Major Biotic Factors Since there is no sunlight, the benthic zone is limited to certain plants, like phytoplankton and algae.
It is occupied mainly by carnivorous animals that are often blind or have special luminous organs and are structurally adapted to withstand the great pressures of this level. |
Major Abiotic FactorsThe Benthic zone has extremely high water pressure. The temperature is 4 degrees Celsius, just about freezing. There is no sunlight, instead many organisms thrive off of hydrothermal vents. The vents send out heated water which creates currents of debris.
The organisms use a process called chemosynthesis, which is the conversion of one or more carbon molecules and nutrients into organic matter through oxidation, to create food. |
HabitatThe habitat of the benthic/abyssal zone is very dark and cold. The ocean at this depth is very calm as it is removed from storms. Because of this the water isn’t agitated and mixed. Even though the water isn’t mixed the salinity is still around 35ppt- the average for the rest of the ocean. The high pressure waters, 11,000 psi, presents few problems for the animals there because the pressures within their bodies are the same as those outside them.
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Human ImpactHumans have a huge impact on the ocean as a whole, including the deepest parts that we can hardly reach. One that makes a huge impact is dumping our waste in the ocean. Dumping sewage or nuclear waste in the ocean affects the abyssal zone because after time goes by the waste will fall to the ocean floor affecting the whole ecosystem. Animals could try to eat the garbage, plants could get sick from the junk in the water, and whole communities of organisms could die. Mining also impacts the benthic zone. Humans mine under the ocean floor which has caused many oil spills causing pollution in the waters. Thousands of kilometers of ocean have become uninhabitable due to these mining accidents.
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Interesting Elements
In order to survive these harsh conditions, animals have had to adapt in very cool ways. Gigantism is one of these ways. It is not fully understood but the tendency is for certain animals to become enormous is size compared to other species like them. For example the colossal squid can be from 12 - 14 m long compared to the average 20 cm squid. Other physical adaptations include gray or black color, which acts as a camouflage in the deep sea environment as it blends in with the lack of light. However, some predators create their own light using bioluminescence to lure prey in. Also many animals have been found to live for decades or even centuries. They seem to mature and reproduce very slow compared to most places in the world. Another adaptation is the ability to find a mate. With it being hard to see, it is believed that animals will use unique light patterns or use scents to find mates.