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Scientists have discovered more than 5,000 new species living on the seabed in an untouched area of the Pacific Ocean that has been identified as a future hotspot for deep-sea mining, according to a review of the environmental surveys carried out in the area.

It is the first time the previously unknown biodiversity of the Clarion-Clipperton Zone (CCZ), a mineral-rich area of the ocean floor that spans 1.7m sq miles between Hawaii and Mexico in the Pacific, has been comprehensively documented. The research will be critical to assessing the risk of extinction of the species, given contracts for deep-sea mining in the near-pristine area appear imminent.

Most of the animals identified by researchers exploring the zone are new to science, and almost all are unique to the region: only six, including a carnivorous sponge and a sea cucumber, have been seen elsewhere.

Contracts for mining exploration in the CCZ have been granted to 17 deep-sea mining contractors in an area covering 745,000 sq miles. The companies, which are backed by countries including Britain, the US and China, want to dig for minerals including cobalt manganese and nickel in part to sell to the alternative energy sector.

To better understand the impact of mining this fragile ecosystem and its newly discovered inhabitants, an international team of scientists has built the first “CCZ checklist” by compiling all the records from expeditions to the region. Published in the journal Current Biology, it includes 5,578 different species, of which an estimated 88% to 92% had never before been seen.

To study and collect specimens (样品) from the ocean floor, biologists have joined research cruises in the Pacific that send remote-controlled vehicles to traverse (穿越) the seabed 4,000 to 6,000 meters below. Adrian Glover, a deep-sea biologist at the NHM and senior author of the study described it as an “incredible privilege”. The expedition, funded through the Natural Environment Research Council and others, is backed by UK Seabed Resources (UKSR), a deep-sea mining company that operates the UK’s exploration area. The scientists watch operations by video link direct from the boat as new species are gathered by remote control vehicles in the darkness below.

The seabed, Glover said, is an “amazing place” where, despite the extreme cold and dark, life thrives. “One of the characteristics of the abyssal plain is the lack of food, but life has a way of persisting down there,” he said, “It’s a mystery.” One of the deep-sea animals discovered was nicknamed the “gummy squirrel”, because of its huge tail and jelly-like appearance, he said. There are also glass sponges, some of which look like vases.

With approval for deep-sea mining looming, Glover said he believed it was “imperative that we work with the companies looking to mine these resources to ensure any such activity is done in a way that limits its impact upon the natural world”.