Oil Spills

Fifteen years of debate have not resolved the United States public policy issue: "Should we allow for drilling of oil in Alaska's Arctic  National Wildlife Refuge?"  To people concerned about oil-spill  accidents, such drilling and transporting of oil threatens the areas' rich ecology. 
Birds covered with oil will die
Oil-spill victim. Source: NOAA

Living safely in the Artic refuge now are bears, wolves, foxes, musk oxen, millions of migratory birds, and a 130,000 caribou herd. These animals, and the plants too, can be harmed in three different ways: 1) direct contact, 2) poisoning after ingestion, and 3) destruction of habitat.

To people concerned about energy consumption in the U.S. and about the country's dependence on unreliable foreign sources, drilling in the Alaska Refuge could supply all the oil we use over six months to two years.

Are oil spills common? The U.S. Environmental Protection Agency says there are about 70 per day.  Typically, these are small and do no serious harm. But big spills do occur sometimes, and the damage to ecosystems can be very great.

What to do?  This is not the place to discuss world politics or even U.S. government energy and environment policy. There is a strong argument for drilling for more oil, especially now that we have newer drilling techniques that reduce the chances of accidents. But in this ecology lesson, the appropriate thing to do is to  learn about what oil spills can do to the environment.

How Have Spills Occurred?

  • Overflowing waste pits
  • Spills from trucks
  • Pipeline breaks
  • Tanker ships running aground, hitting iceberg (1989 Exxon Valdez accident)
  • Noise of drilling, trucks, pipes banging, etc.
  • Roads to bring in equipment and workers, haul out oil
  • Vandals/terrorists

What Is It In Oil That Is Hazardous?

  • Fumes are irritating to eyes, nose, mouth and lungs
  • If burned, contributes CO2 to global warming and to sulphur- and nitrogen-based gases that cause acid rain
  • Mechanical effects
    • clumps settle out on ocean flood, covering up habitat
    • collapses air space in fur and feathers (see below)

The Good News

  • Newer drilling and oil handling technologies reduce chances of oil spills
  • Oil spills can be cleaned up
  • Sunlight and bacteria degrade oil into less-harmful compounds

Effects on Wildlife Behavior

  • Home range may be reduced (caribou don't like the noise at drilling sites)
  • Birds nest in the waste dumps - foxes, ravens, and  gulls feed on their eggs. This spreads toxins across species.
  • Birds that get oil on feathers cannot fly and can't get to food and fresh water

Oil "wets" the fur of marine mammals and makes it hard for them to stay warm in cold water. They also have to breathe the toxic vapors of oil spills.

Losses in the  Exxon Valdez Spill
in Alaska in 1989

  • 15,000 otters dead
  • 36,000 sea birds dead
  • 100 bald Eagles dead

Source: www.iclei.org/efacts/oilspill.htm

Specific Examples of Bad Effects

  • Humans (from eating oil-contaminated plants and animals)
    Oil contains cancer-inducing PAH (polycyclic aromatic hydrocarbons)
  • Sea Otters, other Marine Mammals Without Much Blubber
    Oil wets the fur, collapses air spaces, makes it hard to keep warm
  • Fish
    Toxic compounds in oil can kill the eggs or juvenile stages
    Oil coating on gills interferes with gas exchange
    Changes in growth, fin erosion, cancer in sensitive species
  • Birds
    Oil on feathers collapses the air space between  feathers that keep birds warm and buoyant. Ingesting oil by cleaning themselves or eating oil-contaminated food can cause reproductive disorders, red blood cell deficiency (anemia), pneumonia
    PAHs on eggs lower hatching rate
  • Polar Bears
    Some have died from grooming oil off their fur
  • Invertebrates (intertidal)
    Many are killed by oil
    Habitat destroyed for bottom dwellers when oil settles
    Spawning grounds may be ruined
  • Plants
    Marsh grass, mangrove, and some intertidal plants can be killed by oil
Cleaning Up An Oil Spill

Principle: scoop or suck up as much as you can, disperse or dilute the rest

Specific Approaches:

  • Mechanical
    • floats to trap the oil
    • skimmer boats to gather oil and transfer to barges
    • absorbent pads to soak up oil
  • Fire - burn off the oil
  • Chemical - coagulating agents to make it clump for easier pickup
  • Water - spray beaches to move oil into collectible pools
  • Other
    • Bacteria - some species "eat" oil
    • Wind and waves will disperse oil
Washing oil off of rocks and beaches is tedious and time consuming work

You can see the use of absorbent mops after Valdez accident. These mops soak up to 70 times their weight of oil.
Source: EPA

The photo above shows workers washing the shore line after the Valdez oil spill. This removed the oil, but probably also destroyed many organisms living on the beach.
Source: EPA


Floating traps can confine oil spills for easier cleanup

Barricade to protect salmon hatchery from oil spill.
Source: NOAA

Web sites to check:

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