What does Trump's deep-sea mining push mean for the ocean?

• Deep-sea mining poses risk of ecological collapse
• Companies exploit legal loopholes offshore
• Global competition rises over seabed control

LONDON - A Canadian mining company has been boosted by U.S. President Donald Trump in its push to exploit the ocean floor for minerals such as lithium that are critical to the world's clean energy transition.

The Metals Company submitted applications to the U.S. government to start exploration in international waters at the end of April.

However, experts say the plan might violate international law, cause major ecological damage and even accelerate climate change.

The move follows an executive order by Trump to expedite mining permits to offset China's control of the critical minerals industry.

But more than 90% of the species within the Clarion Clipperton Zone (CCZ), one of the first areas to be mined, are currently unknown to scientists, according to a report by the National Committee of the Netherlands, a non-governmental international nature organisation.

Here's what you need to know.

Where do companies want to mine?

The Metals Company (TMC) is hoping to mine a 25,000 square kilometre (9,653 square mile) area of the CCZ - approximately 1,300 nautical miles south of San Diego, California in international waters.

Currently 22 organisations are mining the CCZ, including the government of India, Germany's Federal Institute for Geosciences and Natural Resources and the China Ocean Mineral Resources R&D Association.

Most exploration contracts are held by public research institutions focused on scientific study, but some contractors, often state-sponsored, combine both research and mining objectives.

The CCZ holds estimated millions of tonnes of nickel, copper, cobalt and manganese, resources vital to energy, infrastructure and defence industries.

Consequently, countries have debated whether to allow commercial mining for several years.

TMC is using a loophole in the U.S. 1980 Deep Seabed Act to bypass United Nation rules on navigational rights, marine research and the conservation and management of marine resources, provided its activities do not violate U.S. obligations or threaten safety, peace or other uses of the high seas.

It also is invoking a section of a U.N. seabed treaty that says if mining rules are not finalised within two years, the application should be approved.

The International Seabed Authority (ISA), an international body created by the U.N., is still negotiating this rule.

Moreover, the United States, unlike 166 other U.N. members, has not ratified the seabed treaty.

Impossible Metals, a U.S. mining company, also wants to conduct deep-sea mining off the coast of American Samoa, but that is within the country's jurisdiction.

What would the environmental impacts be?

Proponents of deep-sea mining say it is more sustainable than obtaining minerals on land because it avoids issues such as deforestation or displacement of communities.

The minerals can then be used for green technologies.

But because so little is known about the ocean depths, the effects could be drastic.

Impacts could include light pollution in a pitch-black ecosystem, sediment plumes stirred up by machinery and noise pollution that could disrupt whale communication.

Warm mining wastewater could also kill marine life through overheating and poisoning, which could have knock-on climate impacts.

The loss of deep-sea biodiversity may have an impact on the ocean's carbon cycle and reduce its ability to help mitigate global temperature rise, according to the global research non-profit World Resources Institute.

What are the political impacts?

Trump's order directs the government to expedite reviews of seabed mining permits "in areas beyond the national jurisdiction."

Leticia Reis de Carvalho, secretary-general of the ISA, said in a statement that unilateral action by the United States against the "common heritage of humankind" could "destabilize the entire system of global ocean governance."

Last month, China's foreign ministry said no country should bypass international laws to mine the seabed.

China produces about 90% of the world's rare earth metals, which the U.S. imports.

(Reporting by Adam Smith, Editing by Jack Graham and Ellen Wulfhorst.)