Megan Mlynarski - 3 Invertebrates Assessing Water Quality

 Names: Megan Jack Bianca Scott Assessing Water Quality with Invertebrates - Virtual Lab http://www.mhhe.com/biosci/genbio/virtual_labs/BL_09/BL_09.html

In this investigation you will demonstrate how water quality can be assessed by studying the effects of acid rain on different populations of aquatic invertebrates. Aquarium Analysis Data Table pH

Population size

Species:

Leech

Stonefly Nymph

Sideswimmer

7.0

20

20

20

6.7

20

20

14

6.4

20

20

7

6.1

20

20

2

5.8

20

16

0

5.5

20

11

0

5.2

19

7

0

4.9

8

0

0

4.6

0

0

0

4.3 4.0 3.7 3.4 3.1 2.8 Analysis Questions p H each of the following species went 1. Go around the room talking to your classmates. Find out at what pH locally extinct:

Species

Aquatic earthworms

Snails

Tubifex worms

Clams

Leeches

 pH

3.7

6.4

3.4

6.4

4.6

Species

Side-swimmers

Dragonfly

Crayfish

Fairy shrimp

Stonefly nymphs

nymphs  pH

5.8

5.2

6.4

5.8

4.9

2. In your own words , what are macroinvertebrates? 3.

4.

5.

6.

7.

8.

9. 10. 11.

12. 13.

a. Answer: They are organisms without a spine, but pretty large given that. How does rain become acidic? (Use the “Information” section to help you answer this question.) a. Answer: Rain becomes acidic by all rain naturally having some form of acidity level, yet in highly industrialized areas have higher levels. Also the rain becomes acidic by determined by the  ph scale, so the lower the ph level is the more acidic the solution is. What are the 2 types of acids in acid rain? (Use the “Information” section to help you answer this question.) a. Answer: The two types of acid in acid rain are sulfuric acid and nitr oxides acid. What is the major source of acid rain pollution? (Use the “Information” section to help you answer this question.) a. Answer: They come from the release of pollutants in the air, like fossil fuels. Does acid rain typically have a positive or negative effect on ecosystems? Explain why. (Use the “Information” section to help you answer this qu estion.) a. Answer: Negative effect on ecosystems because when acid precipitation falls into a lake, it can lower the pH of the water and will kill many aquatic organisms. What is an indicator species? (Use the “Information” section to help you answer this question.) a. Answer: Indicator species are particular aquatic invertebrates that alert us to pollution problems in an environment. The populations of these organisms change rapidly in response to changes in ecological variables, such as food availability, water temperature, amount of dissolved oxygen in the water, pH levels, and other factors. How are indicator species used to assess pollution levels in the environment? Would an increase or decrease in an indicator species’ population indicate an increase in pollution? (Use the “Information” section to help you answer this question.) a. Answer: Compare the indicator to what is really there. Draw conclusions about the relative pH of the pond. Decrease in indicator species would indicate an increase in pollution. Which species was the most tolerant of increased acidity in the aquarium? a. Answer: Tubifex worms were the most tolerant. Which species were the least tolerant? a. Answer: Clams, Snails, and Crayfish What could you conclude about a lake that contained only tubifex worms, leeches, and aquatic earthworms? a. Answer: The pond has a low pH. What could you conclude about a lake that contains many clams, snails, and crayfish? a. Answer: Though still acidic, the pond has a relatively more basic pH. Suppose you are an ecologist studying the effects of acid precipitation on plant life. Describe an experiment you would perform in order to determine which plant species would be a useful indicator species for acid rain pollution. a. Answer: I would separate them in diferent “ecosystmes”