Biology is one of the main reasons for ocean exploration as oceans contain 80% of all life on earth. The ocean surface is probably the most investigated part of the ocean as light is able to reach these areas, and the pressure is not that great compared to the deeper ocean. However, around 650 feet light starts fading rapidly, the temperature drops and the pressure increases tremendously. At 13,000 feet, there is no light at all and the temperatures are around freezing point, yet there are still signs of life at these great depths. Researchers are discovering thousands of animals that live in these areas that may look alien to the average person as these animals have adapted to survive the intense conditions (Smithsonian Ocean). Unlike ecosystems on land and in shallow waters that are based around sunlight, there are chemosynthetic ecosystems in the deep oceans that thrive off of chemicals released by the Earth’s geological processes such as hydrogen sulfide and methane (Nautilus Live). Vents in the Pacific Ridge system, which is a range of underwater volcanoes, spew large amounts of hydrogen sulfide into the environment, which are taken up by chemosynthetic bacteria in the tissues of large clams and tube worms. More than 500 new species have been discovered at seafloor vents since the discovery of chemosynthetic organisms. With much of the ocean ridge still unexplored, scientists anticipate the discovery of more unknown species in the future (The National Academies, NASEM).