An orange crab taken from the waters near the Marshall Islands’ Rongelap Atoll bears no outward evidence of the radioactive compounds that pollute its habitat.

In the 1940s and ‘50s, the United States conducted a series of nuclear tests in the Bikini Atoll, a ring of Pacific islands. Radioactive fallout still pollutes Rongelap Atoll, about 100 miles (160 kilometers) to the east, but recent studies have found no long-term impact on marine life there.

(Photo shot on assignment for, but not published in, “Testing the Waters of Rongelap,” April 1998, National Geographic magazine)