Deep Seabed Mining in the Pacific – Is it a good idea?

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Written by: Siana Whaterau

What is Deep Seabed mining?

Deep seabed mining is the extraction of material from the sea floor of deep seas (greater than
200m depth).[6] The main target of seabed mining in the Pacific is to retrieve poly-metallic
nodules. Nodules form when minerals are deposited on the sea floor. They can contain precious
metals such as manganese, copper and zinc.[2] These minerals are highly sought after to be used
in the tech-sector for products like batteries and electronics. Recently, many commercial
organisations have become interested in the oceans mining potential because of the
overexploitation of minerals on land.

Where is the Seabed mining industry today?

Although some mining has occurred in shallow waters, deep seabed mining in the Pacific ocean is
still in the exploration phase.[6] There is little scientific knowledge of the deep sea, mineral
extraction and its environmental impacts. There is current explorative efforts taking place in the
Exclusive Economic Zones (EEZ) of Pacific nations such as New Zealand, the Cook Islands,
Kiribati, Samoa and Nauru. These efforts include assessing mineral rich zones for biodiversity and
the potential environmental impacts of mineral extraction.[5]

Seabed exploitation in the deep sea is predicted to begin as early as 2025.[1]

How would seabed minerals be mined?

The process of ocean mineral extraction will involve intense dredging, ploughing and scraping of
the seafloor with large remote machinery. Minerals will be vacuumed and piped from the seabed
to be processed. Waste materials will be returned to the sea. [1]

Sea vessel and remote harvesters image from International Mining [3]

What are the potential impacts?


The extraction process could cause major disturbance to the seafloor ecosystem, water column
and even climate.

Countless species in the deep seas rely on the seabed habitat for survival and will be directly
negatively impacted by its removal and destruction.[8] The seabed is also a key source of
nutrients for phytoplankton, a key organism in the ocean’s carbon cycle, and any negative
impacts on them will be felt like a domino effect throughout other marine life.[6] Since most of the
deep seas are unexplored, the extent of damage on its biodiversity and ecosystem is still

Heavy disturbance in the sediment could also cause sediment plumes in the water column,
potentially changing environmental conditions for marine life above the seafloor and burying
seabed life as it resettles. Similar issues can occur when waste materials are pumped back into
the water.[5]

The deep sea houses a large proportion of the Earths carbon through carbon rich sediment/
waters. Disturbing the deep sea environment could release carbon into shallow waters and the
atmosphere. This would cause major climate issues as it imbalances our global carbon cycles.[4]
The Pacific Ocean is the largest in the world and therefore has more widespread effects on global
issues such as climate change when environmental issues occur.


Although initial payoff would be high, sustainable revenue can not be guaranteed because mineral
nodules form gradually over decades.[2] Throughout the Pacific, particularly in small island
nations, fisheries and tourism are dependable economic sectors. Major distress to the marine
environment could see to the ruin of some marine-dependent industries.


Tangata whenua and Tangata moana throughout the Pacific view the disruption of the sea poorly.

Is it a good idea?

Failure to monitor and sustainably manage commercial seabed mining will cause some major
environmental shifts. Without sufficient baseline studies, these shifts and the extent of their
consequences are still unknown. This should be reason enough to suggest that we are not ready
to commercially mine in the Pacific.


  1. Aldred J. (2019). Explainer: Deep seabed mining. China Dialogue Ocean.
  2. Hein et al. (2020). Deep-ocean polymetallic nodules as a resource for critical materials.
  3. IM. (2014). [© Copyright International Mining 2021]. Seven new exploration licences for deep
    sea mining. URL: sea-mining/ . Accessed 06/03/21
  4. J.L. Stauber, A. Chariton, S. Apte. (2016). Chapter 10 – Global Change. Academic Press.
  5. Levin et al. (2016). Defining “serious harm” to the marine environment in the context of deep seabed mining.
  6. Miller et al. (2018). An Overview of Seabed Mining Including the Current State of Development,
    Environmental Impacts, and Knowledge Gaps. Frontiers in Marine Science. URL: https:// . Accessed 06/03/21
  7. One News. (2020). More research needed on deep sea mining in Pacific say experts. URL: pacific-say-experts?
    QD_IAdCcvIaAvr7EALw_wcB Accessed 05/03/21
  8. RNZ. (2020). Pacific warned of seabed mining’s irreversible impacts. URL: https:// irreversible-impacts Accessed 05/03/21