President Donald Trump is trying to fast track a brand new, highly controversial industry – mining critical minerals in the deep sea.

President Donald Trump on Thursday signed an executive order aimed at boosting the deep-sea mining industry, marking his latest attempt to boost U.S. access to nickel, copper and other critical minerals used widely across the economy.

The practice of deep-sea mining involves using heavy machinery to remove minerals and metals from the seabed, where they build up into potato-sized nodules.