The Oceans Vanessa Borgia Ecology

Geography 360 million km, Continuous interconnected mass of water 360 million km, Continuous interconnected mass of water 3 major basins 3 major basins –Pacific- 180 million km 2, deepest~ 4000 m –Atlantic- 106 million km 2, pole to pole –Indian- under 75 million km 2, Southern Hemisphere Undersea mountain stud the floor Undersea mountain stud the floor

Structure Littoral/ intertidal- shallow shorelines under rise and fall of the tides Littoral/ intertidal- shallow shorelines under rise and fall of the tides Neritic zone- from coast to the margin of the continental shelf. Neritic zone- from coast to the margin of the continental shelf. Oceanic zone- beyond continental shelf. Oceanic zone- beyond continental shelf. 3 vertical depth zones 3 vertical depth zones –Mesopelagic m –Bathypelagic m –Abyssal m Hadal Zone- deepest part of ocean Hadal Zone- deepest part of ocean Benthic- habitats on bottom of ocean Benthic- habitats on bottom of ocean Pelagic- off the bottom regardless of depth Pelagic- off the bottom regardless of depth

Physical Conditions Light Light –80% solar energy absorbed in first 10m. Ultraviolet/infrared first few meters. Below m it is a blue twilight. Temperature Temperature –Sunlight increased kinetic state or velocity of motion of water molecules, keeps temp up. Thermocline- layer of cold water on bottom and warm on top. Thermal Stratification- layering of water by temp. Water Movements Water Movements –Winds drive currents-transport nutrients and O2. Currents moderate climate, fertilize the surface H20 and stimulate photosynthesis. Gynes- currents sweep over oceans to create circulation system. Upwelling- deep H20 moved to the surface.

Chemical Conditions Salinity Salinity –Varies with latitude among sea. 34g of salt per kg of water= about 36.5%. Baltic Sea- surrounded by temp and boral forest biomes receives large inputs of freshwater, local salinities of 7% or lower. Red Sea- deserts over 40% salinities. Oxygen Oxygen –Increase near ocean surface and decrease with depth.

Biology Phytoplankton- microscopic organisms that drift with the currents. Phytoplankton- microscopic organisms that drift with the currents. Zooplankton- small animals that drift w/ current. Zooplankton- small animals that drift w/ current. Deep sea organisms are nourished by organic matter fixed by photosynthesis near the surface. Deep sea organisms are nourished by organic matter fixed by photosynthesis near the surface. Ocean shines with blue of pure water and is called a “biological desert.” Ocean shines with blue of pure water and is called a “biological desert.”

Human Influences Decline of large whale population gave a warning of what we can do to open an ocean system. Decline of large whale population gave a warning of what we can do to open an ocean system. Overfishing led to major decline in commercially important fish stocks. Overfishing led to major decline in commercially important fish stocks. Another threat possibility of dumping nuclear and chemical wastes. Another threat possibility of dumping nuclear and chemical wastes.