Saltwater vs Freshwater Ecosystems

• Ecosystems for saltwater and freshwater differ greatly.

Saltwater Biomes

• Oceans
• Seas
• Coral Reefs

Freshwater Biomes

• Lakes
• Ponds
• Marshes
• Rivers and Streams

Freshwater Characteristics

• Less dense than saltwater
• Only 3% of the world's water supply
• 70% of freshwater is frozen
• 20% of freshwater is groundwater
• Only 10% of freshwater is available for human consumption
• Has less buoyancy than saltwater

Saltwater Characteristics

• More dense than freshwater
• 97% of the world's water supply
• Has more buoyancy than freshwater
• Unsafe for consumption

Liquid Water

• Found both above and below ground

Surface Water

• Oceans have an average depth of 3.2 km and are saltwater reservoirs
• Freshwater includes water in rivers, streams, lakes, ponds, and wetlands
• Freshwater is collected in man-made reservoirs

Underground Water (Groundwater)

• More of Canada's freshwater exists underground than on the surface
• Accounts for an estimated one-third of the world's freshwater
• Rainwater soaks into the soil and flows down between soil particles until it reaches an impenetrable layer
• The groundwater zone is the area where water fills all air spaces in the soil and rock
• The water table is the upper surface of the groundwater zone
• Aquifers are underground freshwater reservoirs

Solid Water

• All of the solid (frozen) water on Earth is fresh water
• Ocean water requires a lower temperature to freeze, averaging -1.8°C
• Salt does not freeze with the water, so ocean ice becomes frozen fresh water
• Glaciers and ice sheets contain more than 40 million km3 of frozen fresh water
• Snow accumulates over centuries in high altitude areas, forming glaciers
• A glacier is a mass of ice and snow that moves slowly down a mountain slope
• An ice sheet is a large glacier that covers the land
• Only two ice sheets exist on Earth, in Greenland and Antarctica
• A polar icecap refers to big ice masses at the poles
• An ice shelf is floating ice where an ice sheet reaches the ocean
• Icebergs are large sections of an ice shelf that break off

Gaseous Water

• Exists as water vapor in the atmosphere
• Water vapor forms through evaporation from oceans, lakes, and rivers
• Warm air can hold more water vapor than cold air
• Water vapor condenses into water droplets to form clouds
• Transpiration is the process of water evaporation from plant leaves
• Animals exhale water vapor during respiration

Vocabulary

• Aquifer: A saturated area of loose rock and soil
• Atmosphere: The layers of gases surrounding the Earth held by gravity
• Bacteria: Tiny, single-celled organisms in all natural environments
• Bioremediation: The use of microbes to clean up contaminated soil, water, and air
• Chlorine: An element used as a disinfectant in water purification; too much is dangerous
• Climate Change: Long-term shifts in temperatures and weather patterns due to trapped heat, causing extreme weather, droughts, and rising sea levels
• Condensation: Water vapor changing from a gas to a liquid by losing thermal energy
• Contaminants: Polluting or poisonous substances that make something impure; can be biological, chemical, or physical
• Desalination: Removing salt from seawater using electrically charged membranes
• Evaporation: A liquid changing to a gas by absorbing thermal energy
• Filtration: Removing contaminants from a substance, like water
• Freezing: A liquid changing to a solid by losing thermal energy
• Glaciers: Rivers of ice formed from collected snow moving downhill with gravity
• Groundwater: Liquid water seeping into the ground
• Heat Capacity: The amount of heat needed to raise the temperature of an object by one degree Celsius
• Melting: A solid changing to a liquid by gaining thermal energy
• Sublimation: A solid changing directly to a gas by adding thermal energy
• Polar Ice Sheets: Frozen fields of ice covering either the North or South Pole
• Surface Water: All water on the surface of the Earth
• Runoff: Water from precipitation or snowmelt flowing over the Earth’s surface
• Water Table: The depth where loose rock and soil contain water
• Water Cycle: A repeating cycle where water changes state as it moves on, above, or below the Earth's surface
• Ice Caps: A permanent, large area of ice that covers land
• Salinity: How salty water is or how much salt has dissolved in a body of water
• Turbid: A liquid that is cloudy, thick, or opaque with suspended matter

Human Factors Affecting Water Tables

• Bottled Water
• Fracking
• Agriculture
• Use of Wells
• Inefficient Toilets and Showers
• Lawn Watering
• Landfills

Natural Factors Affecting Water Tables

• Floods
• Earthquakes
• Droughts

Water Cycle

• Water in a watershed is reused in a water cycle
• Water evaporates from water bodies and is transported to clouds
• Water droplets fall as precipitation and become runoff or groundwater
• Groundwater flows to a body of water, continuing the water cycle
• Plants and trees use water to grow

Watersheds

• Watersheds recycle all water within the system
• Water flows down to the ocean or evaporates
• Watersheds capture, filter, and release water
• Key features include freshwater holdings, plants, animals, and land formations
• Boundaries are defined by hills and heights
• Open watersheds lead to the ocean
• Closed watersheds lose water through evaporation or groundwater
• Water shares the same fate and flows to the same place
• Watersheds are sensitive to pollution and land use

Water Filtration

• Water quality depends on water usage in the region
• Chemicals and sediments are called contaminants
• Biological contaminants: visible (zebra mussels) and microscopic (bacteria and viruses)
• Chemical contaminants: dissolved substances from natural processes (dissolved limestone) or human activities (road salt)
• Physical contaminants: materials that do not dissolve in water (animal waste and plant debris)

Water Testing

• Important to understand which chemicals and bacteria exist in the water
• At-home testing kits use testing strips that change color based on mineral levels
• pH measures how acidic water is, with the best levels between 6.5 and 8.5
• A pH level of less than 7 indicates the water is too acidic
• Salinity refers to the salt content in water, measured using electric currents

Water Sustainability

• 41% of water in the USA is used for agriculture
• The USA spends over 400 million gallons of water per day

Water Usage in Production

• It takes 3 gallons of water to make a water bottle
• It takes 10 gallons of water per hour to use a microwave
• It takes 10 gallons of water per hour to power electronics in an average household
• It takes 3 gallons of water to print a single piece of paper
• It takes 76 gallons of water to make a single liter of Coca-Cola
• It takes 634 gallons of water to make a hamburger
• It takes 23 gallons of water to make corn on the cob
• It takes 39,090 gallons of water to make a car

Clothing Production and Water Impact

• Clothing production can cause water pollution and overuse
• Chemical indigo and other chemicals pollute water
• Water tables can become impossible to farm if heavily polluted
• A t-shirt takes around 7,000 liters of water to make
• Using linen instead of cotton can lower the cost of a t-shirt to 6.5 liters of water
• Reusing recycled jeans is also better for water conservation

Mexico Water Shortage

• Too much water leaks from pipes
• Too much water is used by breweries
• Not enough water is coming into Mexico
• The Colorado River is dry by the time it reaches Mexico due to USA water usage
• Too much water is extracted from groundwater reserves

Hidden Water

• Hidden water refers to water used in daily life without direct awareness
• Appliances at home, printing paper, and using the microwave all use water

Day Zero

• Day Zero is when the water supply is shut down
• Some cities that may face Day Zero in the future include Sao Paulo, Melbourne, Jakarta, Tokyo, Beijing, Istanbul, Cape Town, London, Bangalore, Barcelona, and Mexico City

Textbook Questions

Particles in water:

• Hydrogen(2), oxygen(1)

States of water:

• Solid (ice), liquid (water in oceans), gas (water vapor rising into the atmosphere)

Aquifer:

• Sediment (rocks) holding groundwater that can guide it to springs and lakes
• Hydrogeology studies groundwater flow in aquifers

Role of the sun in the water cycle:

• The sun’s UV rays cause the particles in water to quickly vibrate and expand, this causes them to evaporate and rise into the atmosphere

Sustainability:

• Sustainability refers to sustaining (keeping) enough resources for future generations

How evaporation affects the total amount of water on Earth:

• Evaporation only temporarily removes water from the earth, it will eventually become participation and most likely become a runoff or groundwater

Condensation vs precipitation:

• Condensation is the process where water vapor becomes liquid, and precipitation is that water falling back to the earth