How big are the numbers?
We're not talking small numbers when we discuss invasive species. You go to some areas, particularly islands, and find that they have been enormously impacted. You go to the lowlands of Oahu, in the Hawaiian Islands, and find there's not a single native species left in that system. And in the islands, as a whole, 40 percent of the entire fauna is new in the last couple hundred years. You can see all the reptiles, all the amphibians, virtually all the fresh water fish, most of the birds are all recent invaders. Cardinals in Hawaii, where do they come from? The east coast of the United States. In the United States, looking at arthropods species, you find that they're coming from all over the world, 1,600 species mainly from Europe. That's because these trends follow the main lines of commerce. I'll talk about the lines of trade and how they influence where we get things and how the new developing trade routes are going to alter that. I have discussed species coming into the United States but we have a counter offensive. The zebra mussel from Europe exploded into the Great Lakes, and in turn, we inadvertently introduced a jelly-like ctenophore which destroyed the fisheries in the Black Sea.
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