Reply #14: High DDT was found in the shells of pelican eggs [View All]

Pelicans use their highly vascular feet to incubate their eggs, but their eggshells were paper-thin and the eggs were crushed under the weight of the adults. In 1969, 750 nests were found, but only 4 chicks were born. The scientists found high concentrations of DDT in the Brown Pelicans' blood. DDT had moved up the food chain, a process called bio magnification, and the animals highest on the chain, received the highest concentration of DDT.

DDT wasn’t banned until a brave woman named Rachel Carson, wrote Silent Spring, which was published in 1962 and quickly rocketed to the New York Times best-seller list. Two years later, Rachel Carson died of breast cancer, but the fervor generated by her meticulously written book, in which she labeled pesticides "elixirs of death," would lead to a nationwide ban on DDT in 1972. Because DDT can take up to 15 years to break down in the environment, its effects remained well into the next decade.

The population of brown pelican colonies off Southern California shrank by more than 90 percent during the late 1960s. In 1970, there were 550 nests and only one chick survived; the California Brown Pelican was put on the federal Endangered Species list.

It was later discovered that from 1947 to 1983, the Montrose Chemical Corporation plant in Los Angeles had discharged DDT laden wastewater into the city’s sewers, which emptied into the ocean. There it was absorbed and stored in the tissues of anchovies and other fish eaten by pelicans.

Life was not easy and since the California Brown Pelican was put on the State’s endangered list in 1971, it has only recovered to an estimated population of 8,000 breeding pairs.

http://www.ibrrc.org/pelican_history.html