American ichthyologist known for her research on poisonous fish and shark behavior. In 1949 the United States Office of Naval Research sent her to the South Seas to collect species of poisonous fish. From that experience she wrote Lady with a Spear (1953). In the early 1960s she turned her attention to shark behavior, the subject of The Lady and the Sharks (1969). In addition to her worldwide travels and studies, Clark led a series of deep-sea expeditions in the late-1980s and is an advocate for ocean conservation.