Abyssal Zone on the Bottom of the Ocean

The ocean zone where you would find organisms such as worms, sea urchins, and chemosynthetic bacteria is the abyssal zone. • Worms

Hydrothermal Vent Communities • Chemosynthetic bacteria are producers. • Energy rich hydrogen sulfide is used. • Hydrogen Sulfide comes from superheating of seawater. • Rich ecosystem • Very patchy in space and time.

Hydrothermal Vents www. divediscover. whoi. edu/vents

Hydrothermal Vents

oceanexplorer. noaa. gov Starfish and Sea Urchin Flatfish Sablefish Mushroom Corals

Sea Urchins

• Scientists once thought that sunlight was the source of energy for all life and that photosynthesis was the only way to make food. • It is now known that reduced chemicals from hydrothermal vents provide chemosynthetic energy for some lifeforms.

• High temperatures and high concentrations of dissolved minerals in seawater form compounds such as hydrogen sulfide.

• In a biochemical process, bacteria oxidize hydrogen sulfide and use the liberated energy to produce carbohydrates (stored chemical energy).

Chemosynthesis • Unlike photosynthesis, chemosynthesis requires no light and can occur at the extreme temperatures and high pressures of the deep ocean.

Chemosynthetic Food Web • The chemosynthetic food web supports dense populations of uniquely adapted organisms