1. The Science of Environmental Sustainability
TESC 211
The Science of Environmental Sustainability
Autumn Quarter 2011 UWT

2. Mountains occupy about 25% of the Earth’s surface.
They play major roles in modifying the Earth’s climate (reflection from snow and ice)
Storing water
Contain majority of Earth’s forests
The 2005 Millennium ecosystem assessment ~62% of the World’s major terrestrial ecosystems are being degraded or used unsustainably.

3. Oceans cover 71% of the Earth’s surface and contain 97% of the Earth’s water.
In contrast, fresh water systems cover 2.2% of the Earth’s surface.

4. The aquatic equivalent of biomes are “aquatic life zones”.
The species and number of organisms that live in these aquatic life zones are largely determined by:
Salinity (freshwater vs marine)
Temperature
Dissolved oxygen content
Food
Light
Nutrients

5. Marine or saltwater life zones can be divided into three major types:
Coastal zone
Open ocean
Ocean bottom
The coastal zone extends from the high tide mark on land to the edge of the continental shelf.
Occupies < 10% of ocean area are BUT contains ~90% of all marine species.
The location of most commercial fisheries.

6. The abundance of sunlight and nutrients results in most coastal zone marine life zones having a high net primary productivity.
net primary production = gross pp - respiration

7. Estuaries are formed by partially enclosed bodies of water where a river meets the ocean.
Estuaries high NPP is supported by nutrients delivered by freshwater streams and run-off from the land.
Their proximity to the land makes them particularly vulnerable to human activities.

8. Coral reefs form in the coastal zones of tropical and sub-tropical oceans.
They are among the most productive ecosystems on the planet. They host ~25% of all marine species.

9. Coastal ecosystems provide a variety of ecosystem services including:
Provide food
Filter excess nutrients, sediments and pollutants
Provide habitat and nursery sites for a wide range of organisms
Reduce storm damage and coastal erosion by absorbing waves and excess water caused by storms

10. Coastal ecosystems provide a variety of ecosystem services including:
Provide food
Filter excess nutrients, sediments and pollutants
Provide habitat and nursery sites for a wide range of organisms
Reduce storm damage and coastal erosion by absorbing waves and excess water caused by storms

11. At the edge of the continental shelf there is a sharp increase in water depth.
Water beyond the continental shelf is characterized as being the “open sea”

12. The “open sea” is divided into three vertical zones on the basis of increasing depth, decreasing sunlight and decreasing temperature.
Euphotic zone (well lit)
Bathyal
Abyssal

13. Temperature drops rapidly between the euphotic and abyssal zones in an area called the thermocline.

14. Net primary production per unit area is relatively low for the open sea.
However, as so much of the Earth’s surface is covered with open sea it makes the largest contribution to overall NPP.
NPP of the open sea is greatest in regions of “upwelling” where currents and winds result in nutrients being carried to the surface for use by producers.

15. How are human activities impacting marine systems?
Human activities have particularly impacted coastal marine systems.
Why?
Major threats to marine systems include:
Over fishing
Pollution from land (run-off)
Coastal development
Anchor damage
Trawling

16. Freshwater life zones include:
Standing (lentic) bodies of water
Lakes
Ponds
Inland wetlands
Flowing (lotic) bodies of water
Rivers
Streams
Lakes form when depressions fill with freshwater from:
Ground water seepage
Precipitation
Surface run-off

17. Lakes are often classified according to the abundance of plant nutrients:
Oligotrophic lakes (poorly nourished)
Low levels of nutrients
Low NPP
Clear water
Eutrophic (well nourished)
Large supply of nutrients
High NPP
Murky brown or green water
In an excess of nutrients a lake may become hypereutrophic

18. Precipitation that doesn’t sink into the ground or evaporate becomes surface run-off.
A watershed or drainage basin is the land area that delivers run-off, sediment and dissolved substances to a stream.
Small streams join together forming rivers and ultimately flow downhill to the oceans.
Streams receive many of their nutrients from adjacent terrestrial systems, thus, are intimately dependent upon what is occurring in their watershed.

19. Inland wetlands are lands either permanently or intermittently covered in freshwater.
e.g.
Marshes
Swamps
Prairie pot holes
Floodplains
Wetlands ecosystem services include:
Filter and remove toxic materials
Replenish streams
Flood prevention

20. How are human activities impacting freshwater systems?
Fragmentation as a result of dam and canal construction:
40% of the World’s largest rivers are impacted by dams and canals
reduce flow of water to coastal systems
destroys habitat
Flood control levees and dikes disconnect waterways from surrounding systems:
impedes function of surrounding wetlands

21. How are human activities impacting freshwater systems?
Addition of anthropogenic nutrients and pollutants:
Changing land use:
draining wetlands
covering with impervious surfaces
diverting to agricultural , residential or industrial use