According to scientists, mining activities on the high seas could affect cetaceans due to noise pollution, which could interfere with their communication processes.
A team of experts believes that impact assessments of such activities have focused on seabed species rather than sizable animals transiting areas where mining is planned, and that research is urgently needed to understand the potential impact on cetaceans.
However, one mining company says that the potential impact of planned activities on cetaceans is being assessed by examining acoustic data collected during its recent test mining at the Clarion-Clipperton rift zone, which will be analyzed alongside relevant environmental baseline data. over a period of three years.
International deepwater mining could begin this year after the Pacific island state of Nauru, which is supportive of the operations of a Canadian mining company's subsidiary, asked to speed up mining permits.
According to experts who urgently need to research the matter, the potentially imminent start of international deep-sea mining could affect whales, dolphins and porpoises, especially in terms of noise pollution.
In a new article posted on the Frontiers in Marine Science website , scientists working for the University of Exeter, Greenpeace Research Laboratories and Oregon State University argue that proposed deep-sea mining would likely produce a range of noises with frequencies equal to those used by cetaceans to communicate, which can potentially lead to changes in their behavior in these animals.
The authors say that most assessments of the potential impact of deep-sea mining on biodiversity have focused on 'seabed-related species and not transiting sizable animals' such as whales and dolphins. This is partly due to the paucity of data on cetaceans in mined areas, says lead author Kirsten Thompson, a marine science specialist at the University of Exeter in the UK.
“Cetaceans are a very diverse group of animals and most of what we know about them comes from studies done more closely inshore and on offshore islands,” Thompson wrote to Mongabay via email. “we know about the species that live in such areas”.
Sensitive to Noise
The report draws particular attention to the Clarion-Clipperton Fracture Zone, a 4.5 million square kilometer area in the Pacific Ocean earmarked for deep-sea mining, which is home to 30 cetacean species, there including sperm whales ( Physeter macrocephalus ), fin whales ( Balaenoptera physalus ) and critically endangered blue whales ( Balaenoptera musculus ). Beaked whales, known to be extremely sensitive to man-made sounds such as military sonars, also live in the area.
“These elusive [beaked] whales are the true deep-sea divers of the whale family and likely feed at depths where mining could occur,” says Thompson.
In September 2022, TMC and its business partner, AllSeas, conducted a mining test at the Clarion-Clipperton Rift Zone harvesting approximately 14 tons of nodules. The test has been the subject of controversy after scientists tasked with monitoring its progress leaked a video showing sediment being dumped onto the ocean surface, raising questions about the environmental impact of mining activities. A 2020 report suggested that dumping may be environmentally destructive due to the dispersion of sediment and dissolved metals . In an answerPosted on its website, the TMC called the incident a "case of limited significance" that "could not cause damage to marine habitat."
TMC CEO Gerard Barron also told Mongabay that the company is testing the noise generated and the potential effects on cetaceans by developing a "validated underwater noise model," created in collaboration with HR experts. Wallingford, an environmental hydraulics and engineering group, and the Scottish Association of Marine Science. In an email sent to Mongabay, he also added that the company has collected noise data during its recent verification mines at the Clarion-Clipperton rift zone.
According to Barron, “The data collected during the pilot trials of the harvesting system will allow us to understand the possible impacts on marine mammals and, if necessary, how we can optimize our system to mitigate those impacts. He added that the company is taking steps to ensure its operations "remain within environmentally friendly thresholds."
The company notes that TMC's Environmental Impact Statement would be made public if, eventually, the company asks to start mining.
Thompson, of the University of Exeter, believes it is important to ensure that there are peer-reviewed scientific assessments of mining noise and its impact on cetaceans, but that these assessments have not yet been published.
“We know that noise pollution in the oceans is already a problem for cetaceans and starting a new type of activity that would have to run 24/7 would inevitably create more man-made noise if mining activities in deep waters were to continue,” says Thompson. "Despite the lack of information, it appears that industrial-scale mining may soon begin in one of the few untouched habitats on the planet."