Deep Sea Fish: Strangest, Deepest and Ugliest

Home | Category: Oceans and Sea Life / Ocean Fish



On deep see fish found on seamounts in an around the Cocos Islands in the Indian Ocean, 2,500 kilometers west of Australia, Nature reported: There is the adorable deep-sea batfish, which looks like a bit of limbed, well-cooked ravioli with a 'please love me' expression on its tiny face. This odd little creature shuffles its way along the seabed on stubby little fin-legs with big 'feet'. "These are tiny little anglerfish relatives … they've got a tiny little lure that sits in a depression on their snout that they can actually move to attract prey and they essentially walk over the floor on their modified arms and legs," Dianne Bray, Senior Collections Manager at the Museums Victoria Research Institute in Australia, explains. Another fish was caught anchored to the ground with bizarrely elongated stilt-fins, with which it can hover effortlessly just above the seafloor, waiting to pounce on unsuspecting prey below. [Source: Tessa Koumoundouros, Nature, November 4, 2022]

The highfin lizard fish is hermaphroditic, with both functioning ovaries and testes, and a voracious hunter. It has clear translucent skin, a characteristic of some deep-sea animals that don't see the light of day. The bony-eared assfish has a massive head and a tiny body. It is a kind of conger eel that was found one kilometer (0.6 miles below the surface. Congers usually emerge up from the seabed like grasses. The Slender Snipe Eel has a long tail that can stretch over one meter (three feet in length). The tail is similar to a thread, though. The entire animal weighs under 57 grams (two ounces). [Source: Marianne Guenot, Business Insider, December 2, 2022; Fox News,, December 9, 2022]

Viper fish look very scarey. They have bioluminescent spots. Their dagger-like teeth are strictly for seizing prey that they swallow it whole. The Sloane’s viperfish has teeth so large they stick out of its mouth. This creature also lights up when it wants to, using a set of photophores ( glandular organ that appears as luminous spots) that line its whole body. The tribute spiderfish's long fins are hardened, allowing it to prop itself up on the seabed like a tripod. It is an ambush predator that perches itself above the sea floor catching shrimp drifting past it on the current. The fangfish is a vicious predator that lurks in the near darkness of the deep sea during the day, then rises to shallower waters to hunt at night, in a process known as diel migration.

Deepest Ever Fish Filmed off Japan

In April 2023, scientists announced that they had filmed a fish swimming at the deepest depth ever recorded for a fish. The creature — a kind of snailfish of the genus Pseudoliparis — was filmed swimming at 8,336 meters (27,349 feet) by an autonomous "lander" dropped into the Izu-Ogasawara Trench, south of Japan beating the previous deepest fish observation — made at 8,178 meters further south in the Pacific in the Mariana Trench — by 158 meters. That fish that held that record was also a snailfish. [Source: Jonathan Amos - BBC Science Correspondent, April 2, 2023]


The BBC reported: The lead scientist said the snailfish could be at, or very close to, the maximum depth any fish can survive. "If this record is broken, it would only be by minute increments, potentially by just a few meters," Prof Alan Jamieson, who lead the dive, told BBC News. The University of Western Australia deep sea scientist made a prediction 10 years ago that fish would likely be found as deep as 8,200 to 8,400 meters. Prof Jamieson has pioneered the use of instrumented deep-ocean landers.

The juvenile Pseudoliparis was filmed by a camera system attached to a weighted frame released from over the side of a ship, the DSSV Pressure Drop. Bait was added to the frame to attract sea life. Although a specimen was not caught to fully identify its species type, several fish were trapped slightly higher up in the water column in the nearby Japan Trench at a depth of 8,022m. These, again, were snailfish, Pseudoliparis belyaevi, and set a record for the deepest fish ever caught.

Prof Jamieson says the discovery of a fish deeper than those found in the Mariana Trench is probably due to the Izu-Ogasawara's slightly warmer waters. "We predicted the deepest fish would be there and we predicted it would be a snailfish," he said. "I get frustrated when people tell me we know nothing about the deep sea. We do. Things are changing really fast." Prof Jamieson is credited with discovering not just the deepest fish in our oceans but also the deepest octopus, jellyfish and squid.


Snailfish are world’s deepest-living fish. According to the BBC: Snailfish are truly remarkable. There are over 300 species, most of which are actually shallow-water creatures and can be found in river estuaries. But the snailfish group have also adapted to life in the cold waters of the Arctic and Antarctic, and also under the extreme pressure conditions that exist in the world's deepest trenches. [Source: Jonathan Amos - BBC Science Correspondent, April 2, 2023]

At eight kilometers down, they are experiencing more than 80 megapascals, or 800 times the pressure at the ocean surface. Their gelatinous bodies help them survive. Not having a swim bladder, the gas-filled organ to control buoyancy that is found in many other fish, is an additional advantage. Likewise, their approach to food — they are suction feeders and consume tiny crustaceans, of which there are many in trenches.

Elizabeth Kolbert wrote in The New Yorker: “To survive under such conditions, the snailfish has come up with various ingenious adaptations: its skull is not completely closed, its bones are unusually rubbery, and it produces special chemicals to prevent its proteins from denaturing under stress. The creature can barely see and instead relies on fluid-filled chambers along its jaws, which detect the movements of small crustaceans known as amphipods. [Source: Elizabeth Kolbert, The New Yorker, June 14, 2021]

Different species of hadal snailfish have been found in trenches worldwide, including the Kermadec Trench off New Zealand, the Japan and Kurile-Kamchatka trenches in the northwestern Pacific, and the Peru-Chile Trench. Hilary Duncanson wrote in The Independent that a “new type of snailfish was found living at a depth of 7,000 meters in the Peru-Chile trench of the South East Pacific Ocean — a part of the ocean previously thought to be entirely free of fish, scientists said. Mass groupings of cusk-eels and large crustacean scavengers were also discovered living at these depths for the first time, scientists said. The findings, in one of the deepest places on the planet, were made by a team of marine biologists from the University of Aberdeen and experts from Japan and New Zealand. [Source: Hilary Duncanson, The Independent, 15 October 2010]

Snailfish in the Mariana Trench

Elizabeth Kolbert wrote in The New Yorker: “The Mariana snailfish, as its name suggests, occupies the Mariana Trench — the ocean’s deepest depression — in the western Pacific. It’s a few inches long and looks like a large, pale-pink tadpole. The Mariana snailfish has been found more than twenty-six thousand feet below sea level, where the pressure is eight hundred times greater than at the surface. [Source: Elizabeth Kolbert, The New Yorker, June 14, 2021]

The team that made the discovery took part in a three-week expedition, during which they used deep-sea imaging technology to take 6,000 pictures at depths between 4,500 meters and 8,000 meters within the trench. The University of Aberdeen said these latest discoveries helped shed new light on life in the depths of the Earth. Oceanlab's Dr Alan Jamieson, who led the expedition, said: "Our findings, which revealed diverse and abundant species at depths previously thought to be void of fish, will prompt a rethink into marine populations at extreme depths. his expedition was prompted by our findings in 2008 and 2009 off Japan and New Zealand where we discovered new species of snailfish known as Liparids inhabiting trenches... at depths of 7,000 meters — with each trench hosting its own unique species of the fish. "To test whether these species would be found in all trenches, we repeated our experiments on the other side of the Pacific Ocean off Peru and Chile, some 6,000 miles (9,656 kilometers) from our last observations. What we found was that indeed there was another unique species of snailfish living at 7,000 meters — entirely new to science — which had never been caught or seen before.

Hadal Snailfish — One of the World’s Deepest-Dwelling Fish

Mackenzie Gerringer wrote: One of the world’s deepest-dwelling fish — known as a hadal snailfish — is small, pink and completely scaleless. Its skin is so transparent that you can see right through to its liver. Nonetheless, hadal snailfish are some of the most successful animals found in the ocean’s deepest places. We discovered this fish during a survey of the Mariana Trench in the western Pacific Ocean in 2014 in the Mariana Trench. It has been seen living at depths of almost 27,000 feet (8,200 meters). We officially christened it Pseudoliparis swirei. Studying its adaptations for living at such great depths has provided new insights about what kinds of life can survive in the deep ocean. [Source: Mackenzie Gerringer, Postdoctoral Researcher, University of Washington, February 1, 2018]

Hadal snailfish have several adaptations to help them live under high pressure. Their bodies do not contain any air spaces, such as the swim bladders that bony fish use to ascend and descend in the water. Instead, hadal snailfish have a layer of gelatinous goo under their skins that aids buoyancy and also makes them more streamlined. Hadal animals have also adapted to pressure on a molecular level. We’ve even found that some enzymes in the muscles of hadal fish are adapted to function better under high pressure.

However, to survive at the highest water pressures in the ocean, fish would need so much TMAO (trimethylamine N-oxide, a metabolite produced by gut bacteria). in their systems that their cells would reach higher concentrations than seawater. At that high concentration, water would tend to flow into the cells due to a process called osmosis, in which water flows from areas of high concentration to low concentration to equalize. To keep these highly concentrated cells from rupturing, fish would have to continually pump water out of their cells to survive.

The evidence suggests that fish don’t actually live all the way to the deepest ocean depths because they are not able to keep enough TMAO in their cells to combat the high pressure at that depth. This means that around 27,000 feet (8,200 meters) may be a physiological depth limit for fish. There may be fish that live at levels as deep, or even slightly deeper, than the Mariana snailfish.


The four-inch Macropinna fish drew a lot attention when pictures of its clear head, with visible organs that protects its eyes, were published. The eyes can shift forward through tubes. Muscles outside the tubes make the movement possible. What look like eyes are actually nostrils. The real eyes have green lenses adapted to catch light. The green pigments filter downwelling light to make prey easier to see. The fluid-filled dome shields their eyes from stinging animals without blocking the view. The eyes point upwards in a sort of default position so the fish can track food above it. When prey is within range muscles twitch and the eyes pop forward to help the fish aim its bite. The barrel eyes also allows Macropinna to cruise below jellyfish allowing it to get food trapped in their tentacles. “Choosing a target, it swings its body vertical and its eyes front, then steals the prey.” [Source: Jennifer S. Holland, National Geographic]

It was originally thought that Macropinna’s tubular eyes were fixed in place only allowing it to see above its head. However, in 2008, scientists discovered that its eyes were able to rotate both up and forward in its transparent shield. Macropinna has a tiny mouth and most of its body is covered with large scales. The fish normally sit nearly motionless in the water, at a depth of about 600 meters (2,000 feet) to 800 meters (2,600 feet), using its large fins for stability and with its eyes directed upward. In the low light conditions it is assumed the fish detects prey by its silhouette. MBARI researchers Bruce Robison and Kim Reisenbichler observed that when prey such as small fish and jellyfish are spotted, the eyes rotate like binoculars, facing forward as it turns its body from a horizontal to a vertical position to feed. Robison speculates that M. microstoma steals food from siphonophores. [Source: Wikipedia]

Macropinna microstoma was discovered in 1939 by marine biologist W. M. Chapman, in deep temperate waters off of the Pacific, Indian, and Atlantic oceans. It is restricted to deep oceanic water by its light-sensitive tubular eyes and is not known to have been photographed alive until 2004. . The fish has a strong digestive system. It is thought to be a pelagic spawner (the eggs are coated with a layer of oil that allows them to float on the closest surface of the sea until they hatch). The female lays eggs in water and male releases sperms in water. After hatching, the larvae begin to descend to the depths as they grow, feeding on zooplankton and other small particles of organic material. It is believed that there is no sexual dimorphism between the male and the female and that they do not care for their young.


Cetomimidae is a family of small, deep-sea cetomimiform fish. They are among the most deep-living fish known, with some species recorded at depths in excess of 3,500 meters (11,500 feet), and have no scales and tiny eyes. Males, females and juveniles look so different from one another they were long thought to be separate species. Females are known as flabby whalefishes, Males are known as bignose fishes, while juveniles are known as tapetails and were formerly thought to be in a separate family,

In 2021 an ultra-rare wild whalefish was spotted in waters off of Monterey Bay, California. By a remotely operated vehicle (ROV) at a depth of 2,000 meters (6,600 feet). According to Nerdist: look a bit like whales but that’s where the similarities end, and they have some very odd characteristics. Male whalefish feed off of their huge livers and use their large nasal organs to sniff for females. Females are much larger than the males — 18 inches versus 1.5 inches! — and have a fiery orange color — which strangely enough help them fish blend in with their surroundings. [Source: Matthew Hart, Nerdist, August 13, 2021].

“Perhaps the most fascinating part of the female whalefish, however, is how it sees. Or rather, doesn’t see. As a female whalefish evolves from a larva into an adult, it loses its eyes’ lenses and the ability to form images. Consequently, a system of pressure-sensing pores that runs along its head and down the length of its body develops. Which, in turn, allows it to detect its surroundings via vibrations in the water.


The blobfish — based on a photograph in which it looked like a pale pink gelatinous blob with a droopy, frowning mouth and large, sagging nose — was named the world’s ugliest animal in 2013 according to survey by the Ugly Animal Preservation Society. Afterwards its fame soared . Songs, soft toys, memes and even TV characters created based on it but, according to scientist Richard Arnott, the fish’s bad rap was the result of “a vast bullying campaign.” The fish only looks the way it did because of tissue damage it suffered due to rapid depressurization as it was pulled to the surface from its 1,200-meter-deep seafloor home. [Source: National Geographic]

According to National Geographic: Blobfish (Psychrolutes microporos)” look almost unrecognizable underwater: These tadpole-shaped fish have bulbous heads, large jaws, tapered tails, and feathery pectoral fins. Rather than scales, they have loose, flabby skin. They don’t have strong bones or thick muscle—instead, they rely on the water pressure to hold their shape together. That’s why blobfish collapse into a squishy mush when they are pulled up to the surface.”

The blobfish that was in the famous picture sits in a basement in a jar at the Australian Museum’s Ichthyology Collection, in Sydney. Dredged up from 1,200-meter (3,940-feet) -deep sea-floor off the coast of New Zealand during a 2003 research voyage along with hundreds of deep-sea creatures, the blobfish became so blobby when it was wrested from its home in part because it has hardly any muscle. This because it mainly just sits on the ocean floor eating what floats into its mouth — mostly crustaceans.[Source: Franz Lidz, Smithsonian magazine, November 2015]


The anglerfish is arguably one of the ocean's ugliest creatures. It sits motionless in the water with its mouth agape waiting for prey to pass its way. The fleshy-tip of the fish's hair-thin dorsal fin hangs in front of its mouth like a worm. When prey comes near, the angelfish sucks it into its mouth faster than the human eye can see. If the prey gets the bait. No problem. The anglerfish simply grows another fleshy tip. Deep sea anglerfish use a lure with bacterial light to attract fish.

There are 168 known species of anglerfish, most of which are found at ocean depths beneath about 300 meters. Some species mate through a process known as sexual parasitism. Males, which are often less than 10 millimeters in length, attach to the body of the larger female. In some cases male anglerfish attach themselves to females that 1,000 times larger than they are.

The sea devil anglerfish is is one of the world’s more spectacular-looking fishes. Katherine J. Wu and Rachael Lallensack wrote in Smithsonian magazine: The iconic image of the anglerfish — a deep-sea creature sporting jagged, translucent teeth and a luminescent lure to bait prey — represents only the females of this bunch. Petite, stunted and devoid of glowy baubles, male anglerfish are harder to photograph and far less interesting to look at. Males that luck upon a mate in the deep ocean attach themselves to her much large body for keeps, sucking in nutrients from her body while fertilzing her eggs. [Source: Katherine J. Wu , Rachael Lallensack,, February 14, 2020]

Opah— The Only Known Warm-Blooded Fish

Not all fish are cold-blooded. In 2015, researchers with the NOAA Southwest Fisheries Science Center revealed the opah, or moonfish, as the first fully warm-blooded fish. Although not as warm as mammals and birds, the opah circulates heated blood throughout its body, giving it a competitive advantage in the cold ocean depths from 47 to 400 meters (150 to 1,300 feet) below the surface. [Source: NOAA]

Its body temperature isn’t the only thing that makes this fish stand out from the rest in its environment. Most fish living in the dark and chilly depths rely on ambush to catch their prey, but the agile opah is fast and efficient, flapping its bright red pectoral fins to race through the water. The constant flapping of its fins heats the opah’s body, speeding its metabolism, movement, and reaction times.

Abigail Tucker wrote in Smithsonian magazine:“The rotund, silvery opah looks less like a deep-sea predator than a Mylar balloon, with curved pectoral fins that flap like wings. Its chest muscles account for almost a fifth of its body mass and, cleverly marinated, can pass for beef. “The coolest part — well, not cool in terms of temperature, but the neatest part — is that the opah has a warm heart,” says Kenneth Goldman, an Alaska shark biologist. [Source: Abigail Tucker, Smithsonian magazine, September 2015]

Opah ( Scientific name: Lampris guttatus, Lampris spp.) are found in tropical and temperate waters around the world. Also known as moonfish, they live in deep open ocean waters but sometimes swims up near the surface of ocean water where sunlight penetrates. In the U.S. they can be found off New England and Mid-Atlantic, Hawaii, other Pacific Islands, the Southeast and the West Coast.

The opah is a valuable species for commercial and recreational fishermen. However, researchers do not have a full understanding of the basic biology and ecology of this species. NOAA's Southwest Fisheries Science Center began collecting biological samples from opah in 2009 and initiated an electronic tagging program in 2011. Scientists hope to continue tagging opah to learn about their movements and range. This research will provide the basic life history information necessary for future population assessments and management. NOAA Fisheries is also working with the seafood industry to help reduce waste during the processing of opah.

Opah Characteristics

About the same size as a large automobile tire, the opah is equipped with specialized blood vessels that carry warm blood to its gills to rewarm the blood that cools as the fish breathes and absorbs oxygen from the water. These heat-exchanging blood vessels minimize the loss of body heat to the opah’s cold environment, ensuring a warm core body temperature, increasing muscle output and swimming capacity, and boosting eye and brain function. The opah is also able to stay in deep water longer without risking reduced function to its heart and other organs because the fatty tissue surrounding its gills, heart, and muscle tissue acts as insulation against icy waters.

The opah is one of the most colorful of the commercial fish species, and is particularly popular in Hawaii. It is overall red with white spots and turns a silvery-grey when it dies. Its fins are crimson, and its large eyes are with gold. The fish’s large, round profile is thought to be the origin of its “moonfish” nickname. These combined characteristics certainly make this “warm-blooded fish” unique among the many wondrous creatures of the ocean.

Opah are an unusual looking fish. They have a round, flat body that’s silvery gray in color. Toward the belly, the silver shades to a rose red, dotted with white spots. Their fins and mouth are red, and their large eyes are encircled with gold. [Source: NOAA]

Because opah are not a major commercial seafood species and they live in the deep ocean, scientists know very little about their biology and ecology. Scientists assume opah share general characteristics with other Pacific Ocean pelagic fish. Scientists estimate that opah grow quickly. Although they’re not sure of opah’s exact life span, scientists age opah by their fin rays, assuming fin ray marks are formed annually. Most opah caught in longline fisheries are estimated to be between 1 and 6 years old. They average about 45 kilograms (100 pounds) with a diameter of one meter (3 feet). It

Opah spawn in warm surface waters throughout the year in the tropics and more seasonally in cooler waters. They seem to be very productive, potentially spawning many times throughout the spawning season. Opah are capable of traveling long distances, often in response to changing oceanic conditions such as temperature..

Opah Warmbloodedness

Abigail Tucker wrote in Smithsonian magazine: “Scientists have long known that some fish, including select species of billfish, shark and tuna, are partially warmblooded. In 1835, British physician John Davy noted that a tuna’s blood temperature was “much the same, or little less than the blood of a pig.” That was a bit of an overstatement. Most partially warmblooded fish stay just a few degrees above the surrounding water temperature. But that’s enough to give them a predatory edge, relative to their “thermoconformist” peers. [Source: Abigail Tucker, Smithsonian magazine, September 2015]

“Warmer fish can expand their range, in latitude and depth, and cruise faster because of increased red muscle output, benefits brought to an extreme in birds and mammals, whose stable body temperatures might have led to the development of complex central nervous systems. While mammals make meta-bolic heat even at rest, fish mostly keep warm through active movement. Thus the opah’s juiced-up pecs.

“Partial warmbloodedness has evolved several times in fish, and yet it’s rare, found in less than 0.1 percent of fish species. It’s tough to retain warmth in water, which is far denser than air and sucks body heat, particularly where it meets blood for oxygen exchange. (One critique of the movie Waterworld is that a gilled Kevin Costner would have died of hypothermia.) Specialized blood vessel systems called retia mirabilia — “wonderful nets” — work like radiators to heat isolated organs. Some stomachs are warm for better digestion. And the opah is known to have warm eyes. But typically only a few organs benefit.

“Not so in the opah. Nicholas Wegner, who has been tagging live opah and dissecting dead ones with his NMFS team, found the retia mirabilia embedded right in the opah’s gill arches, meaning that heat circulates throughout the whole body. When a colleague, Owyn Snodgrass, checked core opah temperatures in living fish, they were uniformly warm. Yet warmth does not equal invincibility. Sometimes a tagged opah’s light sensor will go dark and its heat sensor will mysteriously warm, suggesting that a study animal has ended up inside the warm belly of a cold-hearted shark.

Opah Fishing

In 2021, the commercial landings in the U.S. of opah in Hawaii totaled 210,000 kilograms (460,000 pounds) and were valued at $1.8 million, according to the NOAA Fisheries commercial fishing landings database. While there is no directed fishery for opah, they are harvested in small but significant quantities. U.S. fishermen catch them incidentally in tuna and swordfish fisheries around the U.S. Pacific Islands and off southern California. In Hawaii, opah are caught using longlines set deep below the surface to target bigeye tuna. Off California, they're taken incidentally in the California drift gillnet fishery targeting swordfish. Although not commonly caught, opah are prized by deepwater recreational anglers for their unique colors and light flavor. [Source: NOAA]

U.S. wild-caught opah is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations. The population level is unknown but presumed stable. The fishing rate is at recommended level. Fishing gear used to catch opah rarely contacts the ocean floor so habitat impacts are minimal. There is no directed fishery. Regulations are in place to minimize bycatch in the tuna and swordfish fisheries, which incidentally catch opah. Population Status: Opah has never been assessed, but there is no evidence that populations are in decline or that fishing rates are too high.

NOAA Fisheries and the Western Pacific Fishery Management Council manage this fishery in the Pacific Islands. The species are managed under the Fishery Ecosystem Plan for the Pelagic Fisheries of the Western Pacific: No management measures specifically apply to opah. However, general management measures apply to the fisheries that harvest opah. Fishermen are required to have permits and record their catch. Gear restrictions and operational requirements to minimize bycatch and potential gear conflicts among different fisheries. A limit on the number of permits for Hawaii and American Samoa longline fisheries controls participation in the fishery.

Longline fishing is prohibited in some areas to protect endangered Hawaiian monk seals, reduce conflicts between fishermen, and prevent localized stock depletion (when a large quantity of fish are removed from an area). These zones are enforced through the NOAA Fisheries vessel monitoring system program (longline boats must be equipped with a satellite transponder that provides real-time position updates and tracks vessel movements). Hawaii- and American Samoa–based longline vessels must carry onboard observers when requested by NOAA Fisheries, in part to record interactions with sea turtles, seabirds, and marine mammals.Annual training in safe handling and release techniques for protected species is required, and all vessels must carry and use specific equipment for handling and releasing these animals.

Studying the Deep Sea

Mackenzie Gerringer wrote: Sending instruments to the ocean floor is pretty straightforward. Bringing them back up is not. Researchers studying the deep sea often use nets, cameras or robots connected to ships by cables. But a 7-mile-long cable, even if it is very strong, can break under its own weight. We used free-falling landers — mechanical platforms that carry instruments and steel weights and are not connected to the ship. When we deploy landers, it takes about four hours for them to sink to the bottom. To call them back, we use an acoustic signal that causes them to release their ballast and float to the surface. Then we search for them in the water (each carries an orange flag), retrieve them and collect their data. [Source: Mackenzie Gerringer, Postdoctoral Researcher, University of Washington, February 1, 2018]

Elizabeth Kolbert wrote in The New Yorker: “It’s so hard for humans to get to the deep sea — and, once there, to record what they’re seeing. “Edith Widder has spent much of her career trying to figure out ways to study bioluminescence remotely. She’s developed special deep-sea cameras that rely on red light, which marine creatures mostly can’t detect. Much of “Below the Edge of Darkness” is occupied with the travails of getting these cameras placed, a project that involves journeys so nauseating that Widder describes cycling through the five stages of seasickness. In the fourth, she explains, “you’re afraid you’re going to die,” and in the last “you’re afraid you’re not.” [Source: Elizabeth Kolbert, The New Yorker, June 14, 2021]

“The experience that she really wants to convey, though, is not queasiness but wonder. The creatures of the deep have been putting on the world’s greatest light show for tens of millions of years. Widder thinks that if people could witness this spectacle — or even just be made aware of it — they’d pay a lot more attention to life at the bottom of the seas and the many hazards that threaten it. These include but are not limited to global warming, ocean acidification, overfishing, agricultural runoff, oil spills, invasive species, bottom trawling, plastic waste, and seabed mining.

“We seem to be in a Catch-22 scenario where we haven’t explored the deep ocean because we don’t appreciate what a remarkable, mysterious, and wondrous place it is, and we don’t know what an astonishing place it is because we haven’t explored it,” she argues. Meanwhile, she writes, “we are managing to destroy the ocean before we even know what’s in it.” All marine photosynthesis takes place in the sunlight zone. Beneath that, food is in such short supply that the occasional dead whale that falls to the ocean floor represents a major source of nutrients. Nevertheless, even in the farthest recesses of the oceans, life finds a way.

Image Sources: Wikimedia Commons; YouTube, Animal Diversity Web, NOAA

Text Sources: Animal Diversity Web (ADW); National Oceanic and Atmospheric Administration (NOAA); Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated March 2023

This site contains copyrighted material the use of which has not always been authorized by the copyright owner. Such material is made available in an effort to advance understanding of country or topic discussed in the article. This constitutes 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. If you are the copyright owner and would like this content removed from, please contact me.