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 o F, but quickly cool to 73 o F 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

Tube worms- pogonophorans Other 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 dioxide sugar + sulfuric acid H 2 S + 6H C0 2 C 6 H 12 O 6 + 6H 2 S0 4

Photosynthesis: 6H 2 O + 6CO 2 + nutrients + light energy C 6 H 12 O 6 + 6O 2 Chemosynthesis: H 2 S + 6H C0 2 C 6 H 12 O 6 + 6H 2 S0 4

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.