Researchers call for balance between mining and ecosystem protection
New research shows that proposed mining on the seafloor of the Pacific Ocean would likely have a huge impact on marine biodiversity. A study published in the journal Scientific Reports, documents an “impressive abundance and diversity among the creatures” on the seafloor in the Clarion-Clipperton Zone — an area in the equatorial Pacific Ocean being targeted for deep-sea mining.
“We found that this exploration claim area harbors one of the most diverse communities of megafauna (animals over 2 cm in size) to be recorded at abyssal depths in the deep sea,” lead author Diva Amon said in a press release.
The researchers explained that a combination of biological, chemical and geological processes formed a high concentrations of polymetallic “manganese” nodules on the deep seafloor in the CCZ–an area nearly the size of the contiguous United States. These nodules are potentially valuable sources of copper, nickel, cobalt and manganese, among other metals, which has led to an interest in mining this region.
The preliminary data from the new research showed that more animals live on the seafloor in areas with higher nodule abundance, and that the biodiversity is linked with the polymetallic nodules themselves, and thus are likely to be negatively affected by mining impacts.
“The biggest surprises of this study were the high diversity, the large numbers of new species and the fact that more than half of the species seen rely on the nodules–the very part of the habitat that will be removed during the mining process,” said Amon, a post-doctoral researcher at the University of Hawai’i at Mānoa School of Ocean and Earth Science and Technology. More than half of the species collected were new to science, showing how little is known about life on the seafloor in this region.
The study, part of the ABYSSLINE Project, was the first to characterize the abundance and diversity of seafloor-dwelling animals, a key component of deep-sea ecosystems. The researchers used a remotely operated vehicle to survey the seafloor at four sites within the UK-1 exploration contract area and at a site east of the UK-1 area to estimate abundance and diversity of the ecosystems.
Exploitation plans are pushing ahead even though knowledge of the seafloor ecosystem in this region is still limited.
“In order to more effectively manage the area and mitigate the environmental impacts of deep-sea mining in the CCZ and within the UK-1 contract area, baseline knowledge of the abundance, diversity, and species ranges of megafauna–a key component of this ecosystem–is essential,” said Craig Smith, oceanography professor at UHM SOEST and ABYSSLINE lead investigator.
The ABYSSLINE team will be publishing many more papers about the seafloor biology of the CCZ, with forthcoming papers from UHM scientists including an atlas of megafauna from the UK-1 exploration contract area, a study documenting extremely high diversity in the community of macrofaunal community (crustaceans, worms, mollusks and other invertebrates between 2 and 0.3 cm in size) in the UK-1 exploration claim area.