There, a breeder was investigating the insects as a source of genes for a better silk worm. Conn. The reason, he argues, is that marine invaders stay effectively hidden from the human world until they are fairly well established. For instance, ballast-water intake and discharge controls have met strong opposition even though ballast water is recognized a major conduit for the dispersal of organisms around the world, Carlton notes. At one time, he notes, biologists were adventurers, trekking the wilds, and getting up close and personal with countless members of a species. Not only did this allow them to appreciate and recognize the natural variation within a species, but it also permitted them to quickly distinguish organisms that didn t belong the aliens.
Few individuals understand the magnitude of havoc that a single alien species can wreak.
And though such alarming economic impacts often do occur, they tend to show up only after an invader has become so entrenched that it s virtually impossible to rout. Recent improvements in water quality are making many ports increasingly hospitable to foreign invaders. In the 1960s, he muses, Lake Erie was so polluted that an alien species would be as likely to croak as to thrive. Now, however, as coastal water quality continues to improve, alien species may find U.S. waters to be like a resort spa. Squelching gypsy moths.