European green crab.
Photo Credit: University of Georgia

Researchers have found that a species invasion that starts at the upstream edge of its range may have a major advantage over downstream competitors, at least in environments with a strong prevailing direction of water or wind currents.

Scientists from the University of Georgia, University of New Hampshire, Smithsonian Environmental Research Center and University of Vermont studied populations of European green crab, Carcinus maenas. The species was introduced to the East Coast of North America twice, at both the upper and lower edges of its range. Their findings, recently published in the Proceedings of the National Academy of Sciences, may help inform the control of invasive species and the conservation of imperiled native species.