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
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.