It’s mind-boggling to think that we live in a world where we know more about space than we do about our own ocean. Our ocean covers more than 70% of earth’s surface with the deep sea encompassing 95% of our world’s available living space. Yet surprisingly, out of all our waters only 5% have been explored. Deep sea exploration is crucial to further understanding our planet. It’s important to learn what lives in this dark underworld, and the effects that humans might be having there.
The Deepest Point
We do know that the Challenger Deep, located at the south end of the Mariana trench, is the deepest part of the ocean. Here we can reach depths of 36,200 feet! It has been deduced that the median depth of the ocean is 12,100 feet or 2.3 miles.
Properties Of Water In The Deep Sea
As you travel deeper and deeper beneath the ocean’s surface, the physical characteristics of water change.
When traveling deep in the ocean there is a decrease in light and temperature and an increase in pressure. For every 10 meters you travel the pressure increases by 1 atmosphere (atm). Therefore, at approximately 1000 meters organisms with gas chambers, such as lungs, would experience such extreme pressures that it would crush these organs.
Light will eventually decrease to the point of almost total darkness.
Temperature, on the other hand, will decrease until approximately 5° C and remain stable unless near the presence of hydrothermal vents.
Hydrothermal Vents And Seamounts
The deep sea is unique because it contains hydrothermal vents and seamounts.
Hydrothermal vents are formed when seawater enters the cracks of separating tectonic plates. The seawater then interacts with magma found below the seafloor. Once in contact, various chemical reactions occur leading heated fluids to enter the ocean. These fluids can achieve temperatures of 400° C! Despite extreme temperatures, there is sea life specially evolved to live near these fluids, including microbes that feed on the fluid.
The energy emitted at hydrothermal vents gives life in these dark corners of the world an energy source to rely on. The hydrothermal fluids also undergo more chemical reactions one mixed with seawater, leading to the production of metals and minerals on the ocean floor.
Seamounts are mountains found submerged underwater. Once active volcanoes, they have developed through old volcanic activity. Seamounts are located near the edges of tectonic plates and possibly near mid-plate hotspots.
Seamounts are so crucial because they can act as island paradises for marine species in the middle of a vast, open ocean. Some seamounts even support life found nowhere else on Earth!
These seamounts are crucial for the underwater ecosystem because of their diverse slopes and ridges. The steep slopes are responsible for carrying nutrients from the depths to the ocean surface. The nutrients then provide a critical food source for a variety of marine organisms. Seamounts are also home to a wide array of marine life including deep sea coral, crustaceans, cephalopods and fish.
Can Humans Impact The Deep Sea?
Given all this information, the real questions to ask are what is deep sea exploration? And what can happen to these delicate ecosystems living here?
New technologies have developed to promote the exploration of the deep sea. The development of underwater drones has the potential to map sea floors and explore depths humans can not reach. Some drones have even been developed to measure ocean wave patterns. The use of drones would allow us to study the deep sea without disrupting the ecosystem.
Advancements have also been made to promote drilling within the deep sea. Japan has developed a research vessel, used in the Integrated Ocean Drilling Program, that is capable of drilling into the seafloor reaching depths of 23,000 feet. The drill is used to measure the history and the properties of earth’s crust. The hope is that this research vessel may one day drill into earth’s mantle.
While this drilling is used for scientific purposes, we are most familiar with another form of drilling: offshore oil drilling. Oil companies have in recent history used drills to extract oil from reserves in the deep sea. The process of offshore oil drilling leads to environmental destruction including the production of runoff water, brine wastes, possible oil leaks and drilling muds. Drilling muds are comprised of excess fluids and metal shavings that lead to toxic waste entering our oceans.
Bottom trawling the ocean floor is another form of deep sea destruction. Bottom trawling is the process of dragging weighted nets across the ocean floor to catch everything in its path. It’s a fishing method used to target bottom fish living close to the seafloor. These nets destroy vast expanses of the seafloor, ripping up all life and vegetation in their path.
Bottom trawling and offshore oil drilling can be detrimental to deep sea ecosystems. The organisms found in the deep sea are slow growing and have a slow reproduction rate. The destruction of their habitat and incidental deaths can lead to a rapid decline in their populations and difficulties in repopulation.
Although deep sea exploration is important, it is also crucial to take proper protocols to ensure the survival of deep sea life.
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