GAO: Invasive species in ballast still a threat to U.S. waters

GAO: Invasive species in ballast still a threat to U.S. waters    A congressional watchdog agency told the House Regulatory Affairs Subcommittee late last week that invasive species in ship ballast continue to threaten U.S. waters despite recent legislative efforts to keep it clean.
   According to the Government Accountability Office (GAO), at least 160 non-native aquatic pests have become established in the Great Lakes alone since the 1800s ' one-third of which were introduced in the past 30 years. The zebra mussel alone has caused up to $1 billion in costs between 1989 and 2000, the GAO said.
   Congress passed legislation in 1990 and 1996 to help prevent the introduction of invasive species from ship ballast in U.S. waters.
   While the ballast discharge regulations have had some success, the GAO said the overall impact has been limited. The reasons for the lack of success are:
   * Many ships are exempt from current ballast water exchange requirements.
   * The Coast Guard has not established alternative discharge zones that could be used by ships unable to conduct ballast water exchange for various reasons.
   * Ballast water exchange is not always effective at removing or killing potential invasive species.
   GAO also told the House subcommittee that shipboard technology to purify ballast water is not where it should be.
   The agency reported that some state governments and others are frustrated by the ineffectiveness of federal regulations and have developed their own rules for ship ballast discharge.