FAQs: Wildlife and the Deepwater Horizon oil spill

(Updated Dec. 10, 2010)

Note: Very few long-term studies have been conducted on the effects of oil on wildlife, and little is known.

How are animals and fish generally affected by oil spills?

Generally, direct contact with oil or consumption of oil-tainted items can cause health problems, such as organ failure, skin irritations, breathing problems and a variety of other health problems that can lead to death.

Indirect contact through bioaccumulation of oil in the food chain is of high concern. Bioaccumulation is the transfer of toxins from the environment into the food chain. Typically higher-order animals accumulate toxic levels of these poisons from eating many items that have smaller, less-toxic levels of the poison. Reduced egg production, abnormal larval development, poor health and death can occur from exposure to oil.

How can I help rescue oiled birds or other animals?

People who find injured or oiled wildlife should not attempt to handle or help those animals themselves because the oil is toxic to humans as well as wildlife. There is specific hazardous-materials training that is required for anyone coming into contact with these animals.  Also, it is important to have training in handling wildlife because those animals can sometimes cause serious injuries when they are under the stress of captivity.

Should I move a shorebird nest that is in imminent danger from the oil spill?

No, you should not move shorebird nests.  Report oiled shorebird and wildlife sightings by calling 888-404-3922. Removing eggs from a nest will cause the birds to abandon the nest. Only highly trained personnel are equipped with the skills and resources necessary to rescue eggs or hatchlings.

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How are birds affected by oil spills?

Symptoms include dehydration and emaciation. Birds may lose their ability to regulate their body temperature.

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What happens if a bird ingests oil?

Ingestion of oil causes an irritation to the lining of the mouth, esophagus and stomach. It also interrupts the intestines' ability to absorb nutrients, proteins and water. Dehydration causes organ failure by blocking the normal flow of liquid in the kidneys, liver and spleen, which further leads to a buildup of toxic fluids that can cause death. Weakened and emaciated birds also are more susceptible to fungal and bacterial diseases.

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What should I do if I see a sea turtle nest on a beach contaminated by oil?

You should treat this as an incident in which wildlife have been affected by oil from the spill.  Report this sighting by calling 888-404-3922. Trained responders will be sent to the site to evaluate the situation.  Do not attempt to restrain or interfere with the nesting sea turtle.  Permits are required for anyone who is going to work with nesting sea turtles, sea turtle nests and hatchlings. The FWC is developing procedures for taking care of sea turtles and their nests throughout the course of this event.

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What should I do if a beach gets contaminated with oil after sea turtles nest on it?

You should treat this as an incident in which wildlife have been affected by oil from the spill.  Report this sighting by calling 800-320-0519. Decontaminating a nest is an extremely delicate process, and if the eggs have to be removed, special skills and facilities are needed to ensure the animals can be returned to the wild with a chance of survival. Even though compassion motivates many people to help animals in trouble, it is necessary to have trained and permitted responders evaluate the situation and determine the best way to take care of sea turtle nests that may be affected in this way.

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How are sea turtles affected by oil spills?

Sea turtles and their nests are highly sensitive to exposure to oil, and direct exposure to oil can cause death. Oil clings to the nostrils and eyes and can damage airways and lungs of sea turtles. Exposure to oil can irritate and damage skin and mucous membranes (nose, throat and eyes) increasing the risk of infection. Oil exposure also can affect the immune system as well as the turtles' oxygen-carrying capabilities. Turtles may eat anything of appropriate size, including tar balls, which may result in the absorption of toxins or cause a blockage in the digestive system.

Oil on contaminated eggs can alter the incubation environment, potentially resulting in death.

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How are fish affected by oil spills?

Fish in all life stages, including eggs, larvae and young of all species, are sensitive to oil. Exposure to oil can lead to death. Fish populations most at risk are those that are spawning during an oil spill.

Low concentrations of oil affect reproduction and feeding in fish. Impacts include:

  • reduced egg hatching;
  • reduced larval survival;
  • larval abnormalities.

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How are crustaceans affected by oil spills?

Currently, the spawning seasons for blue crabs, stone crabs, shrimp and horseshoe crabs are ongoing. Direct exposure to oil and oil dispersants can kill larvae. Exposure to oil can coat the outer skeleton and sensory organs (feelers, eyes, etc.).

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How are mollusks affected by oil spills?

Mollusks are a group of soft-bodied invertebrates, including oysters, clams, scallops and snails. Many mollusks, such as oysters, are highly susceptible to oil contamination because they filter large volumes of water for food and oxygen.

Oil exposure can cause reduced egg production and hatching rates; abnormal larval development or survival; respiration, feeding and growth problems; general poor health or death. Exposure to contaminants can enhance effects of pre-existing infections and increase susceptibility to new infection.

Oil contamination is of special concern for oysters during the spring because they are just beginning their spawning season.

Some species, such as oysters, can temporarily avoid impacts from oil exposure by closing their shells.

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How are corals affected by oil spills?

Oil exposure, even short-term, can kill an entire coral colony. Longer exposure (4-48 hours) to low concentrations of oil may be more toxic than shorter exposures at higher concentrations.

All types of corals are susceptible to oil damage. Impacts include tissue death, impaired feeding, impaired polyp retraction, increased mucus production (which impairs feeding), reduced growth in hard structure, reproductive damage, including an overall decrease in larval production, premature larval expulsion, larval death and prevention of new coral larvae from settling.

Coral is a colony of organisms that have a mutually benefiting and required relationship. Coral polyps provide structure and cover for the algae, and the algae provide a food source for the polyps. If the oil interrupts the photosynthetic process, the algae cannot provide the coral polyps with energy necessary to survive. Eventually this can lead to expulsion of the algae by stressed corals.

Oil concentrates in the sediments surrounding corals.  These sediments can then act as a chronic source of contamination for future reef communities by continually leaching out the stored oil.

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How are mangroves affected by oil spills?

Mangroves are highly susceptible to oil exposure, which can kill them within a few weeks to several months. Most deaths occur in the first six months of exposure. Lighter oils are more acutely toxic to mangroves than heavier oils.

Impacts include yellowing of leaves, loss of leaves, failure to germinate from propagules or seeds and increased mutation. Mangrove-associated invertebrates and plants recover more quickly from oiling than do the mangroves themselves. A NOAA study found that more than 96 percent of seedlings exposed to crude oil died.

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How are seagrasses affected by oil spills?

The oil will adhere to the seagrass, which will quickly lose oiled blades. Plants have the capacity to grow new leaves unless the sediments are heavily oiled.

Oil commonly passes over seagrass beds with minimal impacts. However, organisms living on the seagrass blades or using the beds as nurseries are highly sensitive to oil on the seagrass and sediments.

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How are manatees, whales and dolphins affected by oil spills?

Little is known about the effects of oil on manatees. Therefore the symptoms as described are all theoretical, as observed in other species.

Manatees, whales and dolphins are air-breathers and must come to the surface frequently to breathe. In a large oil spill, these animals may be exposed to volatile chemicals during inhalation.

Exposure to the chemicals in oil can lead to death and occurs in two ways:

  • Internally - Eating or swallowing oil, consuming prey containing oil-based chemicals or inhaling volatile oil-related compounds.
  • Externally - Swimming in oil and/or dispersants.

External effects:

  • They do not have fur which can be oiled and do not depend on fur for insulation. Therefore they are not susceptible to the insulation effects (hypothermia) that often puts haired marine mammals (such as otters and seals) at risk.
  • Oil and chemicals on skin and body may result in skin and eye irritation, burns to mucous membranes of eyes and mouth, and increased susceptibility to infection. For large whales, oil can foul the baleen they use to filter-feed, thereby decreasing their ability to eat. For manatees, oil exposure may damage the sensory hairs around their mouths, which serve as sensors in detecting edible seagrasses.

Internal effects:

  • Inhaling volatile organics from oil or dispersants may cause respiratory irritation, inflammation, emphysema or pneumonia.
  • Ingesting oil or dispersants may cause inflammation, ulcers, bleeding, diarrhea and digestive problems.
  • Absorption of inhaled and ingested chemicals may damage organs such as the liver or kidneys, resulting in anemia, immunity problems and reproductive failure or death.

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What should I do if I spot a sea turtle, bird or marine mammal in distress from the oil spill?

Report any sightings of wildlife oiled or injured as a result of the Deepwater Horizon oil spill by calling, toll-free, 888-404-3922.  Do not attempt to rescue the animal. Such rescues require hazardous-material training, permits and animal-handling skills to ensure human safety and the best interests of the animal.

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FWC Facts:
The Florida snail kite is aptly named - it feeds almost exclusively on apple snails and, in the United States, is found only in Florida.

Learn More at AskFWC