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Nestled between Hawaii and the western coast of Mexico lies the Pacific Ocean’s Clarion-Clipperton Zone (CCZ), a 4.5 million-kilometer-square area of abyssal plain bordered by the Clarion and Clipperton Fracture Zones. Although this stretch of sea is a vibrant ecosystem filled with marine life, the CCZ is known best for its immense collection of potato-sized rocks known as polymetallic nodules. These rocks, of which there are potentially trillions, are filled with rich deposits of nickel, manganese, copper, zinc, cobalt……..Continue reading…
By: Darren Orf
Source: Popular Mechanics
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Organisms in the deep sea are almost entirely reliant upon sinking living and dead organic matter which falls at approximately 100 meters per day. In addition, only about 1 to 3% of the production from the surface reaches the seabed, mostly in the form of marine snow. This ends up accumulating on the benthic floor, around 1 cm every 1,000 years. Larger food falls, such as whale carcasses, also occur and studies have shown that these may happen more often than currently believed.
There are many scavengers that feed primarily or entirely upon large food falls and the distance between whale carcasses is estimated to only be 8 kilometers. In addition, there are a number of filter feeders that feed upon organic particles using tentacles, such as Freyella elegans. Marine bacteriophages play an important role in cycling nutrients in deep sea sediments. They are extremely abundant (between 5×1012 and 1×1013 phages per square meter) in sediments around the world.
Despite being so isolated deep sea organisms have still been harmed by human interaction with the oceans. The London Convention aims to protect the marine environment from dumping of wastes such as sewage sludge and radioactive waste. A study found that at one region there had been a decrease in deep sea coral from 2007 to 2011, with the decrease being attributed to global warming and ocean acidification, and biodiversity estimated as being at the lowest levels in 58 years.
Ocean acidification is particularly harmful to deep sea corals because they are made of aragonite, an easily soluble carbonate, and because they are particularly slow growing and will take years to recover. Deep sea trawling is also harming the biodiversity by destroying deep sea habitats which can take years to form. Another human activity that has altered deep sea biology is mining. One study found that at one mining site fish populations had decreased at six months and at three years, and that after twenty six years populations had returned to the same levels as prior to the disturbance.
There are a number of species that do not primarily rely upon dissolved organic matter for their food. These species and communities are found at hydrothermal vents at sea-floor spreading zones. One example is the symbiotic relationship between the tube worm Riftia and chemosynthetic bacteria. It is this chemosynthesis that supports the complex communities that can be found around hydrothermal vents. These complex communities are one of the few ecosystems on the planet that do not rely upon sunlight for their supply of energy.
Deep-sea fish have different adaptations in their proteins, anatomical structures, and metabolic systems to survive in the Deep sea, where the inhabitants have to withstand great amount of hydrostatic pressure. While other factors like food availability and predator avoidance are important, the deep-sea organisms must have the ability to maintain well-regulated metabolic system in the face of high pressures. In order to adjust for the extreme environment, these organisms have developed unique characteristics.
Proteins are affected greatly by the elevated hydrostatic pressure, as they undergo changes in water organization during hydration and dehydration reactions of the binding events. This is due to the fact that most enzyme-ligand interactions form through charged or polar non-charge interactions. Because hydrostatic pressure affects both protein folding and assembly and enzymatic activity, the deep sea species must undergo physiological and structural adaptations to preserve protein functionality against pressure.
Actin is a protein that is essential for different cellular functions. The α-actin serves as a main component for muscle fiber, and it is highly conserved across numerous different species. Some Deep-sea fish developed pressure tolerance through the change in mechanism of their α-actin. In some species that live in depths greater than 5 km (3.1 mi), C.armatus and C.yaquinae have specific substitutions on the active sites of α-Actin, which serves as the main component of muscle fiber.
These specific substitutions, Q137K and V54A from C.armatus or I67P from C.yaquinae are predicted to have importance in pressure tolerance Substitution in the active sites of actin result in significant changes in the salt bridge patterns of the protein, which allows for better stabilization in ATP binding and sub unit arrangement, confirmed by the free energy analysis and molecular dynamics simulation.It was found that deep sea fish have more salt bridges in their actins compared to fish inhabiting the upper zones of the sea.
In relations to protein substitution, specific osmolytes were found to be abundant in deep sea fish under high hydrostatic pressure. For certain chondrichthyans, it was found that Trimethylamine N-oxide (TMAO) increased with depth, replacing other osmolytes and urea. Due to the ability of TMAO being able to protect proteins from high hydrostatic pressure destabilizing proteins, the osmolyte adjustment serves are an important adaptation for deep sea fish to withstand high hydrostatic pressure.
Deep-sea organisms possess molecular adaptations to survive and thrive in the deep oceans. Mariana hadal snailfish developed modification in the Osteocalcin(burlap) gene, where premature termination of the gene was found. Osteocalcin gene regulates bone development and tissue mineralization, and the frameshift mutation seems to have resulted in the open skull and cartilage-based bone formation.
Due to high hydrostatic pressure in the deep sea, closed skulls that organisms living on the surface develop cannot withstand the enforcing stress. Similarly, common bone developments seen in surface vertebrates cannot maintain their structural integrity under constant high pressure.
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Label: #DeepSeaLevel #MarineLife #UnderwaterExploration #OceanDepths #DeepSea #AquaticAdventure #Oceanography #SubmarineJourney #SecretsOfTheSea #BeneathTheWaves #HydrographicResearch #MarineEcosystems #OceanConservation #BluePlanet #DeepSeaCreatures #EDCProjects #SeafloorMapping #WondersOfTheOcean #NatureDocumentary
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