an emergency situation 16 July."
"The U.S. military is aware of its professional responsibility to mitigate the environmental impact of its exercises/operations. As partners with our Australian counterparts, and particularly in the context of Exercise Talisman Saber, the U.S. military conscientiously conforms to the proper rules and protocols set forth by Australian military and civilian authorities."
Here is Australian news coverage from news.au.com and video from Sky News: