Out of Eden: An Odyssey of Ecological Invasion, by Alan Burdick is fascinating non-fiction, but it was sometimes slow going for me, because the author goes into great depth on some species and the mechanisms of their ecological invasions. He also describes current methodological and philosophical debates among ecologists, which is is good, because he's not over-simplifying things, but it let's face it: reading about plankton identification techniques, the ways to test the climbing abilities of brown tree snakes, and our inability to know the history of marine invertebrate ecology may not be everyone's cup of tea.
Burdick focuses on three main areas: Guam and the brown tree snake (originally from Australia); Hawaii and it's native birds & fruitflies and intoduced pigs, earthworms, wasps, and trees; and San Francisco Bay and the green crabs and hundreds of other marine plants & animals that are irrevocably changing our oceans and shores.
I learned a ton of mind boggling things - for example, the Hawaiian Islands are part of an ongoing geological process, and its birds (the ones not already extinct), different on each island, are descended from birds that were blown from islands that have already sunk back into the ocean.
There are more bizarre varieties of marine invertebrates that I could have imagined. Many are larval forms of jellyfish, sponges, and things not clearly plant or animal, visible only under a microscrope. Every shoreline and different part of the ocean has native species with its own interactions, but ballast water (thousands of gallons pumped in & out to balance ships) has transported hundreds of these species to entirely new places, with unknown consequences. Voila! Zebra mussels in the Great Lakes and the Mississippi watershed.
There are nice biographical bits on several seminal ecologists (with a few good jokes concerning their larval states), the history of "alien" research, what these scientists actually spend their time doing, and their hopes for the future.
What this book doesn't do is try to cover all of the different kinds of invasive species that may be changing your local environs today - so don't expect an overview of garlic mustard, the emerald ash borer, the mosquito that carries the West Nile virus, or carp (all relatively recent anthropogenic introductions to Michigan).
This would be a good place to include a link to the Invasive Species Weblog.