Scavengers: These are the literal bottom-feeders, the creatures that eat detritus and scraps that fall to the sea floor. Around some hydrothermal vents, tube worms have reached sizes of over 2 m long! These include extremophile bacteria, which are a food source for other micro-organisms, which then become a resource for small invertebrates, which in turn feed larger species like fish, crabs, and tube worms. Hydrothermal vents spew out tons of nutrients along with the hot water, which makes an ideal environment for chemotrophs, or organisms that survive off of chemical soup. Many squids and other cephalopods also fall into this category.Ĭhemotrophs: In the very deepest areas like the trenches, the main source of energy is from hydrothermal vents, columns of water heated by the Earth’s molten mantle. These include things like angler fish, gulper eels, and deep-water sharks (the sorts of creatures that make people say “nope” when it comes to the deep ocean). But here are a few we do know about:Īmbush predators: Many fish species that live in deep ocean are ambush predators that use their big sensitive eyes and bioluminescence to catch prey. Scientists estimate that the vast majority of unknown species live in the ocean. Until the recent invention of traps incorporating pressure chambers, most of the specimens we brought up from the deep ocean to study did not survive the trip to the surface.īecause it’s so difficult for us to access the deep ocean, we know very little about what lives there, especially compared to how much we know about ecosystems on land. So if you live 10,000 m down in the Mariana Trench, you’re experiencing 1,000x the amount of pressure we feel at sea level from the weight of the atmosphere above us! But deep sea dwellers are specially adapted to deal with it, and they have just as much trouble dealing with low pressure as we would have with such high pressures. About every 10 meters below the surface, the pressure increases by 1 atm. The other main challenge that deep sea critters have to deal with is extreme pressure.

Along the seafloor, energy can also come from volcanic vents that produce lots of nutrients (a major factor in those super-deep trenches formed by plate collisions). Marine snow is made up of organic material (including dead creatures and waste) that drifts down from the shallower parts of the ocean where sunlight does penetrate (also known as the “photic zone”). Many survive off of a sort of detritus known as “marine snow”, a nice name for a not-so-nice material. Creatures living down there have to get energy from other sources instead. Living at the very bottom of the ocean presents some tough challenges! First of all, sunlight doesn’t reach the deep ocean, which means no plant life, no photosynthesis, and no plant-based energy production (the main form of energy production in just about every other ecosystem on the planet).

Deep water abyssal zone animals