According to analysis of seabed ecology undertaken after drilling tests in 2020 in Japan – the country’s first successful extraction of cobalt crusts from deep-sea mountains – there was a decrease in marine life such as fish and shrimp at the site a year later. The density had dropped even further in areas outside the impact zone, by more than half.
The team of scientists analysed data from visits by Japanese mining engineers to the Takuyo-Daigo seamount. A year after the test extraction, researchers observed a 43% drop in fish and shrimp density in the “deposition” areas directly affected by sediment pollution, and a 56% drop in surrounding areas.
“There is still so much we don’t know, but it will likely be decades to answer some of those questions.”