The Northern Territory has banned seabed mining in a bid to protect its fishing, aquaculture, pearling and tourism industries.
Subsea mining poses a significant risk to fragile coastal and marine environments, Environment Minister Eva Lawler says.
"Our natural environment is one of our best assets and it's a large part of what makes living in the Territory so special," she said in a statement on Wednesday.
Ms Lawler said the lack of information about the potential impacts of subsea mining contributed to the decision.
As did the limited resources available about how to manage the impacts or to rehabilitate the seabed once mining is complete.
The Declaration of Prohibited Action: Subsea Mining, which came into force on Wednesday, was the final step to formalise the ban.
It follows public consultation on a draft declaration, which was released in February and showed strong support for the ban.
Subsea mining has never been undertaken in the NT.
