Orcutt Speaks on Deep-Sea Mining for Congressional Panel


Bigelow Laboratory Senior Research Scientist and Vice President for Research Beth Orcutt was recently in Washington D.C. to participate in a panel exploring the environmental, technological, and policy challenges around deep-sea mining. The event, hosted by the Oceans Caucus Foundation and the Senate and House Oceans Caucus, was moderated by a representative from the Congressional Research Service and included panelists from the Wilson Center and U.S. State Department. As a microbial ecologist, Orcutt’s research focuses on illuminating how deep-sea ecosystems function and respond to change. With that expertise, she has been active in international discussions around deep-sea mining, working to ensure that science — and science-informed policy — remains front and center. The following are her prepared remarks at the recent event.


I am the Vice President for Research and a Senior Scientist at the Bigelow Laboratory for Ocean Sciences in Maine, which is an independent research institute focused on studying the foundation of global ocean health to unlock its potential.

I have over twenty years of experience in deep-sea research, having spent over seven hundred days at sea on thirty-five national and international expeditions to explore the deep sea with robots and submarines.

I specialize in the study of microorganisms in the deep-sea, including those that make rocks and those that eat rocks.

As a scientific expert, I have participated at meetings of the International Seabed Authority to provide scientific context about the on-going negotiations to develop a mining code for international waters.

This participation has been either as an independent expert participating in ISA expert groups to develop recommendations for the Legal and Technical Commission of the ISA, or as part of an official Observer delegation of scientific experts providing objective input to the ISA Council on the developing mining code.

Finally, I co-direct an NSF-funded network-of-networks called COBRA focused on accelerating scientific understanding of the deep sea to inform decision making.

These experiences allow me to speak with you today about the life and environment of the deep-sea and about the important services that these habitats provide to humanity.

They also prepare me to speak about the potential environmental impacts of deep-sea mining.

I can also speak to you about the major knowledge gaps we have about these impacts, the obstacles to solving them, and about what research is happening in the U.S. and abroad to close the gaps.

I look forward to your questions and thank you again for inviting me to this dialogue.

What do we know about the kinds of organisms that live in the deep sea and the services that the deep sea provides to humanity?

You are absolutely right that we are learning more about life in the deep sea every day. New species are continually being discovered, which I find fascinating. Yet despite these advances, humans have only seen or imaged about 5% of the seafloor, and only 20% is currently mapped at high resolution. We have better maps of Mars than we do of Earth’s seafloor.

The deep sea is not a monolithic place, though; there are many different types of habitats. Three of these are targeted for mining. First, relatively flat muddy areas under the gyres of the ocean, where potato-sized nodules of manganese oxides have formed over hundreds of thousands to millions of years. Second, there are underwater ancient volcanoes where rocks become encrusted in manganese oxides over millions of years. Most of these habitats are in the northwestern Pacific between Hawaii and Guam. And third, along the mid-ocean ridges where hydrothermal vents have created deposits of sulfide minerals. Importantly, the rocks in these habitats are often associated with higher animal abundances.

We are learning that the different habitats themselves are diverse in terms of their physical properties. For example, I was part of a team that recently found new hydrothermal vents supporting octopus nurseries on underwater ancient volcanoes, yet no two of these underwater features were the same.

We are learning that the different deep-sea habitats targeted for mining have many unique species. Many of these species seem to be rare, making them more vulnerable to local extinction. For example, in the Clarion Clipperton Zone where the most nodule exploration contracts are located, it is estimated that there are around six thousand to eight thousand different species, but only 10% have been found so far. Furthermore, it is estimated that sixty to seventy percent of the species that provide structure for other animals — such as corals and sponges — depend on the nodule surfaces. The animals and microbes that live on the rocks are often different than what is in the surrounding mud and in the water. For most of the species, though, we do not know much about how they reproduce.

The animals and microorganisms in these environments contain an immense genetic diversity, which humanity might exploit for other purposes such as pharmaceuticals, biofouling solutions, and many other innovations. Microbes also harness this genetic diversity to provide important nutrient and waste recycling services in the deep sea that are essential to the functioning of the larger ocean ecosystem.

Beyond the seafloor, areas targeted for mining can overlap with commercial fisheries, such as for tuna, as well as the migratory paths for marine mammals and birds. These overlaps are expected to increase as species shift distribution in response to warming ocean waters.

Finally, the nodule-bearing habitats provide another important service in being places for carbon burial. This carbon removal helps to regulate global climate.

How would the deep sea and the species that live there be affected by deep sea mining?

I’ll focus on nodule mining, since this has received the most attention so far. Based on the prototypes tested for nodule mining, the mining machines would remove the nodules from the seabed using a jet of water to lift them up into a pipe to send to a ship.

For a sense of scale of this activity, it is estimated that each nodule mining contract would need to mine roughly 120 square miles of seafloor each year to be viable. This would be equivalent in spatial extent to mining an area the size of Tampa or Charleston or Portland, Oregon, each year for each mining contract. It is estimated that this activity would last for decades, and there are currently 18 contracts for nodule exploration in the Clarion Clipperton Zone between Hawaii and Mexico. The spatial impact in the water would be even greater than 120 square miles.

This mining process would create a plume of mud, crushed nodule particles, and crushed animal debris behind the mining machine. After the nodules are pumped up to a support vessel and dewatered, a slurry of wastewater would then be reinjected somewhere into the ocean, creating another plume of particle-laden and warmer water. In addition to the removal of nodule habitat, these activities would affect life in the deep sea by potentially smothering nearby animals with sediment, which could be especially problematic for the animals that don’t move around, like corals and sponges. The plumes could also blanket the areas where animal larvae would typically settle. The particles in both plumes could clog the filters of filter-feeding animals, could lead to ingestion of particles with higher metal contents that might be toxic and/or magnify up the food chain, and/or could lead to increased metal concentrations in the water that could be toxic to some life. These impacts would likely lead to a large loss of genetic diversity and biodiversity, since again, 60-70% of animal species need the nodules for habitat, and roughly 80% of these species are likely rare.

The noise and vibration in the water, which is estimated to travel hundreds of miles, could impact the migration of whales, fish, and other animals in the ocean. Likewise, continuous light pollution on the seafloor might alter animal behaviors, and the continual light pollution from support vessels could alter bird migration.

Finally, disturbance of the sediment surrounding the nodules could impact the carbon burial of this habitat, as the carbon in the resuspended sediment could be used as food for deep sea microbes, who would then respire this organic carbon into carbon dioxide. While the amount of carbon in a given teaspoon of sediment is relatively low, when you scale this to 120 square miles of impact each year, the amount of impact to diminishing carbon burial could be quite large.

What are the biggest knowledge gaps about impacts of deep-seabed mining, and what are obstacles to solving them?

A peer-reviewed report I co-authored in Marine Policy just two years ago identified many large knowledge gaps about deep-sea mining impacts. Overall, only one percent of the twenty scientific topics we assessed across these habitats had sufficient knowledge to enable evidence-based management. This includes topics like baseline information on animal reproduction, the magnitudes of ecosystem services, and response of these habitats to disturbance. For the Clarion Clipperton Zone, where the most baseline data exist, still only one of 20 topics had sufficient information.

Importantly, for the mid-water region where waste water plumes might be injected, baseline information is not publicly available for any of the regions where exploration contracts have been issued. Likewise, the report could not identify any studies on light, noise, and vibration impacts in these habitats.

Ninety percent of experts interviewed for this report indicated that it would take six to twenty years of intensive scientific research, on a scale not seen before, to generate sufficient baseline information to ensure effective protection of the marine environment. A big obstacle to conducting the scale of research required is the lack of sufficiently large research vessels that can conduct multi-week operations in these regions.

Importantly, while there are increasing studies within contracted areas, there are far fewer studies within the areas that have been set aside for protection. Moreover, typically these set aside areas are selected after contracted areas are decided, so it is likely that the areas set aside are not actually representative of the areas being contracted, diminishing the ability of these protection tools to ensure effective protection.

As I mentioned before, the plumes are expected to increase metal concentrations in the water, which might be toxic to life, but we currently have almost no data about acute or chronic metal toxicity impacts for deep-sea species conducted under the high-pressure and cold conditions that exist in the deep-sea. Thus, understanding what concentrations might be harmful is lacking.

Finally, unlike mining on land, where damage can be mitigated or offset, such as replanting forests, there is currently no scientific evidence that mitigation or offsetting would work in the deep sea to restore ecosystems and their functions. Thus, damages would essentially be permanent. Studies that have revisited the sites of trial, small-scale perturbations have seen little evidence of restoration even after decades.

What science is happening in the United States to address these knowledge gaps?

As I mentioned earlier, I co-lead a network-of-networks called COBRA, funded by the U.S. National Science Foundation, that brings together scientists with other stakeholders to accelerate research and information sharing about the deep sea to inform decision making. While there is a lot of scientific interest in the U.S. in understanding the environmental impacts of deep-sea mining, there is currently no large coordinated research program tackling this issue. A team of scientists from the University of Hawaii recently led the largest U.S.-based study within the Clarion Clipperton Zone, with funding from a private foundation. These studies formed the basis of a lot of the limited knowledge that we currently have from this location, along with research led by the UK, Belgium, Germany, and other European nations supporting ecosystem research in this environment. Importantly, most of these studies are snapshots in time, with few repeat measurements at the same place over time, to allow for understanding natural variability and the reproductive life cycles of animals.

Several US-based academic scientists are involved in helping with baseline assessments and monitoring for international contractors in the Clarion Clipperton Zone. For the most part, the involvement of these scientists allows for scientific publication of the work, so as not to impede scientific progress, yet it should be noted that the scientists are not in control of sampling plans to allow for full scientific rigor.

Scientists at the Global Marine Minerals Program of the USGS are analyzing the mineral composition of the mineral crusts that form on seafloor rocks that they collect, as well as samples of opportunity that are sent to them, to develop a better understanding of the mineral resources of the deep sea.

A major impediment to U.S. leadership in deep-sea research is the decreasing capability of the U.S. academic research fleet, which has significantly fewer ships than it did a decade ago. When newer ships are built, they are generally smaller in capacity than those that they are replacing. This doesn’t allow for the multi-week expeditions that are required for this kind of deep-sea research. The U.S. will also be losing our decades-long international leadership in scientific ocean drilling with the retirement this year of the flagship JOIDES Resolution drill ship out of Texas. The U.S. currently only has two vessels that are really dedicated to mapping the seabed of the deep-sea, as part of NOAA Ocean Exploration operations. With this level of effort, it would take many decades just to map the deep-sea in the U.S. Exclusive Economic Zone, let alone to collect samples for analysis.

What role does Congress have, or could Congress have, in the deep seabed mining space?

We are currently in the middle of the UN Decade of Ocean Science for Sustainable Development. Maintaining US-leadership in deep-sea science to enable understanding deep sea mining — and if it can be considered sustainable development — requires investment in ships, investment in exploration assets like robots and autonomous vehicles, investment in expansion of ocean observing to allow for real-time monitoring and sampling the environment, investment in the development of new methods and sensors for quickly sensing change in the environment, and investment in laboratory and seafloor experiments to understand the response of animals and microorganisms to perturbations. The National Science Foundation is currently undergoing a decadal survey to determine ocean science priorities. I hope that research focused on understanding impacts of emerging human industries like deep-sea mining will be identified as a priority. Furthermore, I hope that there are opportunities to determine the value of the natural capital and services of the deep sea, and how that value compares to the potential economic value of perturbing the deep-sea for mining.

If Congress decides to ratify the UN Convention on the Law of the Sea, it could allow the U.S. to have a stronger voice in international decision making about how, and if, mining could proceed while ensuring the effective protection of the marine environment.

Senior Research Scientist Beth Orcutt (second from left) on a congressional panel on deep-sea mining discussing the potential environmental impacts of this emerging industry. Photo courtesy of Carolyn Weis of the International Conservation Caucus Foundation.