Shallow Water Mining
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- A new research by University of Helsinki, Finland has found that mining metals such as gold, cobalt and copper from depths of 200 metres (m) below the sea, also known as ‘shallow-water mining’, could trigger local extinctions of marine species.
Sea Bed Mining and Shallow Water Mining Activities
- The term ‘seabed mining’ refers to the extraction of high-value commodities, such as metals or gemstones, from the seabed. The term is used for both deep-sea and shallow-water mining activities and thus encompasses a range of activities under different environmental and regulatory contexts.
- Shallow-water mining is not strictly defined by depth, but rather, shallow-water operations are usually considered to be those occurring on the continental shelf with easier access to the coast, as opposed to deep-sea operations that target less accessible resources and require specialized technology.
- The main types of shallow-water minerals include:
- Mineral rich sands;
- Polymetallic nodules and phosphorites; and
- Placer deposits, consisting of metallic minerals or gemstones, such as tin, gold, or diamonds.
Shallow Water Mining over Deep Sea Mining
- Deep-Sea mining has not been implemented yet due to concerns over the environmental impacts of mining activities.
- Meanwhile, there is interest in shallow-water mining as it is considered a relatively low-risk and low-cost option to satisfy the demand for metals and minerals. Also, technology for shallow-water mining already exists.
Countries adopting Shallow Water Mining
- Namibia has been mining diamonds off its coast in depths of up to 130 m.
- Indonesia has been extracting placer deposits — sediments containing gold, silver, tin, and platinum.
- Mexico, New Zealand and Sweden have proposed shallow-water.
- Mexico is considering mining marine phosphorites, phosphate-rich nodules used in fertiliser and industrial chemicals, in water depths of 50-100 m.
- Sweden is interested in exploring the shallow waters (60-150 m) of the Bothnian Sea for polymetallic nodules, mineral deposits containing nickel, cobalt, copper, titanium and rare earth elements.
Polymetallic nodules, also called manganese nodules, are mineral concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. As nodules can be found in vast quantities, and contain valuable metals, deposits have been identified as a potential economic interest. Nodules vary in size from tiny particles visible only under a microscope to large pellets more than 20 centimeters across. However, most nodules are between 3 and 10 cm in diameter. Nodules lie on the seabed sediment. Polymetallic nodules are found in both shallow (e.g. the Baltic Sea) and deeper waters (e.g. the central Pacific), even in lakes.
Findings of the new Research
- Despite representing only a fraction of the global ocean, continental shelves (shallow water) support high species diversity, habitat heterogeneity, and biological productivity
- Shallow Water Mining was not a sustainable substitute for deep-sea mining, where valuable minerals needed to build batteries critical for clean energy transition are mined from ocean depths greater than 200 m.
- Despite countries adopting Shallow Water Mining the impacts of shallow-water mining haven’t been thoroughly investigated. This could be because “shallow-water mining has been on many occasions compared directly to sand and gravel extraction.
- Further environmental impact studies have not been conducted as they have been thought to be similar to the impacts of sand and gravel mining.
Impact on marine life
- Shallow-water mining involves removing sediment-bearing minerals, which offer refuge to seafloor organisms. This could trigger local extinctions and changes in species composition.
- Also, ploughing the seafloor releases plumes, which could impact water quality.
- Other issues could be the release of harmful substances from the sediment and disturbance from noise and light.
- As shallow-water ecosystems are already under stress due to pollution, and the impacts of climate change, even small-scale mining activities can drastically affect marine ecosystems, especially at local scales.
- Mineral extraction removes the sediment, resident seafloor organisms, and ultimately the habitat, potentially resulting in local extinctions and changes in species composition.
- Shallow-water mining exerts additional pressures on vulnerable coastal ecosystems which are already burdened with cumulative impacts from human activities and the effects of climate change, making them less resilient to new human activities.
Concerns and Way Ahead
- Nations have not agreed on whether deep-sea mining should be permitted amid environmental concerns at the recently concluded 27th session of the Assembly of the International Seabed Authority. There need to be deliberations and agreement on this.
- There is not enough rigorous scientific information available concerning the biology, ecology and connectivity of deep-sea species and ecosystems, or all the ecosystem services they provide. Without this information, one could not understand the potential risks of the mining activity for deep-ocean biodiversity, ecosystems and human well-being. More scientific research is needed.
- As shallow-water mining has not been previously considered in many areas, its environmental regulation is inadequately reflected in national legislations. Appropriate policies need to be laid down and their proper implementation needs to be ensured.
The post-2020 Global Biodiversity Framework, introduced by the Convention on Biological Diversity, aims to protect 30% of the planet by 2030, and legislative frameworks, such as Maritime Spatial Planning and the EU Marine Strategy Framework Directive
, are in place to guide sustainable use of marine ecosystems. The UN global Sustainable Development Goals have aspirational targets to conserve and sustainably use the oceans, and the UN Convention on the Law of the Sea calls for protection of the marine environment from harmful maritime activities, including those resulting from extractive industries.
- In light of international commitments to halt biodiversity loss and to comply with the Sustainable Development Goals, countries should apply similar precautions to shallow-water mining as is being advocated for deep-sea mining. Even if technology would allow it, unrestricted expansion of maritime activities does not align with sustainable use of ocean resources.
- Amidst the global transition to a low-carbon economy, precautionary conservation measures and systematic comparisons of alternative ways to obtain the required minerals must be taken before seabed mining, be it in the shallow water or in the deep sea, is allowed to proceed.
- Researchers said shallow-water mining activities should not be considered the “silver bullet to resolve the growing global need for metals” until the environmental and socioeconomic impacts are thoroughly investigated.