“Fishing, fertilizer runoff, pollution, shipping, climate change—these are just a few of the ways that human activities influence the oceans that cover 70 percent of Earth’s surface. And in all that vastness—139 million square miles (360 million square kilometers)—less than 4 percent remains unaffected, and more than a third has suffered serious human impacts, according to a new map published in Science.
Marine ecologist Ben Halpern of the University of California, Santa Barbara’s National Center for Ecological Analysis and Synthesis and an international team of colleagues first listed 17 ways humans affect the oceans and then mapped each of them. By overlaying each impact on top of one another, the ecologists created a “current state of affairs for the oceans,” Halpern says. “I was really surprised that there is no single spot on the planet that isn’t being affected by at least one of these factors.””