Deep seabed mining has potential to cause significant environmental damage and should be regulated
Deep seabed mining could have serious impacts on the ocean environment and the future livelihoods and well being of coastal communities. An international, multi-sector approach to management and protection, similar to that under development by the International Seabed Authority under UNCLOS, is needed, if we are to ensure the health and sustainable use of our oceans.
A growing number of companies and governments2 – including Canada, Japan, South Korea, China and the UK – are currently rushing to claim rights to explore and exploit minerals found in and on the seabed, such as copper, manganese, cobalt and rare earth metals. There are currently 17 exploration contracts3 for the seabed that lies beyond national jurisdiction in the deep seas of the Pacific, Atlantic and Indian oceans, compared with only 8 contracts in 2010. Contract holders will be able to apply for licences to carry out commercial mining in the high seas as soon as regulations for exploitation are developed – anticipated as early as 2016.4 There is also significant exploration interest within national waters, particularly in the Pacific Ocean, and one licence to mine the deep seabed has already been granted in Papua New Guinean waters. However, very little is known about deep-sea habitats, or the impact that mining operations will have on ecosystems and the wider functioning of our oceans. Once thought to be relatively lifeless, scientists now recognise that the deep sea is actually a species-rich environment5, with many species still to be discovered. Because deep-sea species live in rarely disturbed environments and tend to be slow growing and late maturing, with some unique to their particular habitat types (such as hydrothermal vents) or even specific locations, they are highly vulnerable to disturbance or even extinction.6
Deep seabed mining could have serious impacts on the ocean environment and the future livelihoods and wellbeing of coastal communities. Only 3% of the oceans are protected and less than 1% of the high seas7, making them some of the least protected places on Earth. The emerging threat of seabed mining is an urgent wake-up call: the world’s governments must act now to protect the high seas, including by creating a global network of marine reserves8 that will be crucial sanctuaries at sea for marine life and the ecosystems which we all rely on for our survival. An international, multi-sector approach to management and protection is needed, if we are to ensure the health and sustainable use of our oceans.
The remote deep and open oceans host a major part of the world’s biodiversity, and are vital for our survival on Earth.9 The deep sea plays an important role in regulating planetary processes, including regulation of temperature and greenhouse gases.10 It supports ocean life by cycling nutrients and providing habitat for a staggering array of species.
Seabed mining poses a major threat to our oceans. All types of seabed mining will kill whatever can’t escape the mineral extraction operations. Organisms that grow on the seabed will be smothered as a result of sediment disturbance and the discharge of waste. The current lack of scientific knowledge on the deep-sea environment, and the lack of knowledge of the technology employed, limits our ability to predict the environmental impacts of mining operations and to determine whether habitats can ever recover from the disturbance.15
We know that deep-sea species from many habitats, such as seamounts and abyssal plains, are particularly vulnerable due to their slow growth rates, their low resilience to changes in their environment, and slow recovery rates after disturbance.16 Some hydrothermal vent communities may be more resilient to impacts because of the high natural levels of turnover of these ecosystems, although this is dependent on the underlying geology and biogeography of the individual systems.17
Mining licences for hydrothermal vents have already been granted to Nautilus Minerals by the Papua New Guinean government to mine for sea floor massive sulphides in national waters 1,500 metres under the sea, despite significant environmental concerns and community opposition. A study at the mining site found 20 new species, with more species likely to be found in the future.18 The impacts on the actual mining site will be very high, but the resilience of this system is unknown, as are the effectiveness of the proposed efforts to assist natural recovery. The wider impacts of the mining operation on surrounding ecosystems are also unknown.19
Deep-sea communities live in relative silence, and in the dark. Studies have shown that deep-sea fish communicate at low sound frequencies26, and are sensitive to acoustic changes to sense food falls – the fall of organic matter that provides an important source of nutrients to the deep sea27. Whales rely on sound for communication and navigation, and when encountering increased noise, change their vocalisation patterns and behaviour, and move away to new areas.28 Studies show that baleen whales experience chronic stress when exposed to increased shipping noise.29 Low-frequency mining noise could travel far from the mining site, with one estimate suggesting that noise from the Nautilus operation near Papua New Guinea could travel up to 600km from the site.30 This could have negative impacts on deep diving whales in the area.
Mining will also introduce bright light into an environment that, but for bioluminescence, is constantly dark, impacting species that are adapted to these conditions, such as deep-sea vent shrimp, which have been shown to be blinded by the lights used by researchers.31
The seabed and deep sea is the last frontier on Earth, the vast majority of it unexplored by humans. We have more detailed maps of Mars than we have of the seafloor. Some deep-sea communities, such as those found on and around hydrothermal vents, are barely understood. First discovered in 1977, these hydrothermal vents are like underwater hot springs, spouting out clouds of metal sulphides from within the Earth. As the hot clouds cool and solidify, they create towering chimneys, known as “black smokers”. The organisms that live there are like nothing else on Earth, as they draw their energy not from the sun but from the chemicals gushing from the vents. These thriving communities live in an extreme environment – one that is dark, deep (up to 5,000m depth), hot (up to 400°C), and usually strongly acidic, yet hosts an extraordinary array of life.33 Over 700 vent species have been discovered, and due to factors such as geographical isolation, many are unique to their particular regions or even locations. Species include giant tube worms, crabs, shrimps and fish.34 On average, two new species were discovered every month for the 25 years up to 200235, and we’ve still barely scratched the surface.
The deep sea is also the largest reservoir of marine genetic resources, and is of major interest to pharmaceutical companies, a number of which already hold patents for products discovered in the deep.36 Enzymes from hydrothermal vent species are estimated to have an annual commercial value of $150m US dollars.37 Despite their intrinsic ecological and scientific value and their potential benefit to humankind, deep seabed mining could destroy these genetic resources before they are fully understood or even discovered38 – resources that could, for example, hold cures for diseases such as cancer.
Seabed mining could cause fish mortality, due to habitat loss and a decline in food sources. For example, phosphate extraction proposed in shallow water near Namibia is expected to impact fish populations through habitat and food source removal, with mining operations set to take place within migratory routes and spawning grounds.39
Similarly, within the deep sea, mineral deposits often occur in habitats that support important and diverse fish populations. For example, cobalt-rich crusts are often located on the flanks and summits of seamounts, underwater mountains that host a great abundance of species. These include slow-growing fish species such as orange roughy, grenadiers and redfish, the status of which – in the cases where data exist – is generally considered already overexploited or depleted by deep-sea fishing.40 In cases where seamounts have been severely destroyed by bottom trawling, there has been no sign of recovery of large bottom-dwelling fauna five years after trawling stopped, highlighting the vulnerability of these communities.41 Research suggests that it will take many decades or more for seamount communities to recover from such trawling.42 Greenpeace has been calling for a ban on deep-sea bottom trawling to stop the potentially irreversible impacts of this destructive fishing practice on sensitive deep-sea habitats and species. The impacts of mining in these areas would be even more devastating to the already threatened fragile ecosystems of the deep ocean.
Many are skeptical of deep-sea mining's supposed benefits, and its environmental implications are relatively unknown. Nautilus has hired the environmental consulting firm Earth Economics to try to assess how a seabed mine might compare with a terrestrial mine. The analysis, released last month, compares likely impacts of the Solwara mine with three terrestrial mines of similar proportions -- Bingham Canyon in Utah, Prominent Hill in Australia, and the proposed Intag mine in Ecuador.
The analysis found that, unlike with terrestrial mines, there aren't issues like community displacement, use of freshwater supplies, erosion, or loss of land for other uses like food production, recreation, or cultural and historic conservation. Deep-sea mining would cause a loss of habitat and genetic resources, affect air and water quality, and use energy and raw materials, according to the analysis. But the overall environmental impact of deep-sea mining would not be as severe as that of an onshore mine, the analysis said.
The report also predicted that demand for copper, for wiring and other needs, is likely to continue, and neither land-based mines nor recycling are likely to supply enough.
Maya Kocian, a senior economist at Earth Economics, said the firm was cautious in taking on the analysis. Earth Economics normally studies the value of parks and recreation areas, she said. "Nautilus had to come to Seattle to convince our board to do it," said Kocian. "There was hesitation to move forward."
In the end, Kocian said, the firm found that there would be environmental impacts, but the comparison yielded interesting findings.
Germany has called for a pause in the controversial deep-sea mining industry, saying not enough is known about the likely impacts of digging up the ocean floor for metals.[ More ]
A growing number of countries are backing calls for a moratorium on mining the oceans’ floor but the UN body responsible is pushing to greenlight the industry in 2023.[ More ]
Mining companies are planning to profit from the new industry, but environmental campaigners warn of disastrous consequences.[ More ]
Commercial deep seabed mining could begin as early as 2024 but the ecological harm would be vast and scientists can't say yet whether it would be permanent or excessive.[ More ]
The UN-affiliated organisation that oversees deep-sea mining, a controversial new industry, has been accused of failings of transparency after an independent body responsible for reporting on negotiations was kicked out.[ More ]
Deep-sea mining in international waters is currently illegal, and environmental organizations, scientists, and many governments want to keep it that way. They argue that the practice could irreversibly harm one of the planet’s remotest ecosystems, one of the few places on Earth that has largely escaped human disruption.[ More ]
As the deep ocean faces growing peril from climate change, seabed mining and other threats, scientists have discovered that seafloor sediments are home to vast populations of previously unknown organisms that may play a crucial role in carbon sequestration and marine food webs. The finding will only further complicate the debate over the tradeoffs from deep seabed mining for critical metals needed for a transition to green energy.[ More ]
Almost two-thirds of the hundreds of mollusc species that live in the deep sea are at risk of extinction, according to a new study that rings another alarm bell over the impact on biodiversity of mining the seabed.[ More ]
Canadian startup DeepGreen is touting seabed mining as a green alternative to land-based mineral extraction but scientists warn that seabed mining could result in environmental damages “irreversible on multi-generational timescales.”[ More ]
DeepGreen built a nearly $3 billion valuation on the dream of gently excavating the ocean floor. Now environmentalists want to block its plans to go public.[ More ]