The CCZ, a massive underwater plain that lies between Hawaii and Mexico, is the world’s largest deep-sea mining area. It’s the site of a special ecosystem teeming with bizarre and endemic creatures—most of which remain undiscovered by science. The deep seabed is covered with unusual, metal-rich rocks known as “nodules.”
Incredible Natural Formations
Scientists estimate that these delicate formations took millions of years to grow. These nodules are enriched in a number of metals including cobalt and nickel, vital for technologies known in our pocket, smartphones, and rechargeable batteries. The CCZ has a minimum predicted 21 billion tonnes of nodules covering its several million square kilometer seabed. This bounty has already generated tremendous excitement among those who are eager to unlock these valuable resources.
In 1979, private companies went in for a pilot test in the CCZ to determine the technical feasibility of harvesting these nodules. This test produced a crater measuring 1,600 feet across and 150 feet deep. It plowed a half mile wide swath of nodules and big gouging tracks, eight meters spaced, from the deep sea mining machine. These tracks have unbelievably remained in view for more than 40 years. This has led scientists in the UK to assess the long-term effects of historical mining operations. Their study, published in the journal Nature, is the longest-term evaluation of a deep-sea mining track.
The Environmental Impact
The research underscores how the physical impacts of mining in the CCZ can linger for many decades. More than forty years later, the imprint from the 1979 detonation still shines through, sharply outlined on the ocean floor. This permanent legacy effect is especially troubling given the potentially deadly environmental impacts of future mining activity that could occur on the site.
"Visible physical impacts of the collection can be assumed to last for at least many decades," authors of the research stated.
The nodules themselves are habitats for marine life, their removal releasing sediment and destroying entire ecosystems in the process. Fisheries researchers have shattered the dream that full recovery of the seabed “is achievable,” the moment these nodules are removed from the ocean floor.
Prospects for Recovery
The study by UK scientists reveals early evidence of biological return within the tracks. The populations of most animal species were severely impacted.
"The numbers of many animals were reduced within the tracks but we did see some of the first signs of biological recovery," said Daniel Jones, the lead author from the National Oceanography Center.
Though new machinery could reduce the damage, full restoration of these fragile ecosystems is never guaranteed. These results suggest that innovation can make technological progress continue to reduce and even reverse environmental harm. The permanence of the physical scars left from mining could last for generations or decades if not longer.
Future Considerations
Global demand for metals such as cobalt and nickel is surging, propelled by their use in rapidly developing technologies. This boom in demand has created a strong appeal for deep-sea mining, particularly in areas such as the CCZ. At the same time, this study highlights the need to use clear methodology to justify weighing environmental costs against possible economic benefits. The enduring legacy seen today from the 1979 test should be a lesson and warning for any such undertaking going forward.