Quality Core Curriculum Objectives:

HS  Biology  #1 – Uses terms and processes employed in scientific research

                        #2 – Uses reference sources appropriately.

#26 – Assesses man’s impact on the environment/explore ways to help solve

ecological problems.

Students Will be able to:

1) identify ways oil spills can affect birds adversely; and

2) describe possible negative consequences to wildlife, people, and the environment from human-caused pollutants.

Materials:  water, cooking oil, shallow containers, eyedropper, hand lens, hard-boiled eggs, liquid detergent (dishwashing liquid), feathers (natural) 

Background:

The impacts of environmental pollution often are difficult to see.  A major oil spill, however, provides dramatic evidence of potential impact to wildlife.  Examples include damage to feathers, killing of embryos when oil seeps into eggs, suffocation of fish when gills are clogged, and death to marine and terrestrial animals by ingesting food and water contaminated by the oil.

People are involved in efforts to prevent oil spills and their consequences.  They are also involved in efforts to “clean up” after such spills occur.  Such actions are not always successful, and sometimes they have unfortunate consequences.  For example, the process of using detergents to clean oil from the feathers of birds caught in spills may also damage their feather structure and arrangement and thus the birds’ waterproofing.  Birds may also be more susceptible to disease during this time of stress, and may be weakened to the extent that it is more difficult for them to secure their necessary food and water.  Obviously, the food and water sources may also be affected in quality.

Procedure:

1.      Divide the class into groups of three or four.  Each group needs a shallow pan partially filled with water.  Add a known amount of oil, one drop to one dropper full, depending on the size of the container.  Observe the interaction of oil and water.  Measure the area covered by the oil.  Using this information, estimate the area that might be affected by an oil spill involving:

a)     A tanker truck holding 8,000 gallons.

b)     A ship holding 300,000 gallons.

c)      A supertanker holding 83,000,000 gallons

Discuss and compare estimates with other groups.  Graph estimates and compute average  figures.

2.      Put enough oil in a small container to submerge three hard-boiled eggs.  Add the eggs.   Put the eggs under a good light and watch closely.  Remove one egg after five minutes and examine it – before, during, and after peeling off the shell.  Try to remove the excess oil from the outside before attempting to peel the egg.

3.      Remove the second egg after 15 minutes and the third egg after 30 minutes, repeating the procedure, examining each carefully.  Discuss observations.  What effect could oil have on the eggs of birds nesting near the water?

4.      Examine a feather with a hand lens.  Sketch what you see.  Dip the feather in water for one – two minutes, and examine again with a hand lens.  Sketch and compare to the original observations.  Place the feather in the oil for an additional two minutes, then examine again with the hand lens, sketch, and compare with the other sketches. 

5.      Clean the feather in detergent, rinse in water, and dry it.  Examine with the hand lens, sketch, and compare with previous sketches.  Discuss changes in the feather after exposure to oil and then to detergents.  What effect could these changes have on normal bird activity?

6.      Discuss other possible effects on birds from an oil spill.  Discuss possible impacts on other wildlife species, on humans, and on the environment.  What trade-offs are involved?  Do we have to choose between oil and birds, as well as other wildlife?  What are some alternatives?  What are other examples of human-caused pollutants that can have negative consequences for wildlife, people, and the environment?  What is being done or can be done about these as well?

OPTIONAL:  Use a variety of oils – cooking oil, motor oil, crude oil, and compare their effects.  Food coloring can be added to clear oils to facilitate observation of effects.

Extension:

Oil spills are just one example of the kinds of pollutants that can have adverse short- and long-term effects on wildlife, people, and the environment.  The impact of DDT on the food chain is well-known, for instance.  DDT’s influence on thinner egg shells in bald eagles and other birds is well documented.  For extra credit, have the students prepare reports on DDT and its cumulative effect on food chains.