Knowledge Hub

Tethered to a life at the surface because they require breathable oxygen, many large animals will make impressive dives to the deep sea in search of their favorite foods. Sperm whales, southern elephant seals, leatherback sea turtles, emperor penguins, and beaked whales are especially good divers. A Cuvier’s beaked whale is known to dive 9,816 feet (2,992 m) deep, and can stay down as long and 3 hours and 42 minutes, making it the deepest diving mammal in the world. As the sun sets, fish and zooplankton make massive migrations from the depths up to the ocean’s surface. Despite their small size (some no bigger than a mosquito), these creatures can travel hundreds of meters in just a few hours.

The Deep Sea Conservation Coalition uses science to help protect and preserve the deep sea.

Yet significant uncertainties remain about the environmental impacts of this proposed industry, in which miners would send heavy machinery into the deep ocean to collect valuable minerals, such as manganese, cobalt, copper and nickel. Some animals can thrive by feeding on marine snow.2 In 1960, a bathyscaphe called Trieste went down to the bottom of the Mariana Trench, which is the deepest point on Earth. There aren’t any plants at all in these depths, so all fish in the deep are carnivores. This article will dive into the depths of the deep sea, exploring its characteristics, life forms, and why it is essential for the Earth’s health. In July 2025, a request was made for the ISA Secretariat to investigate whether deep-sea mining companies applying for licenses and permits under the United States’ mining code are at risk of violating existing ISA exploration contracts. UNCLOS prohibits unilateral mining activities, and mining companies may have exploration contracts revoked if found to be in violation of this.

Deep-sea crown jelly

Some in the mining industry say the mining is necessary to a green transition – and essential to democratizing that transition globally since the supply chain is currently dominated by a single country, China. Meanwhile, some scientists caution against mining before the full scope of environmental damage can be understood. In addition to discharging wastewater below 2,000 m, it proposes that international organizations and conservation bodies, such as the ISA and IUCN, regularly update evaluations of deep-sea mining threats to chondrichthyans.

The landscapes of the deep sea

These layers of ocean ooze are important carbon sinks—drawing down the decomposing bits of carbon, laying them to rest on the seafloor, and finally burying them. Bioluminescence first arose roughly 540 million years ago in a group of corals known as the octocorals. Animals can use their light to lure prey towards their mouths, or even to light up the area nearby so that they can see their next meal a bit better. Sometimes the prey being lured can be small plankton, like those attracted to the bioluminescence around the beak of the Stauroteuthis octopus.

• The yeti crab waves its arms in the water to help cultivate bacteria on tiny arm hairs which it then consumes.
• Their blood contains hemoglobin that binds tightly to both oxygen and hydrogen sulfide.
• Images taken with a camera system towed by the research icebreaker Polarstern captured countless nests of the ice fish species Neopagetopsis ionah on the seafloor, at depths from 420 to 535 metres.
• In the months and years after a whale fall the site will become the home and food source for millions of creatures.
• Indeed, ‘the blue archive and the blue frontier are two sides of the same coin’ (Han 2024, 30), and special attention must be paid to how we collectively make sense of the deep sea.
• It also showed to politicians, fishers, and tourism operators the danger of taking marine resources for granted (Adler 2019).

Its margin, referred to as the continental shelf, can extend up to 500 metres below the water’s surface; only after this point does the deep sea begin. In contrast, in most other regions, this transition begins just 200 metres below sea level. Between 1840 and 1880, British and American scientists and hydrographers extensively studied the deep sea, a period marked by heightened cultural fascination with maritime depths. Scientific exploration during this era intersected with a broader acknowledgment of the economic and social importance of the maritime world, shaped by mid-nineteenth century maritime practices, technologies, and cultures. This setting was characterised by a masculine naval culture, physical challenges, and harsh conditions—a blending of scientific inquiry with maritime work cultures.

What Are the Potential Benefits of Deep-Sea Mining?

Polyphonic in nature, this entry invites readers to explore the deep sea through multiple social science perspectives, collectively capturing its complexity and significance. The study indicates that sulfide and crust mining would likely pose the most significant and direct risks to sharks, rays and chimaeras, mainly because of the substantial overlap between these species and the mining areas. For instance, 26 of the 30 species identified in the study inhabit zones proposed for sulfide mining, and some of them lay their eggs around vent systems, where sulfide mineral deposits occur.

Landmark conviction exposes Sri Lanka’s deep-rooted illegal elephant trade

• The chaos and ‘messiness’ of the deep sea are also key factors in ethnographies that analyse how companies, for example, legitimise deep-sea mining projects (Childs 2019; Han 2022).
• This executive order on deep-sea mining serves as an extension to President Trump’s earlier order in March 2025 to increase domestic investment in mineral production.
• The rocky ledges are a perfect place for deep sea corals to attach, and the muddy bottom is a soft home for worms and mollusks to burrow.
• However, most deep-sea mining interest is concentrated in international waters.
• This mostly includes waste, such as dead and decomposing animals, poop, silt and other organic items washed into the sea from land.
• The deep-sea anglerfish lures prey straight to its mouth with a dangling bioluminescent barbel, lit by glowing bacteria.
• The term ‘marine snow’ is used for all sorts of things in the ocean that start at the top or middle layers of water and slowly drift to the seafloor.

In these areas, seawater seeps into cracks in the seafloor, heating up as it meets molten rock beneath the crust and then rising again to gush out of seafloor openings. The water that emerges from them can reach temperatures of 400 °C and is extremely rich in minerals. Cold seeps are similar to hydrothermal vents as they also occur in tectonically active locations, but they emit hydrocarbon-rich fluids. The palette ranges from plastic bags and fragments, to glass bottles and the remains of fishing nets, to paint buckets. Packages and bags have been discovered that have apparently been on the seafloor for decades, virtually untouched by time.
The deep sea is not yet a distinct subfield within anthropology, nor is it likely to become one. It will probably be integrated into the broader domain of the anthropology of the ocean. Yet this does not diminish its significance as a site for anthropological reflection. On the contrary, the issues raised by scholars engaging with the Deep Sea deep sea are deeply anthropological in nature. They involve questions of otherness and estrangement, which unsettle terrestrial assumptions and challenge conventional ethnographic methods. The deep sea also invites to contemplate concepts such as chaos and disorder, and to critically examine the politics of corporate legitimacy.
Some scholars have even called for the Middle Passage to be formally recognised as cultural heritage within the legal framework of the International Seabed Authority (ISA), which governs DSM activities in international waters (Turner et al. 2020). Indeed, ‘the blue archive and the blue frontier are two sides of the same coin’ (Han 2024, 30), and special attention must be paid to how we collectively make sense of the deep sea. This perspective challenges visions of the ‘cyborgs of the deep’ as the only ‘heroes’ that will allow society to meet the requests of the ‘Green Shift’, i.e. of transitioning towards more environmentally friendly ways of living (Palermo and Steinberg 2024, 9). The deep sea is populated by ‘unseen bodies … whose hauntings persist’ even as their stories are obscured by the plumes of the remotely operated vehicles (ROVs) used to collect minerals (Palermo and Steinberg 2024). Recognising these ghosts and incorporating Black history into our understanding of the deep sea means examining the relationship between colonialism, exploration and the ocean.
Species potentially impacted by sulfide mining included chocolate skates, Portuguese dogfish (Centroscymnus coelolepis), great lantern sharks (Etmopterus princeps) and small-eyed rabbitfish. Cobalt-rich ferromanganese crust mining could impact 21 of the identified species, the study showed, including whale sharks, cookiecutter sharks (Isistius brasiliensis) and sicklefin devil rays (Mobula tarapacana). As the global energy transition accelerates, the ocean floor has emerged as the next frontier in critical mineral competition between the United States and China, as both countries seek geopolitical and energy dominance. Modern economies depend on a consistent and constant supply of energy, and the United States and China recognize the importance of rare earth elements (REEs) in continuing innovation and energy security.

Overcoming Critical Minerals Shortages Is Key to Achieving US Climate Goals

Here we bring together the latest deep-sea science, traditional knowledge, and expert insights that shape our work to safeguard these incredible habitats and species. Through blogs, interviews, fact files, and stories from those working in and with the deep, we shine a light on why the deep sea matters and why it needs our protection. Despite its importance, the deep sea faces significant threats, from deep-sea mining and overfishing to pollution and climate change. By protecting this fragile ecosystem, we’re preserving the life it holds, the climate it regulates, and the mysteries it continues to reveal.
In short, President Trump’s executive order bypasses international regulation, placing the United States on a collision course with both the ISA and China. In 2024, ISA controlled deep-sea mining in roughly 54 percent of the world’s ocean through specialized contracts, regulations, and procedures. However, the US refused to ratify UNCLOS in 1982, specifically due to its provisions on deep-sea mining, and is not a member of the ISA. Previously, this lack of membership was not a significant point of contention.
The study notes that filter feeders and light-sensitive species might be particularly vulnerable to these kinds of stressors. From the 1970s into the 1980s, the United States led the production and refinement of REEs, processing roughly three times more REE than the rest of the world combined. However, as early as the 1960s, China took notice and began investing, taking over the United States’s historical dominance by the 1990s. In 2024, China possessed 60 percent of the global REEs market and processed 90 percent of the global REEs market. Seeking further REE supply, China has increased its investment in the burgeoning industry of deep-sea mining. Deep-sea mining would involve extracting rocky deposits called polymetallic nodules or manganese nodules from the bottom of the ocean floor.