Thousands of residents from US territories have signed a petition to oppose proposed deep-sea mining in waters surrounding the Mariana Islands archipelago and American Samoa, joining a wider Pasifika movement over the exclusion of Indigenous communities from consultation.

The petition, filed by the coalition of Friends of the Mariana Trench, Micronesia Climate Change Alliance, Right to Democracy, and America the Beautiful for All Coalition will be sent to the US federal government to addressed attempts to pursue mining proposals without a "free, prior and informed" consent from Pacific 'custodians of the sea'.

In a letter to Guam US senator Therese Terlaje, authors said the -sea mining proposal will only highlight the limited political power residents of the territories have, where Pasifika voices are legislatively sidelined in decisions which directly affect their livelihoods.

Elected representatives from Guam, the Northern Mariana Islands and American Samoa nation-states — as well as other territories including Puerto Rico and the US Virgin Islands and theDistrict of Colombia — are deemed non-voting delegates in both the Senate and House of Representatives.

The Guam Legislature held a public hearing on Wednesday to form a resolution position which reaffirms the island's call for a moratorium on deep-sea mining, objecting to US federal plans to lease waters of the Northern Mariana Islands for the mineral extraction.

The resolution highlights the impact to Guam's Chamoru community — the identical Indigenous people of the Marianas also — whose cultural identities, livelihoods, food systems, spiritual traditions and connections are tied to the sea.

They say deep-sea mining could have negative impacts including fisheries damage, and harm to sacred seamounts which are used in traditional navigation in addition to the loss of culturally-significant ocean spaces.

"I introduced this resolution to renew and reaffirm the Guam Legislature's call for a moratorium on deep-sea mining to protect the legal, environmental, cultural, social, and economic rights of the people of Guam," Democrat Senator Terlaje said in a statement.

"The voices of the people of Guam should always matter.

"Our waters are our way of life and the basis of our health and economy, and a disregard of our voices and input shows a great disrespect to the people of Guam, as stewards of the land and sea."

The Northern Mariana Islands and American Samoan petition claims deep-sea mining is incompatible with a "healthy marine environment and threatens biodiversity, cultural heritage and traditional ocean stewardship".

It adds Pacific Islander communities "depend on the ocean for their survival and identity, and that the permanent extraction of seabed minerals would amount to a one-time loss of resources that have existed since the dawn of time," especially since climate change has accelerated environmental pressures.

Pasifika communities, including the Maori iwi in Aotearoa, Kūki 'Airani Maori in the Cook Islands, Polynesians in Tonga, Kanaks in New Caledonia and iTaukei in Fiji, have already opposed seabed mining, largely from US interests, in forms of protest and defiance.

The waters around the Pacific Ocean are estimated to contain large amounts of potato-shaped rocks, known as polymetallic nodules, which are used to produce electric vehicles and for other electronic devices.

Drawing parallels with past extractive industries in the Pacific, the signatories of the petition also argue future seabed mining activities are set to bring a "long-term environmental harm while undermining self-determination and Indigenous governance".

They are calling on the US government to immediately cease plans for deep-sea mining in both the Marianas sub-region and American Samoa, and to commit to inclusive, community-led decision-making to ensure Indigenous people remain informed.

The petition, which has attracted more than 3000 adult signatories, also questions why islander communities continue to bear the risks of resource extraction for the global-energy transition while investments to reduce their reliance on fossil fuels remain limited.

Seabed mining is said to affect the future of around 45,000 current residents, including children in each of the Northern Mariana Islands and American Samoa.

Organisers said they will continue to collect signatures and formally submit the petition before the public comment period closes on January 12.