To fulfill the green energy transition’s great thirst for batteries to store renewable energy, mining companies are eyeing the floor of the deep ocean.
There they hope to extract the huge amounts of cobalt, nickel, manganese and copper the transition requires. But California’s environmental movement is averting its gaze.
A bill introduced in February by California State Representative Luz Rivas of San Fernando Valley would ban mineral extraction from state tidal waters, or the area up to three miles out to sea from the shoreline. No one is mining that seafloor now – and actually no one is doing this kind of seafloor mining anywhere, yet – but that’s precisely why the California Seabed Mining Prevention Act is so named.
“Mining which has mostly been on land in the past is very controversial because it comes with social justice and environmental issues,” said Laura Walsh, California policy manager at the Surfrider Foundation. “But the world’s going to need massive amounts of cobalt and nickel.”
The ocean floor contains baked potato-sized rocks formed millions of years ago in some of the ocean’s deepest waters roughly 2,000 meters below surface. Some of these deposits are called phosphorites, which could be used to produce fertilizers. Others are called polymetallic, meaning they contain multiple metals, nodules, manganese crests and massive sulfides, which form near underwater vents spewing heat from below the Earth’s crust.
Mining companies seem to be most interested in those polymetallic nodules that contain elements needed to make batteries for everything from electric vehicles to iPhones. But some studies have shown there may be deposits containing gold or other desirable metals, too.
But some scientists question the need to dig below water, especially since humans know very little about what lives on the deep ocean floor or how a disturbance like minerals mining might upset the sea’s food chain.
A Pacific football fish preserved and on display at Birch Aquarium in La Jolla. The rarely-seen deep sea fish washed ashore in Encinitas on December 10, 2021. / Photo by MacKenzie Elmer
Scientists used to think the ocean floor was food poor and homogenous up until we started using sonar to map it, said Lisa Levin, a biological oceanographer at University of California-San Diego’s Scripps Institution of Oceanography, in a 2015 presentation. Among discovering hundreds of thousands of underwater volcanoes with crusts rich in precious metals, researchers discovered really old fish living in the deep sea and a biodiversity rich in marine life, she said.
Now her research is focused on what kinds of microscopic life live on the mineral resources themselves.
“Sea bed mining may remove food resources for bottom fish but it may also release contamination or create suspended sediment plumes that interfere with larval fish development,” Levin said in an interview.
There are likely some phosphorites, the rock that could be useful as fertilizer, off the coast of San Diego, which could be protected by the state bill. But the battery resources are likely concentrated in waters not controlled by the state of California.
Much of the known mining interests will be governed by the International Seabed Authority, a body representing 167 member states and the European Union. Levin said the authority has only granted leases to explore the ocean floor, not remove or exploit them, yet. The closest area of interest is the Clarion Clipperton Zone west of the Mexican coast.
I tried to get a better picture of what deep sea mining looks like from the companies that do it. The Metals Company, based in Vancouver, declined an interview request but sent a video that describes its proposed technology: autonomous robots that suck up the ocean rocks and flush whatever ocean crust it collects back onto the floor.
Ideally the mining system could shut down should it sense an area with high oceanic life. The rocks would then be sent to an onshore plant powered by renewable energy to separate the desired electric vehicle battery metals, according to the video.
The company has also funded research on the impacts of ocean floor metals mining on deep sea habitats and organisms along the water column. That January 2022 paper suggests waste from deep ocean minerals mining could produce less toxic waste than mining on land, and the research argues that the quality and abundance of battery metals on land is decreasing.
That’s up for debate. Levin said there are likely resources on land that could fulfill the planet’s metals needs for the next 20 years.
“Over that time, technologies for batteries may change,” Levin said.
Resource extraction debates are tough ethical lines to follow because they are not straightforward.
I’ve reported on impacts of copper and lithium mining to indiegnous communities in Chile that subsequently rely on that labor for employment. Those communities call themselves “sacrifice zones” as the world scrambles to transition to fossil fuel-free vehicles and renewable energy.
The sacrifice zones in the deep ocean are arguably the hardest to see – therefore will likely be the most difficult to verify.