Water PollutionNitrogen and Phosphorus

D24

• Explain how the accumulation of mercury, phosphates and nitrates affects the quality of water and the organisms that live in rivers, lakes and oceans.

Learning Targets• I can explain the causes of nutrient

pollution.• I can explain the effects of nutrient

pollution.• I can identify ways to reduce

nutrient pollution.

What is water pollution?

Water pollution is any contamination of water with chemicals or other foreign substances that are detrimental to human, plant, or animal health.

What is an impaired water?

• Waters which are not suitable for their designated uses

• They can no longer be used for drinking, irrigation, industry, recreation or fishing

Water Pollution

What is nutrient pollution?

• An environmental problem caused by excess nitrogen and phosphorus in the air and water

What is the role of N and P in aquatic ecosystems?

• Supports the growth of algae and aquatic plants (this is normal)

What happens when there is excess N & P in a body of water?• Eutrophication• Causes an algal bloom

www.nysun.com

What happens as a lake starts to become eutrophic?

• Algae can overtake the body of water, turning it green

• Overgrowth of plants choke water movement

What are the later stages of eutrophication?

• Plants and algae use up all of the resources and they die

• They use up the available oxygen as they decompose

• Water that is low in oxygen = hypoxia

What happens if all of the dissolved oxygen is used up?

• Water becomes anoxic• Creates a dead zone

chemistry.about.com www.cosmosmagazine.com

What are the 5 primary sources of nutrient pollution?

• Agriculture• Stormwater• Wastewater• Fossil fuels• Pollution from in and around the

house

What are the effects of nutrient pollution?

• Environmental– Harmful algal blooms

(HAB)– Hypoxic areas– Dead zones– Acid rain

• Human– Blue baby syndrome– Illness from HAB

• Economic– Water treatment costs– Tourism losses– Commercial fishing and

shellfish losses– Real estate losses

How can we prevent nutrient pollution?

• In our homes– Choose phosphate-free detergents,

soaps, and household cleaners– Use the appropriate amount of

detergent; more is not better– Always pick up after your pet– Proper septic system maintenance– Be energy efficient

How can we prevent nutrient pollution?

• In our yards– Use fertilizer responsibly– Don't overwater gardens and yards– Landscape with native plants

• In the community– Get involved

Learning Target Checkpoint

• What causes nutrient pollution?• What are the effects of nutrient

pollution?• How can you prevent nutrient

pollution?