Hot Topic: How Do Marshes and Beaches Recover from Oil Spills?

Rutgers Today: Do beaches, marshes, and wetlands have natural defenses? 

Burger: Yes – up to a point. Small, burrowing animals can put a plug of mud in the entrances of their burrows; fish can swim away; birds can fly away.  But these defenses are ineffective when the oil is spread over a large area, or is less visible, or keeps arriving day after day, or when large amounts penetrate high into the marsh or beach as a result of storm tides.  Then, individual plants and animals have few defenses. If they are heavily oiled, they will die. Tidal waters, however, generally penetrate from the ocean or Gulf and may leave the higher beach or marsh free from oil, while the front beach and intertidal area sustain the damage.  The vegetation, invertebrates, and other animals that live high on the marsh can then re-colonize the marsh as the oil is removed by natural processes.    . 

Rutgers Today: How long will it take wildlife to recover, assuming no human intervention?

Burger: Recovery from small, isolated spills can take years or decades. Recovery from widespread oil spills, like Deepwater Horizon, can take decades to centuries. Oil from the Exxon Valdez spill can still be found under rocks 20 years later. Local breeding populations of birds in the Arthur Kill, which relied on local food resources contaminated by the Exxon spill back in 1991, haven’t recovered completely yet. After an oil spill in Panama, mangroves did not recover for decades, and the invertebrates, fish and other wildlife could not recover until the mangroves were intact. Following the Exxon Valdez accident in Alaska, many breeding bird colonies, marine mammals, and mussels and other invertebrates still have not recovered. When ecosystems do not recover completely for decades or longer, commercial and recreational fishing, tourism, and other human activities also cannot recover. 

Rutgers Today: Will any human actions help the Gulf recover?

Burger: It’s far better to prevent oil spills then to deal with oiled ecosystems after a massive spill. Steam or pressure cleaning beaches can seemingly remove oil but does irreparable damage to small shellfish and other invertebrates.  Cleaning sea birds may save a few birds but cannot begin to address the hundreds or thousands of birds that will be oiled in the Gulf and die without reaching shore.  Many birds float on the water to feed, dipping through oil to catch fish, and others plunge-dive into the waters, moving through oil slicks.  Oiled birds die slowly over a period of days and often die even when cleaned, rehabilitated, and released.  Even lightly oiled birds can transfer oil from breast feathers to their eggs, which then don’t hatch. Cleaning itself is traumatic for birds and exposes them to stresses and diseases in captivity, and it is unclear what effect this has on avian populations.