Eutrophication

Eutrophication Nutrification (adding nutrients) to a body of water. Nitrogen & Phosphorus Primary Source: Inorganic fertilizers

Oligotrophic NO Nutrients New lake systems Clear waters No life!

Mesotrophic Most lakes Nutrients are limited Plant and animal populations are balanced

Eutrophic Large amount of phosphorus and nitrogen present in water Leads to algal bloom Unlimited plant growth

Step One Farmers and homeowners use nitrogen and phosphorus based fertilizers to ensure plant growth.

Step Two Excess fertilizer not absorbed and assimilated into plants runs off into streams and rivers.

Step Three Nitrogen and phosphorus are carried to the ocean.

Step Four Nitrogen and phosphorus (limiting nutrients) are in excess and allow for a massive algal bloom.

Step Five Algae’s short lifespan leads to the addition of massive amounts of detritus to coastal waters.

Step Six Microorganisms including protist and bacteria (decomposers) feed on the dead algae.

Step Seven Microorganisms deplete the oxygen in the water creating a “zone of hypoxia”.

Step Eight Fish and other aerobic aquatic organisms die leading to a “dead zone”.

Journal Entry Which two cycles are out of balance and contribute to cultural eutrophication? What is the anthropogenic source of the excess nutrients?