Exotic aquarium fish and plants are beautiful and soothing in their containers. But if they get out into our natural waters, they can cause enormous problems. Bruce Robinson talks with a researcher who has been studying this issue.
Importing exotic tropical fish to meet the demand from aquarium owners does inevitably increase the risk that some of those species may get out into the wild. But Susan Williams, Professor of Evolution and Ecology at the Bodega Bay Marine Lab points out that this trade also helps preserve other threatened ecosystems.