Belly of Charybdis

By Rebekah Booth

INTRODUCTION

This is a record of known information on the subject of the Benthic and Pelagic ocean zones covering the depths of 1,000-11,000 meters (3,280-36,089 feet), otherwise known as the Midnight, Abyssal, and Trench Zones. Throughout this paper, discussions will range from various deep-sea species, such as the anglerfish, Japanese spider crab, and xenophyophores. I will also discuss the phenomena of natural whalefalls as well as the audioscape within the Challenger Deep. 

Years of research have contributed to the exploration of the deep sea. As of June 2025, only 27.3% of the seafloor has been mapped via multibeam sonar systems. There is still an overwhelming amount of the ocean yet to be studied. Only 0.001% of the deep ocean (classified as everything below 200 meters/656 feet) has been seen. Given that 90% of the ocean is “deep ocean”, we as a species have seen very, very little of it. Part of this is due to the fact that only by 1922 did the technology to explore the ocean become accurate enough to be useful. Prince Albert of Monaco sailed for years collecting oceanic data via weather balloons and kites. The rest of the lack of data can be traced to the common human fear of the ocean. According to analysis, 2-9% of the world is afraid of the deep, open ocean.

This fear is classified as thalassaphobia, the irrational fear of large bodies of water. There is a lesser-known subset of this, known as megalohydrothalassaphobia. This is the irrational fear of large, unseen objects and creatures within large bodies of water (ie. shipwrecks, whales, etc.). Both of these phobias often go hand-in-hand when it comes to people avoiding the shoreline. 

These fears are also what helped ancient minds shape the classic legends of sea monsters, such as the Greek Charybdis and the Japanese Umibozu. Monsters and demons brought to life from the horrifying visages of creatures hypothetically much better-seen during those times. Things with bulging eyes and see-through bodies, things the length of ships with more teeth than any modern predator, things that loved to lurk just underneath the crystal waves. 

While these reasonable fears, along with several others (vorarephobia, the fear of being eaten), have kept the human race from exploring the largest part of our planet, there has still been significant information collected on different species and natural events. In this paper, I will compile a comprehensive report on these subjects as an attempt to connect past data and infer what future data might uncover.

Bathypelagic Zone

DEPTH: 1,000 meters | 3,280 feet TEMPERATURE: 4°C | 39.2°F

HYDROSTATIC PRESSURE: 100 - 400 atmospheres VISIBILITY: Nonexistent

There are 200 known species of anglerfish (Order: Lophiiformes) between the Atlantic and Arctic oceans. They are not persistence predators. They ambush. That is why the females evolved to develop their signature bioluminescent lures—a long rod with a bulbous sac of bacteria which produce the glow. They are small, but stocky, a compact body with short fins. A gaping mouth and an expandable stomach that allows them to swallow prey twice their size. Some females (Caulophrynidae) developed additional bioluminescent tendrils, like jellyfish, to heighten their chance for prey. While some species reside in shallower waters at about 200-2,000 meters, these particular types (deep-sea anglers) exist between 1,000 and 4,000 meters. This depth is colloquially known as the Midnight Zone.

 The deepest recorded dive by a human male using specialized equipment, without a submersible, was marked at 332 meters. For recreational divers without the same equipment, that number is reduced to approximately forty meters. The safest depth for people—as in, the deepest point a person can dive without dying—theoretically rests at 35 kilometers (35,000 meters/114,829 feet). Beyond that, the human body cannot survive. At 235 meters, your lungs collapse. Blood overwhelms your vessels and causes them to burst, but not before your bones are crushed beneath tonnes of pressure and you die without a scream because you gave up your last breath at the surface and all the air was gone when the sun left and—

Can you feel them? The eyes?

Light enters the eyes through electrochemical sensors that are then interpreted by the brain. Said light is picked up by cones (maximize daylight) and rods (maximize darkness), both of which contain light-sensitive proteins called opsins. Most vertebrates' cones operate with four different opsins that allow a range of color. However, deep-sea creatures such as anglerfish rely on hypersensitive rods to detect weaker light, since sunlight is unavailable at those depths. The closest it gets is bioluminescence and the rare submersible floodlight. 

They can see you. They know you are there. Don’t look.

Because there is not much light within the Midnight Zone, the anglerfish must operate using more tactile sensations. They have something called a “lateral line system” down the center of their backs that allow them to sense slight pressure shifts and vibrations in the water caused by nearby prey. Alongside this, male anglerfish have developed heightened olfactory organs to aid them in hunting down mates by

Do you see that light? They have been following you for leagues. You have not noticed.

Stay where you are. They are hunting you. There is no retreating—you will die going down, you will die going up. They can see you.

following pheromone trails. These specialized traits allow anglerfish, of every species, to survive at depths that would otherwise kill a weaker (uoy) animal. For all their frightening features, CAN YOU SEE THEM YET? these elusive deep-sea creatures are truly fascinating.

There are other creatures that live in this part of the ocean besides the anglers, who actually evolved quite similarly! One such species is known by several names, such as the pelican eel, whiptail gulper, umbrella-mouth gulper, etc. Her scientific name is Saccopharynx lavenbergi, and she lives in the Eastern Pacific ocean. Much like the deep-sea anglers, the gulper eel evolved to develop sensitive eyes, tactile senses, and bioluminescence. However, scientists actually are not sure if the eels use their bioluminescence (in their case, a sac at the tip of their tail) in the same way as anglers. This is because their sacs produce red light, something that is nearly invisible 

You are not invisible. They are getting closer.

in those deep waters. Some scientists assume that they use it to attract specific prey, such as some species of shrimp, that can see red light. Others assume it is a way to communicate with other eels, to warn of predators and attract mates. Unfortunately, because very little is known about the whiptail gulper eel, there is not enough evidence to form a conclusive answer.

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³ Smile! They can see you!

Abyssopelagic Zone

DEPTH: 4,000 meters | 13,123 feet TEMPERATURE: 2°C | 36°F

HYDROSTATIC PRESSURE: 200 - 600 atmospheres VISIBILITY: Nonexistent

The seafloor is composed of more than sand. The majority of it is basaltic crust, which is a dark, fine-grained igneous rock that forms as magma cools and hardens (meaning this crust would have formed shortly after the Earth did). This process is what creates new crust as tectonic plates shift. The remainder of the floor is a mixture of sediment created by eroded continental rocks (clay, silt, dust) and “oozes” formed by the calcium carbonate shells of plankton as well as silica skeletons of algae and protozoans. 

Japanese spider crabs (Macrocheira kaempferi) wander this abyssal plain in search of food. Spider crabs eat a diet of dead and decaying fish, other invertebrates, and algae (this is because they are floorbound and cannot swim), though their easiest meal is much rarer—whalefall. This phenomenon occurs after a whale’s death. After one expires, its insides decay over several months, causing the body to bloat with gas and rise to the ocean’s surface. Because of the whale’s high blubber content, it will stay afloat longer, and its flesh will provide food for sharks and seabirds for weeks. Then it will sink, faster as the temperature drops and the pressure increases, this lifeless giant falling falling falling all the way to the bottom of the sea.

This is now classified as a whalefall. 

The spider crab will happen upon it along with thousands of other organisms: hagfish, sleeper sharks, lobsters, other crabs, worms, and bacteria. These scavengers will eat the remainder of the muscle and blubber down to the bone. Bacteria will live in its skeleton for years after, breaking down the last fatty lipids within the bone matrix. From this, they create hydrogen sulfide (H₂S), which other bacteria use alongside the water’s oxygen to create energy through the process of chemosynthesis. These processes form a thick, nutrient-rich blanket which provides food to the thousands of bottom-dwelling organisms that do not actively hunt.

A human body decomposes in much the same way as the whale’s. It takes roughly seven seconds for your corpse to sink to the seabed because you are much leaner than a whale. Because of the temperature, you will remain on the seafloor (in much more tropical waters you would float on the surface and become birdfood). After about a week your skin will peel off and sea lice will eat away at the lingering flesh. Because of the extreme pressure and temperatures, both the whale and you would remain on the seafloor until your bones join the thousands turned to dust in the currents.

The freezing conditions will speed up the formation of adipocere. This is a waxy substance that coats your body and partially protects you from decomposition. It forms from anaerobic bacterial hydrolysis of fat in tissues. This process is known as saponification. It is why bodies have been retrieved from the ocean almost perfectly intact after several weeks, and 

Your body would not be found. Nets do not reach the abyssal zone. Your corpse would remain in stasis until your flesh has been eaten to reveal your bones. 

There would be no recovery for you.

Whalefall is a necessary part of the circle of life within the deep ocean. These giants spend their lives moving, hunting, living, and in death they return to the depths as nourishment for other creatures. However, many of these events are artificial. There are very rarely sighted natural whalefalls, so as a way to gather data as close to naturally as possible, scientists would purposely sink the corpses of beached whales. HOW DID YOU GET HERE? That way, it removed the corpse from the shore and provides both nutrients to scavengers as well as breakthroughs to scientists!

Hadalpelagic Zone

DEPTH: 10,994 meters | 369,069 feet TEMPERATURE: 1°C | 34°F

HYDROSTATIC PRESSURE: 1,080 - 1,100 atmospheres         VISIBILITY: NONEXISTENT

You made it. Welcome.

 You are in the end. 

Take a look around; there is nothing here but you. 

You and xenophyophores, anyway. They’re the largest

single-celled organism found this deep. They live in the

brainlike structures tucked into pockets of this abyss’s steep walls,

and some of them

have been here since long before this trench was named.

They are not paying any attention to you. I would not count on them for

help.

I don’t think they count as “something”. So we will ignore them.

Here in the Deep the void stretches for miles—

the water so dark it can no longer be called blue.

If you managed to sink this far and not turn into paper, congratulations. 

You are now completely alone.

Can you feel it? That emptiness, pressing against you 

from every angle? It is the only touch you will feel down here.

You have reached deeper than even the tallest man-made structure,

taller even than the tallest mountain peak.

On the bright side, it is not completely silent here.

You can hear the rumble of earthquakes. 

Whalesong (not the dead ones). The occasional typhoon.

Is that better? I didn’t think so.

Whatever you think you hear, whatever you think you feel, you are

utterly, absolutely

alone.

By Rebekah Booth