Deep Sea

016b

100m

dysphotic

aphotic

photic

Deep Ocean Characteristics

• Cold• Still• Stable• Dark• Essentially no productivity• Sparse Life• Extremely high pressure• Little food

Deep sea orgs are dependant upon surface production from:

Dead phytoplankton, zooplankton, fish, mammals

Fecal pellets and crustacean molts

Macrophyte detritus

Animal migrations

Potential food source for deep sea organisms

Scavengers can feed on carcass in less than 6 months

Whale Fall; i.e., marine snow

Factors affecting organic material reaching the sea floor:

Storms

Seasonal variation

100m

dysphotic

aphotic

photic

• Ballard & Grassle (1977)- Alvin to Galapagos • Sulfur-rich vents 660 oF, but quickly cool to 73 oF• Thermophilic bacteria associated with vent

communities

Hydrothermal vents found at mid-ocean ridge spreading centers.

Active hydrothermal vents were first discovered at Loihi in the late 1980's

Loihi

• 15 mi S.E. of Kilauea

• 3,178 ft below sea level

• Will reach sea level in ~10,000 yrs

Loihi

1. Cold seawater sinks into cracks deep into ocean floor

2. Water heated by magma rises and leaches out minerals from surrounding rocks

3. The water emerges from vents and precipitates out minerals

magma

Bottom current

Seawater seepage

basalt

660oF

FeS, FeS2, CuFeS2

H2SFe, Mg

magma

Bottom current

Seawater seepage

basalt

660oF

FeS, FeS2, CuFeS2

H2SFe, Mg

Tube worms- pogonophoransOther orgs: • Calyptogena- large white clam• Large crabs• Sea anemones• Shrimp

Support communities with high biomass, but low diversity

Primary producers are chemosynthetic bacteria

90% endemism

Communities are small (25-60m in diameter)

Chemosynthesis:Oxygen + hydrogen sulfide + water + carbon dioxidesugar + sulfuric acid

602 + 6H2S + 6H20 + 6C02 C6H12O6 + 6H2S04

                                                        

      

Photosynthesis:6H2O + 6CO2 + nutrients + light energy C6H12O6 + 6O2

Chemosynthesis:

602 + 6H2S + 6H20 + 6C02 C6H12O6 + 6H2S04

Inquiry

1. Where are hydrothermal vents located?

2. How do they form?3. Why doesn’t the vent water boil?4. Describe the chemosynthetic

bacteria's relationship with the vent and other animals living near the vent.