37: Eutrophication

Question 1

What are nutrients?

Answer 1

chemicals that allow plants and animals to live and grow

Question 2

What are examples of inorganic nutrients?

Answer 2

nitrogen and phosphorus compounds

Question 3

What are algae blooms (eutrophication)?

Answer 3

produced by excess phosphorus and nitrogen in water

Question 4

Where do the nutrients come from?

Answer 4

phosphorus and nitrogen are components of fertilizers
- after fertilizers are applied in fields, they runoff to lakes and rivers

Question 5

What is phosphorus also present in?

Answer 5

detergents

Question 6

What is eutrophication?

Answer 6

occurs when a body of water receives an excessive amount of nutrients
- nutrients results in algae blooms
- when the algae die, the decomposers (bacteria) act on the dead matter and consume high levels of oxygen (O2)
- when the levels of dissolved oxygen (DO) go down, there’s massive deaths of fish

Question 7

What is the process of eutrophication?

Answer 7

1. fertilizer is spread on the land
2. fertilizer gets washed away by the rain and absorbed into the soil
3. fertilizer is transported to a lake by an underground river
4. fertilizer causes overgrowth of aquatic plants and algae in the lake
5. means sunlight cannot reach bottom of the lake, so algae die (aquatic plants die)
6. the bacteria decompose the algae, taking up all the oxygen, cause the other organisms in the lake to die (makes lake anoxic)

Question 8

What does anoxic mean?

Answer 8

no oxygen is dissolved in it

Question 9

What is an oligotrophic lake?

Answer 9

oligo= few; beautiful lake that has enough nutrients

Question 10

What is a eutrophic lake?

Answer 10

eu = food; lake with excess nutrients

Question 11

What happens to lakes over the course of history?

Answer 11

over the course of history, most oligotrophic lakes become eutrophic

Question 12

What is natural eutrophication?

Answer 12

natural process that takes a long time; the fate of a lake to become a marsh then completely filled

Question 13

What is cultural eutrophication?

Answer 13

caused by humans and occurs in a short time; very dramatic