One of our multimedia editors has put together this Flash slideshow on invasive species, which you can find on our bay page, but I thought I'd link to it here, too.

It includes the major players: mute swans, nutria, snakeheads. One small thing to note: it says snakeheads showed up here, in the Potomac, in 2004. They were here in 2002, in a Crofton pond behind a Dunkin' Donuts. The fear was that they would get into the Little Patuxent, but they poisoned the heck out of the pond and nobody knows whether they actually did or how they got to the Potomac.

For the record, snakeheads are tasty, but kind of bony. We tried them at Yin Yankee when they got a bunch from New York.