Tired of the hardships of life on dwindling land and the constant floods, some had decided to stay in the depths, becoming Abyssals—those living in the Abyssal zone, the deepest part of the sea.
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Much of the bottom of the Coral Sea, where the Wasp went down, lies between 4,000 and 6,000 meters, in what is known as the abyssal zone: a lightless realm characterized by frigid water temperatures, scant animal life and crushing atmospheric pressure.
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The mesopelagic zone extends from to . The bathyal zone extends from to . The abyssal zone extends from to or , depending on the authority. The hadal zone refers to the greatest depths, deeper than the abyssal zone.
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Both ocean acidification and pollution are decreasing the already small biomass that resides within the abyssal zone. Another problem caused by humans is overfishing. Even though no fishery can fish for organisms anywhere near the abyssal zone, they are still causing harm. The abyssal zone depends on dead organisms from the upper zones sinking to the seafloor, since their ecosystem lacks producers due to lack of sunlight.
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Grimpoteuthis challengeri is a species of large octopus living in the abyssal zone.
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This species occurs in the Atlantic Ocean in the abyssal zone off Argentina.
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Mining could increase the amount of pollution in not only the abyssal zone, but in the ocean as a whole, and would physically destroy habitats and the seafloor. This industry represents a looming threat to the abyssal zone and the rest of the ocean's inhabitants.
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There are four ocean zones: the Sunlight zone, the Twilight zone, the Midnight zone, and the Abyssal zone.
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The area below the abyssal zone is the sparsely inhabited hadal zone. The zone above is the bathyal zone.
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Without producers, the cornerstone of most ecosystems, a unique ecosystem forms. Rather than relying on producers to form the base of the food pyramid, organisms living in the abyssal zone must feed on the dead organic detritus that falls from oceanic layers above. The biomass of the abyssal zone actually increases near the seafloor as compared to areas above as most of the decomposing material and decomposers rest on the seabed. The sea floor of the abyssal zone consists of or is layered by different materials depending on the depth of the sea floor.
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Depiction of the abyssal zone in relation to other major oceanic zones. This is a list of submarine topographical features, oceanic landforms and topographic elements.
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As fish and other animals are removed from the ocean, the frequency and amount of dead material reaching the abyssal zone decreases. A future problem for the abyssal zone could be deep sea mining operations. The talks and planning for this industry are already underway. This could be disastrous for this extremely fragile ecosystem since the ecological dangers from mining for deep sea minerals are many.
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Psychrolutes microporos is a species of deepwater marine fish in the family Psychrolutidae, commonly known as a blobfish or fathead. It is found in the abyssal zone in waters around Australia and New Zealand.
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Historically the hadal zone was not recognized as distinct from the abyssal zone, although the deepest sections were sometimes called "ultra-abyssal". During the early 1950s, the Danish Galathea II and Russian Vitjaz expeditions separately discovered a distinct shift in the life at depths of not recognized by the broad definition of the abyssal zone. The term "hadal" was first proposed in 1956 by Anton Frederik Bruun to describe the parts of the ocean deeper than , leaving abyssal for the parts at . The name refers to Hades, the ancient Greek god of the underworld.
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Uniquely amongst deep-sea anglerfish, adult Thaumatichthys are benthic in nature; T. binghami and T. pagidostomus are found on the continental shelf between 1,000-2,000 m, while T. axeli is found in the abyssal zone at about 3,600 m.
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Psychropotes longicauda is a cosmopolitan abyssal species of sea cucumber and is found on the seabed throughout the world's deep oceans. Its larva is pelagic and is often found more than above the ocean floor but still in the abyssal zone.
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Synaphobranchus kaupii at the IUCN redlist. It dwells at a depth range of , most often between , and inhabits the upper abyssal zone on the continental slope. It is intolerant of the temperatures of higher waters. Males can reach a maximum total length of .
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The abyssal zone or abyssopelagic zone is a layer of the pelagic zone of the ocean. "Abyss" derives from the Greek word , meaning bottomless. At depths of , this zone remains in perpetual darkness. It alone makes up over 83% of the ocean and covers 60% of the Earth.
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The benthic zones are aphotic and correspond to the three deepest zones of the deep-sea. The bathyal zone covers the continental slope down to about . The abyssal zone covers the abyssal plains between 4,000 and 6,000 m. Lastly, the hadal zone corresponds to the hadalpelagic zone, which is found in oceanic trenches.
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Christmas Island consists of an uplifted limestone cap metamorphosed from coral reefs overlying more ancient volcanic andesite bedrock. The underlying seamount lies some southwest of Indonesia, and the isolation by the abyssal zone has led to endemism amongst the marine ecosystem. The park's boundaries extend beyond the low water line. Approximately of the island's shoreline is within the park limits.
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Around the poles, the angle of the sunlight means it does not penetrate as deeply so the aphotic zone is shallower. If the water is turbid, suspended material can block light from penetrating resulting in a shallower aphotic zone. Temperatures can range from roughly to . The aphotic zone is further divided into the mesopelagic zone, the bathyal zone, the abyssal zone, and the hadal zone.
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The majority of species still live in the oceans, from the seashores to the abyssal zone, but some form a significant part of the freshwater fauna and the terrestrial ecosystems. Molluscs are extremely diverse in tropical and temperate regions, but can be found at all latitudes. About 80% of all known mollusc species are gastropods. Cephalopoda such as squid, cuttlefish, and octopuses are among the neurologically most advanced of all invertebrates.
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Thaumatichthys axeli is a bottom-dwelling deep-sea anglerfish of the family Thaumatichthyidae. Thaumatichthys axeli lives at a depth of around 3,600 meters (in the abyssal zone), deeper than any other member of the genus Thaumatichthys. As with other members of the family, they possess a distinctive forked light organ inside their mouth, which they use to lure prey. Large, curved teeth "fringe the upper jaw like a comb".
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Pourtalesia is a genus of the family Pourtalesiidae which belongs to the irregular (bilaterally symmetrical) sea urchins. The animals measure 5–6 cm in length and live in the abyssal zone of the Atlantic, Pacific, Indopacific and Antarctic Oceans where they have been found in more than 3,000 m depth. The mouth opening of these animals is located anteriorly and the lantern of Aristotle is missing as typically for holasteroid sea urchins.
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The shrimp are almost entirely blind, surviving at the interface of cold, deep seawater and supercritical hydrothermal fluid. Other challenges faced by life in the abyssal zone are the pressure and darkness caused by the zone’s depth. Many organisms living in this zone have evolved to minimize internal air spaces, such as swim bladders. This adaptation helps to protect them from the extreme pressure, which can reach around 75 MPa (11,000 psi).
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In 2008, the hadal snailfish (Pseudoliparis amblystomopsis) was observed and recorded at a depth of 7700 meters in the Japan Trench. These are, to date, the deepest living fish ever recorded. Other fish of the abyssal zone include the fishes of the family Ipnopidae, which includes the abyssal spiderfish (Bathypterois longipes), tripodfish (Bathypterois grallator), feeler fish (Bathypterois longifilis), and the black lizardfish (Bathysauropsis gracilis). Some members of this family have been recorded from depths of more than 6000 meters.
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The extant members of the class live only in the deep ocean (the abyssal zone, the continental shelf, and the continental slope) at depths below . Cambrian forms predominately lived in shallow seas, whereas later Paleozoic forms are more commonly found in deeper waters with soft, muddy sea floors. Although superficially resembling limpets when viewed dorsally, monoplacophorans are not anatomically similar to gastropods. Some similarities are shared with the chitons, such as having segmented anatomy (organs arranged in series).
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Scientists believe that over 90% of life in the abyssal zone use some form of bioluminescence. Many animals that are bioluminescent produce blue light, since it moves farther underwater than other colors of light, as explained earlier. Due to this lack of light, complex designs and bright colors are not needed. Most fish species have evolved to be transparent, red, or black so they better blend in with the darkness and don't waste energy on developing and maintaining bright or complex designs.
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Giant tube worms chemosynthesize near hydrothermal vents The abyssal zone remains in perpetual darkness at a depth of . The only organisms that inhabit this zone are chemotrophs and predators that can withstand immense pressures, sometimes as high as . The hadal zone (named after Hades, the Greek god of the underworld) is a zone designated for the deepest trenches in the world, reaching depths of below . The deepest point in the hadal zone is the Marianas Trench, which descends to and has a pressure of .
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Careproctus is a genus of snailfishes found in benthic and benthopelagic habitats in the Atlantic, Pacific, Arctic and Southern Oceans. Whether they truly are absent from the Indian Ocean, except for a couple of species in Subantarctic waters, is unknown and might be an artifact of limited sampling. They range from shallow coastal seas in the far north of their range to the abyssal zone, at depths of . In the Northern Hemisphere they mostly live shallower than Paraliparis, but this pattern is reversed in the Southern Hemisphere.
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Hotspot volcanic island ridges are created by volcanic activity, erupting periodically, as the tectonic plates pass over a hotspot. In areas with volcanic activity and in the oceanic trenches there are hydrothermal vents – releasing high pressure and extremely hot water and chemicals into the typically freezing water around it. Deep ocean water is divided into layers or zones, each with typical features of salinity, pressure, temperature and marine life, according to their depth. Lying along the top of the abyssal plain is the abyssal zone, whose lower boundary lies at about 6,000 m (20,000 ft).
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In most fish species, barbels are used to aid in the acquisition of food in bodies of water that have low visibility due to low light conditions or murky waters. The taste receptors are able to detect enzymes in the water and help the fish identify if it is from a possible food source or possible sources of danger. The abyssal zone scavengers Coryphaenoides armatus possess one small mandible barbel that they use to search the seafloor for carrion to eat. Freckled Goatfish, Upeneus tragula, develop barbels as a response to food availability.
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This means that in the deep ocean, if any light remains then it is most likely blue light so animals wanting to capitalize on that light would need specialized eyes tuned to use it. Many organisms use other specialized organs or methods for sensing their surroundings, some in conjunction with specialized eyes. The ability to make their own light is called bioluminescence. Fishes and organisms living in the abyssal zone have developed this ability not only to produce light for vision, but also to lure in prey or a mate and conceal their silhouette.
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First appearing during the Cambrian, Chondrites is still produced today. It is one of the most common ichnotaxa throughout the fossil record and is widely distributed in all types of marine sedimentary rocks, including sandstone, shale, limestone and marl that formed in environments ranging from subtidal shelves to the abyssal zone. The tracemaker has been able to tolerate highly variable redox conditions. For example, Chondrites is abundant almost to the exclusion of other ichnogenera in Posidonia Shale, formed from laminated, black, carbonaceous clay, deposited in an anoxic, reducing environment.
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The Hellenic Trench, with the inner South Aegean Volcanic Arc, and the outer non-volcanic Hellenic arc The Hellenic Trench is a hemispherical-scale long narrow depression in the Ionian Sea. The Hellenic trench is roughly to 5,300 metres (17,388 feet) deep, placing it in the abyssal zone. The names of the three major parts of the Hellenic trench are: Matapan Deep System or Matapan–Vavilov Deep, roughly , the Kithera–Antikithera System, , and the Zakinthos–Strofadhes system, . The Calypso Deep, located in the Matapan–Vavilov Deep, is roughly deep and is the deepest point in the Mediterranean Sea.
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Echinoderm is the common name given to any member of the phylum Echinodermata (from Ancient Greek, ἐχῖνος, echinos – "hedgehog" and δέρμα, derma – "skin") of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, and include starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the vertebrates, such as birds, fishes, mammals, and reptiles).
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As with all of the rest of the natural world climate change has negative effects. Due to the zone’s depth, increasing global temperatures do not affect it as quickly or drastically as the rest of the world, but the zone is still afflicted by ocean acidification. Along with climate change and ocean acidification, pollutants, such as plastics, are also present in this zone. Plastics are especially bad for the abyssal zone due to the fact that these organisms have evolved to eat or try to eat anything that moves or appears to be detritus, resulting in most organisms consuming plastics instead of nutrients.
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Some of these chimney structures can reach heights of 60 m. An example of such a towering vent was "Godzilla", a structure on the Pacific Ocean deep seafloor near Oregon that rose to 40 m before it fell over in 1996. Black smokers were first discovered in 1979 on the East Pacific Rise at 21° north latitude. A black smoker or deep sea vent is a type of hydrothermal vent found on the seabed, typically in the bathyal zone (with largest frequency in depths from 2500 m to 3000 m), but also in lesser depths as well as deeper in abyssal zone.
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Diagrammatic cross-section of an oceanic basin, showing the relationship of the abyssal plain to a continental rise and an oceanic trench Depiction of the abyssal zone in relation to other major oceanic zones An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between and . Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. They are among the flattest, smoothest, and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins (the other elements being an elevated mid-ocean ridge and flanking abyssal hills).
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The deep-sea floor is called the abyssal plain and is usually about deep. The ocean floor is not all flat but has submarine ridges and deep ocean trenches known as the hadal zone. For comparison, the pelagic zone is the descriptive term for the ecological region above the benthos, including the water-column up to the surface. Depending on the water-body, the benthic zone may include areas that are only a few inches below water, such as a stream or shallow pond; at the other end of the spectrum, benthos of the deep ocean includes the bottom levels of the oceanic abyssal zone.
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Papery burnupena in False Bay There are at least 12,914 marine species in South Africa, but small bodied species are poorly documented and the abyssal zone is almost completely unexplored. Almost a quarter of South Africa's coast line is protected, excluding deeper water. A third of the marine species are endemic to South Africa (though poor levels of taxonomic research in adjoining countries probably affects the apparent endemism.) The degree of endemism varies considerably among taxa: Bryozoa 64%, Mollusca 56%, Echinodermata 3.6%, Porifera 8.8%, Amphipoda 33%, Isopoda 85%, or Cumacea 71%. Fisheries are one of the major threats to the biodiversity of the Agulhas Bank.
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The abyssal zone has temperatures around through the large majority of its mass. Due to there being no light, there are no plants producing oxygen, which primarily comes from ice that had melted long ago from the polar regions. The water along the seafloor of this zone is actually devoid of oxygen, resulting in a death trap for organisms unable to quickly return to the oxygen-enriched water above. This region also contains a much higher concentration of nutrient salts, like nitrogen, phosphorus, and silica, due to the large amount of dead organic material that drifts down from the above ocean zones and decomposes.
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Organisms that live at this depth have had to evolve to overcome challenges provided by the abyssal zone. Fish and invertebrates had to evolve to withstand the sheer cold and intense pressure found at this level. They also had to not only find ways to hunt and survive in constant darkness but to thrive in an ecosystem that has less oxygen and biomass, energy sources or prey items, than the upper zones. To survive in a region with so few resources and low temperatures, many fish and other organisms developed a much slower metabolism and require much less oxygen than those in upper zones.
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It has also been argued that Yelovichnus and similar organisms are xenophyophores, large but single-cellular organisms that exist today in the abyssal zone. Due to similar structures found in their fossils, it is theorized that Yelovichnus may be related to Palaeopascichnus, as well as Aspidella and Neonereites. The main difference between Yelovichnus and Palaeopasicichnus is the shape of their segments: the segments of Yelovichnus took the shape of "closed, ovate-shaped loops", whereas the segments of Palaeopascichnus were quite varied in shape. The genus and species was described by Mikhail A. Fedonkin in 1985 from the Ediacaran (Vendian) deposits of the White Sea area, Russia.
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Sipunculus nudus All sipunculid worms are marine and benthic; they are found throughout the world's oceans including polar waters, equatorial waters and the abyssal zone, but the majority of species occur in shallow water, where they are relatively common. They inhabit a range of habitats including burrowing in sand, mud, clay and gravel, hiding under stones, in rock crevices, in hollow coral heads, in wood, in empty seashells and inside the bones of dead whales. Some hide in kelp holdfasts, under tangles of eelgrass, inside sponges and in the empty tubes of other organisms, and some live among fouling organisms on man-made structures. Some bore into solid rocks to make a shelter for themselves.
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Tides may have a very high range in bays or estuaries. Submarine earthquakes arising from tectonic plate movements under the oceans can lead to destructive tsunamis, as can volcanoes, huge landslides or the impact of large meteorites. A wide variety of organisms, including bacteria, protists, algae, plants, fungi, and animals, live in the sea, which offers a wide range of marine habitats and ecosystems, ranging vertically from the sunlit surface and shoreline to the great depths and pressures of the cold, dark abyssal zone, and in latitude from the cold waters under polar ice caps to the colourful diversity of coral reefs in tropical regions. Many of the major groups of organisms evolved in the sea and life may have started there.
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