Scientists have collected critical minerals from ocean water using seaweed, a type of algae that leaves behind a mineral-rich powder called bio-ore after being processed into biofuels.

Weird ways critical minerals are being mined

Critical minerals like lithium, cobalt, and graphite are economically crucial non-fuel resources subject to supply chain risks. To diversify production, scientists developed odd ways to harvest them. This article breaks down the weirdest approaches, including extracting minerals from seawater using algae, phytomining plants, and asteroids.

Algae can capture carbon dioxide at rates up to 50 times faster than land-based plants and can be grown in tanks that use one-tenth the land footprint of terrestrial plants.

Explaining the engineering challenges of extracting metal-rich nodules from the seafloor

Proposed solutions for collecting these potato-shaped rocks involve lifting a slurry composed of them, organic debris, and water through several kilometers of flexible tubing to a ship on the surface, a process that is more difficult than pumping crude oil. One method would use compressed air, but this method is only 15% energy-efficient.

Distinguishing the three types of mineral deposits collected via deep-sea mining

The greatest interest is in polymetallic nodules—structures formed from metals in seawater collecting around a core of shell, bone, or rock. Cobalt-rich ferromanganese crusts cover underwater mountain ranges and form over millions of years of metal deposition. Polymetallic sulfide deposits accumulate when seawater seeps into volcanic rocks.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

Some algae have helped remove microplastics from water after being bioengineered to clump together with these contaminants, forming an easily collectible microplastic-algae sludge.

Molecules derived from algae can be found in foods such as ice cream, salad dressings, brownie mix, and gravies, as well as in products such as toothpaste, multivitamins, and egg substitutes.

An overview of the metals obtainable through deep-sea mining of nodules and crusts

Polymetallic nodules are a source of manganese, cobalt, nickel, copper, molybdenum, and platinum, which are used in batteries, fuel cells, and metal alloys of electric vehicles. Seamount crusts contain rare-earth elements deemed essential to US national and economic security, including neodymium and dysprosium used to make permanent magnets.

The ocean gets its salt from runoff carrying fragments of eroded rock and from seawater dissolving salts and minerals from magma at seafloor spreading centers.

The world's largest species of marine algae is giant kelp, which can grow as much as two feet per day from depths of about 100 feet up to the ocean surface.

Explaining deep-sea mining, including its economic benefits and potential biomedical risks

Extraction via machines sweeping the ocean floor would reduce child labor and human rights violations currently occurring in land-based operations that collect the minerals needed for modern-day electronics. However, these sweeps may kill undiscovered organisms that possess biologies from which antibiotics could be derived and destabilize deep-sea ecosystems.

Salt is harvested from briny ocean water and underground deposits

Mostly sodium chloride, this compound is produced for human use by collecting seawater in shallow pans and allowing the Sun to evaporate the water until crystals remain. Underground rock salt is mined, crushed, and purified from deposits left behind by ancient seas that have dried-up.

Astronauts on the International Space Station have tested an algae-powered bioreactor that converts carbon dioxide, water, and light into oxygen and edible, protein-rich biomass.

As part of the up to 15 pounds of seafood they consume daily, sea otters eat urchins that feed on kelp forests—sources of shelter and food to over 800 species—thereby making the marine mammal a keystone species.

All clean energy technologies rely heavily on critical minerals

Although many of these minerals have been used for decades, such as copper in electrical wiring, the accelerating demand for them has strained existing extraction and processing systems. Supply chain disruptions for these materials may delay and increase the cost of transitioning to solar, wind, hydroelectric, and geothermal power.

Japanese scientists have developed an eco-friendly plastic that naturally dissolves in hours, leaving behind molecules containing phosphorus and nitrogen, which fertilize soil.

Despite being multicellular and photosynthetic, organisms such as kelp and sea moss are macroalgae, not plants, because they lack specialized roots and stems to pump water.

As of 2026, the Great Atlantic Sargassum Belt is the world's largest macroalgal bloom, with seaweed stretching from the Caribbean to West Africa.

Explore an interactive database of critical minerals and their uses

Columbia University's Critical Materials Monitor identifies 56 elements required for the clean energy transition. The tool provides details on the reserves, production, and trade of each element, alongside what materials are needed for each technology (desktop only).

Geothermal power can reduce the dangerous mining of rare earth elements

Geothermal brines—mineral-rich underground fluids extracted for use in geothermal plants—contain small concentrations of REEs that can be recovered after energy generation. Although researchers suggest that this retrieval requires complex extraction methods at a significant scale to account for high flow rates, the chemical processes also occur in traditional REE processing.

The warmest waters in the ocean are found at hydrothermal vents—hot springs on the seafloor that discharge plumes of mineral-rich water.

The ocean's ability to store carbon long-term is being hindered by marine heatwaves

More than 4,000 robotic floats with biogeochemical data sensors, including oxygen, pH, nitrate, suspended particles, chlorophyll, temperature, and conductivity, have been deployed as part of the Global Ocean Biogeochemical Array. They have identified changes to ecosystem structure affecting the ocean's ability to transport carbon from surface waters into the deep.

Explore a series of articles on the costs of critical mineral extraction

The acquisition of critical minerals—essential materials for clean energy technologies—has often been accompanied by harm to water supplies, natural ecosystems, and Indigenous lands, raising questions about the overall benefit of these technologies.

Deep water corals—located throughout the world's ocean basins at depths beyond 200 meters (660 feet)—slowly build small coral gardens in the dark with the help of underwater worms.

An analysis of fossilized reefs from northern Africa and Germany suggests that shallow water corals and photosynthetic algae formed the mutualistic partnership seen today between 419 and 359 million years ago.

Clean energy technologies are more mineral-intensive than burning fossil fuels

Solar panels use silver due to its high conductivity, hydropower plants use chromium in their steel alloys, and geothermal plants need titanium to withstand abundant heat and pressure. Lithium—used in energy storage—is expected to see over 500% increased demand from 2020 to 2025.

Volcanic activity can lead to the formation of fertile soils

Ejected rock can introduce key minerals found in fertilizers, including iron, magnesium, and potassium, to improve soil quality. Ash and basalt crystals can be easily absorbed into soils, infusing them with sulfur, oxygen, chlorine, phosphorus, calcium, and other critical elements.

Why deep-sea mining companies may begin extraction without global guidelines

International Seabed Authority negotiators have spent over a decade drafting regulations that all countries would have to follow before collecting minerals from the seabed. Because deadlines to finalize these agreements have been missed, some entities have discussed unsanctioned mining, despite about three dozen ISA countries calling for a pause on activity and automakers and tech firms pledging they will not use seabed minerals.

Rare earth elements may be extracted from mine waste and coal ash

Rather than focusing solely on new mining operations, which can take decades to establish, some startups are developing methods to extract these metals from the toxic waste of existing operations and thereby minimize environmental impacts. (Some readers may experience a paywall.)

What revisiting a 1979 experiment reveals about ecosystem recovery after deep-sea mining

A 2023 study co-led by the National Oceanography Centre and the Natural History Museum, London, found that tracks made by the mining vehicle remained largely unchanged since 1979. Small animals, such as amoeba-like xenophyophore, were seen in the cleared areas, but sightings of larger animals known to live in the region were much rarer. (Some readers may experience a paywall.)

A remote Scottish island is awash in forever chemicals even though there are no obvious industrial sources nearby, and scientists suspect the toxic substances are accumulating via sea spray.

Some invasive species' populations have been controlled by turning them into cash crops that can be harvested and sold to produce useful materials.

Despite the misconception that it comes from dinosaurs, crude oil forms when microorganisms, such as algae and plankton, are subjected to high pressure and high temperature while buried under layers of sediment.

Watch underwater photosynthesis make water look like champagne

In shallow waters where sunlight can reach, photosynthetic reactions absorb water and dissolved carbon dioxide, producing bubbles of oxygen at the surface of plants. As these bubbles rise to the water's surface, a fizzy appearance is created.

Scientists can determine Earth's past environmental conditions by analyzing sediment cores—accumulated layers of mud and remains of charcoal, pollen, plants, algae, and other organic material.

Explore the water footprint of producing various proteins, fruits, and vegetables

This interactive gallery highlights the various types of water behind the production of biofuels, foods, and materials such as cotton. Diets high in bovine meat, whose production requires 15,415 liters of water per kilogram (1,847 gallons per pound), are among the most water-intensive, whereas every kilogram of vegetables uses 322 liters of water (39 gal/lb) to produce.

Some marine life can survive the extreme pressure of the deep ocean because of specialized molecules that strengthen proteins, enzymes, and cellular membranes.

Pearls form when a saltwater oyster or a freshwater mussel coats a parasite or other irritant that has entered its shell with concentric layers of calcium carbonate and organic protein.

View a map of the distribution of mineral resources on the seafloor

Polymetallic nodules are found in regions near the middle of the Pacific Ocean, along the eastern coast of South America, and along the western coast of Africa, while cobalt-rich crusts span significant portions of the Pacific tropics east of the Philippines. Polymetallic sulfide deposits occur at tectonic plate boundaries, including areas within national jurisdictions.

Decommissioned oil rigs have been repurposed into artificial reefs that serve as nursery habitats for fish, corals, sponges, and other invertebrates in the decades since their installation.

The adaptations of metallophiles and how they can be harnessed for bioremediation

These extremophiles have adapted to biomes with very high concentrations of metals and toxic chemicals by developing mechanisms to isolate these substances within cellular compartments and break them down into less harmful forms with specialized proteins. They have the potential to support the decontamination of metal-rich wastewater and soil, as well as the extraction of rare-earth metals.

Critical mineral production may lift impoverished regions out of poverty

Mineral wealth can provide public revenue and economic livelihoods to those in mining regions. However, poor management and lack of oversight can cause human rights abuses, environmental degradation, and significant greenhouse gas emissions.

Feeding grazing cattle seaweed cut their methane emissions by almost 40%

The largest share of the 12% of global greenhouse gas emissions from livestock comes from methane released when cows burp. A study found that introducing a seaweed supplement in pellet form significantly reduced these emissions without affecting cattle's health or weight.

Diatomite, a sedimentary rock used as a filtration material in beer, wine, swimming pool water, motor oil, and pharmaceuticals, is formed from the fossilized shells of diatoms, a type of algae.

Climate resilience strategies, which help communities mitigate the effects of climate change, include painting roofs white, building clam gardens, harvesting fog, and feeding cows seaweed.

Mermaid tears are a long-lasting and hazardous form of ocean microplastic pollution, whose chemical composition enables them to contain higher concentrations of certain toxins than the surrounding environment.

Research has found that when their symbiotic algae are not producing oxygen via photosynthesis, corals twirl hairlike structures to circulate water and draw oxygen into their outer tissues.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

Scientists have found that the Great Barrier Reef's microbiome includes an estimated 362,802 distinct viruses and 876 distinct bacterial and archaeal species—584 of which had never been documented before 2026.

Some corals absorb harmful ultraviolet radiation and re-emit it as visible light, thereby protecting symbiotic algae within their tissues and providing them with energy for photosynthesis.