1. Lesson 1.5 Pg

2. Factors that Affect Wetlands and Watersheds
Wetlands and Watersheds are controlled by interactions among chemical, physical, and biological factors
These interactions are controlled in two ways
Human interactions
Natural events and processes

3. Human Activities
More than half of the original 220 million acres of United States wetlands have been lost
These wetlands were destroyed in a variety of ways due to human activities
Mining - Waste disposal
Agriculture - Mosquito control
Urbanization - Industrial processes
Construction - Draining

4. Effects of Agriculture
Agricultural practice can disrupt or even destroy a wetland in different ways
Examples:
Wetlands are degraded when crops are harvested
Drainage and Irrigation Ditches
Inefficient irrigation leads to build up pesticides, pathogens, and nutrients
Accumulation of these substances leads to degradation in water quality in the soil and groundwater

5. Effects of Agricultural Animals
Animal wastes can contaminate wetlands
Overgrazing can also damage wetlands
Exposes soil to erosion by wind and water
Increases the amount of sediment that reaches and often pollutes a wetland

6. Effects of Agricultural Pesticides and Fertilizers
Pesticides and Fertilizers are the most harmful effects of agricultural on wetlands
Contaminate wetlands by direct application in runoff, or by settling out of the air
When these substances reach high enough levels they can:
Kill wildlife
Poison food sources
Destroy the wetlands

7. Urbanization Urbanization is a major cause of Wetland Impairment – EPA
Urbanization of the modern landscape of concrete and other materials increase the amount of runoff
Runoff carries harmful substances that:
Increases: turbidity and salinity
Decreases: the amount of dissolved oxygen

8. Construction
Construction of roads and bridges over wetlands increases the amount of sediment deposited in these ecosystems
Paints, cleaners, salts, herbicides, dust-control substances, and other chemicals used along roads contribute to wetland damage
Roads restrict the movement of species
Leads to death of some species

9. Urbanization and Construction
Canals, Ditches, and levees divert water away from its natural flow
Increase the rate at which water flows into and out of the wetland
Increased flow reduces the buffering ability of wetlands
Increases turbidity
Decreases aquatic plant life

10. Mining Mining operations can result in the loss of wetlands
Phosphate Mining
Eliminated thousands of acres of wetlands in Florida
Peat Mining
Peat = a form of organic matter that is used as fuel
Vegetation is cleared from wetlands
Wetlands are drained and roads are built so they can access the peat

11. Mining Rocks and Minerals
Mining of rocks and minerals (Occurs in PA)
Abandoned and active coal results in acid drainage
Increases the pH of nearby wetlands
Introduces heavy metals

12. Industry
Construction of office buildings, factories, and processing plants can reduce the acreage of wetlands
Work done in the industrial buildings damages the environment
Water intake causes habitat fragmentation
Release of water causes thermal pollution, which leads to algal blooms

13. Waste Disposal Waste is a by-product of urbanization
Most urban waste is placed in landfills
Landfills in the US are usually within 1 mile of wetlands
Landfill leaks are extremely toxic to wetland organisms

14. Waste Disposal
Sludge and wastewater treatment plant effluent are other major forms of waste
Both are rich in nitrogen and phosphorus
Causes algal blooms

15. Effects of Algal Blooms
Excess algae prevents sunlight
Reduces or entirely prevents photosynthesis
Results in plant death
Remove dissolved oxygen from the water , which kills many organism at the bottom of a wetland ecosystem

16. Complete the Following…
Answer Review questions 1 and 2 on page 36
Hold on to them until you complete the rest of the review questions

17. Watershed Quality Human activities also affect watersheds
Agencies are responsible for monitoring watersheds
United States uses the Index of Watershed Indicators (IWI), to gather and assess data about aquatic resources
Also used to determine whether human activities on the land within a watershed place them at risk

18. Condition Indicators IWI includes more than a dozen indicators
One group of indicators reflect actual conditions in a watershed (Condition Indicators)
1. Presence of Contaminated Sediments
Contaminated sediments can harm or even kill organisms
Can also pose a risk to human who eat contaminated fish
When indicators are high, fish consumption advisories are issued

19. Vulnerability Indicators
IWI includes indicators that measure the vulnerability of a watershed
Vulnerability Indicators show whether human activities produce negative effects on the watershed
One vulnerability indicator measures the risk of extinction faced by various organisms
If the indicator is high, measures are taken to protect the species at risk

20. Vulnerability Indicator Examples
One vulnerability indicator measures the risk of extinction faced by various organisms
If the indicator is high, measures are taken to protect the species at risk

21. Vulnerability Indicator Examples
Another vulnerability indicator is human population growth
Rapid increases in population growth can place stress on watersheds
Need of freshwater and runoff produced by humans are important vulnerability indicators
When both indicators are high
Watersheds are at risk of becoming depleted or polluted

22. Vulnerability Indicator Examples
Dams are another vulnerability Indicator
Dams decrease water circulation
Leads to increased temperatures
Leads to decreased dissolved oxygen levels
Leads to changes in salinity and pH
If not corrected leads to deaths of many watershed organisms

23. Complete the Following
On the same sheet of paper with the previous review questions
Contrast the two types of IWI indicators
Give two examples of each and explain how they affect watersheds