Deep-Sea Mining Damage Lingers 44 Years Later, Study Finds

A new study reveals that the impact of deep-sea mining on seafloor ecosystems can persist for decades, with damage still evident 44 years after mining activities ceased. Researchers found that the organic matter that supports life on the ocean floor remained significantly altered, raising concerns about the long-term recovery of these fragile environments. The findings come as interest in extracting rare metals from the deep sea intensifies, driven by demand for minerals used in electronics and renewable energy technologies. The study, published in a peer-reviewed journal, examined a site where a pilot mining operation had removed nodules from the seafloor in the 1970s. Even after more than four decades, the tracks left by the mining equipment were still visible, and the microbial communities and nutrient cycles had not fully returned to their pre-disturbance state. This suggests that deep-sea ecosystems, which are slow to recover due to low temperatures, high pressure, and limited food supply, may be more vulnerable to human activities than previously thought. The authors caution that commercial-scale mining could cause widespread and lasting harm to biodiversity and ecosystem functions that are not yet fully understood. As the International Seabed Authority considers regulations for deep-sea mining, this study provides critical evidence for policymakers weighing the environmental costs against economic benefits. The long-lasting footprint of a single small-scale operation serves as a warning for the potential consequences of industrial extraction in the deep ocean.