Machines mining minerals in the deep ocean have been found to cause significant damage to life on the seabed, scientists carrying out the largest study of its kind say.
The number of animals found in the tracks of the vehicles was reduced by 37% compared to untouched areas, according to the scientists.
The researchers discovered more than 4,000 animals, 90% of which were new species, living on the seafloor in a remote area of the Pacific Ocean.
Vast amounts of critical minerals needed for green technologies could be locked in the deep ocean, but deep sea mining in international waters is very controversial and currently not permitted until more is known about the environmental impacts.
The research by scientists at the Natural History Museum in London, the UK National Oceanography Centre, and the University of Gothenburg was conducted at the request of deep sea mining company The Metals Company.
The team compared biodiversity two years before and two months after the test mining that drove machines for 80km on the seafloor.
They specifically looked at animals 0.3mm – 2cm in size, such as worms, sea spiders, snails, and clams.
Lead author Eva Stewart, a PhD student, noted that the machine removes about the top five centimetres of sediment where most animals live, effectively eliminating them from their habitats.
Despite these findings, a spokesperson for The Metals Company expressed encouragement from the data, stating that impacts are limited to directly mined areas. However, experts warn that the significant impact observed even in test scenarios puts the viability of large-scale commercial operations into question.
The debate surrounding deep-sea mining continues, particularly in light of growing demand for the minerals necessary for renewable energy technologies, against the backdrop of pressing environmental concerns.
