| Re: Bugs on the Moon - invasive
species
(Note: The 'inspiration' for Jim's comments may be found below!) April 9, 2003 By Jim Beers This guy waxes poetic about all the things Europeans brought post-1492. What about all the stuff Siberians and Mongolians (today's "Native" Americans) brought 10,000 years ago as they crossed the Bering Straits? What about the stuff that Irish monks, Vikings, and assorted lost guys brought 600 to 2000 years ago as they washed ashore? What about the stuff that arrived on palm logs or in storms? Alas, just like What's My Line, will the "real native" please stand up? Bugs on the Moon: Preventing interplanetary pollution - Encarta April 9, 2003 By David George Gordon When Christopher Columbus visited the New World, he may have actually left there more than he took with him back to Spain. His ships, like those of subsequent European explorers, were filled with rats, roaches, and disease-causing microbes from the Old World. These pests and pathogens thrived in the Americas. They displaced some native species, dined on others, and, in the case of smallpox and other contagious disease organisms, decimated the continents' indigenous tribes. And that, alas, was just the beginning. Five hundred years after Columbus and his crew departed, we're still bringing unwanted animals and plants with us on our travels. Of course, not every one of those introduced creatures is a problem. With the exception of the turkey, Muscovy duck, and, possibly, one type of chicken, all of our livestock species have been brought to the Americas from somewhere else. The same is true for the majority of our agricultural crops. Only corn, squash, sweet potatoes, some beans, and a few berries were here before Columbus carried his country's cooties overseas. Nonetheless, anyone who has watched English sparrows descend on their birdfeeders or has been laid low by the Hong Kong flu knows how destructive some of those uninvited guests can be. Most alien invaders have difficult times adapting to the new conditions of their unfamiliar environs. But the ones that succeed have a field day--just like Columbus's rats, roaches, and germs. How environmental invaders travel Nowadays, we're considerably more cautious about spreading nonnative organisms. But even with our quarantine stations and border guards, those parasites, pests, and pathogens still manage to sneak in. For instance, before leaving a port, a cargo ship will fill special tanks with seawater, which acts as ballast that causes the vessel to ride lower in the water and gives it greater stability at sea. That ballast water may be rife with planktonic critters, including juvenile fish, clams, sea slugs, and algae, among others. Many of these stowaways can survive transoceanic voyages lasting several weeks. So, when the cargo ship reaches its destination and releases its ballast water, it unintentionally unleashes zillions of nonnative animals and plants into the water. |