Lecture 9: Deep sea vents 1

Question 1

issue with studying:

Answer 1

• ACCES!
• remotely operated vehicles are commonly sent down otherwise can b v dangerous
• v expensive

Question 2

discovery of deep sea vents:

Answer 2

1977, submersible Alvin investigating the Galapagos Spreading Centre
– many have now been discovered worldwide

Question 3

fast spreading vs slow spreading sites =

Answer 3

• fast spreading sites are spreaded 10’s km part

- slow spreading 100 km’s apart, less geothermal activity, organisms must travel further between sites

Question 4

hydrothermal vent =

Answer 4

• volcanic activity below
• black smoker chimney
• plume = 400DC
• sea water = 2DC
• so u get large area of warm sea water
• water doesn’t boil because of high pressure

Question 5

____ communities develop at the vents

Answer 5

complex

Question 6

vent conditions & organisms

Answer 6

• dark
• salty (halophilic)
• hot
• risk of walking into 400 DC plumes
• how do organisms get around?

Question 7

macrofauna organisms found at deep sea vents

Answer 7

• tube worms
• vent shrimp
• pompeii worm
• bivalves
• • all have associations w microorganisms as needed for growth

Question 8

water vents compared to terrestrial hydrothermal vents

Answer 8

• no sunlight = no photosynthesis
• mixing with cold sea water is v rapid so MESOPHILIC organisms dominate
• macrofauna present
• eruptions and tectonic plate movements aren’t static, organisms must be able to disperse

Question 9

___ provides energy for these ecosystems

Answer 9

geochemistry

Question 10

macrofauna / microbes get energy

Answer 10

microbes metabolise geochemical activity to provide energy, MACROFAUNA must rely on these
– allow eukaryotes to exploit energy from microbes

Question 11

the black smoker chimneys contain diverse

Answer 11

Archaea –> hyperthermophiles and halophiles dominant

- Takai et al 2001 brought chimney to surface

Question 12

microbes from hot vents can survive

Answer 12

extreme temperatures

Question 13

upper limit temp for life

Answer 13

121 DC

archaeal microorganism strain 121

Question 14

tubeworm =

Answer 14

• mesophilic (30DC)
• grows up to 3m in length
• fast spreading vents
• symbiotic w bacteria
• requires H2S (hydrogen sulphide) to survive

Question 15

tubeworm and symbionts

Answer 15

• w bacteria
• worm has trophosome full of bacteria
• trophosome = 50% of body
• bacteria fix CO2 (diffuses in) using RUBISCO & uses H2S & O2 through haemoglobin

Question 16

pompeii worms & symbionts

Answer 16

• covered in episymbionts
• bacteria on the outer surface
• the worms feed off their neighbours