Seabed mining can have a significant impact on fragile ecosystems

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