The USGS is studying the effects of mining to help the International Seabed Authority determine what environmental protections are needed.
“It’s important to realize that all types of mining have environmental consequences,” said USGS spokesman Alex Demas.
The USGS is in the very early stages of researching these factors, Demas said.
Last month, a group of Massachusetts Institute of Technology ocean scientists released the results of a study on sediment clouds created by seabed mining. They worked with Global Sea Mineral Resources, a Belgian marine engineering company exploring ways to extract polymetallic nodules.
The MIT researchers equipped what they called a “pre-prototype collector” with instruments and cameras to monitor the sediment plume created by the machine. Their measurements showed that as the sediment plume dispersed, it “remained relatively low, staying within 2 meters of the seafloor,” an MIT publication said.
“The big takeaway is that there are complex processes … that take place when you do this kind of collection,” said Thomas Peacock, an MIT mechanical engineering professor and co-author of the study.
In general, researchers are concerned the plumes could spread beyond the mining site and harm deep-sea life.
Most mining companies applying for Seabed Authority permits use machinery like the collector in the study, which suck rocks and surrounding material from the seafloor.
The Global Sea Mineral Resources system separates nodules from sediment inside the collector. The nodules are sent to a surface vessel through a pipe, while most of the sediment is discharged behind the collector.
Metals Co. said its method carries polymetallic nodules to the surface, with water and sediment discharged to a “midwater column.”
