The insecticide DDT was widely used in the first part of the twentieth century to combat diseases such as malaria by targeting its insect vector, the mosquito. In the late 1950s nature enthusiasts and biologists noted a disturbing reduction in the number of marine birds. This reduction was later linked to the indiscriminate use of DDT, which was subsequently banned in the US. Since its banning many marine bird populations have largely recovered. How do you think this pesticide was able to impact marine birds, which were not the target of the spraying? Why do you think banning the pesticide was an effective strategy?