The best way to reduce the damage caused by invasive species is to prevent their introduction or eradicate them earlier in their establishment phase. Given the tremendous volume of global trade, curtailing it might seem impossible, but some promising strategies do exist. For example, transoceanic transport of invasive species in ballast water could be largely eliminated by the simple procedure of deoxygenating ballast water before it is pumped out. This practice not only kills most organisms in the water but also extends the life of ballast tanks—an economic benefit to shippers.

In 1996 the U.S. Congress responded to concerns about ballast water with legislative action. After years of wrangling, in 2012 the U.S. Coast Guard amended its regulations on managing ballast water to set standards for “the allowable concentration of living organisms in ballast water discharged from ships in waters of the United States.” Despite the adoption of these strict standards for protecting U.S. waterways, transport of invasive aquatic organisms in ballast water is an international problem whose potential solutions continue to run up against political and economic barriers.