Hydrothermal Vent Communities

•How Life Originated?

Hydrothermal vent discovery-1977

•Sea Water sinks through the crust and is

filtered

•Cold seawater sinks down

through the crust.

•O2 and K are removed from the

seawater.

•Ca, SO4, and Mg are removed

from the fluid.

•Na, Ca, and K from the crust

enter the fluid.

•Highest temperatures (350-400

oC), Cu, Zn, Fe, and H2S from

the crust dissolve in the fluids.

•Hot & acidic fluids with dissolved

metals rise up through crust.

•The hydrothermal fluids mix with

cold, O2-rich seawater. Metals

and sulfur combine to form

metal-sulfide minerals: MnO2,

FeO(OH), …

•Basically cold seawater is converted to a very

hot fluid rich in dissolved metals. Promotes robust

chemistry initial phase of life?

www.pmel.noaa.gov/vents

•Robust

and

complex

chemistr

y

Black & White smokers2. As the water heats up, it reacts with the

rocks in the ocean crust

All oxygen is removed.; It becomes acidic.

It picks up dissolved metals, including iron,

copper and zinc.

It picks up hydrogen sulfide.

•3.The hot rising fluids carry the dissolved

metals and hydrogen sulfide with them.

•4. The hydrothermal fluids exit the

chimney and mix with the cold seawater.

The metals carried up in the fluids combine

with sulfur to form black minerals called

metal sulfides. These tiny mineral particles

give the hydrothermal fluid the appearance

of smoke.

Many factors trigger this reaction. One

factor is the cold temperature of the

seawater. A second equally important factor

is the presence of oxygen in the seawater.

Without oxygen, the minerals would never

form.

•The beginning chemistry of life?

Hydrothermal Vent Distribution

Pink, western Pacific; green, northeast Pacific; blue, East Pacific Rise; yellow, Azores; red, Mid-Atlantic Ridge; orange, Indian Ocean

Hydrothermal energy sourceHydrothermal energy source

HH22S + OS + O22 SO SO4 +4 ++ H+ H+ + + ATP+ ATP

Chemosynthetic (sulfur oxidizing) Chemosynthetic (sulfur oxidizing) Thermophilic Bacteria (up to 120Thermophilic Bacteria (up to 120ooC)C) Hot, anoxic, sulfide rich water mixes Hot, anoxic, sulfide rich water mixes

with Cold oxygenated waterwith Cold oxygenated water Hydrothermal Vents as origin of Life?Hydrothermal Vents as origin of Life?

Bacteria from 120oC

http://mollie.berkeley.edu/~volkman/

Vent biological communitiesVent biological communities BACTERIA (Bacteria and Archea)BACTERIA (Bacteria and Archea) 400 morphological invertebrate species400 morphological invertebrate species

• New species every 2 weeks during 25 years!New species every 2 weeks during 25 years! Evolutionary OriginEvolutionary Origin

• Derived from surrounding Deep SeaDerived from surrounding Deep Sea• Derived from Shallow Water speciesDerived from Shallow Water species• Many evolutionary radiations at species levelMany evolutionary radiations at species level• Many vent taxa originated at other organically Many vent taxa originated at other organically

enriched environments (cold seeps and whale enriched environments (cold seeps and whale bones)bones)

Vents as stable refugia from Global Vents as stable refugia from Global extinctionsextinctions

Cold SeepsCold SeepsCHCH44 + O + O22 CO CO22 + H + H220 +ATP0 +ATP

CHCH4 4 CH3 CH3-- + H + H++ +ATP +ATP

HH22S + OS + O22 SO SO4 +4 ++ H+ H+ + + ATP+ ATP Hydrocarbon reservoirsHydrocarbon reservoirs ““methane bubbling”methane bubbling” Continental shelves and TrenchesContinental shelves and Trenches 200 invertebrate species200 invertebrate species

•ATP is used as an energy carrier for

cells; natural synthesis

Invertebrate food sourcesInvertebrate food sourcesFood chain based on sulfur-oxidizing bacteriaFood chain based on sulfur-oxidizing bacteria Symbiosis with BacteriaSymbiosis with Bacteria

tube wormstube worms Vent Mussels and vent clamsVent Mussels and vent clams

Ingestion of BacteriaIngestion of Bacteria Grazers (gastropod limpets and snails)Grazers (gastropod limpets and snails) Filter Feeders (vent shrimp, polychaete worms, amphipods, Filter Feeders (vent shrimp, polychaete worms, amphipods,

anemones)anemones) PredatorsPredators

Ventfish, octopusVentfish, octopus ScavengersScavengers

CrabsCrabs

Tube worms

http://web.uvic.ca/%7Everenat/364-13.jpg

www.divediscover.whoi.edu/i

Vent Mussels (Bathymodiolus )

www.divediscover.whoi.edu/i

Vent Clams (Calyptogena)

Vent Shrimp (Bresiliidae)

www.ifremer.fr/

Alvinellid worms

Vent limpets

http://web.uvic.ca/~abates/

www.divediscover.whoi.edu/i

Vent Crabs

www.senckenberg.uni-frankfurt.de/

Ventfish (Thermarces cerberus)

Light organs in vent organisms

www.deepsea.com/

Periferic filter feeders

Sea floor Spreading opens new vent areas over geological time

www.pmel.noaa.gov/vents/PlumeStudies

Chemical Reactions

•Depends on

ambient

temperature

Geol 104/BioES 154

Hydrothermal Vent CommunitesHydrothermal Vent Communites� 25 years of exploration have revealed:25 years of exploration have revealed:

A new phylumA new phylum At least 20 new familiesAt least 20 new families Over 90 new generaOver 90 new genera Over 300 new speciesOver 300 new species Over 250 new strains of Over 250 new strains of

free-living bacteriafree-living bacteria� BiomassBiomass

Up to 30 kg/mUp to 30 kg/m22

1000 x greater than 1000 x greater than typical biomasstypical biomassobserved on observed on deep-sea floordeep-sea floor

Geol 104/BioES 154

Hydrothermal Vent Macrofauna: Hydrothermal Vent Macrofauna: Environmental Constraints on Life Environmental Constraints on Life

Cycles and ReproductionCycles and Reproduction� Suitable vent environments for these Suitable vent environments for these organisms are rare.organisms are rare.

� Individual vents have short life-spans.Individual vents have short life-spans.� Volcanic eruptions and earthquakes pose Volcanic eruptions and earthquakes pose further hazards.further hazards.

�These conditions favor rapid growth rates, These conditions favor rapid growth rates, continuous reproduction, and high continuous reproduction, and high fecundity.fecundity.