Students at Cal have come up with a design for a lab-on-a-chip that would detect invasive species in cargo ships' ballast water, helping to prevent their spread:

Three UC Berkeley bioengineering students are developing an approach to sniff out stowaways on cargo ships. But they're not looking not human stowaways. What they're looking for are invasive marine species that hitch a ride in a ship's ballast water before it leaves home port and wreaks havoc on the non-native ecosystems when that ballast is eventually released. According to the International Maritime Organization, the introduction of invasive species is one of the four greatest threats to the world's oceans.

(thanks, Brandon!)