8.5 eutrophication

Eutrophication process

algae bloom due to increased N/P covers surface of water → blocks sun → kills plants → algae dies off & uses O2 in the water → hypoxia & dead zones → kill aquatic animals

Created feedback loop: less O2 → more dead organisms → more bacterial decomposition→ less O2

Cultural eutrophication

Anthropogenic nutrient pollution (N& P) leads to eutrophication

Major N/P sources

1) discharge from sewage treatment plants

2) animal waste from CAFOS

3) synthetic fertilizer from agricultural fields & lawns

Oligarchic waterways

Waterways with low nutrient levels, stable algae population, & high dissolved oxygen

-lack of nutrient pollution or age of water

-go into succession (sediment buildup → higher nutrient levels)(overtime → ponds shift to oligotrophic to mesotrophic to eutrophication)