Final answer:
Rachel Carson is the marine biologist who launched the modern environmental movement with her book Silent Spring, highlighting the dangers of pesticides like DDT.
Step-by-step explanation:
The marine biologist noted for helping launch the modern environmental movement by publishing Silent Spring in 1962 is Rachel Carson. Her book was a groundbreaking work that exposed the dangers of widespread pesticide use, particularly that of DDT. Carson's research and writings were instrumental in raising public awareness about environmental issues and played a significant role in the ban of DDT usage in U.S agriculture in 1972. Her work tapped into the collective anxiety over the unsustainability of economic growth at the expense of the environment, which was highlighted by ecological disasters of the time, and she brought to light the connection between pesticide use and harm to both the environment and human health. For her contributions, Rachel Carson was posthumously awarded the Presidential Medal of Freedom and was inducted into the American Academy of Arts and Letters.