37: Eutrophication Flashcards
What are nutrients?
chemicals that allow plants and animals to live and grow
What are examples of inorganic nutrients?
nitrogen and phosphorus compounds
What are algae blooms (eutrophication)?
produced by excess phosphorus and nitrogen in water
Where do the nutrients come from?
phosphorus and nitrogen are components of fertilizers
- after fertilizers are applied in fields, they runoff to lakes and rivers
What is phosphorus also present in?
detergents
What is eutrophication?
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
What is the process of eutrophication?
- fertilizer is spread on the land
- fertilizer gets washed away by the rain and absorbed into the soil
- fertilizer is transported to a lake by an underground river
- fertilizer causes overgrowth of aquatic plants and algae in the lake
- means sunlight cannot reach bottom of the lake, so algae die (aquatic plants die)
- the bacteria decompose the algae, taking up all the oxygen, cause the other organisms in the lake to die (makes lake anoxic)
What does anoxic mean?
no oxygen is dissolved in it
What is an oligotrophic lake?
oligo= few; beautiful lake that has enough nutrients
What is a eutrophic lake?
eu = food; lake with excess nutrients
What happens to lakes over the course of history?
over the course of history, most oligotrophic lakes become eutrophic
What is natural eutrophication?
natural process that takes a long time; the fate of a lake to become a marsh then completely filled
What is cultural eutrophication?
caused by humans and occurs in a short time; very dramatic
