EARTH: Setting sail on unknown seas

On June 5, 2012, a massive dock made landfall on Oregon's Agate Beach, just north of Newport. The dock carried with it a host of castaways, including as many as a hundred species of mollusks, anemones, sponges, oysters, crabs, barnacles, worms, sea stars, mussels and sea urchins. A placard on the side written in Japanese revealed that the dock had been unmoored from the Japanese coastal city of Misawa during the catastrophic tsunami on March 11, 2011, bringing with it an essentially intact subtidal community of Asian species to the Pacific Northwest. Although natural rafts have likely been ferrying organisms around the planet since the very beginning of life on Earth, the geologically recent advent of human settlement, culture and infrastructure is fundamentally changing the rafting game, as EARTH explores in our March issue.

Anything that floats can be used as a raft: algae mats, detached wads of kelp, dead whales, ice floes, volcanic pumice, uprooted trees, docks or plastics. What was once a rare phenomenon is now happening much more frequently. "Rafting opportunities for organisms are much higher now than they have been at any time in the past," says Martin Thiel, an evolutionary biologist at the Catholic University of the North in Coquimbo, Chile. What are the implications for the spread of invasive species and the health of native ecosystems around the world? Read the story at EARTH online at http://bit.ly/YSThEo.

Provided by American Geosciences Institute