Chapter 28Pollution of the Hydrosphere

Sediment Pollution Rapid introduction

of sediments into water ecosystems due to runoff

Sources include: exposed

agricultural fields clear cut logging construction sites

Effects of sediment pollutionHurts aquatic organisms

reduces the amount of photosynthesis that can occur in water

reduces the ability to absorb oxygen may clog gills

Nutrient Pollution An increase in nutrients in an aquatic

ecosystem Leads to a rapid increase in growth of plants

and algae

Algal bloom is a rapid increase in algae due to the introduction of nutrient fertilizers into an ecosystem.

Eutrophication Nutrient pollution due to an increase in

nitrates and phosphates Caused by use of fertilizers, leakage from

septic/sewage systems

Nutrient Pollution (Eutrophication)Sources are:

Detergents Nitrogen compounds Runoff from streets and lawns Fertilizers from agriculture Discharges of sewage treatment

plants and septic tanks

Effects of Eutrophication• Hurts aquatic organisms• Reduces amount of light for

photosynthesis • Increases the amount of dying algae• Results in bacterial growth that

depletes oxygen in the water• Decreased dissolved oxygen creates

hypoxic (low/no oxygen) conditions, toxic to living organisms

Toxic Organic Compounds ORGANIC (natural) = contains CARBON!

Examples: Oil, Gasoline, Pesticides Hurts aquatic organisms:

heavy oil pollution in the water can be deadly

BP Oil Spill (2010) Gulf of Mexico

In April 2010 an explosion on the Deep water Horizon drilling rig killed 11 men and sent millions of gallons of oil gushing into the

Gulf of Mexico

Toxic Inorganic Compounds

It includes synthetic industrial chemicals and heavy metals, such as: Lead, Mercury, Arsenic

Sources include: poor waste disposal toxic chemicals infiltrating and

contaminating groundwater May be worse than toxic organic compounds

because they can remain deadly for years and usually are not broken down naturally.

Disease-Causing AgentsSpecific organisms that cause or spread

diseases, such as viruses and bacteria.Waterborne illnesses is a type of

disease caused by an organism that lives in water.

Some examples are: Typhoid Malaria Hepatitis

Disease-Causing Agents

Wastewater: polluted water that is unfit for drinking or for introduction into the environment because it has been previously used and contaminated

Wastewater affects organisms Can contaminate shellfish and other fish Humans may eat contaminated fish and

develop health problems

Thermal Pollution Caused by a change in temperature. The temperature of the water and the amount

of dissolved oxygen is an inverse (opposite) relationship.

Nuclear power causes thermal pollution Water used for cooling towers increases the

temperature of surface water when released Aquatic animals need a constant temperature to

survive

Thermal Pollution

Construction of dams causes thermal pollution by lowering water temperature

The temperature of the river drops about 10 degrees

Native fish cannot tolerate the temperature change.

Test Your Knowledge1. The most widespread pollution is..

Sediment Pollution2. The enrichment of fertilizers in an aquatic ecosystem is called...

Nutrient Pollution3. Runoff from a construction site can result in..

Decreased Photosynthesis

Test Your Knowledge (cont.)4. Leaking septic systems located around lakes and ponds can cause..

Nutrient Pollution5. A rapid increase in the population of aquatic plants is known as..

Algal Bloom6. Increasing amounts of nitrates and phosphate fertilizers in water cause..

Eutrophication

Test Your Knowledge (cont.)7. As the temperature of the water increases, what happens to the level of dissolved oxygen within the water?

It Decreases8. What is the main source of waterborne illnesses?

Wastewater9. PCB’s are an example of what?

Toxic Inorganic Compounds

Test Your Knowledge (cont.)10. An increase or decrease in water temperature caused by human activity is known as what?

Thermal Pollution