A new report by an environmental charity says deep sea mining may not make any money.
The Ocean Foundation said there is high uncertainty around prices for metals and the circular economy could make deep sea mining unnecessary.
Deep sea mining involves extracting rocks called nodules from the sea floor kilometres deep, which are packed with metals that can be used for electric car batteries.
However, The Ocean Foundation's report said despite electric vehicle production increasing by 2000 percent from 2016 to 2023, the price of cobalt - one of the main metals found in the nodules - had decreased.
One of the authors and deep seabed mining focal point at Foundation, Bobbi-Jo Dobush, said getting the nodules off the sea floor will be an expensive task.
"The financial modelling to date around seabed minerals has been criticised as being hyper-optimistic checking the best case scenario box at every turn," Dobush said.
"I think of it sometimes as a checklist - in order for anyone to make money off this these 10 things would have to go right - well there's no guarantee these things will go right and a lot of them seem to be going the other way."
Dobush said car batteries are moving away from cobalt and nickel.
"Seabed mining hopes to bring up metals for what miners would say is a green revolution or decarbonising our economy but these are the battery metals that are either current or last generation that we are not going to need if and when they could ever get to market."
'Desperate individuals, organisations trying to derail'
However, The Metals Company which is looking to mine in Clarion-Clipperton Zone (CCZ) in the Pacific's high seas is confident money will be made.
"There is no doubt that collecting polymetallic nodules from the CCZ will be an economic exercise," chief executive Gerard Barron said.
He said the price of cobalt had run ahead of itself, and the nodules contain multiple minerals reducing the risk of one metal losing its value.
"The polymetallic nature of a nodule has a nice mixture of nickel and copper and cobalt and manganese, and sometimes you find all of those commodities are high but often you will find one is high and one is less high, and they balance each other out."
Barron said more metals are going to be needed in the future, not just for electric vehicle batteries but also for the ongoing industrialisation of the developing world.
"This [report] is another attempt by a desperate group of individuals, small organisations who are trying to derail something that is inevitable and that is, where should we be getting the metals that are needed for this transition that has only just begun."
Three companies in the Cook Islands are exploring the nations waters to see if mining can happen.
Cook Islands 'focus on exploration'
Cook Islands seabed minerals commissioner Alex Herman said it is too premature to discuss the potential earnings if mining does eventually go ahead.
"At this stage we want to continue to focus on exploration, we don't want to get to ahead of ourselves but we are aware that there are potential economic benefits if the sector does progress to the harvesting phase.
"We won't allow seabed minerals activities to progress to that next phase unless we're satisfied about that, so the onus is on the companies to prove that this is a commercially feasible industry."
Herman said in the current exploration phase there have already been economic benefits to the country like training opportunities and scholarships given to Cook Islanders.