In the 20 years between 1992 and 2012, there was a huge explosion in traffic in every shipping lane in the world apart from the pirate-infested waters off Somalia, according to a new study. Researchers used satellite data to estimate shipping traffic worldwide and found that there had been a 300% increase during that period, with growth accelerating in the second decade. Jean Tournadre, lead author of the study published in the journal of the American Geophysical Union, warns that while the increase shows global trade is in good health, it could be disastrous news for the marine environment.
"I found it quite worrisome that the ship traffic grew so much, even in very remote regions of the world," he says, "especially when we know that they are the major source of pollution" on the open ocean. Tournadre adds that cargo ships not only dump fuel and waste in the water, they are a major source of air pollution—especially in the Indian Ocean, which saw the biggest increase in traffic—and noise pollution, which can be harmful to marine mammals. He says he hopes the research will aid understanding of how human activity is affecting marine ecosystems. (Last year, a major freighter crossed the Northwest Passage in the Arctic for the first time.)