Battling the Bioinvaders

Mosquitoes infected with the West Nile virus fly through American air; green crabs and other foreign crustaceans feed on indigenous sea life in San Francisco Bay; the Formosan termite is feasting on historic New Orleans; and the next boat or plane arriving in the United States from anywhere could be hauling who-knows-what in its ballast waters or cargo hold. Collectively called invasive species, these uninvited animals, insects, flora, and pathogens continue to exacerbate eradication efforts of

By | September 17, 2001

Mosquitoes infected with the West Nile virus fly through American air; green crabs and other foreign crustaceans feed on indigenous sea life in San Francisco Bay; the Formosan termite is feasting on historic New Orleans; and the next boat or plane arriving in the United States from anywhere could be hauling who-knows-what in its ballast waters or cargo hold.

Collectively called invasive species, these uninvited animals, insects, flora, and pathogens continue to exacerbate eradication efforts of scientists, government officials, business people, and other stakeholders. According to a January report issued by the National Invasive Species Council, the annual battle costs the United States $137 billion a year.1 Between 1961 and 1995, according to the San Francisco Estuary Institute, one new species invaded the bay's ecosystem every 14 weeks, and at least four of them a year became established.

Historically, the federal government has fought a usually divided battle against these foes, with various agencies and departments confronting invaders in their area of expertise. The Centers for Disease Control and Prevention deals with one aspect of West Nile, for example, and the US Department of Agriculture deals with another. About $997 million in federal funds were set aside for the efforts this year.

Forming a Defensive Line

To deal with the coordination problem, former President Bill Clinton signed Executive Order 13112 in 1999, establishing the National Invasive Species Council.2 Until then, some 20-plus federal agencies were working individually. "All of the programs are good," says Lori Williams, the council's executive director, but there [was] not a lot of coordination ... and there [was] no overall government plan." In late July, Williams appeared before a US House of Representatives science committee and talked about such a plan, which includes "57 action items" addressing coordination, leadership, prevention, research, and more.

Whether the Bush administration will adopt such a plan, which, among other items, calls for scientific exchanges by researchers worldwide, remains to be seen. "We know there's support for the council," Williams says, "but as far as specific commitments x, y, and z, ... that has not been flushed out. And it was not reflected in the budget that was put out by [the Bush] administration."

"The plan itself set some pretty lofty goals, but it was a little short on exactly who was going to implement them, and how soon," adds Phyllis N. Windle, of the Union of Concerned Scientists. "It really is crucial to find out what will happen in this new administration."

Another unknown is how the Bush White House feels about reauthorization of the 1990 Nonindigeneous Aquatic Nuisance Prevention and Control Act. This law was passed in hopes of preventing and controlling the spread of zebra mussels and other pests, which has been a costly business. According to a federal press release, controlling sea lampreys in the Great Lakes fisheries costs the U.S. and Canada $13 million a year to control.

Regarding the council, says Mitch Snow, spokesperson for the US Fish and Wildlife Services, "there is no thought of changing [it]. There is some talk of pumping it up." But regarding the nuisance control act, the administration "hasn't developed a position yet, but will be doing so shortly."

Some hints about the administration's position are appearing. A recent release from US Department of Health and Human Services regarding a coordinated plan to fight bovine spongiform encephalopathy and other prion disorders says that, among other strategies, plans call for doubling the current spending on research on these diseases by the end of fiscal year 2002.

By January, Washington will face another issue, which also promises to be pricey: whether to mandate ships, sailing from outside the so-called Exclusive Economic Zone, to exchange ballast water in the open ocean. At the moment, this is a voluntary federal program, save for those ships heading for the Great Lakes or parts of the Hudson River. "It's no surprise to us [that the] voluntary program isn't working," says US Coast Guard Lt. J.G. JoAnne Hanson, of the guard's education outreach program. It is the Coast Guard, along with a research group from the Smithsonian Institution, which is administering the voluntary program. The two know it's not working because of what the law does require: all ships must submit a report on what they do with their ballast water; they do have the option to retain the water.

Between July 1, 1999 and June 30, 2000, 20.8 percent of ships submitted reports. "It remains difficult to estimate reliably ... the patterns of ballast water delivery and ... the compliance with voluntary guidelines for ballast water management," according to a recent report. The Coast Guard, Hanson says, believes the numbers are poor because violating the law has no penalties and because some states, including California and Washington, have their own, more stringent water ballast requirements. "The industry is saying, this isn't working, because the states are coming up with their own [rules]," she says.

The 1996 National Invasive Species Act, which mandated the ballast-water reporting program, is also up for reauthorization. Both this law, and its 1990 predecessor, are under review by the House subcommittee on environment, technology, and standards. It was before this group that Williams spoke in July. At the hearing those in attendance saw a selection of invasive species, including purple loosestrife and giant salvinia. Among the fish were an Asian swamp eel and a sea lamprey. There was even a stuffed nutria, which is a web-footed, semi-aquatic rodent similar to a muskrat.

The Great Lakes as Poster Child

"The Great Lakes have been considered the poster child for invasive species ever since the appearance of the zebra mussel captured the interest of the nation," testified Stephen B. Brandt, director of National Oceanic and Atmospheric Administration (NOAA) Great Lakes environmental research lab. Since then, a dozen new species now call the Great Lakes home, nine of which are thought to have come from ballast water.

The barnacle-like zebra mussel is an infamous case in point. A filter feeder that arrived from Eurasia, it can dramatically alter aquatic food webs by reducing phytoplankton levels. Although its life history was thoroughly studied and various successful control methods were developed, the mussel remains virtually impossible to eliminate. It has spread through the Mississippi River into many states, traveling as far south as New Orleans. According to Rep. Peter Hoekstra (R-Mich.), the mollusk's estimated economic impact over the next decade on US and Canadian industries in the Great Lakes region will exceed $5 billion. Control costs range up to $400 million annually, Brandt said.

"The zebra mussel is our nightmare in the West," declared Scott S. Smith, aquatic nuisance species coordinator in the Washington State Department of Fish and Wildlife. Although the shellfish have not yet invaded the West Coast, he said two ships were found encrusted with them over the past six months. Brandt said that once a species has invaded a large aquatic ecosystem, elimination is nearly impossible. One solution is adaptive management. In Michigan for example, the non-native alewife, once considered a pest, is now feed for larger fish that are popular with recreational fishermen.

Hoekstra has introduced a bill to help stem the introduction of invasive species from ballast water by controlling its discharge and developing best practice standards. About three-fourths of the roughly 600 transoceanic vessels that annually enter the Great Lakes do not have to re-empty their ballasts because they have already emptied their tanks in the open ocean. However, significant amounts of water and sediment remain in the tanks, often harboring cysts and eggs.

NOAA and other organizations have conducted intensive research in recent years on treating residual ballast water and sediment. These studies have involved ultraviolet light, ozone injection, organic and inorganic biocides, dissolved air flotation, filtration, onshore treatment, and cyclonic or centrifugal separation. In a three-year collaboration between NOAA and the University of Michigan, glutaraldehyde is being tested as a disinfectant for residual ballast water and sediment. In other arms of that research, a surfactant is added to enhance the compound's toxicity, and efficacy is compared to that of chlorine.

On the Maritime Administration ship Cape May in Baltimore Harbor, a centrifugal separator has been installed to clear larger organisms and particles from the water, followed by either ultraviolet treatment or one of two biocides. The Environmental Protection Agency has a similar project on a cruise ship on the West Coast. Other such trials are occurring on ships and barges in the Great Lakes under a joint venture between the State of Minnesota, universities, industry, and nongovernmental organizations.

But the available money for such research isn't enough, testified James T. Carlton, a Williams College marine sciences professor who has studied aquatic invasions for four decades. Sea Grant, NOAA's major program for funding work on aquatic nuisance species, has $2.7 million this year for all research, Carlton pointed out. If this amount is divided by 50 projects and the overheads are subtracted, each project is left with just $35,000. "What we can expect from invasion research is only proportional to what we invest in it, and that investment over the past 10 years has been strikingly disproportionate to the nature of the problem," he warned.

Several subcommittee members said that their constituents want action rather than more studies. "The tug of war between having scientific certitude and taking fundamental action is one we struggle with every day," explained Cathleen Short, assistant director of fisheries and habitat conservation in the US Fish and Wildlife Service. "How do we develop an arsenal of tools before we find ourselves confronting an emergency situation and wondering how to respond? I think that's a very real issue."

The constituents that do want action are those most directly affected by the invasion of a zebra mussel or mitten crab. The invasive species issue has not hit the collective radar of the American public, some say. "I have theory to why that is," says Ken Burton, a spokesperson for the US Fish and Wildlife Service. "Nobody has been inconvenienced yet. Pockets of places have been inconvenienced ... and nobody has been damaged by it yet either. It will register when people start being troubled by it."

Jean McCann, Steve Bunk, Eugene Russo, and Christine Bahls all contributed to this report.
1. D. Pimentel et al., "Environmental and economic costs of nonindigenous species in the United States," BioScience, 50[1]:53-5, 2000.

2. A.J.S. Rayl, "Bioinvaders proliferate in US waterways," The Scientist, 13[16]:6, Aug. 16, 1999.

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