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Blocking Invasive Aquatic Species

Federal law must be updated to stop introductions of nonnative organisms, especially by ships.

Voracious snakehead fish from China crawl out of a Maryland pond, while 100-pound Asian carp smash into recreational boats on the Mississippi River. Armies of alien rats, numbering in the millions and weighing up to 20 pounds, raze wetland vegetation in Louisiana. Softball-sized snails called Rapa whelks silently devour any and all Chesapeake Bay shellfish in their paths. The images would be comic if they were not real. Instead, they have helped to convince Congress that the threat to the U.S. economy and environment from these and other nonnative species is enormous and that the federal government should get serious about keeping them out.

If Congress does act, then we owe these cartoon villains a debt of gratitude. In the world of alien species prevention, there is no time like the present. The list of invader species plaguing U.S. coasts is long, diverse, and growing. A recent Pew Oceans Report cites aquatic invasive species as a top threat to marine biodiversity, and the Environmental Protection Agency (EPA) has reported that invasive species are second only to habitat destruction as a threat to endangered species.

The environmental effects of invasive organisms can be as subtle as they are serious. A wasting syndrome afflicting the fry of native sport fish in Lake Ontario results from the adult fish eating nutritionally deficient nonnative forage fish. Ecosystem effects of an invasive organism do not just come and go; they ripple and morph over time. Recent die-offs among Great Lakes waterfowl due to botulism are being traced to the zebra mussel infestation that occurred more than 15 years ago.

Goods traded in markets are not exempt from degradation by invasive species. Commercial fishing, aquaculture, water-related recreation, and waterborne transportation, which together comprise much of the economic base of coastal regions, are all vulnerable to dramatic downturns precipitated by foreign animals, plants, fish, and insects. The EPA estimates the annual economic cost of the damage in the United States to be $100 billion.

Good start left adrift

The potential destructiveness of future invaders should motivate the nation to do its utmost to prevent new arrivals. Ships are a good place to start. Scientists believe that most invasive aquatic organisms hitch rides to U.S. coastal waters by adhering to the hulls of commercial ships or by traveling in their ballast water (the water pumped into below-deck tanks to increase a ship's stability). Today, ships move more than 80 percent of consumer goods, and the steady growth in global trade is increasing the opportunities for invasive species to reach new habitats.

Until now, invasive species have been a cost of global trade that the U.S. public has unwittingly accepted. But growing awareness of the ecological and economic impact of aquatic invaders now attracts a diverse array of interest groups to an increasingly vibrant policy debate. Environmentalists want strict regulations to block the entry of nonindigenous species. Ship owners are concerned about the cost of methods to combat the threat. Port operators, sport and commercial fishers, and regulators also have a stake. Internationally, a debate rages between the "flag states," such as Liberia, Cyprus, and Panama, which register many ships and oppose regulation, and "port states," such as the United States, Australia, and Norway, which favor regulation in order to protect their coastal resources.

In the United States, Congress has enacted a statute to combat invasive species transfers by ships, but federal agencies have not aggressively implemented the law and industry has not taken the required actions. Now, the nation has a timely opportunity to set this situation aright.

In 1990, Congress passed the Nonindigenous Aquatic Nuisance Prevention and Control Act (NANPCA), the first-ever federal regulation of ships with the purpose of reducing the transfer of nonnative organisms. The act required ships entering the Great Lakes after operating outside the U.S. Exclusive Economic Zone either to first purge their ballast in the open ocean, using a process called ballast water exchange (BWE), or to otherwise treat the water with an environmentally sound alternative technology that is at least as effective as BWE in preventing the discharge of potentially troublesome organisms.

In 1996, Congress reauthorized the original act as the National Invasive Species Act (NISA), which expanded the ballast-management program to be national in scope. Although the new program was to be voluntary at first, the NISA directed the secretary of transportation to make the program mandatory if compliance proved inadequate. In June 2002, with only 20 percent of vessels visiting U.S. ports even bothering to report their ballast operations, much less comply with the new management guidelines, the U.S. Coast Guard announced its intent to make the program mandatory--at some future date.

Why have federal efforts to prevent new introductions of species by ships been so anemic? Certainly, some fault resides with underfunding and a lack of attention to congressional directives by implementing agencies. The national program is running about two years behind schedule, and the Great Lakes program, which was implemented on schedule, has never been reviewed or revised during its decade of operation. As a pioneer regulatory effort, the Great Lakes program would have benefited greatly from a midcourse evaluation and revision. Since 1990, economics have driven more and more ships to enter the lakes in the loaded condition. Ships loaded with cargo still carry large quantities of viable organisms in the unpumpable ballast, which can be resuspended and discharged into the lakes. Because ballast water exchange cannot be implemented on a ship in the loaded condition, we need to replace the practices prescribed in the regulations implementing the 1990 law with a suite of management practices better suited to current conditions.

Another problem has been a lack of clarity regarding what ships should be asked to do. When the original NANPCA was enacted, it was well known that BWE had many limitations, which led Congress to allow for the possibility of alternative treatment of ballast water aboard ships, even though no such technology was yet known. The greatest of BWE's limitations are that it is difficult to monitor and enforce, has unknown (perhaps unknowable) effectiveness, and can occasionally be unsafe for ships.

Although a silver bullet technology that can effectively and efficiently treat ballast water of any type of ship or voyage is unlikely, a toolbox of treatment methods could address the variety of environmental, economic, and operational contexts in which ballast treatment must take place. To help fill this toolbox, Congress sought to spark development of ballast-treatment technologies through authorizing grants to help inventors of potential treatments demonstrate their systems and to enable researchers to assess their effectiveness. Consequently, during the past six years, treatment alternatives such as ozone, ultraviolet (UV) radiation, filtration, heat, chemical biocides, and deoxygenation have matured to the point of readiness for shipboard demonstration. Although it is too soon to know for sure, the effectiveness of these approaches could well prove to be competitive with BWE, especially when the numerous disadvantages of BWE are factored in. But 10 years after Congress first gave ship owners the option to treat their ballast as an alternative to BWE in Great Lakes trade, there is still no process in place for motivated ship owners to experiment with that option.

New tools needed

The lack of a clear procedure for approving technologies is nested in a larger problem: There is no quantitative standard for alternatives to BWE. Federal law says that ships can use alternatives to BWE if they are at least as effective, but the government never developed a measure of BWE effectiveness to which the alternatives can be compared. The main reason for this lassitude is that the biological effectiveness of BWE is notoriously variable, even among the ballast tanks within a single ship, and difficult to measure. A report of the Ballast Water and Shipping Committee to the Aquatic Nuisance Species Task Force found that BWE effectiveness ranged from "39 percent to 99.9 percent, depending upon the taxonomic groups and ships studied." And these estimates may exaggerate effectiveness, because in practice it is often impossible to conduct BWE at all because of safety, cargo load, and route constraints.

In the face of such difficulties, the Coast Guard has abandoned the task of providing a working estimate of BWE effectiveness to which other treatments could be compared. Instead, the agency now directs interested ship owners to conduct complex shipboard experiments to provide direct and real-time comparisons between BWE and alternative treatment. This emphasis on case-by-case demonstration of the superiority of any treatment to BWE may solve problems for the Coast Guard, but it conflicts with the nation's policy objectives. The science required for precise real-time comparisons between BWE and treatment aboard an operating cargo ship is so onerous that even the most motivated ship owners are unlikely to accept the challenge. The difficulties include the size and complexity of the experimental subject (a ship), the rate of flow of the subject medium (ballast water), and the diversity of biological communities at the source and discharge of the treated water. Moreover, such comparisons likely will not be accurate. Because the effectiveness of BWE is so variable, many repetitions are needed for a comparison study to produce useful information.

A strong domestic program will improve U.S. credibility in international discussions of alternative ballast-treatment standards.

The consequences of the current approach to approving treatment alternatives are severe for the vendors of prospective treatments, for ship owners who might like to purchase them, and for the environment. At a September 2001 Northeast-Midwest Institute conference on development of ballast treatment systems, venture capitalists stated that although the global market potential for ballast treatment could exceed $1 billion per year, they will have no interest in supporting such inventions until a quantitative standard is set, and ship owners will not experiment with using them until clear guidelines for approval are laid out. The current approach essentially removes the bottom rung of the research and development ladder. We cannot learn how well treatments can be made to work on ships without experience using treatments on ships.

The lack of a clear standard is also creating regulatory chaos. In the absence of a clear federal program to address ballast water transfers of organisms, the user groups negatively affected by invader species have pressured states to step into the void. California, Illinois, Maryland, Michigan, New York, Ohio, Oregon, Virginia, and Washington have passed or are considering legislation addressing ballast operations of ships. Some of these laws come with their own treatment standards. A bill pending in New York would require ballast water to be sterilized to meet standards set by the state department of environmental conservation. Washington has passed a law that features a peer-review process for approving proposed ballast-treatment alternatives. California is exercising a process it developed for approving alternatives in the context of its mandatory ballast-management program.

Other agencies and jurisdictions also are becoming involved. The St. Lawrence Seaway Development Corporation requires ships visiting the Great Lakes to carry out management practices over and above those required by the Coast Guard. Environmental advocates have initiated legal action that asserts that the Clean Water Act requires the EPA to assume responsibility for regulating ballast discharges.

Good time for improvement

Order must be brought to this chaos. Developing a simplified regulatory landscape that promotes use of treatment technology on ships would improve the efficiency of trade, assure more consistent environmental protection, and guarantee safety for ships. In addition, a strong domestic program will improve U.S. credibility in international discussions of alternative ballast-treatment standards. Fortunately, the time is now ripe for implementing such a practical federal approach.

When Congress authorized the NISA in 1996, it did so for a period of six years. Thus, the act expired in 2002. Congress now has the opportunity to reauthorize the law to better structure a way forward, a way that urges effective action by implementing agencies and encourages use of treatment by ships. In September 2002, Sens Carl Levin (D-Mich.) and Susan Collins (R-Me.), along with Reps. Wayne Gilchrest (R-Md.), Vernon Ehlers (R-Mich.), Ron Baird (D-Wa.), and Pete Hoekstra (R-Mich.), introduced the National Aquatic Invasive Species Act (NAISA). They are reintroducing the act in 2003. The proposed legislation provides the structure needed to advance the program in a way that is sensitive to the needs of the maritime industry, implementing agencies, and the environment.

This structure includes two clear phases: an interim phase (up to no later than 2011) during which BWE remains an option regardless of its biological effectiveness, and a final phase (beginning no later than 2011) in which BWE and all other treatment options will be held to a standard that will ensure protection of the environment. As regards to the interim period, Congress would provide greater direction to the Coast Guard on what it means by equivalency between BWE and alternative treatments. Because no single number can adequately describe all potential levels of BWE effectiveness, establishing an equivalency standard for treatment is less a technical challenge and more an exercise in policymaking. Sponsors of the NAISA therefore are correct to propose an interim benchmark. The legislation establishes 95 percent "kill or removal" of vertebrates, invertebrates, phytoplankton, and larger forms of algae. This working estimate is based on the best-expected performance of BWE.

The implementing agencies are charged with defining an environmentally protective standard for the final phase of regulation. In order to eliminate risk, the standard may well have to involve aspects of the ship other than ballast water; the ship's hull, anchor chain, and sea chest (where the ballast water enters the ship), for example, are also means by which aquatic hitchhikers move about the globe. The standard during the final phase must be met using the best available technology that is economically achievable, and these criteria should be recalculated every three years by class of ship and by new versus existing ships. This approach provides incentive for treatment vendors to attempt to produce treatments that achieve complete protectiveness. Where technology does not yet exist to achieve that high level of environmental protection, the best available treatment must be employed.

So are there treatments that can do the job in either the interim or final phases of regulation? The answer will vary across ship types, between new and existing ships, and over time. Experiments by the Great Lakes Ballast Technology Demonstration Project on a barge platform, as well as on ships, show the strong potential for filtration and UV radiation to meet the initial standard in some ship applications. Filtration with a 50-micrometer screen removed more than 90 percent of live zooplankton, and when combined with a relatively low dose of UV, the reduction exceeded 95 percent. Other experiments suggest that deoxygenation can be effective, at least during the interim period, and that additional techniques could well prove effective for meeting the final standard.

Areas for action

Clearly, more testing should be taking place. But without a structure in place to guide that work, it simply will not happen. The NISA left the structure building entirely up to the implementing agency; fortunately, the NAISA reauthorization bill does not. The new act would mandate government action in a number of critical areas, some of them ranging beyond setting standards for ballast treatment. Among the areas covered are:

All ships. The NAISA would require all ships to report ballast operations; to conduct best management practices; to have an invasive species management plan on board; to cooperate with approved local rapid-response efforts; and if the ships entered service after 2002, to be fully equipped with an approved ballast treatment system.

Transoceanic vessels. For vessels that visit U.S. ports after operating outside the U.S. Exclusive Economic Zone, the proposed act sets forth a two-stage process with solid deadlines for requiring state-of-the-art ballast management. It establishes an interim standard for treatment and BWE for the first stage, from enactment to no later than 2011, and calls for a final standard to be developed for the second stage, with the goal of eliminating the risk of introducing nonnative organisms.

Coastal shipping. The large volume of shipping that occurs along the coasts of the United States, Canada, and Mexico can create the same type of invasive species problems caused by transoceanic shipping, but such ships were not covered by any of the previous legislation. Coastal shipping was exempted from ballast rules because the sole approved treatment, BWE, could be performed only in the open ocean, where these ships never venture. The NAISA would require coastal ships to keep records of their ballast operations and to adhere to the same rapid-response contingency strategies that apply to transoceanic ships. The act also accelerates the adoption of ballast treatment by providing incentives and setting a date for when ballast treatment would be mandatory.

Past invasions have taught that time is critical in mounting an effective and affordable response.

Rapid response. Past invasions have taught that time is critical in mounting an effective and affordable response. Agencies must be notified, appropriate response tools must be found, and money must flow--all in a closely coordinated manner. But currently there is no established process for such cooperation. The proposed act creates a process for contingency planning and for the rapid disbursement of funds to support federal teams (when invited by states), as well as state and interstate entities with approved plans.

Planned importation of species. Although many invasive species arrive as stowaways, some are deliberately imported for use as live food, in aquaculture, in the pet and aquarium trade, and for fish stocking. Even organisms that are not intended to be released into open water can escape and may become invasive. Under existing law, there is no uniform, systematic process for screening or regulating proposed importation of live organisms. The NAISA would establish a common screening process for all imported species, regardless of planned use. The goal would be to identify potential problems early and take appropriate action to prevent them.

Environmental soundness. Federal legislation designed to protect waters and lands from pollution by pesticides and herbicides says nothing about measures to control and contain invasive species. And although the NISA authorized in 1996 required that ballast treatment be environmentally sound, it provided little structure for the administration of this requirement. Under the proposed act, aquatic nuisance species will be managed and controlled using a number of methods. These methods include chemical, mechanical, and physical approaches (such as ballast treatment) to prevent the introduction of troublesome organisms, as well as approaches to control and contain any outbreaks that may occur. The act also will help resolve the problem of lack of adequate oversight and direction by assigning an agency responsibility for creating standards and establishing a screening method for evaluating environmental soundness.

Dispersal barriers. Waterways that connect hydrologically distinct basins and water bodies can serve as pathways for the transmission of aquatic nuisance species. The Army Corps of Engineers recently completed construction of a barrier that will prevent fish and other swimming organisms from moving between the Great Lakes and the Mississippi River. Additional work on dispersal barrier technologies has been conducted on the Champlain Canal, which is the probable point of entry to Lake Champlain for 50 percent of nuisance species, including the sea lamprey, the zebra mussel, the white perch, and the water chestnut. The NAISA would fund research to evaluate the effectiveness of such barriers and would expand the dispersal barrier program to address other waterways.

Research and monitoring. Our knowledge of invasive species is limited. We need to know more about how they arrive, how their arrival can be blocked, how to recognize when a species has become a problem, how to respond when a problem arises, and how to evaluate the overall effectiveness of our programs. The proposed act creates a national interagency aquatic research program designed to address these questions with a minimum of redundancy and competition among agencies.

That is the promise, but the future of the NAISA is not assured. The act is the product of intense negotiations among the various interest groups. Each of those stakeholders, although for different reasons, wants national legislation that provides a comprehensive response to the threat of invasive species. If those groups maintain their commitment to cooperation, then the NAISA could be approved early in the 108th Congress. If stakeholders press their individual demands, however, then the bill could well stall, allowing invasive species the chance to cause further ecological and economic damage.

Recommended reading

Carlton, J. T., Introduced Species in U.S. Coastal Waters: Environmental Impacts and Management Priorities. Arlington, Virginia: Pew Oceans Commission, 2001.

Committee on Ships' Ballast Operations, National Research Council, Stemming the Tide: Controlling Introductions of Nonindigenous Species by Ships' Ballast Water. Washington, DC: National Academy Press, 1996.

U.S. Coast Guard, Report to Congress on the Voluntary National Guidelines for Ballast Water Management, November 2001.

U.S. Environmental Protection Agency, Aquatic Nuisance Species in Ballast Water Discharges: Issues and Options, September 2001.

Allegra Cangelosi (, a senior policy analyst with the Northeast-Midwest Institute in Washington, D.C., is a member of the U.S. delegation to the International Maritime Organization's Marine Environment Protection Committee and a member of the Invasive Species Advisory Committee.