Rachel Carson And The Question That Started A Movement:
Rachel Carson, a marine biologist, wrote The Sea Trilogy: Under the Sea-Wind, The Sea Around Us, and The Edge of the Sea. Her first book, Under the Sea-Wind, was written in 1941, when she was a freelance writer for the U.S. Bureau of Fisheries and was asked to write an introduction to a brochure on marine life. Here, Carson wrote about the natural world in a relatable narrative, written from the perspectives of sea creatures (a sanderling, a mackerel, and an eel). Writing from this perspective allows the reader to build empathy towards these living creatures by reading about their experiences from their point of view. This book helped demonstrate the interconnectedness we share with sea creatures. The Sea Around Us, written in 1951, became a National Book Award Winner. It was turned into a documentary by film and television producer Irwin Allen and went on to win an Academy Award for Best Documentary Feature. Here, she explored oceanography, meteorology, and Earth's history. In the final book of the trilogy, The Edge of the Sea (1955), she explored the ecology of the Atlantic shoreline, rocky coasts, and tide pools.[13]
In 1962, she warned the world about the dangers of pesticides in her most famous book, Silent Spring.[14] In the book, she designed investigations, followed the evidence through food webs, and discovered the effects of DDT at each step of the food chain. It was this book that helped set the stage for the environmental movement. Carson had an ecological view of nature that connected all its living creatures through complex webs. This book questioned the effects of DDT on birds and other wildlife. Partly due to Carson’s detailed investigations and evidence, the United Farm Workers (UFW) protested the exposure to chemical pesticides suffered by laborers in the fields.[15]
DDT
DDT (dichlorodiphenyltrichloroethane) is a synthetic chemical compound that was invented by Austrian chemist Othmar Zeidler in 1874 as part of his university work, and in 1939, chemist Paul Hermann Müller discovered that it could kill a wide variety of insects. Because of this discovery, DDT was used in WWII to protect U.S. soldiers from malaria and typhus by delousing them. Attacking the insect that causes malaria in the South Pacific Islands helped save millions of lives. During this time, DDT was the strongest chemical the world had ever seen, and it seemed to work. By 1942, DDT was available for civilian use. Farmers began using it to protect their crops and livestock. Homeowners used it indoors and in their gardens, and trucks even drove around neighborhoods to kill mosquitoes as people watched.[16]
Silent Spring documented the effects of DDT on the environment, particularly on birds, as the title alludes to the quietness of spring after songbird populations declined. DDT accumulated in the food chain, causing severe environmental damage. DDT interferes with how a bird’s body metabolizes calcium, making the eggshell thin and fragile. This caused the eggs to crack under the parents’ weight during incubation. Due to their toxicity, populations of apex predators such as bald eagles, ospreys, and peregrine falcons decreased sharply.[17] As someone who was not afraid to ask questions, Carson’s book was met with opposition from chemical companies. This opposition did not stop the message from reaching the masses. Eventually, DDT was banned.
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Pelican eggshell affected by DDT
Eagles and Other Birds of Prey
Even before DDT, eagle populations were declining. Eagles were seen as a threat to livestock, and their decline began before civilian use of DDT. The killing of eagles was a common practice and even encouraged in the United States. In Alaska, the Alaska Territorial Legislature, a local government, paid bounties for their feet or heads. Farmers killed eagles to protect their livestock.[19] As an attempt to save the declining population, in 1940, Congress passed the Bald Eagle Protection Act and banned the killing of eagles. Even with the Bald Eagle Protection Act in place, by the mid-1940s, when DDT was used extensively, their population decreased catastrophically. In 1963, the widespread use of DDT had decreased the bald eagle population to only 417 nesting pairs in the lower 48 states.[20]
As with the eagles, DDT also nearly drove the peregrine falcon to extinction by disrupting calcium production during reproduction and causing thin eggshells. In the late 1960s, brown pelican colonies in Southern California declined by 90 percent. A chemical plant in Los Angeles had been discharging thousands of pounds of pesticides into the sewers. It was absorbed by the fish that the pelicans ate. Eventually, the environmental movement, which was partially influenced by her book, led to the creation of the U.S. Environmental Protection Agency (EPA). In 1972, the U.S. Environmental Protection Agency (EPA) issued a ban on DDT. Rachel Carson died while these birds of prey were disappearing and never saw the influence Silent Spring had on the environmental movement. As of 2009, there are now 316,700 individual bald eagles and 71,400 nesting pairs. [21] The peregrine falcon and brown pelican were eventually removed from the Endangered Species List.[22]
American Robins and other Songbirds
In the 1930s, Dutch Elm fungal disease was accidentally introduced into the United States by the transportation of elm logs. The disease was mainly transmitted by elm bark beetles (vectors-agents that carry spores that allow the fungus to pass from tree to tree) and killed millions of elm trees. For a time, it seemed that the use of DDT would stop the disease from spreading, but again, the devastating side effects were soon discovered. Our songbirds, specifically the American robin, were dying. The infestation of the fungus that was introduced in the 1930s reached its peak in the 1970s. Rachel Carson consistently argued that spraying chemicals was not the answer to Dutch elm disease, but the spraying continued until its ban in 1972.[23] Like the birds of prey, this ban helped stabilize small bird populations.
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