Deep Sea

A cold seep gets its name not because the liquid and gas that emerge are colder than the surrounding seawater, but because they are cooler than the scalding temperature of the similar hydrothermal vent. The size of the whale, the depth of the seafloor, and the location all contribute to the types of animals that colonize the area and determine how long it takes for the skeleton to disappear. Our knowledge of whale falls comes from few and far between ROV and AUV encounters, so though whale falls are scarce, scientists estimate they exist at every 5 to 16 km in the Pacific Ocean.

Environmental impacts

The creatures that live at these depths have adapted to a way of life in one of the world’s most challenging environments. The deep sea is one of our planet’s most mysterious and least explored regions. It covers more than 60% of Earth’s surface and is crucial in regulating the planet’s climate, supporting marine biodiversity, and even influencing human life. Despite its significance, the deep sea remains largely unexplored due to its extreme conditions, such as complete darkness, crushing pressure, and freezing temperatures. Members of Deep-Seafas recently contributed to the CCAMLR (Convention for the Conservation of Antarctic Marine Living Resources) Ecosystem Monitoring and Management working group. Deep-sea fisheries take place between depths of 200 and meters, and target species on continental shelves, seamounts and ocean ridges using bottom and deep mid-water trawls, gillnets, longlines and pots.

• Whale bone consists of roughly 60 percent fat by weight, up to 200 times the amount of nutrients typically found at the seafloor.
• By protecting this fragile ecosystem, we’re preserving the life it holds, the climate it regulates, and the mysteries it continues to reveal.
• These tiny particles can even be found in the snow cover on Arctic ice floes.
• They may look scary, but when you look at them, don’t forget that they’re really small in size, almost never measuring over 10 centimeters.
• This unusual shark occurs in warm, oceanic waters worldwide, and has been recorded as deep as 3.7km.

The deep water column, from 200 meters below the surface down to the seafloor, accounts for more than 95% of the volume of the ocean. It is vital to Deep Sea many of Earth’s regulatory processes, including nutrient cycling, carbon cycling and storage, and heat absorption. The ocean has absorbed over 90% of the excess heat generated by the burning of fossil fuels; much of this heat has been transported to the deep by ocean currents.

Vampire Squid

• The Knowledge Hub is your gateway to discovering the wonders of the deep, and learning how this hidden world is connected to all of us.
• Pressure increases at approximately one atmosphere for every 10 meters meaning that some areas of the deep sea can reach pressures of above 1,000 atmospheres.
• Covering more than half of the planet’s surface, this hidden world is teeming with unique and bizarre life forms—from glowing jellyfish to fish that can withstand crushing pressure.
• Within hours of falling, sleeper sharks, rattail fish, and black hagfish flock to the carcass like moths to a flame.
• Nearly two thirds of the world’s ocean — including most of the deep sea — is outside national jurisdiction.

Despite the low temperatures, extreme ambient pressures, absence of sunlight and low resource availability, it supports a rich abundance of life in an array of unique ecosystems. Hydrothermal vents, for example, host ecosystems that thrive without sunlight, challenging our understanding of where and how life can exist. Studying these environments can reveal insights into resilience and adaptation, possibly helping us tackle challenges in medicine, technology, and sustainability. But some of the companies applying to explore deep-sea mining are using a loophole. TMC, for example, instead of being supervised by its home country of Canada, sought out the small Pacific Island nation of Nauru, home to about 12,000 islanders, as its sponsor.

Diving into the World of Black Corals: A Q&A with Deep-Sea Scientist Erika Gress

But due to chemical and physical properties of water, this is, in fact, a reality.
Like on land, deep canyons can stretch for hundreds of miles across the seafloor. The walls, ledges, and bottoms of canyons create a diverse variety of habitats—many of which are steep, and scoured by currents rich in tiny food particles—that enable an array of sea creatures to live there. 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. Fish, too, find shelter within the canyon walls, and also a good place to catch a meal. A 60,000 km underwater mountain range stretches around our planet, formed as the plates that make up the Earth’s crust move against, or apart from, each other. 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.

What is the Deep Sea?

A seamount is an underwater mountain that can rise thousands of feet above the seafloor. Just as canyons funnel water, seamounts also influence the flow of water, often diverting deep currents. They are often found at the edges of tectonic plates where magma is able to rise through the surface crust. When dense, nutrient rich ocean currents hit the seamount they deflect up toward the surface, allowing marine life to thrive on the newly supplied food.

There are vibrant seamounts (underwater mountains, like those found off the coast  of Chile), teeming with corals, sponges, and fish, as well as hydrothermal vents, sometimes likened to hot springs on the ocean floor. Seamounts are crusted in cobalt, iron, nickel, and manganese, while hydrothermal vents produce small structures rich in gold, nickel, copper, and other metals. Curator Karen Osborn wants to know how and why animals adapt in order to survive in a cold, dark, and pressurized environment. Many animals that live in this largest of the earth’s habitats are very bizarre and dramatically different from their closest relatives. For example, some make an extreme effort to see, building huge bulbous eyes that can detect even the smallest glimmer of light, while others completely forfeit any form of sight and instead rely on heightened scent and touch. Organisms that hope to survive in these habitats have to face a range of challenges – from a lack of food, to cold and perpetual darkness, to extreme pressures (e.g. 200 times surface pressure at a depth of 2,000 metres).

The Bathypelagic Zone (1000–4000 meters) – Midnight Zone

Some species, such as the one above, have modified their snouts, transforming them into sensory organs capable to detect prey by sensing its electrical field. They’re also “living fossils” like the goblin shark — similar creatures were found in the fossil record 160 million years ago. They can be found on the bottom of deep seas scavenging any food that may fall from the shallow waters or hunting anything that’s smaller or slower than them.
They obtain the energy and nutrients they need to survive by trapping tiny organisms in their polyps from passing currents. The bathypelagic is between 3,300 and 13,100 feet (1,000 and 4,000 m) beneath the ocean surface. It is an area void of light (called aphotic) and at 39 degrees Fahrenheit (4 degrees Celsius), it is very cold. Creatures in this zone must live with minimal food, so many have slow metabolisms. The black hagfish, viperfish, anglerfish, and sleeper shark are common fish that call this zone home.
“Fast-tracking deep-sea mining by the ISA’s global regulatory processes would set a dangerous precedent and would be a violation of customary international law,” says Duncan Currie, legal adviser for the Deep Sea Conservation Coalition. The mouth cavity can stretch and expand to a much larger size than is expected for such a small fish and would perhaps be expected to allow this species to capture and swallow large prey items. However, study of the stomach contents or large numbers of specimens have shown that they mostly eat small crustaceans. But we’re now able to explore more and more parts of this remote realm—thanks to a new generation of incredible underwater vehicles. Flashy displays may seem easy to spot, but in the dark expanse of the deep, distance and the immense area can make even bright lights hard to see.