The sediment plume from mining is expected to move south with sea currents. That would bring it into Ngā Rauru's mana moana area.
Ngā Rauru people count Tangaroa (the sea ) as a part of them.
"Turama will share with the EPA some of our special korero, including 'Ko au ko Tangaroa, ko Tangaroa ko au' - I am the sea, and the sea is me.
"The risk of catastrophic damage through this underwater version of open cast mining is totally foreign to our concept of kaitiakitanga," Mr Davis said.
The tribe has a long list of gripes about the hearing process. It wanted the hearings to be close to where mining is proposed. Instead they are being held only in Wellington and New Plymouth.
Ngā Rauru will have to pay $1500 for a bus to get its people to New Plymouth on Monday.
The hearings are happening before Ngā Rauru has resolved its claim for customary rights under the Takutai Moana Act.
The tribe has not be consulted about consent conditions.
Members were also excluded from two years of consultation between the Conservation Department and TTR - they were not told it was happening until it was over.
The process was certainly not one of "free, prior and informed consent," Mr Davis said, so
granting the consent could be a breach of the Treaty of Waitangi.
The EPA's Maori advisory committee has said the cultural values assessment presented by TTR doesn't meet required standards.