Effects of Oil Spills

oil spill
Cause of Water Pollution

The effects of oil spills reach far beyond the location of the original spill. Within a short period of time even a small spill can impact miles of habitat.

Oil in Ocean and Other Waterways

Oil is spilled into the oceans and waterways through a variety of circumstances. About half of the 706 million gallons of oil that are estimated to enter the ocean every year are from run-off. Improper handling of used motor oil is a big part of this percentage. Although offshore drilling gets a lot of publicity when there is a spill, it actually accounts for less than eight percent of the annual total of oil spilled in the ocean. The rest of the oil comes from the following:

  • Routine maintenance on ships: 20 percent
  • Air pollution settling on the water: 13 percent
  • Natural leaks in the ocean floor: estimated between 8 and 10 percent

It doesn't take much oil to spread over a large area. In the right conditions, a gallon of oil can create an oil slick as large as two acres wide.

Effects of Oil Spills on Habitats

One of the areas that is most obviously affected after an oil spill is the shoreline. The oil washes up on the beaches coating the sand, rocks, and plants with oily residue. When the sand is covered with oil it can't support the vegetation that normally would grow there. Wildlife may eat the contaminated vegetation and become sick or die.

Tidal pools and other small ecosystems can't support life when they become contaminated. The creatures in a tidal pool are part of the food chain so predators may either get sick from eating toxins in their prey or can starve from a lack of food.

Coral Reefs are destroyed by many factors, including oil spills. These reefs provide a habitat for aquatic life as well as being beautiful to look at.

Economic Effects

The local economy is affected by an oil spill. Recreational areas that are covered with oil are not appealing to tourists and towns that depend on tourism can find themselves in a difficult financial situation.

Property values may drop drastically after an oil spill. Investors may not want to invest in the area because of concern over a long-term drop in tourism. Restaurants, hotels, and retail establishments can be seriously compromised if the cleanup is not efficient, fast, and complete. After a spill it can take months or years to win tourists back to an area that has been affected by a spill.

Fishermen may not be able to fish because the sea is contaminated. Over a long period of time, the population of fish and shellfish in an area can be greatly reduced or totally lost from an oil spill. Boats and machinery can be damaged by the oil that floats on the surface of the water and nets and traps can be ruined. Cleanup crews can disrupt fishing schedules and there may even be a temporary ban placed on fishing as a precaution against contaminated fish becoming part of someone's dinner.

Besides the obvious economic effects of an oil spill there can be serious threats to the well being of residents. A power plant that has intakes that draw in seawater may need to close until cleanup can be completed. The machinery can be ruined by the oil that could come in with the water.

Effects of Spills on Wildlife

Probably one of the areas of greatest concern is the effect of the oil spill on wildlife. From the smallest plankton to the largest whale, all marine life is impacted by an oil spill.


Plankton is not only a habitat for fish eggs and larvae, but is also the main diet of many ocean creatures. Without this basic organism, the entire ecosystem can be thrown off. Scientists know that toxins affect the number of plankton in an area, but the ocean is so large, it is difficult to come to any solid conclusions about percentages .


Many seabirds dive for their food. Often, they must dive through a layer of oil to get to the fish they eat. This leaves the oil residue on their feathers, which can cause numerous problems. When the birds attempt to preen, or clean themselves, they ingest the oil, which is toxic. However, the most common cause of death for these birds is from drowning, loss of body heat, or starvation because of the oil on their feathers. The eggs that the birds lay often have weak shells that break easily.

Entire colonies of birds can be wiped out by a single, serious oil spill, whether from illness, plumage contamination, or habitat loss.


Seals, otters, and other marine mammals that breed on the shoreline are particularly at risk for problems after an oil spill. If oil gets on their fur they can no longer regulate their body temperatures and can die of hypothermia or even overheating. If the fish population has been affected, then the mammals can starve from lack of food. When oil washes up onto the shore and affects breeding areas, the birth rate may drop rapidly.

Fish, Turtles, and Other Life

Like other marine life fish and turtles, shellfish, and other organisms can be seriously compromised by an oil spill. Common problems include:

  • Behavioral changes
  • Blindness
  • Damage to internal organs
  • Spread to other habitats
  • Sores
  • Stress

Oil spills from oceans can be washed into inland wetlands and marshes, affecting the plant and animal life in these areas. Plants in wetland areas will die when they are covered with oil. Animals, birds, and other inland creatures may suffer from a variety of illnesses as the oil contaminates their habitat.

Far Reaching Effects

The effects of oil spills reach much farther than the ocean, and it is more than just the animals that are affected. From the economy to the ecosystem, oil spills disrupt lives.

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Effects of Oil Spills