Deep-sea mining would extract cobalt, copper, nickel, and manganese - key battery materials - from small rocks on the sea floor at depths of 4-6 km
* Nauru says draft exploitation rules "nearly complete"
* Lawyer says debate over royalties and rules ongoing
* Nauru, The Metals Co say seabed mining more sustainable
* Environmentalists seek ban, saying too little is known (Adds ISA statement)
By Helen Reid
June 29 (Reuters) - The tiny Pacific island nation of Nauru has notified a U.N. body of plans to start deep-sea mining, giving the International Seabed Authority (ISA) two years to complete long-running talks on rules governing the new and controversial industry.
Nauru President Lionel Aingimea notified ISA about the mining plans to be carried out by a subsidiary of The Metals Co in a letter dated June 25 and seen by Reuters on Tuesday.
Reuters reported on Friday that Nauru planned to trigger the so-called "two-year rule", which allows for a mining plan to be approved after two years under whatever rules are in place at that time.
Nauru is a sponsoring state for Nauru Ocean Resources Inc (NORI), a wholly-owned subsidiary of The Metals Co, formerly known as DeepGreen, which plans to list on the U.S. Nasdaq in the third quarter in a merger with blank-check company Sustainable Opportunities Acquisition Corp (SOAC).
Aingimea's letter asked the ISA "to complete the adoption of rules, regulations, and procedures required to facilitate the approval of plans of work for exploitation in the area within two years" from June 30.
The Metals Co, which aims to start mining in 2024, did not immediately reply to a request for comment. Nauru's ambassador to the ISA did not immediately respond to a request for comment.
Deep-sea mining would extract cobalt, copper, nickel, and manganese - key battery materials - from potato-sized rocks called "polymetallic nodules" on the sea floor at depths of 4-6 km (2.5-4 miles). They are abundant in the Clarion-Clipperton Zone (CCZ) in the North Pacific Ocean between Hawaii and Mexico.
The Metals Co has deals with Nauru, Tonga and Kiribati for CCZ exploration rights covering 224,533 square km, roughly the area of Romania.
Aingimea's letter said Nauru believed draft deep-sea mining regulations were nearly complete after seven years of talks.
But environmental groups, some of which have called for a ban on the activity arguing that too little is known about its impact, said the draft was far from ready.
"Forcing the regulations through prematurely and without due process or enough scientific knowledge about the deep sea is not in line with the precautionary approach and other principles of international environmental law," the World Wildlife Fund said.
ISA states still differ over issues including a royalty regime for deep-sea minerals, said Duncan Currie, a lawyer who has followed the ISA talks since 2012.
U.N. law defines resources on the international seabed as the common heritage of mankind, so benefits should be shared among all countries, not just nations sponsoring mining firms.
Alphabet's Google, carmaker BMW and battery producer Samsung SDI back WWF's call for a moratorium on deep-sea mining.
Nauru, with 12,000 inhabitants, said 80% of its land was uninhabitable because of colonial-era phosphate mining and deep-sea mining was more sustainable. The Metals Co has said deep-sea mining would have less impact than mining for battery metals on land.
But SOAC said in a filing to the U.S. Securities and Exchange Commission (SEC) last week it was not yet known whether mining the seabed would have less impact on biodiversity than mining for the same quantity of metals on land.
"We cannot predict ... whether the environment and biodiversity is impacted by our activities, and if so, how long the environment and biodiversity will take to recover," it said.
In a statement reacting to Nauru's move to trigger the two-year rule, Greenpeace said: "This is now a test of governments who claim to want to protect the oceans."
The ISA in a statement acknowledged Nauru's letter and said it aimed to resume this year work on mining regulations, which had earlier been delayed due pandemic travel restrictions. (Reporting by Helen Reid; additional reporting by Jeff Lewis; Editing by Edmund Blair and Louise Heavens)