Greenpeace Aotearoa is calling leaked undercover footage of wastewater pouring into the Pacific ocean during deep sea mining tests "damning", saying it exposes the industry greenwash and just how damaging deep sea mining could be to ocean health.

The undercover footage of the latest deep sea mining tests in the Pacific Ocean shows wastewater being dumped by Canadian miner The Metals Company (TMC) at the ocean surface, with unknown toxicity and ecological impacts.

The tests were carried out between mid-September and mid-November 2022 by TMC and its Swiss operating partner and shareholder Allseas using the drill ship "Hidden Gem" in the Clarion Clipperton Zone between México and Hawaii.

Comprising rock, debris and sediment, the waste has the potential to smother and poison ocean life. The spill has not been publically reported by TMC or Allseas.

Greenpeace Aotearoa seabed mining campaigner James Hita says, "This footage is damning evidence of the potential threat that deep sea mining poses for ocean health and illustrates exactly why Greenpeace and our allies are urgently calling for a halt to deep sea mining."

The release of the footage comes after Hita and Greenpeace allies confronted the Hidden Gem in November last year off the coast of Manzanillo, México as it returned to port from the Pacific. One of the biggest vessels of its type in the world, the ship planned to mine 3,600 tonnes of polymetallic nodules from the seafloor in a trial that could pave the way for full scale commercial mining.

"What you're seeing in this footage is pulverized rock and sediment pulled from the deep, where it’s supposed to be, spilling off The Hidden Gem onto the surface of the ocean in a dirty plume - potentially smothering marine life in the process.

"This is a far cry from the images circulated by the Metals Company showing shiny, futuristic mining machinery - literally artists impressions - which are being used to sanitize and greenwash an industry that threatens ocean health."

Hita says the incident has not been publicly reported by the company or the ISA, the body charged with regulating deep sea mining, and highlights TMC’s technical and scientific incompetence.

"Our message to The Metals Company and the deep sea mining industry remains the same. We will not stand by while industry places profit before people and the health of the planet. We are courageous and we will oppose you at every step."

Hita added the tide is turning on deep sea mining after the New Zealand Government announced last year its support for a conditional global moratorium on deep sea mining, until such a time that strong regulations, backed by robust science, were in place to protect the marine environment in international waters.

"The undercover footage makes it clear why the New Zealand Government needs to champion a global ban on deep sea mining at the International Seabed Authority (ISA) conference in March this year. We need urgent action that protects the ocean.

"Waiho papa moana. Leave the seabed alone."

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