what is it? eutrophication is the addition of excessive nutrients (animal waste, fertilizer, sewage)...
TRANSCRIPT
5.4 Eutrophication
What is it?Eutrophication is the addition of excessive
nutrients (animal waste, fertilizer, sewage) to a body of water (runoff) and causes excessive algae growth to occur.
Dense algae growth blocks out light and kills aquatic plants
Decaying plants causes a severe loss of oxygen (no photosynthesis) Low DO Levels
Bacteria flourish as a result of all the decay and deplete the oxygen supply of water High BOD levels
Fish and consumers die due to lack of oxygen
What causes it? Eutrophication can be a natural process Accelerated greatly by addition of nitrates and
phosphates.Largely a result of run off of…
detergents,Sewage/ wastefertilizersTopsoil erosion
What are the effects? DO levels dropFood chain collapseBiodiversity decreasesContaminated drinking water
Case Study: Lake ErieComplete the assignment
“Lake Erie is Dead!” The “death” of Lake Erie
in 1960’s Eutrophication caused
by dumping a lot of detergents and fertilizers over short period of time.
Some lakes were designated to study the effects of eutrophication.
The following slides are the results of the experiment.
Video “ Lake Erie is Dead”
Aerial view of Lake 227 circa 1975Aerial view of Lake 227 circa 1975
Aerial view of Lake 227 in 1994. Note the bright green color caused by algae stimulated by the experimental addition of phosphorus for the 26th
consecutive year. Lake 305 in the background is unfertilized. Aerial view of Lake 227 in 1994
Experimental Lake 227Previous Slide: Bright green color shows
algae growth caused by experimental addition of phosphorus for 26 years.
Lake 305 in the background is unfertilized.
Next Slide: Lake 226 with a divider curtain in August 1973.
The bright green color results from bluegreen algae (Cyanobacteria), which are growing on phosphorus added to the near side of the curtain.
Lake 226
Divider Curtain
Possible SolutionsReduce nutrients released into water ways
Reduce use/production of phosphate detergents
Restore wetlands to act as buffer zones between farms and surface waters
Reduce amount of livestock = less wasteTreat polluted areas by…
Removing algae Pumping air into waterTreat run off and sewage properly