Brown Pelicans Thrive In Wake of DDT Ban And Establishment of Earth Day

LA JOLLA, CA - APRIL 21: A California brown pelican, with a typical wingspan of 6 1/2 - to 7 1/2 -feet, flies past a pair of kayakers at La Jolla Cove on the eve of Earth Day on April 21, 2007 in La Jolla, California. At the time of the first Earth Day in 1970, California brown pelicans were well on their way to extinction because of the pesticide DDT. The pesticide used on inland farms into was leaching streams and eventually being washed to sea. It moved up the food chain in a process called bio magnification, increasing the concentration of DDT at each step with animals at the top on the food chain receiving the highest dosage. DDT concentrations in California brown pelicans reached as high as 100 parts per million, approximately 1,000,000 times the initial state of the spray when it was used on crops far away from the ocean. The California Brown Pelican was put on the federal Endangered Species list by the Environmental Protection Agency (EPA) and in 1972; DDT was banned throughout the US. Although still listed as endangered and under the protection of the Endangered Species Act, the California brown pelican has made a slow recovery to an estimated population of 8,000 breeding pairs so far and is commonly seen along much of the California coastline. The eastern variety was removed from the endangered list in 2001. (Photo by David McNew/Getty Images)