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The Oil Spill Quiz

Most of us use oil, or products made from oil, every day. We use it to
fuel our cars, trucks, and buses, and to heat our houses; to lubricate
all types of machinery; to make the asphalt we use to pave roads; to
make plastics; and to make medicines, ink, fertilizers, pesticides,
paints, varnishes, and electricity. It's important to understand that
because we rely on oil, we run the risk of oil spills. All of us share
responsibility both for creating the problem of oil spills and for
finding ways to solve the problem.

Take this interactive quiz to test your knowledge of oil spills, as well
as what you have learned about the recovery of Prince William Sound
since the *Exxon Valdez* oil spill in 1989. Good luck!

1.  Of the *Exxon Valdez* oil that now remains in Prince William Sound,
    the majority is located where?

    A.  On the surface of sandy, cobbled, or rocky beaches.

    B.  In the water of the Sound.

    C.  In the sediments at the bottom of the Sound.

    D.  **In the subsurface sediments of sandy, cobbled, or rocky
        beaches.**

    E.  None of the above.

The correct answer is **D**; most of the remaining oil from the *Exxon
Valdez* is now located in the subsurface (meaning below the surface)
sediments of the beaches that were affected by the spill.

2.  Oil is ONLY harmful to an animal if it is ingested (swallowed).

    A.  True

    B.  **False**

The correct answer is **B**---**False**.

Not only does oil sicken or kill animals when they ingest it when
cleaning themselves, but oil can harm them in a variety of other ways.
For example, oil destroys the insulating ability of fur-bearing mammals,
such as sea otters, and the water-repellant properties of a bird\'s
feathers, thus exposing them to the harsh elements. Oil can also cause
liver damage or blindness. A sick or impaired animal cannot compete for
food or avoid predators, which decrease its chances of survival. Oil can
also impair reproduction, possibly affecting the future of the species'
population.

In addition, thick layers of oil washing ashore can smother **aquatic
invertebrates** (barnacles, limpets, periwinkle snails, hermit crabs,
polychaete worms, etc.), which are important food sources for
**insectivores** such as fish and birds. Oil also changes the **physical
environment** for plants and animals by forming hard, asphalt-like
pavements, which cover and smother the vegetation and other living
things that organisms depend on for food, water, and shelter.

3.  Oil spilled from the tanker *Exxon Valdez* because:

    A.  it ran into an iceberg.

    B.  it collided with another ship.

    C.  it ran aground on a beach.

    D.  **it ran aground on a reef.**

    E.  None of the above.

The correct answer is **D**---it ran aground on a reef.

Shortly after leaving the Port of Valdez in March 1989, the *Exxon
Valdez* ran aground on Bligh Reef in Prince William Sound, Alaska. As a
result, its hull ruptured and nearly 11 million gallons of **crude oil**
spilled into the sound. The ship was traveling outside normal shipping
lanes in an attempt to avoid an iceberg. The spilled oil would
eventually affect over 1,100 miles of coastline in Alaska, making it the
largest oil spill to occur in U.S. waters to date.

4.  Which of the following statements is TRUE regarding the ultimate
    fate of the nearly 11 million gallons of oil spilled by the *Exxon
    Valdez*?

    A.  Most of the oil ended up on the beaches of Prince William Sound.

    B.  **Most of the oil evaporated, dispersed in the water of the
        sound, or degraded through natural processes.**

    C.  Most of the oil was recovered and removed by cleanup crews.

    D.  Most of the oil sank to the bottom subtidal areas of Prince
        William Sound and still resides in those sediments.

    E.  None of the above.

**The correct answer is** B**.**

The great majority of the oil evaporated, dispersed into the water
column or degraded naturally through processes such as **photolysis**.
Cleanup crews recovered about 14 percent of the oil, and approximately
13 percent sank to the sea floor. Only about 2 percent (some 216,000
gallons) remained on the beaches. 

5.  Based on their research, scientists have learned that it is *always*
    preferable to clean up an oiled beach as opposed to simply leaving
    it alone to recover naturally.

    A.  True

# False

The correct answer is **B---False.**

Because of the research conducted after the *Exxon Valdez* oil spill,
scientists now know that their attempts to clean up an oil spill can
also indirectly cause harm to some of the resources they are trying to
protect. For example, using hot water or chemicals to remove oil can
harm plants and animals. In addition, simply sending a team of cleanup
workers into an oiled area can trample sensitive organisms and mix oil
more deeply into a beach or marsh. The experts who respond to oil spills
consider all of these potential problems when evaluating the trade-offs
of how far to go in removing spilled oil.

6.  Today, the LEAST **weathered** oil in Prince William Sound is
    typically found:

# exposed on the surface of beaches.

# floating in the water of the sound.

# buried in the sediments of beaches.

# right below the surface of beaches.

# on rocks and boulders.

The correct answer is **C**; the LEAST weathered oil in Prince William
Sound is found buried in the sediments of beaches.

The remaining oil generally lies below the surface of the beaches in
places that are very sheltered from the actions of wind and waves (which
help to break down and remove stranded oil), and on beaches where oil
initially penetrated very deeply and was not removed**.** At these
beaches, there are signs of **weathered oil** on the surface and
deposits of fresher oil buried beneath. Sometimes this oil makes its way
to the surface and can be seen as a sheen on the water as the **tide**
comes in.

7.  All of the following **marine** organisms are typically found in the
    **intertidal zone** of Prince William Sound EXCEPT:

# Barnacles

# Mussels

# Rockweed

# giant kelp

# periwinkle snails

The correct answer is **D**---giant kelp.

Giant kelp forests are found in the **subtidal zone** (or sublittoral
zone)---the area on the coastline below the low water line. Organisms
living in the subtidal zone are not affected by the daily tides because
they are always underwater. All of the other marine organisms in the
list reside in the **intertidal zone**---areas that are alternately
exposed to seawater (at high tide) and to the atmosphere (at low tide)
every day.

8.  Oil is a mixture of many different chemicals.

# True

# False

The correct answer is **A**---True.

**Oil** is typically a mixture of many different chemicals. Not only
does each of these chemicals have its own toxicity, but each also
behaves differently in the **environment**. Some components are much
more **volatile** than others, and so they tend to **evaporate** more
rapidly when oil is spilled. Some components of oil are more easily
broken down by naturally occurring oil-degrading **microbes** in the
water and on the shorelines. Sunlight can also degrade oil components.

Proportions in the mixture vary even within a single category of oil,
like **crude oil**. For example, Arabian crude oil differs in
composition from Louisiana crude oil, which differs from Alaska North
Slope crude oil. The Alaska North Slope crude oil that spilled from the
*Exxon Valdez* into Prince William Sound contains many chemicals that
can kill plants or animals outright or injure them to the extent that
they may not be able to survive in the wild.

9.  Scientists might "fingerprint" a sample of oil collected at a spill
    site:

# to determine where the oil originated.

# to determine its chemical components.

# to attempt to determine who spilled it.

# to determine how and if it has weathered.

# All of the above.

The correct answer is **E**; all of the above.

The chemical composition of oil found in the environment yields
important clues about where it came from. The process of determining
where an oil residue originated is what scientists call
\"fingerprinting" or "source fingerprinting.\" Source fingerprinting is
a complex procedure that is part art and part science, relying both on
the experience of the analytical chemist and on the results of ratios
between certain components in a mix. Similar to the literal uses of
fingerprinting, experienced chemists can analyze the evidence left at a
\"crime scene\" (spill site) to make a reasonable determination of
\"whodunit\"---that is, if a residue is, in fact, oil, where it might
have originated, and, possibly, who spilled it. For example, the U.S.
Coast Guard uses such forensic methods to determine whom the responsible
party is when an oil spill with no known source washes up on a
shoreline. The degree to which oil has **weathered** is reflected in the
changes in chemical composition of oil residues over time. The more
closely the chemical composition of a residue resembles that of the
unspilled oil, the \"fresher\" it is.

10. What happens to oil when it first hits the water?

# It sinks to the bottom and mixes with the sediments.

# It mixes in evenly throughout the water.

# It floats, and then spreads out quickly on the water's surface, forming an oil slick.

# All of the above.

The correct answer is **C**. When first spilled, oil floats, forming an
oil slick.

Freshly spilled oil floats on salt water (the ocean and the salty
portion of bays) and usually floats on fresh water (rivers, streams, and
lakes). Very heavy oil can sometimes sink in fresh water, but this
happens very rarely. Oil usually spreads out rapidly across the water
surface to form a thin layer that is called an **oil slick**. As the
spreading process continues, the layer becomes thinner and thinner,
finally becoming a very thin layer called a sheen (or a film), which
often looks like a rainbow. You may have seen sheens on roads or parking
lots after a rain.