Project Details Seabed mining and Blue growth: Exploring the potential of the marine mineral deposits as a sustainable source of Rare Earth Elements (MaREE)

Project No.:
Start Date:
01 May 2019
End Date:


The project aims to explore the potential of marine mineral deposits taking into account the growing demand for Rare Earth Elements (REE) to be mainly used in the electronics industry (e.g. smartphones) and green energy technology applications (e.g. permanent magnets of turbines turbines). The blue growth strategy highlights the challenging role of seas and oceans as potential drivers for innovation and sustainable development.
Current projects and ongoing studies show that some coastal, continental shelf and deep-sea mineral formations may turn out to be exploitable resources for REE. However, further exploration is needed to understand and assess the potential of REE mineral resources in the marine environment.  This project will explore and prospect the feasibility and exploitation potential of REE from marine mineral deposits, taking also into account value chain aspects related to responsible sourcing and sustainable mining. The project will focus mainly on exploring the potential deep-sea mineral deposits and placers as new sources for REE. It will also study the effects of REE mining on marine biological communities and habitats, since that knowledge is very limited.


Rare Earth Elements (REE) is a collective name for 17 metallic elements with similar chemical properties. They include the group of lanthanides, scandium and yttrium. Although they are relatively abundant in Earth’s crust, their economic deposits are rather rare. REE exhibit unique physical, chemical and light emitting properties and are therefore very much needed in developing and implementing clean energy technologies. They have multi-functional and industrial uses, such as in high-strength magnets, medical devises, mobile phones, flat-screen TVs, energy-efficient lighting and superconductors.

REE occur in primary mineral deposits of igneous and hydrothermal origin, as well as secondary deposits, associated with sedimentary processes and weathering action. The most important primary REE-bearing mineral deposits are those hosted by alkaline igneous rocks and carbonatites. The secondary ones refer mainly to placer deposition and residual weathering. Placer deposits contain detrital minerals from various primary sources, being often enriched in Ti, Zr and REE. Among the placer deposits, the most important ones are those related to the marine environment. Residual weathering deposits comprise laterites and ion-absorption clay deposits.

Blue Growth initiative, along with the globally growing demand for REE-containing raw materials and the strong surge in REE economic value, motivates and generates the need for increasing exploration efforts to locate minable REE-bearing mineral resources in the marine environment. In this frame, the deep-sea mineral deposits make a potential resource target for REE.

Based on achievements in exploration, beneficiation and mining technologies concerning deep sea mineral resources, it was shown that, except from the REY (rare earth elements and yttrium)-rich deep sea mud, there is also a distinct REE type of mineralization associated with deep sea polymetallic nodules and cobalt rich crusts. Both mineral deposit types are primary i.e many nodule deposits show both a diagenetic and a hydrogenetic compound due to accumulation of metals both from pore water and from seawater. The characteristics of these deposits are i) their usually very large tonnage, and ii) their potential to supply REEs as a byproduct of the extraction of copper, nickel, cobalt, and manganese. Even though the REE grades of the marine mineral deposits are generally lower than those of the deposits on land, the resources are much more extensive.

Ocean mining faces significant technological challenges with cost and time remaining major bottlenecks. On the other hand, placer deposits related to shallow continental shelves appear to be a more potential target for sourcing feasible REE grades. Seabed mining is an environmentally challenging issue with various impacts on marine ecosystems. It may affect benthic (e.g. seaweeds, bivalves, crustaceans) and/or neritic (like fish) marine organisms. Furthermore, a critical issue is the evaluation of the potential for human or animal dietary exposure. A comprehensive monitoring and evaluation need to be established and applied across the production chain to perform an environmentally compliant and sound operation.

Main tasks of the project are to:
• Review the economic geology of REE.
• Provide a critical evaluation of the marine resources mining versus the land-based ones for REE
• Provide an overview of REE-bearing marine deposits worldwide.
• Present the REE exploration and exploitation potential of seabed mineral deposits.
• Evaluate the mineralizing processes of REE in the deep sea.
• Comment on environmental management issues related to marine mining.
• Studying the REE mining impacts on marine biota.
• Make a comparison between placer resources and deep ocean deposits based on various parameters including exploration cost, technological means, socioeconomic and environmental impacts etc.


November 2019 update – project members held a face-to-face, two days meeting, in Brussels discussing project progress, appointing tasks to each member and looking for new contributions to the Task Group.

July 2020 update – preparation of the project logo.

December 2020 update – preparation of a draft paper on the following topics:
➢ Major REE mineral deposit types
➢ Global REE market and resource potential
➢ REE exploration and exploitation potential of seabed mineral deposits
➢ Ecological effects of seabed mining
➢ In search of sustainable exploitation of seabed mineral deposits containing REE
➢ Socio-economic impacts of deep-sea mining
➢ Marine resources mining versus the land-based mining for REE
➢ European projects for marine minerals
➢ Exploration-Exploitation versus preservation of the global ocean

March 2021 update – a manuscript entitled “Seabed mining and Blue growth: Exploring the potential of marine mineral deposits as a sustainable source of Rare Earth Elements (MaREE)” has been submitted to Pure and Applied Chemistry.

Page last updated 12 April 2021