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016b. Deep Sea. Deep Sea. Ocean Zones. photic. 100m. dysphotic. aphotic. Deep Ocean Characteristics. Cold Still Stable Dark Essentially no productivity Sparse Life Extremely high pressure Little food. Potential Food Source for Deep Sea Organisms.
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016b Deep Sea
Ocean Zones photic 100m dysphotic aphotic
Deep Ocean Characteristics • Cold • Still • Stable • Dark • Essentially no productivity • Sparse Life • Extremely high pressure • Little food
Potential Food Source for Deep Sea Organisms Deep sea orgs are dependant upon surface production from: • Dead phytoplankton, zooplankton, fish, mammals • Fecal pellets and crustacean molts • Macrophyte detritus • Animal migrations
Whale Fall; i.e., marine snow Scavengers can feed on carcass in less than 6 months
Factors affecting organic material reaching the sea floor: • Storms • Seasonal variation
Ocean Zones photic 100m dysphotic aphotic
Hydrothermal Vents • Ballard & Grassle (1977)- Alvin to Galapagos • Sulfur-rich vents 660 oF, but quickly cool to 73 oF • Thermophilic bacteria associated with vent communities
Location of Vents Hydrothermal vents found at mid-ocean ridge spreading centers.
Active hydrothermal vents were first discovered at Loihi in the late 1980's
15 mi S.E. of Kilauea • 3,178 ft below sea level • Will reach sea level in ~10,000 yrs Loihi
Formation of Vents • Cold seawater sinks into cracks deep into ocean floor • Water heated by magma rises and leaches out minerals from surrounding rocks • The water emerges from vents and precipitates out minerals
Hydrothermal Vent Communities Tube worms- pogonophorans • Other orgs: • Calyptogena- large white clam • Large crabs • Sea anemones • Shrimp
Hydrothermal Vent Communities • Support communities with high biomass, but low diversity • Primary producers are chemosynthetic bacteria • 90% endemism • Communities are small (25-60m in diameter)
Chemosynthetic Bacteria Chemosynthesis: Oxygen + hydrogen sulfide + water + carbon dioxide sugar + sulfuric acid 602 + 6H2S + 6H20 + 6C02 C6H12O6 + 6H2S04
Photosynthesis vs Chemosynthesis Photosynthesis: 6H2O + 6CO2 + nutrients + light energy C6H12O6 + 6O2 Chemosynthesis: 602 + 6H2S + 6H20 + 6C02 C6H12O6 + 6H2S04
Inquiry • Where are hydrothermal vents located? • How do they form? • Why doesn’t the vent water boil? • Describe the chemosynthetic bacteria's relationship with the vent and other animals living near the vent.