1. Earth Systems and Resources – College Board
C. Global water resources and use:
Freshwater/saltwater
Ocean circulation
Agricultural (use)
Industrial and domestic use
Surface and groundwater issues
Global problems
Conservation

2. Aquatic Ecology – Terms
Abyssal zone
Aphotic zone
Bathyl zone
Benthos (benthic)
Currents
El Nino
Estuary
Euphotic
Eutrophic
Freshwater biome
Inland wetlands
Intertidal zone
Limnetic
Littoral

3. Runoff
Thermocline
Transition zone
Turbidity
Upwelling
Watershed
Marine biome
Nekton
Oligotrophic
Photic zone
Plankton
Riparian zones

5. Properties of Water
Hydrogen bonding - creates properties of water that enable life to exist
High heat capacity
High heat of vaporization
Expands as it freezes
Universal solvent
Adhesive/cohesive

6. Properties of Water High heat capacity
Changes temperature slowly
Uneven heating/cooling creates winds, currents
Moderates climate
Cold places are warmer, warm places are cooler
High heat of Vaporization – as water evaporates, it removes heat
Evaporative cooling

7. Universal Solvent Water can dissolve a lot of compounds
Nitrates, K, Ca, glucose making them available to cells
It can easily become polluted by water-soluble wastes

8. Properties of Water Expands as it freezes Most dense at 4oC
Ice forms at the surface
Upwelling - cooler water rises to the surface, bringing nutrients into the photic zone
Turnover

9. Thermal Stratification
In summer, the surface water is warm - less dense (lighter)
Thermocline - middle layer prevents the transfer of nutrients from the bottom and dissolved oxygen from the top
Oxygen dissolves into water at the surface
Poop and dead stuff floats to the bottom – nitrogen cycle

10. Fall Turnover Temperature begins to fall
Surface layer becomes more dense
Sinks to the bottom
Nutrients circulate to the surface and oxygen to the bottom
Upwelling
Winter – layers are fairly even

11. Spring Turnover Ice melts; cold water warms up
Sinks below the cooler (less dense) water
Oxygen circulates down and nutrients (nitrates) circulate to top (photic)

12. Aquatic Life Zones Abiotic factors determine who lives where:
Sunlight
Salinity
Turbidity
Temperature
Dissolved oxygen
Two aquatic biomes – fresh and marine

13. Marine Biomes – 71 % of Earth
Economic benefits:
Food
Oil, natural gas, minerals
Transportation
Recreation
Ecological benefits:
Moderates climate
Habitat and nursery areas
Absorbs CO2 (CaCO3)
Reduces storm impact

14. Life Zones Plankton – float or weak swimmers
Phytoplankton – algae; Diatoms (1o producer)
Euphotic zone
Zooplankton – 1o consumers
Necton – good swimmers
Benthos – (benthic) bottom dwellers (barnacles, oysters)
Decomposers: breakdown organic compounds (mostly bacteria)

15. Coastal Biome
High tide to continental shelf
90% of all marine life

16. Estuary Where the river meets the oceans
Bays, inlets, sounds, salt marshes, mangrove swamps
Highly productive (1o productivity)
Nutrient-rich nurseries
Filter toxins
Prevent beach erosion

17. Coastal Zones Salt marsh - nursery for many fish Lots of 1o production
Prevent beach erosion
Filters toxins
Intertidal zone – between high and low tides
Coral reef - slow growing coral animals build reefs
Mutualism with zooxanthellae algae
Close to surface

18. Open Ocean
Pelagic
Euphotic zone
Bathyal zone
Abyssal

19. Stratification Abiotic factors vary with depth: Temperature Sunlight
Dissolved oxygen
Nutrient availability
Euphotic zone - sunlight can penetrate

20. Lakes Littoral zone (near shore, shallow, with rooted plants)
Limnetic zone (open, offshore area, euphotic)
Profundal zone (deep, open water, aphotic)
Benthic zone (bottom of lake)

22. Lake Nutrients Oligotrophic - ‘few feed’ Not many food chains
Low nutrients

23. Lake Nutrients Eutrophic – lots of nutrients
Shallow, murky; filled with sediment

24. Cultural Eutrophication
Human activities add too much nutrient to lake

25. Freshwater Inland Wetlands
Reduce flooding, erosion caused by storms
Replenish streams
Recharge groundwater
Habitats
Nursery, spawning grounds
Filter toxins (salt marsh)

26. Peat Moss Bog
A wet area that over time fills in (the last stage of succession is peat moss).
Can be very deep.
May be burned as fuel.

27. Water Cycle
Runoff - water that does not sink into the ground or evaporate
Watershed or drainage basin - the land that drains water into a lake or river

28. Surface Water
Can be flowing (rivers/streams) or standing (lakes, ponds, wetlands)
Source – precipitation
Watershed – Ex. small streams  larger streams  rivers  sea

29. Rivers and Streams Deliver nutrients to sea
Deposit silt that maintains deltas
Purify water
Renew and renourish wetlands
Provide habitats for wildlife

30. Headwaters Cold, clear water; waterfalls and rapids
High amounts of dissolved oxygen (DO)
Oxygen diffuses into water at the surface
Many headwaters form a stream/river

31. Downstream Characteristics
Waters spread out, move more slowly, warmer temperatures, less DO
Algae and cyanobacteria
Littoral zone grows more emergent plants

32. Freshwater
Groundwater - precipitation that penetrates (percolates) the ground and is stored underground (aquifer)
Aquifers–porous rock w/ water flowing through
Water Table – the level of earth’s land crust to which the aquifer is filled
Renewability – the circulation rate of groundwater is slow (300 to 4,600 years).

33. Water Usage Irrigation Industry – coolant (power plant)
Domestic and Municipal
We currently use more than half of the world’s reliable runoff of surface water and could be using 70-90% by 2025
Irrigation = 70%; Industries = 20%; Cities and residences = 10%
About 70% of the water is not returned to the sources

34. Restoration
Build huge aqueduct, or find other sources of fresh water and protect it federally under endangered species act, etc.

35. Flooding
Heavy rainfall, rapid snowmelt, removal of vegetation, and destruction of wetlands cause flooding.
Floodplains, which usually include highly productive wetlands, help provide natural flood and erosion control, maintain high water quality, and recharge groundwater.
To minimize floods, rivers have been narrowed with levees and walls, and dammed to store water.

36. Oxygen released by vegetation
Diverse ecological habitat
Evapotranspiration
Trees reduce soil erosion from heavy rain and wind
Agricultural land
Steady river flow
Leaf litter improves soil fertility
Figure 14.23
Natural capital degradation: hillside before and after deforestation. Once a hillside has been deforested for timber and fuelwood, livestock grazing, or unsustainable farming, water from precipitation rushes down the denuded slopes, erodes precious topsoil, and can increase flooding in local streams. Such deforestation can also increase landslides and mudflows. A 3,000-year-old Chinese proverb says, “To protect your rivers, protect your mountains.”
Tree roots stabilize soil and aid water flow
Vegetation releases water slowly and reduces flooding

37. Evapotranspiration decreases Roads destabilize hillsides
After Deforestation
Tree plantation
Evapotranspiration decreases
Roads destabilize hillsides
Ranching accelerates soil erosion by water and wind
Winds remove fragile topsoil
Gullies and landslides
Agricultural land is flooded and silted up
Figure 14.23
Natural capital degradation: hillside before and after deforestation. Once a hillside has been deforested for timber and fuelwood, livestock grazing, or unsustainable farming, water from precipitation rushes down the denuded slopes, erodes precious topsoil, and can increase flooding in local streams. Such deforestation can also increase landslides and mudflows. A 3,000-year-old Chinese proverb says, “To protect your rivers, protect your mountains.”
Heavy rain leaches nutrients from soil and erodes topsoil
Rapid runoff causes flooding
Silt from erosion blocks rivers and reservoirs and causes flooding downstream
Fig b, p. 330

38. Too Little Water Drought Desertification
Lake levels drop, recreation use drops, fisheries drop, and salinization occurs
Ex. Soviet Union (Aral Sea); the inland sea drained the river that fed into it.

39. Water was diverted (irrigation) from the Aral Sea and its two feeder rivers
About 85% of the wetlands have been eliminated and roughly 50% of the local bird and mammal species have disappeared.
Since 1961, the sea’s salinity has tripled and the water has dropped by 22 meters most likely causing 20 of the 24 native fish species to go extinct.

40. Salinization of Irrigated Soil
Water is poured onto soil and evaporates. Over time, as this is repeated, nothing will grow there anymore.

41. Saltwater Intrusion

42. Miami encroaches on everglades
Drained for water and increased development
People vs. wildlife