deep sea vents

Question 1

why do they form

Answer 1

• Form due to super heating of water as it travels to the core
Don’t exist for long

Question 2

describe hydrothermal vents

Answer 2

• Super heating of water as it is released
• Some bacteria can live here despite the temperatures being so high - usually would have breakdown of protein here
• Vents for at the mid ocean ridges 2000 -3000 m down
• Sea water percolates down to crust, super heats, rushes back
• Around 300-400 degrees C
• As it comes out it cools rapidly, depositing minerals
Termed black/white smokers

Question 3

what are the basis of ecosystems in the vents

Answer 3

•
The bacteria are the basis of the ecosystems that have formed at the deep sea vents - all feeding on base form of bacteria

Question 4

density in the pacific ridge?

Answer 4

○ Density of life exceeds rainforests and reefs
○ 84% of sp. Are restricted to the vents
○ Most live at 4 to 16 degrees c
Bacteria key to diversity of forms - metabolize the sulfur released from the vents for the organisms

Question 5

describe tube worms in the deep ridge

Answer 5

• Show up early - foundation species, lay the basis of the ecosystem (along w the bacteria in them)
• Phylum Vestimentifera (Pogonophora) & related to
Annelida
• tubes 3m+, worms Im+ with rapid growth rates
• Red gills carry sulphides and O2 to the chemosynthetic bacteria
Store bacteria in trophosome - crystalized structure

Question 6

pompeii worms

Answer 6

• Smaller
• Special hemoglobin fixes sulphides, CO2, and O2
• O2 + H2S2 normally toxic! - binds, inactivates hemoglobin from carrying o2
Here, hemoglobin binds via two sites and 2 molecules

Question 7

describe bacteria in the vents

Answer 7

• Several species of bacteria and riftia in these vents
• Mollusks, mussels, clams found in sea vents
○ Also have chemosynthetic bacteria (shares same evolutionary origin)
Some have methanogrophic bacteria
• Vents also have photosynthetic anaerobic bacteria!! - use radiation from the vents
The yeti crabs grow the bacteria in their hair and feed on them

Question 8

atlantic ridge organisms

Answer 8

• has no tube worms
○ Mussels, clams, shrimp (ribicaris)
Shrimps can use their primitive vent structures to detect the vents

Question 9

how are vents colonized

Answer 9

lecithotrophic/planktotrophic larvae enter plumes &
disperse for many KMs
• How they settle is a mystery (transition via whale carcasses)
Vents ephemeral (non-permanent)
• first org. usually vestimentiferans, then bivalves later.

Settle first w bacteria

Question 10

what are cold seeps

Answer 10

• Bathymodiolus childressi with bacteria in bacteriocytes.
• Opposite to black smoker and white smoker - theyre cold
• Gasses coming out of a fisher in the ocean
in continental margins 400-6000m
fissures releasing methane or sulfide
e.g. Louisiana, Florida coast, Gulf of Mexico