It protects us, but do we protect it?

Alvin dive #2141...

the catalyst

Alvin hummed with ease as it began its ascent up SeaMount 7 (M 7.0), an underwater volcano. The new thrusters, battery packs and lift tee Alvin received two years ago, in 1986, improved the human-occupied submersible (HOV) tenfold and the passengers of dive #2141 could tell. Previous Alvin dives lacked maneuverability, but the upgrades were not what set this dive apart.

Alvin’s #2141 pilot held the steering wheel steady as the vehicle continued climbing the flanks of M 7.0. Lisa Levin, a North Carolina State University benthic ecologist, was one of three passengers in dive #2141. From her side of the 6 ft by 6 in sphere, Levin stared out of a small circular viewport. She marveled at all the brittle stars — amazed that they existed in the deep ocean that is supposedly low on food. As she entered the latter hours of the dive, Levin noticed lifeforms fading into the darkness that trailed the HOV. She made note of the change she saw occur around the apex.

It was not until hours later, once she reviewed the findings back on the ship, that Levin understood the changes observed around 750 meters below the Pacific Ocean. On November 25, 1988, around 200 miles off the coast of Acapulco, changed the trajectory of Levin’s career.

During dive #2141, she observed oxygen minimum zones and how they affect ecosystems. Over the following years, Levin wrote many papers on low oxygen zones occurring in the deep ocean. It emboldened her love for the deep sea and inspired her to be at the forefront of ocean policymaking and her want to protect it.

Current status on mining

In the wake of the industrialization, climate change and global warming, the world’s oceans have drastically changed — and not necessarily for the better. While the deep ocean is currently subjected to many stressors, it is also prone to future ones that are in development. “The health of the ocean will ultimately determine the survival of humankind on Earth,” according to Peter Thomson, the U.N. Special Envoy for the Ocean. The deep sea’s health is being placed at further risk due to the impending deadline on an additional ocean stressor — deep sea mining.

In June of 2021, the Republic of Nauru’s former president, Lionel Aingimea, informed the International Seabed Authority (ISA) of the nation’s intent “to apply for approval of a plan of work for exploitation.” By doing so, the small island nation in Micronesia triggered the “two-year rule.” The following is the clause that details the rule from the United Nations Convention on the Law of the Sea (UNCLOS).

“15. The Authority shall elaborate and adopt, in accordance with article 162, paragraph 2(o)(ii), of the Convention, rules, regulations and procedures based on the principles contained in sections 2, 5, 6, 7 and 8 of this Annex, as well as any additional rules, regulations and procedures necessary to facilitate the approval of plans of work for exploration or exploitation, in accordance with the following subparagraphs:

• (a) The Council may undertake such elaboration any time it deems that all or any of such rules, regulations or procedures are required for the conduct of activities in the Area, or when it determines that commercial exploitation is imminent, or at the request of a State whose national intends to apply for approval of a plan of work for exploitation;
  
• (b) If a request is made by a State referred to in subparagraph (a) the Council shall, in accordance with article 162, paragraph 2(o), of the Convention, complete the adoption of such rules, regulations and procedures within two years of the request;
  
• (c) If the Council has not completed the elaboration of the rules, regulations and procedures relating to exploitation within the prescribed time and an application for approval of a plan of work for exploitation is pending, it shall none the less consider and provisionally approve such plan of work based on the provisions of the Convention and any rules, regulations and procedures that the Council may have adopted provisionally, or on the basis of the norms contained in the Convention and the terms and principles contained in this Annex as well as the principle of non-discrimination among contractors.”
  

The ISA, which is the entity mandated by the United Nations to govern seafloor activities, was then thrust into an urgent need to develop rules and regulations on the matter of deep-sea mining. The ISA still has neither fully developed nor reached agreements on comprehensive mining regulations.

Under Article 15 of Section One in UNCLOS, the ISA must be notified by member states of the intent to deep sea mine. Once the member state does that, ISA is required “to adopt rules, regulation and procedures to govern the proposed mining activity[;] if this is not achievable, the ISA must at least evaluate the mining proposal by the end of the two-year period,” according to Mongabay’s 2021 series titled Deep Sea Mining.

The “two-year rule” makes the additional ocean stressor of deep-sea mining a very real possibility. As soon as July of this year, the ISA will need to evaluate Nauru Ocean Resources Incorporated’s (NORI) exploitation mining proposal. Although Nauru submitted the intent, it is important to note that NORI is a subsidiary of The Metals Company. The Canadian corporation has already received a 15-year exploration approval from the ISA for valuable minerals that lay in the Clarion Clipperton Zone (CCZ). Despite reaching out to The Metals Company various times, they declined to comment.

Map courtesy of Center for Biological Diversity via International Seabed Authority

The Clarion Clipperton Zone (CCZ), is a 4.5-million-square-kilometer (1.7-million-square-mile) abyssal plain stretching between Hawai‘i and Mexico. This region of the seafloor has a plethora of abundance of polymetallic nodules. These potato-sized rock accretions can be found on the seafloor. Within this zone, there are vast reserves of commercially valuable mineral resources such as cobalt, manganese, copper, nickel, silver, or gold.

the promise of sustainable development

However, the issue of deep sea mining is causing a rift between scientists and industry stakeholders.

“It is the greenwashing of extraction industries, and the powers that be are using this [two-year rule] as an excuse to extract,” said Patricia Lieberg Clark, a wildlife biologist consultant and Scripps Institution of Oceanography (SIO). volunteer. “It is sickening, and sadly, it is actually effective.”

Shifting away from fossil fuels and lowering emissions is a possible remedy to our world’s climate change problem, which has gained traction in the media. The term “electrification” represents a solution to global warming, and industry around extraction and exploitation is rapidly growing because of it.

In September 2022, the International Energy Agency released an energy system overview analysis on electrification. They reported the following:

“With significant potential to mitigate emissions and decarbonise energy supply chains, electrification is an important strategy to reach net zero goals. As more energy end uses become electrified, the share of electricity in total final energy consumption increases in the Net Zero Emissions by 2050 Scenario from 20% in 2021 to 27% in 2030.”

Many corporations, like The Metals Company, portray their involvement in exploitative extractions as a means to create a greener future. While it is true that polymetallic nodules contain precious metals needed for batteries and electric vehicle components, scientists worry if the risk of habitat degradation, pollution, spreading of low oxygen zones, ecosystem ruination, and decrease in biodiversity — among other harmful effects — are worth scaling up and approving exploitation proposals.

Levin and fellow scientists are worried about the harm that could occur by scaling up mining operations and taking them out to sea. It makes them wonder whether or not the United Nations is even trying to live up to its Sustainable Development Goals (SDGs). One of the 17 SDGs that pertains directly to deep sea mining is Goal 14: Life below water. If deep-sea mining creates stress in the deep ocean, is it truly the champion of sustainable development for a greener future? Goal 14 reads as follows:

“Conserve and sustainably use the oceans, sea and marine resources for sustainable development.”

WHAT DOES IT DO FOR us?

The ocean is in a delicate balance due to its high degree of interconnectivity. Ocean stressors impact its ability, along with the abilities of marine organisms and bacteria, to function while in this delicate balance. The deep ocean is incredibly important in regard to climate change; they function as a carbon sink. While many people like to say “mitigation” when describing the ocean’s efforts against climate change, Levin said that word does not encapsulate everything. People tend to use mitigation as a means to describe extra removal. However, Levin said the ocean’s removal of carbon dioxide is a natural process.

“We sometimes say the ocean is the greatest climate mitigator because it takes up heat and carbon all naturally,” said Levin. “They [legacy emissions] would be much higher if the ocean wasn't taking it up.”

The phytoplankton in the ocean uses heat and carbon dioxide to grow. The ocean plays an integral role in curbing the effects of climate change and global warming because it diffuses a lot of the planet’s heat.

“If we didn't have an ocean, we'd be 93% hotter on this planet,” Levin said.

Despite the ocean’s carbon dioxide removal efforts, climate-related stressors still exist — further jeopardizing the balance. According to Levin, climate-related deoxygenation comes from two main influences. Solubility and stratification are both related to ocean warming.

Since the ocean takes up so much heat, it gets warmer as the air gets warmer. Warmer waters hold less gas. The word for this concept is solubility.

“Oxygen is less soluble when the water is warm,” Levin said. “As the ocean warms from global warming, it is losing oxygen.”

Stratification is more physical rather than chemical and refers to layers. Thermal stratification is the mechanism behind the top of the ocean being warmer and getting colder as you go down deeper. However, stratification has become more intense due to ocean warming.

“The normal process of mixing of oxygen, which happens from the air to the ocean, to the interior surface of the ocean to the interior, is less,” said Levin. “When the ocean is more stratified, there is less vertical mixing of oxygen.”

When combined, solubility and stratification illustrate ways in which climate change causes oxygen decline in the open ocean. The two influences are not sequestered from other stressors. Solubility and stratification can intersect with dead zones, agricultural runoff, eutrophication, sewage drainage, and more in coastal areas. Climate change worsens these coastal processes making oxygen loss occur earlier in the year, thus, making it last for longer. These processes exacerbate deoxygenation.

“Those are the processes at play,” said Levin. “They are all kind of linked.”

Biodiversity, the carbon cycle and more

The deep ocean is quintessential to life as we know it. Many foundational species to the food chain call the deep ocean home and support biodiversity.

“Biodiversity is the diversity of life in a given location, expressed by typically what people say is the diversity of species,” said Rodolfo Dirzo, a professor and associate dean of Stanford University’s Doerr School of Sustainability. “A typical metric to measure biodiversity is the number of species which is also called species richness.”

Johanna Gutleben, a post-doctoral researcher at SIO, said, “Biodiversity is important because it keeps things in balance.”

The deep ocean has a high level of species richness due to its varied ecosystems. When biodiversity decreases, the different life types in different ecosystems are also impacted. It also connects to the carbon cycle.

Courtesy of the

International Atomic Energy Agency

Courtesy of the Woods Hole Oceanographic Institution

The work of the Levin Lab shows how integral benthic communities and ecosystems are to the carbon cycle and ocean health. Olívia Pereira, a PhD candidate in the Levin Lab, studies benthic communities in chemosynthetic ecosystems. One of her areas of focus is invertebrates living on carbonate rocks at methane seeps. Throughout her research, Pereira observed the strong interconnectivity of the deep ocean.

“There are lots of the same animals living on these different chemosynthetic ecosystems and they're connected,” said Pereira. “If you destroy one of them, you break a link.”

The links support the synergy in the ocean. Disruptions, like mining or fishing, to the “connecting links” jeopardizes organisms. Links are crucial for the dispersal of these animals. Pereira believes we could start seeing more endemic species because of this.

“Species are not going to be able to disperse anymore, so they are going to be found in one place, which can lead to extinction,” said Pereira. “In the future, with warming and deoxygenation, the recovery rates of these species and ecosystems might be even worse.”

Another stressor concerning Pereira is the possible expansion of oxygen minimum zones, similar to the one Levin experienced in Alvin dive #2141. Expanding these zones will especially affect deep-sea animals because many of these regions are at the threshold between shallow and deep sea. When these zones expand, habitat compression occurs.

“Animals that are living at 500 meters may have to migrate up because the oxygen minimum zone is extending up, or animals that are at 1000 meters might have to migrate down because the oxygen minimum zone is coming down,” said Pereira. “If you migrate down, you have more pressure and colder waters, so there are a lot of physiological adaptations that might start playing a role, and we don't know if it is even possible.”

Deep sea mining could disrupt a foundational level of the delicately balanced marine ecosystems. By disturbing deep-sea life and destroying benthic communities, ecosystem links and functionality are prone to breaking.

Mining as another stressor

In February 2022, Levin and one of her colleagues in the deep sea science and policy field, Diva J. Amon, published a multi-authored paper in the Marine Policy Journal. Amon, a scientific advisor to the University of California, Santa Barbara’s Benioff Ocean Science Laboratory, assessed the scientific gaps related to effective environmental management of deep-seabed mining in the paper. Amon highlighted the many environmental impacts of deep-seabed mining.

“Serious concerns have been raised over the potential environmental impacts related to deep-seabed mining if it commences, especially given the vast number of unknowns about the relevant habitats,” Amon wrote. She continued to explain the detrimental effects of the mining. Ferromanganese-encrusted seamounts, polymetallic nodules on the abyssal plain and massive sulfides at hydrothermal vents “have been shown to support biodiversity and play a role in biological enrichment, increasing ocean productivity, and carbon sequestration.”

The extraction will damage valuable ecosystems and decrease biodiversity. Part of the destruction comes from the waste produced during the process.

“They call it return water, and it is full of nasty chemicals that have been released, and it gets put back into the deep ocean,” said Levin, who also works at the nexus of science and policy. “They [the International Seabed Authority ] are still debating about whether it [return water] is put back into the sediment surface or whether it is put back in mid-water.”

Amon offered the following explanation of waste pollution:

Movements of the large collecting device (e.g., at 1–2 knots over the seafloor) plus separation of nodules from sediments at the seafloor will create suspended sediment plumes in bottom waters. Entrained water and fine particles lifted to the ship will be reinjected into the water column (depth still to be determined, but ideally at the seabed) through a dewatering pump and pipe. Mining of polymetallic sulfides and cobalt-rich ferromanganese crusts are likely to both employ three machines to extract the deposits: 1) a cutting machine to flatten the topography and create benches, 2) another cutting machine to further disaggregate the benches, and 3) a collecting machine which will suck the disaggregated rock through a pump and riser system as a slurry.

However, the ore processing to actually extract the minerals, which is performed back on land, involves lots of acid waste. “It is done in all sorts of nasty ways,” Levin said while shaking her head. The mining operation also suspends sediments and releases metals — which are in the return water. This impacts habitat and consumption.

“It could lead to reduced oxygen if it stimulated microbial growth and added nutrients; it can reduce the light that animals have to see — like bioluminescence,” said Levin. “It can create particles in the water that they might feed on, instead of food particles; so there are all kinds of problems that [mining] could create.”

The scientific community feels as if the associated effects and direct impacts of deep-seabed mining have not been thoroughly evaluated. This is due, in part, to the lack of data across resources. Ecosystem characteristics do, however, provide much-needed insights on sensitivities to mining disturbances.

The three aforementioned types of mining can produce five categories of environmental impacts. The categories Amon highlighted are as follows:

1. Removal of the resources together with the biologically active benthic zone, i.e. fauna and seafloor surface
   
2. Generation of sediment plumes created from the disturbance on the seafloor (“collector plume”) as well as from the return water (“dewatering plume”) that may cloud the water column or smother/blanket unmined seafloor areas
   
3. Chemical and metals released along with changes to water properties
   
4. Increases in noise, vibration and light
   
5. Cumulative impacts The resulting environmental effects may include loss of seafloor integrity, reduced biogeochemical process rates, and biodiversity, as well as species displacement, and in turn, modified trophic interactions and loss of connectivity, which could lead to species extinctions and loss of ecosystem functions and services
   

The extraction efforts could also negatively impact existing marine industries such as fishing. A decrease in the catch, “displacement of fishing effort and/or spatial concentration of fishing effort promoting depletion of background areas,” are all prone to occur with deep-seabed mining. The mining will remove resources that are valuable not only to humans but also to marine life. Amon explained how recent studies conducted in the Peru Basin and CCZ prove that mining-type removal — like nodule removal — on a small-scale “reduced faunal biodiversity and altered species composition and ecosystem functions remain over 2- 4 decades later.”

“This could lead to an irreversible change, decline, or loss in key ecosystem functions such as nutrient and carbon cycling, habitat provision, maintenance of population connectivity, regulation of food webs, especially in directly disturbed areas and lead to local extinctions of species reliant on nodules,” wrote Amon, who is also a National Geographic Emerging Explorer and a Pew Fellow in Marine Conservation. “The recovery of these ecosystems for motile sediment-dwelling fauna could take hundreds to thousands of years due to low sedimentation rates, whereas fauna that rely on the nodules may not recover for millions of years as the nodules regrow very slowly.”

Graphic Courtesy of Amon et al.

The above graphic is Figure 1 from the 2022 Amon paper. “Current level of scientific knowledge in relation to evidence-based environmental management of deep-seabed mining in regions where exploration contracts have been granted by the ISA. This has been compiled from a synthesis of the peer-reviewed literature and expert opinion and includes both target and non-target areas within each region."

( * denotes benthic and pelagic habitats)

Fighting for our seas

The deep ocean starts at 200 meters below the surface — making up 90% of the ocean. The deep sea is all around us, despite seeming far away. Although deep-sea mining seems out of reach and definitely out of sight, it is closer than we think. June 25, 2023, marks two years since President Aingimea wrote to the ISA and informed their 26th session of Nauru’s intent to participate in deep-seabed mining. The two-year rule lets up in a matter of days.

With the critical role the ocean plays in our daily lives, many scientists find it is important now more than ever to protect and conserve it. Deep ocean stewardship will ensure the well-being, proper functionality, maintenance and overall health of the world’s oceans — especially in the CCZ.

Apart from making a vested effort to slow down emissions and curb the effects of climate change, scientists, policymakers and laypeople alike should focus on decreasing the list of ocean stressors rather than adding to it. If enough ISA member countries come together to stop deep sea mining, a moratorium can be placed on exploitative extraction, thus, protecting the deep ocean.

“It [deep ocean] is already doing its job; it has been,” said Pereira. “Protect it.”

Nearly 37 years ago, Levin experienced not just the wonders of the deep-ocean but also a soon-to-be budding concern in her benthic marine ecology career. Levin challenges us to point the finger back at ourselves. The deep ocean has protected us, despite all the stressors we throw at it – like climate change effects, pollution, eutrophication, exploitative industries and more. So I implore you all to ruminate on this question. It protects us, but are we doing the same?

Deep Ocean Stewardship Initiative (DOSI)

Crustal Ocean Biosphere Research Accelerator (COBRA)

at the Bigelow Laboratory for Ocean Sciences

Deep Ocean Observing Strategy (DOOS)