Take a DEEP Dive for National Ocean Month
While many of us are familiar with the shimmering surface of the ocean, the deep ocean is a place that’s largely out of sight, but should definitely not be out of mind. Despite being one of the largest living spaces on the planet and playing a vital role in our everyday lives and Earth’s overall ecosystem, the deep ocean remains largely unexplored.
As we celebrate National Ocean Month this June, join us for a daily look at just a few of the things that make the deep ocean special, mysterious, exciting, and important to understand and explore. We’ll reveal a new fact each day, so check back often or follow us on social media!
Exploration is key to increasing our understanding of the ocean, so we can more effectively manage, conserve, and sustainably use ocean resources that are vital to our economy and to all of our lives.
June 1, 2022
Despite the fact that the ocean covers approximately 70% of Earth’s surface and plays a critical role in supporting life on our planet, from the air we breathe and the food we eat to weather and climate patterns, our understanding of the ocean, in particular the deep ocean, remains limited.
Ocean exploration is about making discoveries, searching for things that are unusual and unexpected. The data collected through exploration contribute to the protection of ocean health, understanding of climate change impacts on the ocean and our planet, sustainable management of our nation’s marine resources, acceleration of our national economy, and the building of a better appreciation of the value and importance of the ocean in our everyday lives.
We can’t manage, sustainably use, restore, or protect what we don’t know about or understand. Exploration is the first step to unlocking our ocean’s full potential.
The “deep” ocean is generally defined as 200 meters (656 feet) and deeper.
June 2, 2022
NOAA Ocean Exploration focuses exploration efforts on depths greater than 200 meters. This is the depth at which light begins to dwindle, meaning that the “deep” is the part of our ocean that’s dark, cold, and food-poor. It’s also subject to intense pressure and lower oxygen levels. Despite these extreme conditions, life has found a way to thrive, and with each new mission to explore the deep, we make new discoveries that increase our understanding of one of the largest, but least understood, living spaces on our planet.Learn more
Scientists estimate there may be between 700,000 and 1 million species in the ocean (excluding most microorganisms, of which there are millions). Most of these species have yet to be discovered.
June 3, 2022
The ocean is the largest living space on Earth, so it’s not surprising that it’s home to a large number of organisms. What may be slightly more surprising is that scientists estimate that roughly two-thirds of the species in the ocean, possibly more, have yet to be discovered or officially described. Each year, almost 2,000 new species are accepted by the scientific community — but that still leaves a lot left to discover!Learn more
While most medicines derived from natural sources currently come from land-based organisms, research suggests that the ocean, with its amazing biodiversity and large number of yet-undiscovered species, may be a rich source for new medicines.
June 4, 2022
As demand grows for discovery of novel industrial enzymes and new medicines, researchers are increasingly looking toward the ocean. Systematic searches for new drugs have shown that marine invertebrates produce more antibiotic, anti-cancer, and anti-inflammatory substances than any group of terrestrial organisms. Particularly promising invertebrate groups include sponges, tunicates, ascidians, bryozoans, octocorals, and some molluscs, annelids, and echinoderms.
It’s only through ocean exploration that we can find new microorganisms, sponges, corals, and other marine organisms rich in natural products that can be cultured and developed into medicines to treat diseases.Learn more
Studying shipwrecks can help us understand the past, connect us to our cultural heritage, and teach us lessons on how the environment and human error can impact each other.
June 5, 2022
Shipwrecks are like time capsules, preserving a single point in time. By studying them, we can discover how people in the past lived, how they adapted to their environments, how they used natural resources, and how they changed the world around them. Scientists also use shipwreck sites to learn how sunken ships influence ecology in the deepwater marine environment and how the environment has changed over time. Shipwrecks can also serve as tools to teach us important lessons about how currents, weather, technology, and human error can impact the environment.Learn more
While disturbances such as waves caused by strong hurricane winds do not reach the deep ocean, the churning of surface waters can result in more food falling to the seafloor.
June 6, 2022
While the physical effects of hurricanes on near-shore ecosystems like shallow-water coral reefs are well documented, little research has been conducted on the direct impacts of hurricanes on the deep ocean.
Measurable disturbances of a hurricane only reach a maximum depth of about 90 meters (300 feet) below the surface. As most deep-ocean exploration occurs below 200 meters (656 feet), the churning of waves and strong winds are felt much less profoundly by the deep-sea animals encountered during remotely operated vehicle dives.
However, there may be an unexpected benefit for deep-sea life after a storm passes. By churning up water and encouraging more upwelling, additional nutrients are delivered to phytoplankton that form the base of the oceanic food chain. While phytoplankton don’t typically make it to the deep ocean, animals that feed on them may, providing a potential food source for animals on the seafloor.Learn more
In the deep ocean, food resources are scarce, meaning organisms are often in fierce competition for a meal.
June 7, 2022
Whether we happen to observe animals capturing and devouring dinner or fighting each other for a prize catch, predation events in the deep ocean are always exciting to watch. Being able to observe these rare feeding events also provides us with unique glimpses into the lives and behaviors of animals of the deep.
A better understanding of how life works in the remote depths of the ocean helps us to understand the ocean ecosystem as a whole, allowing us to better manage, conserve, and sustainably use the ocean resources that are vital to all of our lives as well as the economy, health, and security of our nation.Learn more
Happy World Ocean Day!
June 8, 2022
Today is World Ocean Day, a day to celebrate the ocean and recognize how it connects, sustains, and supports us all. Additionally, President Joe Biden declared June 2022 to be National Ocean Month, a time for us to work together to protect, conserve, and restore our ocean and coasts. Yet we can’t manage, sustainably use, restore, or protect what we don’t know about or understand. We need to know what is out there. Exploration is the first step to unlocking our ocean’s full potential.
As deposit feeders, sea cucumbers play an important role in the ocean by cycling nutrients found in sediment on the seafloor.
June 9, 2022
Despite their common name, sea cucumbers, also known as holothurians, are not something you’d ever find in your garden. Instead, these squishy invertebrate animals are found throughout the world’s ocean basins, from shallows to great depths.
As food is scarce in the deep ocean, sea cucumbers feed on nutrients attached to sediments on the seafloor. They use their tube feet to “eat” seafloor mud, extracting what little nutrition may have survived the slow sinking from the productive upper ocean and then expelling undigested mud. As they eat and excrete sediment, they’re helping to release nutrients trapped in the sediment such as nitrogen and phosphorus that may be important to other animals on the seafloor.Learn more
Unlike other octopods that use jet propulsion to swim, dumbo octopods rely on ear-like fins that protrude just above their eyes as their primary means of locomotion.
June 10, 2022
There are six families of finned deep-sea octopods that all belong to the suborder Cirrata. Cirrate octopods move by slowly flapping their ear-like fins, using their arms to steer. These fins have earned some in this group the nickname "dumbo octopus," in honor of the ears of the famous Disney elephant, Dumbo. They are always a favorite when we encounter them during a dive!Learn more
Though it makes up 95 to 99% of the total livable volume of the planet, the water column remains one of the most poorly explored environments on Earth.
June 11, 2022
The water column, which includes all of the water in the ocean between the surface and the seafloor, is home to a range of marine life, from phytoplankton and gelatinous animals such as jellyfish, siphonophores, and tunicates to fish and marine mammals. These organisms play important roles in the marine ecosystem, including helping to move massive quantities of energy from the surface to the deep ocean in what is known as the "carbon pump.” Despite its importance, we know very little about this part of our ocean or the animals that live there. We are, however, working to change that by increasingly applying tools and technologies to learn about the abundant life that lives between the sea surface and the seafloor.Learn more
The deepest place in the ocean is 10,935 meters (35,876 feet) deep and is found in the Pacific Ocean’s Mariana Trench, at a place called Challenger Deep.
June 12, 2022
Consider that Mount Everest, the highest point on Earth topping out at an impressive 8,849 meters (29,032 feet), would fit inside of Challenger Deep — with room to spare. Yet, while thousands of people have reached the summit of Mount Everest, only a handful have ever explored Challenger Deep.
This highlights the challenges of exploring the deep reaches of the ocean, which are places with almost freezing temperatures, corrosive saltwater, limited or no light, and extreme pressures. Developing the tools and technology needed to get to these extreme places is a challenge, we’re working on it!Learn more
Bigfin squid (Magnapinna sp.) can live deeper than any other known squid, and while sightings of them have been recorded globally, the total number of sightings is likely less than two dozen.
June 13, 2022
The current depth record for a bigfin squid is 4,735 meters (3 miles). We saw the one in this video at a depth of 2,385 meters (1.5 miles) while exploring off the West Florida Escarpment during the Windows to the Deep 2021 expedition. While we did not get a length estimate on this squid, the largest known bigfin squid was 6.4 meters (21 feet) long. Its arms and tentacles were 6.1 meters (20 feet) long. That’s 20 times the length of its body!Learn more
Bioluminescence is light produced by an organism using a chemical reaction.
June 14, 2022
Deep-ocean environments are almost completely dark; yet light is still important in these environments. Bioluminescence, or the ability of an organism to produce its own light, may provide a survival advantage in the darkness of the deep ocean by helping organisms find food, reproduce, and defend themselves. But, we don’t really know the main purpose or function of bioluminescence. In fact, although many marine species are able to produce this “living light,” much about bioluminescence remains a mystery.Learn more
Cold seeps occur where highly saline and hydrocarbon-rich fluids, such as methane and sulfides, escape from the seafloor at temperatures close to that of the surrounding seawater.
June 15, 2022
Unlike hydrothermal vents, which occur at the edges of tectonic plates where new seafloor is formed in fiery processes, cold seeps lie within plates and leak fluids and gases that are at or close to ambient deep-ocean water temperatures. Cold seeps can form above geologic faults or salt deposits or at places where canyons cut into sediments that trap fluid and gas. Some cold seeps develop where warm ocean water causes special methane-containing deposits (gas hydrates) to release their gas.
Cold seeps are an important component of deep-sea ecosystems because they often fuel entire communities that rely upon bacteria that convert chemicals to food through a process called chemosynthesis.
Since 2012, mapping activities and visual surveys have resulted in the identification of bubble plumes emanating from the seafloor that are indicative of hydrocarbon gas leakage, with thousands of seeps found via various NOAA Ocean Exploration and partner efforts.Learn more
Marine snow is mostly biological debris that originates from the top layers of the ocean and drifts to the seafloor, providing a primary source of energy for animals in the deep ocean.
June 16, 2022
As food is scarce in the dark depths of the ocean, material drifting down from the waters above is an important component in the ocean food web. Many animals in the deep ocean filter marine snow from the water or scavenge it from the seabed as their main source of food. Characterizing the quality and supply of this food helps us understand the distribution, biodiversity, and function of deep-ocean communities.Learn more
At ocean depths below 4,000-6,000 meters (2.5-3.6 miles), pale white or colorless fish are the norm, and at the greatest depths where fish live, most species are pale white.
June 17, 2022
The reason for the ghostly color patterns seen in the deepest-living ocean fish likely has a lot to do with the absence of sunlight. The bright colors and patterns that work to the advantage of shallow-water and twilight zone fish are useless in the abyss and deeper where they can’t be seen in the darkness.
Two additional theories for the very pale pigment in deep-ocean fish is that it takes too much valuable energy to develop pigment patterns in the deep ocean where food is scarce and that the absence or presence of pigment doesn’t matter — although white fish in shallow water are highly visible targets for predators, there is no such natural selection that eliminates pale animals in very deep water.
However, these are just theories. We know little about the vision of the deepest-living fish that would influence the evolution of their color. The ghostly appearance of fish in the abyss is another deep-sea puzzle in need of more exploration.Learn more
Deep-sea corals grow very slowly and can live for a very long time, with some specimens found to be thousands of years old.
June 18, 2022
In addition to making deep-sea corals some of the oldest living organisms on Earth, their slow growth rates mean that it takes them hundreds of years to recover from damage, if they recover at all.
As deep-sea corals represent some of the most valuable marine ecosystems on the planet, creating structures that provide shelter, food, and nursery habitat to other invertebrates and fish, it’s important for us to understand the dynamics and distributions of these valuable habitats in order to sustainably manage them and protect their biodiversity. But first we need to know that they are there. Deep-sea exploration is the first step toward increasing our understanding about these wonderful and diverse habitats.Learn more
The average depth of the ocean is 3,682 meters, or 12,080 feet.
June 19, 2022
Overall, the ocean is pretty deep; however, its bottom is not flat or uniform, which means water depths in the ocean also vary. The most-recent estimate of the average ocean depth was calculated using satellite measurements. While satellite measurements yielded better estimates of ocean depth than we have had in the past, rather than measuring the seafloor itself, satellites actually look at the sea surface and detect changes over features like a mountain on the seafloor.
High-resolution seafloor mapping is needed to fine tune the satellite data. Since we have only mapped about 20 percent of the Earth’s seafloor in high resolution, estimates of average ocean depth remain just that: estimates.Learn more
Most of the active volcanoes on Earth are located underwater, along the aptly named “Ring of Fire” in the Pacific Ocean.
June 20, 2022
Made up of more than 450 volcanoes, the Ring of Fire stretches for nearly 40,250 kilometers (25,000 miles), running in the shape of a horseshoe (as opposed to an actual ring) from the southern tip of South America, along the west coast of North America, across the Bering Strait, down through Japan, and into New Zealand.Learn more
Over half of all known coral species are found in cold, deep, and dark waters.
June 21, 2022
When most people think about corals, they imagine a sunny tropical reef speckled with fishes and other creatures on a colorful rocky outcrop. However, over half of all known coral species are actually found in deep, dark waters where temperatures range from 4-12°C (39-54°F).
While we have known about these deepwater corals for hundreds of years, overall, they remain poorly studied. We do know, however, that they are important as habitat for fish and other invertebrates, can hold records about past ocean climate and productivity, and are hotspots of biodiversity. In order to sustainably manage and maintain these valuable habitats, first we need to know that they are there. Enter deep-ocean exploration.Learn more
We have explored less than one-tenth of a percent of the thousands of seamounts that rise at least 1,000 meters (3,280 feet) or more off the seafloor.
June 22, 2022
A seamount is an underwater mountain with steep sides rising from the seafloor. Seamounts are found in every world ocean basin, and while it’s not known precisely how many seamounts there are, they are very numerous. In fact, based on satellite altimetry data and bathymetric mapping data from survey ships, there are thought to be tens of thousands. Despite their abundance and importance as biological hotspots, we have explored only a fraction of them.Learn more
Deep-ocean chemosynthetic animals that use energy released by inorganic chemical reactions to produce food were not discovered until 1977.
June 23, 2022
Chemosynthesis occurs when bacteria and other organisms use chemical energy from sulfides, methane, and other inorganic compounds to produce food. These bacteria form the basis of the food chain for life at places on the seafloor where photosynthesis is not possible, such as hydrothermal vents and cold seeps.
The discovery of chemosynthetic life in the deep ocean, made off the coast of South America a mere 45 years ago, changed our understanding of the requirements for life. Prior to this, it was thought that all life revolved around sunlight, whereby plants use energy from the sun to make food via photosynthesis. Now we know that, together, photosynthesis and chemosynthesis fuel all life on Earth.Learn more
Sponges are ancient animals that may appear simplistic, but the more we study them, the more we realize how complex they are and how important they are to the marine environment and to us.
June 24, 2022
Sponges come in all shapes, sizes, and colors. These invertebrate animals help create habitat; filter particles from seawater and contribute to carbon, nitrogen, and silica cycling. Additionally, many sponges produce medically important chemicals called marine natural products, which can be used to treat human diseases.
Sponges are bizarre and beautiful — nothing like the yellow, plastic rectangle next to your kitchen sink.Learn more
When looking at a siphonophore, you may think that these marine invertebrates are single organisms, but a siphonophore is actually a colony of many individuals working together.
June 25, 2022
The individual animals that collectively make up a siphonophore are called zooids, each specialized for different functions such as swimming, feeding, reproduction, and defense. Each individual zooid is similar to other solitary animals, but the individuals are all attached to each other instead of living independently. Siphonophores are considered to be some of the most complex colonial animals.
There are approximately 175 described species of siphonophores, and they are all marine, found in ocean basins around the world. The familiar Portuguese man o’ war is the only species of siphonophore that lives in surface waters; the rest are found at greater depths. Because they are so delicate, they are hard to study, so our understanding of them is limited.Learn more
Telepresence technology in ocean exploration allows the delivery of data and video in real time from ships to scientists, teachers, students, and members of the general public on shore.
June 26, 2022
Telepresence involves the use of technology to allow a person to feel, interact, and collaborate as if they were present at one location when in fact they are at a different location. When applied to ocean exploration, telepresence allows a potentially unlimited number of scientists on shore to participate in at-sea ocean exploration, adding their expertise to missions no matter where in the world a ship, or the scientists, are located. In addition to providing input from a broad range of scientific experts, telepresence also allows the public to observe and follow expeditions in real time.Learn more
Animals in the deep ocean often grow much larger than their shallow-water relatives, a concept known as gigantism.
June 27, 2022
Unlike humans, many animals in the deep ocean have indeterminate growth, meaning that there is no set size at which they stop growing — as long as they get enough food, and aren’t eaten, they just keep growing (longer and wider, not just wider, like us!). Also, there are fewer predators in the deep ocean, meaning animals are less likely to get eaten before reaching these extraordinarily large sizes.
On the flip side, being bigger means needing more food and while there are fewer predators at depth, there are also fewer prey. So, there is a risk of starving to death due to lack of food needed to fuel a growing body. That’s why the deep ocean is not filled with huge shrimp, giant squid are few and far between, and jellyfish the size of cars have only rarely been seen.Learn more
Despite their common name, sea spiders are not actually true spiders.
June 28, 2022
Sea spiders are more formally known as pycnogonids because they belong to the class Pycnogonida within the phylum Arthropoda. The look-alike land-dwelling spiders after which they are named are also arthropods, but land-dwelling spiders belong to the class Arachnida.
Classified in the order Pantopoda, which means “all legs,” sea spiders are also known as pantopods. While not quite all legs, they are mostly legs (usually eight), and they use those legs to walk along the seafloor and even swim above it.
Despite their presence throughout all regions and depths of the ocean and the role that they play in the ocean ecosystem, they are not well studied and much remains to learn about them.Learn more
Red light does not reach ocean depths, so deep-sea animals that are red actually appear black and thus are less visible to predators and prey.
June 29, 2022
If you’ve ever looked beneath the ocean’s surface, you may have noticed that water transforms light and that colors appear differently. This is because water absorbs warm colors like red and orange and scatters cooler colors like blue. Red light is quickly filtered from water as depth increases and it effectively never reaches deep-ocean depths. This provides animals in the deep ocean with an interesting form of camouflage: Being red.
A color must be present in the surrounding environment in order to be seen. So, in an environment like the deep ocean where there are no red light wavelengths, a red animal appears to be lacking color and is essentially invisible to animals around it.
When scientists exploring the deep ocean shine the artificial lights of an instrument like a remotely operated vehicle on animals, we bring in all wavelengths of the rainbow and are often treated to a bright array of colors, many of which are vibrant shades of red.Learn more
Sea stars play an important role in deep-sea ecosystems, especially as predators of sponges and corals (mostly octocorals).
June 30, 2022
Feeding observations in the deep-ocean are uncommon, but they can tell us a lot about the predators, their prey, and their surrounding environments. Observations during deep-ocean exploration dives have revealed sea stars feeding on various corals, including octocorals, black corals, and stony coral; on sponges; and even in the sediment.
While they may not be the fastest of predators, their feeding has an impact on deep-sea ecosystem activity and diversity. For example, when sea stars devour coral tissue, the coral’s skeletons can become habitats for other organisms to live in, on, or around. Interactions between these deep-sea predators and their prey requires additional research and observation to fully understand, demonstrating just how little we know about these extraordinary creatures.Learn more