Sea Squirts Fouling an Oyster Cage

Invasive species can have a range of environmental and economic impacts. In this photo sea squirts foul an oyster cage. Scientists at the Smithsonian Environmental Research Center's Marine Invasions Lab study the movement and effects of non-native species around the globe. One region they've been examining closely is Alaska, where the cold coastal waters have been relatively free of invasive species. A 2011 study warned that could change and that species from more temperate waters may be able to thrive farther north