A Rich Ecosystem
Deep sea mussels
Amid the near lifeless abyss of the deep sea, hydrothermal vents are oases of life with surprisingly diverse ecosystems. Many types of organisms coexist in near the hydrothermal vents. The basis of the ecosystems are chemoautotrophic bacteria. These bacteria break down hydrogen sulfide, a chemical that is found under the crust that is brought up in the vent water, to create carbohydrates. The bacteria must use the hydrogen sulfide because there is no light on sea floor to use for photosynthesis. Hydrogen sulfide is poisonous to almost all other creatures on the Earth, but these bacteria turn it into food with a process called chemosynthesis. This process breaks down the hydrogen sulfide along with oxygen and carbon dioxide in the seawater to form carbohydrates. Sulfur and water are by-products of this process. Without these bacteria, the entire ecosystem of hydrothermal vents could not exist, so the bacteria are the first to colonize the vent area.
Primary consumers in the ecosystem depend on these bacteria for food. Many animals, like the giant tube worms pictured above, have colonies of these bacteria inside their protective shells (what we see of the worm) and use the sugars made by the bacteria for fuel. Giant tube worms have no mouth or stomach, so they are fully dependent on the bacteria, are are among the first to colonize the vent area. Clams and mussels are also present. These deep-sea clams and mussels use the sugars from the bacteria as well as filter food out of the water. Crabs and shrimp are among the crustaceans at the vents. Some species of crab are predators, but some, like the "squat lobster" (a type of crab) feeds of off the bacteria's sugar and is a scavenger, like many deep-sea creatures. "Dandelions" are a colony of tiny organisms that stick together to form one body. "Dandelions" latch onto the rock and are scavengers. However, usually when these appear a vent is inactive or dying, and the ecosystem will not last much longer. The major predators of the vents are the deep-sea octopus and the zoarcid fish. The octopi have heads the size of oranges and eat clams, mussels, crabs and shrimp. The Zoarcid fish is a 2 meter long fish that eats almost anything alive, including the giant tube worms.
Below is a sample plausible food chain:
Bacteria > Mussels > Crab > Octopus
Primary consumers in the ecosystem depend on these bacteria for food. Many animals, like the giant tube worms pictured above, have colonies of these bacteria inside their protective shells (what we see of the worm) and use the sugars made by the bacteria for fuel. Giant tube worms have no mouth or stomach, so they are fully dependent on the bacteria, are are among the first to colonize the vent area. Clams and mussels are also present. These deep-sea clams and mussels use the sugars from the bacteria as well as filter food out of the water. Crabs and shrimp are among the crustaceans at the vents. Some species of crab are predators, but some, like the "squat lobster" (a type of crab) feeds of off the bacteria's sugar and is a scavenger, like many deep-sea creatures. "Dandelions" are a colony of tiny organisms that stick together to form one body. "Dandelions" latch onto the rock and are scavengers. However, usually when these appear a vent is inactive or dying, and the ecosystem will not last much longer. The major predators of the vents are the deep-sea octopus and the zoarcid fish. The octopi have heads the size of oranges and eat clams, mussels, crabs and shrimp. The Zoarcid fish is a 2 meter long fish that eats almost anything alive, including the giant tube worms.
Below is a sample plausible food chain:
Bacteria > Mussels > Crab > Octopus