2. Answers
P. 389
1) The death of young fish due to changes in the acid content of the lake would result in the eventual decline of fish populations as the remaining fish aged and died
2) Temporarily high levels of toxins and acids in the spring meltwater can destroy the eggs and larval forms of many vertebrates and invertebrates. This may result in the destruction of the downstream ecosystems and the eventual loss of many fish species.

3. Answers
P. 391
1. a) Diversity means that there are a great number of different types of organisms in an area as opposed to only a few
B) A small puddle could not support the same level of diversity as a pond. There are more ‘niches’ or different places to live in a pond than there are in a puddle. A puddle could, however, support a diversity of bacteria and small protozoa
2. The three levels in a lake are:
Upper zone- from the shore to where aquatic plants stop growing
Middle zone- open water and still has light penetration
Lowest zone – deep water without light

4. Answers
3. All the animals live in aquatic environments and have gills instead of lungs. Gills are necessary for aquatic organisms to exchange gases such as oxygen and carbon dioxide with their environment
4. A population is a group of organisms of one species living in a defined area. Individual members of a species make up populations.
5. Answer should clearly describe a specific change, identify whether it’s seasonal, short-term, or long-term, and give valid reasons for the classification
6. Every fish species has a specific range of tolerance for temperature and the chemical composition of the water. When water quality decreases, such as an increase in the hardness or a decrease in the amount of dissolved oxygen, it may result in the decline in the numbers of a specific fish species.

7. Human Activities Affect Aquatic Environments: How Humans Use Water
4.0
what is the quickest way to count cows?
use a cow-culator

8. Human Activities affect Aquatic Environments
The total water on Earth is a renewable resource.
The location of the water can change dramatically from year to year.
Water location can be changes because of nature and human activities.

10. How humans Use Water
Humans use water directly and indirectly.

12. Copy This Down
The Major Uses of Water
All life uses water, but humans make the greatest and most diverse use of it.
The three major types of water use worldwide.
1) Agriculture – 73% of all water use is used for irrigation to grow crops.
Important for the economy, and food for people.
However, over-irrigation can cause many problems. (ex. Salts dissolved on surface)

13. Copy This Down
The Major Uses of Water
2) Industry – 22 % of all water use is by industries as:
Coolants, solvents, washing, diluting pollutants
Different industries use different amounts of water.
Can affect water in the environment if the used water isn’t cleaned or diluted properly
Plastics industry uses large volumes of water. (indirect use)
Governments regulate industries but they are important for the economy because they provide jobs, products, and services.

14. Copy This Down
The Major Uses of Water
3) Domestic – 5 % of the total water use is in our homes.
Most developed countries have clean/safe piped in water.
Most developing countries need
to walk to their water supply.

16. Practices and Technologies Affect water Quality
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Practices and Technologies Affect water Quality
 Many human water uses affect the overall quality of our environment.
Example: Dams (p. 396)
Do dams have + or – effects on water system resources?

18. Human Activities Affecting Water Quality

19. Homework!
P. 399 C & R 1 2 3