ABSTRACT

In fighting the spread of invasive species, national boundaries are an appealing line of defense. Goods and people crossing those boundaries are under some scrutiny in any case and are generally restricted to a few entry points. In the United States, most trade and travel involves transportation across oceans, which means many of the life forms arriving at ports would almost never appear in the natural course of their own movements. Preventing problem species from arriving in the country has so far been the main focus of federal efforts, and environmental activists interested in the question mostly want to see more of the same. Bans are currently being sought on both the importation of logs that have not been heat-treated and on the use of solid-wood packing materials (chunks of wood used to prevent cargo from unpredictable shifting that can damage it), both of which are common pathways for forest pathogens. Others urge a crackdown on the importation of live organisms.