Abyssal ZoneAbyssal Zone

Zone on the Bottom of the Zone on the Bottom of the OceanOcean

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

• WormsWorms

Hydrothermal Vent Hydrothermal Vent CommunitiesCommunities

• Chemosynthetic bacteria are Chemosynthetic bacteria are producers.producers.

• Energy rich hydrogen sulfide is used.Energy rich hydrogen sulfide is used.

• Hydrogen Sulfide comes from Hydrogen Sulfide comes from superheating of seawater.superheating of seawater.

• Rich ecosystemRich ecosystem

• Very patchy in space and time.Very patchy in space and time.

Hydrothermal VentsHydrothermal Vents

www.divediscover.whoi.edu/vents

Hydrothermal VentsHydrothermal Vents

Starfish and Sea Urchin

Flatfish

Mushroom Corals

Sablefish

oceanexplorer.noaa.gov

Sea UrchinsSea Urchins

• Scientists once thought that sunlight Scientists once thought that sunlight was the source of energy for all life was the source of energy for all life and that and that photosynthesisphotosynthesis was the was the only way to make food. only way to make food.

• It is now known that reduced It is now known that reduced chemicals from hydrothermal vents chemicals from hydrothermal vents provide provide chemosyntheticchemosynthetic energy for energy for some lifeforms.some lifeforms.

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

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

ChemosynthesisChemosynthesis

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

Chemosynthetic Food Chemosynthetic Food WebWeb

• The The chemosynthetic chemosynthetic food webfood web supports supports dense populations dense populations of uniquely of uniquely adapted organismsadapted organisms