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Seabed Mining


In the Cook Islands we have manganese nodules which are spherical to potato-shaped rocks found partially buried in sediments on our seafloor. They are found at depths of  greater than 4,500  metres. 

Cobalt was originally considered to be the target mineral in the nodules as well as other important quantities of copper, nickel, titanium and minor amounts of rare earth elements. A recent assessment and with changing mineral prices Cook Islands nodules should now be considered as a Co-Mn-Ti-REE (Cobalt, Manganese, Titanium and Rare Earth Element) resource, with economic quantities of copper, nickel vanadium and other associated minerals.

A recent estimate for nodules within the Cook Islands’ EEZ is that there are 10 billion tonnes. Of this a smaller but very significant amount are likely to be recoverable. This is generally considered the second largest deposit of metal-rich nodules. As the world’s demand for minerals continues to increase, our manganese nodules have generated commercial interest from a mining perspective.


This is a decision that needs to be made by government in consultation with the public. Mining may occur if it can be shown that this activity will not impact the physical, chemical or biological integrity of the ocean. This means that a significantly small area of the ocean might possibly be mined where ocean systems are not affected and species extinctions can be avoided. Before any mining happens in Cook Islands waters the Seabed Minerals Authority must ensure that the public is widely consulted and educated about the risks.

Any decisions on whether recovery of seabed minerals will take place will depend on the gathering of the necessary information to make the next decision or not. This includes detailed mapping of the bathymetry of the seabed, mapping and evaluating the distribution of the nodules and their elements, a complete understanding of the ecology where the recovery of the nodules will take place, economic analyses and mining feasibility plans and the development of suitable recovery technology. 

If this research finds that mining can occur without an environmental impact, the intention is to have mining companies go through a rigorous planning process. Applications must be made to government for a mining permit. Recovery proposal plans, environmental impact assessments, mitigation plans, and a range of other key documents will need to be prepared and submitted to government for assessment to determine environmental consents and operating licences prior to any operations commencing. Overall, it will need to be proven to what scale seabed mining will impact the environment, before it can be determined whether seabed mining will be allowed in or near the Marine Park. It’s worth noting that no commercial mining of deep seabed minerals has yet taken place anywhere in the world.

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