As Deep-Sea Mining Threats Abound, So Do Calls for Safe Zones, Moratorium

A week before Western Pacific Fishery Management Council members railed against a proposal to expand the Pacific Remote Islands Marine National Monument, a member of the council’s Scientific and Statistical Committee (SSC) suggested that there was at least one aspect that might have some merit: its protection against deep-sea mining.

The proposal, initiated by a group called the Pacific Remote Islands Coalition, calls for the extension of the monument boundaries around Howland and Baker islands and Kingman Reef and Palmyra Atoll from 50 nautical miles to 200 nm, which is the outer extent of the U.S. Exclusive Economic Zone.

The proposed expansion area has 98 largely unexplored seamounts, which are “ecological hotspots for biodiversity” with new species being cataloged on every dive, states a coalition report.

The proposed monument expansion areas sit amidst regions abundant with polymetallic nodules and cobalt-rich crusts.

New Zealand’s Shelton Harley, an SSC member who has helped develop tuna stock assessments for the Western and Central Pacific Fisheries Commission, argued at the committee’s meeting last month that simply expanding protected areas in the Pacific to meet a Biden administration goal to protect 30 percent of the nation’s waters doesn’t really promote biodiversity.

“Putting all your eggs in one basket, it doesn’t make sense scientifically because you are not protecting representative habitats,” he said. However, he added, “I wonder if there are some aspects that might have some support,” referring to the proposal’s focus on the threat of seabed mining.

While fishing effort within the proposed expansion areas by U.S. longline and purse seine vessels is minimal, according to tracking data compiled by Global Fishing Watch, the coalition notes that “mining interests have identified PRI’s waters as a high value, and therefore high interest area.”

The coalition argues that deep-sea mining threatens to damage the environment, including fisheries, and will kill deep-sea benthic organisms and create toxic wastewater tailings. At the SSC meeting, University of California at Santa Barbara marine science professor Doug McCauley expanded on the potentially harmful impacts deep sea mining may have.

First, there’s the noise pollution from the massive vessels and machinery that would be operating on 24 hours a day. “This may be one of the loudest things we’ve done in the ocean,” he said.

With regard to the effluent plume released into the mid-water column, he said there is a lot of uncertainty over the biosolubility of the minerals it will contain. Those minerals are likely to include copper, cadmium, cobalt, chromium, iron, nickel and zinc. Will the cadmium, a known carcinogen, build up in tuna tissue? “There are no empirical measurements one can make because it hasn’t started yet,” he said.

With a 1,000 kilometer-wide plume potentially clouding waters that have historically been crystal clear and “don’t have an ecological history of dealing with that, would you be eroding some of the forage grounds?” he added.

A recent report published by the UNEP suggests that the plumes might be smaller, closer to tens of kilometers wide, and they could persist for a up to a year, smothering habitats and interfering with foraging.

Harley asked McCauley whether any relevant work has been done on the impact mining activities may have on carbon sequestration.

McCauley said there are at least two ways mining could affect carbon storage and capture. Carbon that has been stored in the earth for millennia will be unearthed by mining, he explained. “There’s a lot of uncertainty on what it will mean for where carbon is located.” He added that the industry’s effluent plumes may impact communities (i.e., phytoplankton) that control the amount of carbon that is sequestered in the ocean.

The UNEP report expands on the potential for deep-sea mining to exacerbate climate change.

“[M]arine sediments store approximately twice as much organic carbon as terrestrial soils. Sediments in abyss/basin zones account for 79 per cent of global marine sediment carbon and, as such, represent a large and globally important carbon-sink. However, the lack of protection for marine carbon makes it vulnerable to human disturbances that can lead to their remineralization to CO2, further aggravating climate change impacts.”

“I would say there are way more questions than there are answers about climate impacts,” McCauley told Hawley. McCauley added that there is a rich set of pure, industry-funded science on the biodiversity on the sea floor, but he’s seen little research on potential impacts on fishing or climate.

He did note that a 2021 study published in Marine Policy reported that the Clarion-Clipperton Zone southeast of the Main Hawaiian Islands, which is being targeted for mining, accounts for up to 10.5 percent of the combined catches of skipjack, yellowfin, and bigeye tuna in the Eastern Pacific with an assumed “no-fishing” buffer of 200 km around the zone.

In addition to all of the potential harms McCauley described, the UNEP report warns that mining activities would also “introduce artificial light to deep sea environments that are normally light-deprived (both of which may attract or deter some fish species, and may alter normal feeding and reproduction behaviours).” They would also release oxygen-rich water into low-oxygen environments, it stated.

The U.N.’s International Seabed Authority (ISA) is meeting this month to continue its development of regulations for industry activities on the high seas, pursuant to the U.N. Law of the Sea Convention. 

The ISA is pushing to get rules in place because the island nation of Nauru indicated last year that it plans to mine polymetallic nodules in the Clarion-Clipperton Zone. With or without ISA rules, the country and The Metals Company may apply as early as July 2023 to start mining. If approved, mining may begin the following year.

With the possibility that this new industry may break ground soon and harm the marine environment, Palau and Fiji last month called for a moratorium, according to Reuters.

Because the United States is not a signatory of the Law of the Sea Convention, it is not a member of the ISA and may merely observe its proceedings.

With regard to the possibility of deep-sea mining occurring within the U.S. EEZ around the Pacific Remote Islands, any such mining would require approval from Congress. McCauley noted that during the Trump administration, there was a significant increase at ISA meetings in the number of representatives from the United States who were interested in accelerating seabed mining.

— Teresa Dawson

Leave a Reply

Your email address will not be published. Required fields are marked *