Dr. Erica Miller, left, and Danene Birtell of Tri-State Bird Rescue and Research (Alex Brandon/AP photo)The first birds covered in oil from the Deepwater Horizon oil disaster are receiving care now. The northern gannet in this picture is getting cleaned by veterinary workers with the nonprofit Tri-State Bird Rescue and Research. They're doing their best, surely, and yet the situation is just awful. Best estimates say that the Exxon Valdez spill killed between 375,000 and 435,000 birds, despite intensive rescue efforts. Between 3,500 and 5,000 otters are believed to have been killed as well. There's some evidence that blasting the oil off beaches with high-pressure sprays in Alaska killed off mussels and barnacles, which are of course part of the food chain. Ecologist Dee Boersma of the University of Washington in Seattle tells Discovery that a lot of the birds you saw being washed died anyway, with extra stress from having been grabbed and cleaned:
"Washing sand or rocks or birds doesn't do a lot of good," Boersma told Discovery News. "It just makes us feel better."
Oil, by disrupting the interlocking structure of feathers, destroys the waterproofing and insulating properties of plumage. The oiled bird may suffer from chilling, may be unable to fly, or may be unable to remain afloat in the water. A bird’s direct contact with oil components can result in chemical burns and the absorption of toxic chemicals through its skin. Depending on the degree of impact, an oiled bird may have difficulty obtaining food or escaping predators. The decreased foraging ability of the animal, combined with the presence of oil in the environment, usually results in a loss of attainable food sources....
Direct toxic effects on the gastrointestinal tract, pancreas and liver have all been documented. Ingestion of oil by birds attempting to clean feathers through preening frequently results in injury to the gastrointestinal tract. This damage prevents the animal's digestive system from utilizing food or water, causing the animal to become progressively weaker in a very short time. A similar irritation of other mucosal surfaces can lead to ulceration of eye surfaces, and the moist surfaces inside the mouth. Kidney damage, a common finding in oiled birds, is believed to occur both as a direct effect of the toxins in the oil and secondary to severe dehydration. Dehydration and decreased body temperatures are medical emergencies and can result in clinical shock and eventual loss of life. As an oiled bird becomes more debilitated, its immune system is compromised and the bird becomes susceptible to secondary bacterial and fungal infections which are potentially life-threatening.