WORLDS WATER SOURCES:

Average # or people Love hustle & bustle The great outdoors Mid- Altitude

Salinity Total amount of solid material dissolved in water Typical salinity is 3.5% Six elements make up 99% of dissolved solids in seawater Fig. 5.12

Salinity variations Open ocean salinity varies from 33 to 37 o/oo (PPT) Influx of freshwater lowers salinity Greater rate of evaporation raises salinity Salinity may vary with seasons (dry/rain)

http://eesc. columbia. edu/courses/ees/climate/lectures/saltyatlantic http://eesc.columbia.edu/courses/ees/climate/lectures/saltyatlantic.html

Results in Less Water or More water?? Streams carry water to the ocean Seawater freezes in cold ocean areas Warm temperatures cause sea ice floats to liquify Rain, sleet, hail or snow falls directly on ocean Glacial ice breaks off (calves) into the ocean and melts Results in Less Water or More water??

Sources of Ocean Salts Weathering and erosion of earth’s crust through rain runoff etc Dissolved from rocks below the sea floor through hydrothermal vents Volcanic ash

Temperature Varies between -2 & 30 degrees (28-86 F) Increases the metabolic rates of aquatic organisms Affects the rate of photosynthesis by aquatic plants and algae Increases the sensitivity of organisms to disease, parasites and pollution Raising water temperature increases decomposition rate of organic matter in the water depleting dissolve oxygen supplies

Density Colder, saltier water sinks creating currents Responsible for upwelling of nutrients to the surface upwelling demo

Carbon dioxide – buildup in the air ends up in the ocean This causes acidic conditions that prevent shells from forming! Acid Test: The Global Challenge of Ocean Acidification – YouTube Nitrates - Excess amounts of nitrates can cause algae to bloom wildly reducing oxygen levels for fish and sometimes causing their death (fertilizers!)

Dissolved Gases Oxygen – most concentrated in colder waters, effects distributions of animals

Transparency/Turbidity can be affected by plant nutrients coming from sewage treatment or fertilizers. Suspended sediments in the coastal ocean may have come from re-suspension, coastal erosion, agricultural runoff of sediments and chemicals, and urban storm runoff. All of these elements, among others, affect the turbidity and transparency of the water a general indication of problems with algae, zooplankton, and silt

Pressure Places limitations on physical structure of organisms Ex. Fish in the deep sea lack a gas-filled bladder

Epipelagic/Photic Zone Enough light for photo-synthesis, most ocean life exists here 0-200m Mesopelagic/Twilight Zone – small amount of light, vertically migrating species here 200-1000m Bathypelagic zone No light, many species have bioluminescence Abyssopelagic / Hadal Zone – deepest parts, no light, high pressure, low muscle mass, lack of color, no swim bladders

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pH Pure water = 7.0 (neutral) Ocean Water = about 8.0 – 8.3 (slightly basic) Extremely high or low pH levels (above 11.0 and below 4.5) become lethal for most organisms