Oceanographers and amateur naturalists, along with people from many other walks of life waited eagerly for James Cameron to make his descent to the bottom of the ocean in March 2012, then held their breath in anticipation of his safe return to the surface with his submersible, the Deepsea Challenger. What Cameron found at the bottom the Mariana Trench, which is the lowest spot on the ocean floor, is simply incredible.
The Mariana Trench
Sometimes referred to as the Marianas Trench, the Mariana Trench is located in the western Pacific, just east of the Marianas Island. The trench is roughly 2,550 kilometers long, with an average width of 69 kilometers. The underwater valley is crescent-shaped, and has a maximum depth of 10,911 meters, give or take approximately forty meters. At the trench’s bottom, which is sometimes referred to as the Challenger Deep, the water column overhead exerts an astonishing pressure of 1,086 bars, which is more than 1,000 times that of standard atmospheric pressure found at sea level.
Life Under Pressure
Including Cameron’s descent to the Challenger Deep, three other descents have been achieved. The first was in 1960, when the bathyscaphe Trieste, a United States Navy-owned submersible designed in Switzerland and built in Italy made it to a depth of 10,916 meters. In 1996 and 2009, ROV’s Kaiko and Nereus made the descent.
In 1960, sole, flounder, and shrimp were reportedly seen, and during the unmanned expeditions, seabed samples containing microorganisms were collected. In addition, cameras caught sight of giant-sized single-cell amoeba approximately ten centimeters long.
Unlike previous expeditions into the deep, Cameron’s submersible was perfectly equipped for gliding along underwater cliff faces, collecting sediment samples, and using a specialized “slurp gun” to collect small marine animals for later study at the surface. The sub is 2.5 stories tall, and is also equipped with temperature, pressure, and salinity gauges, along with 3-D video cameras that captured the entire journey, lit by an eight-foot tower of LED lights, on film. The cockpit – nicknamed the “coffin” – is just 43 inches wide. Cameron emerged a bit stiff and sore from remaining in such tight quarters for the hours, but his findings made the physical challenges he faced well worth the effort.
At the Serena Deep, which is located near Challenger Deep, Cameron’s cameras caught sight of rocks covered in intriguing microbial mats which are thought to be much like some of the first life to take hold on our planet. Other than that, most of what was seen included rocky outcroppings which are part of the earth’s mantle, and which geologists surmise to be undergoing a process called Serpentization, which is a type of primordial metabolism that brings biochemistry and geochemistry together to create circumstances ideal for the creation of new life. During this process, sea water reacts with the minerals contained within the rocks, releasing a blend of methane and hydrogen, both of which provide the necessary energy to feed microbial communities located at the site.
In comparison with findings at the New Britain Trench in the Solomon Sea, which has a maximum depth of 9,140 meters, the Challenger Deep and Serena Deep appeared to be much like deserts, as life found at the New Britain Trench, where James Cameron and his team spotted giant colonies of sea anemones and acorn worms feeding on nutrients including logs from the nearby Solomon Islands. But when viewed on a cellular scale, the life at the bottom of the Marianas Trench is equally amazing, though much of it cannot be seen with the naked eye.
While you might not be able to make it to the bottom of the Marianas Trench while on vacation, tourism opportunities involving submersibles do exist throughout the Caribbean, the Red Sea, the Mediterranean, and other seas and oceans worldwide. One of the most challenging sub rides for casual explorers is available in Roatan, Honduras, where you can descend to a depth of 2000 feet into the Cayman trench for views of deepwater coral, Tripod Fish, luminous sponges, and more.
The bottom line? No matter where you go, you’ll find that our oceans are beyond amazing. Thanks to explorers like James Cameron, who are willing to go the distance, our knowledge of life beyond recreational diving limits continues to expand.