Sir David Attenborough has backed calls for a halt to deep sea mining, which conservationists warn could have huge impacts on wildlife and climate change.

A report from Fauna & Flora International (FFI) calls for a moratorium on moves to exploit the deep sea for minerals that are in increasingly high demand for use in items such as mobile phones and batteries.

Scientists at the conservation organisation who have assessed the risks and potential impacts of deep seabed mining warn it could include the disruption of entire ecosystems that are home to largely unstudied wildlife.

The process could also create large plumes of sediments that smother areas far away from the mining sites themselves and kill marine life.

There are also concerns about the release of toxic and heavy metals and the spread of toxins to areas of the oceans that are important for fisheries.

Mining could also lead to the loss of microbes that capture methane and carbon and disrupt the oceans “biological pump” which takes carbon from the atmosphere and transports energy and nutrients through the oceans, they warn.

Sir David, a vice-president of FFI, warned: “Mining the deep sea could create a devastating series of impacts that threaten the processes that are critical to the health and function of our oceans.

“Fauna & Flora International is calling on global governments to put in place a moratorium on all deep sea mining – a call I wholeheartedly support.”

In a foreword to the report, he also said the idea that people should be considering the destruction of deep sea places before they have understood them or the role they play in the health of the planet “is beyond reason”.

“The rush to mine this pristine and unexplored environment risks creating terrible impacts that cannot be reversed.

“We need to be guided by science when faced with decisions of such great environmental consequence.”

Deep-sea mining
Conservationists have warned deep sea mining could have huge impacts on marine wildlife (NOAA Office of Ocean Exploration/PA)

Exploratory deep sea mining is already under way, but mining on a large scale is on hold until nations have agreed the rules covering it, which are being developed under the UN International Seabed Authority with efforts to finalise them in 2020.

FFI warned that human activity was already putting a huge strain on the oceans, which have absorbed a third of our carbon emissions and 93% of the extra heat trapped by greenhouse gases.

Oceans are becoming more acidic because of the carbon dioxide dissolving into them, fisheries are under pressure as a result of over-exploitation and there are hundreds of huge “dead-zones”.

Pippa Howard, director at FFI and lead author of the report, said: “Minerals on the seabed are centre-pieces of deep sea ecosystems. Plans to mine the deep sea must be put on hold.

“The conclusions we have come to after extensive study could hardly be more troubling.

“From methane release to disruption of the ocean’s life-support systems and the destruction of unstudied ecosystems, the risks of deep sea mining are numerous and potentially disastrous.”

She added: “To place the ocean under the additional stresses that would be created by deep sea mining would be rolling the dice with the functioning of key planet-wide processes. We take this step at our peril.”

Deep-sea mining
The FFI has called for deep sea mining plans to be put on hold (NOAA Office of Ocean Exploration and Research/PA)

A Government spokesman said: “The UK continues to press for the highest international environmental standards, including on deep sea mineral extraction.

“While we have sponsored two exploration licences, these allow only for marine research to understand the effects of deep sea mining.

“We will not issue a single exploitation licence without a full assessment of the environmental impact.”