Management Plan: An Action Plan for the Nation - Prevention
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Summary] | [Introduction] | [Survey of Federal Roles & Responsibilities]
[An Action Plan for the Nation]
| [Conclusion] | [Appendices]
| Prevention | Detection | Control
| Restoration |
International | Research
| Info Management | Education
The first-line of defense and,
over the long term, the most cost-effective strategy against
invasive species is preventing them from becoming established.
Prevention is two-pronged because some species are intentionally
introduced for a specific purpose, whereas others arrive unintentionally
as "hitchhikers" on a commodity, conveyance, or person.
Diverse tools and methods are
needed to prevent invasive species from becoming established
in ecosystems where they are not native. A risk-based approach
is mandated by the Order, and requires consideration of the likelihood
an invasive species will establish and spread, as well as the
degree of harm it could cause.
Currently, a limited number of
invasive species are listed as regulated species under Federal
laws governing specific types of species such as noxious weeds,
injurious fish or wildlife species, or aquatic nuisance species.
These laws provide for public input and stakeholder involvement
in the listing process.
At present, there are procedures
for listing species that are known to be invasive. Such listings
may be petitioned and involve stakeholders and the public in
the course of the rulemaking process. Importation and interstate
transport is prohibited for species that are Federally listed
as noxious weeds or injurious wildlife. The adequacy of such
listing procedures will be examined in the analysis of legal
gaps, which is listed as an action item under Section B: Leadership
and Coordination. Enforcement of prohibitions on listed species
and exclusion of invasive species is largely dependent on inspection
services at ports of entry.
For species that have not been
listed, a key tool for prevention is a risk analysis and screening
system for evaluating first-time intentional introductions of
non-native species, before entry is allowed, and realistically
applying similar principles or other management options for species
currently in trade. In addition, a key priority will be identifying
high-risk invasive species pathways and developing effective
technologies and education programs to reduce the movement of
invasive species through those pathways. Pathway management is
the most efficient way to address unintentional introductions.
Another line of attack is to identify high-risk invasive species
not yet established, the likely pathways for their entry, and
then management of the pathways to prevent introduction.
Preventing invasions requires
more than analysis. Both appropriate regulation and voluntary
codes of conduct are essential. Research is needed on the biology
of invasive species and ecosystem vulnerability to them, and
on means to detect and interdict invasive species that are en
route to establishment. Finally, steps are needed to make sure
the general public understands the harm that invasive species
cause and the importance of preventing their introduction.
Currently, one of the most effective
means of excluding invasive insects, other animals, and plants
is inspection of shipments at ports of entry. Port of entry inspection
works in two ways, first by directly examining pathways for the
presence of invasive species and second, by monitoring imports
to insure that regulatory requirements for reducing the risk
of introduction have been met. Both APHIS and FWS have relevant
inspection services. Even though they have made an effort to
focus on shipments from high-risk areas, they are unable to examine
more than a small percentage of shipments entering the United
- As resources permit,
APHIS and the FWS will dedicate additional human and financial
resources to strengthening inspection services at ports of entry.
The action items below call for
the development of a risk-based screening process for intentionally
introduced species in a series of steps or phases. During the
first phase a screening system for first-time intentional introductions
will be developed, with different agencies taking the lead as
appropriate for the different types of species. The screening
system will then be modified by those same lead agencies during
the second phase to deal with species already moving in the U.S.
- By December 2003,
the Council will develop a fair, feasible, and risk-based comprehensive
screening system for evaluating first-time intentionally introduced
non-native species (see items a-e below).
To accomplish this task, appropriate Federal agencies will take
the lead in developing and testing the screening system based
on input from other Council members, ISAC, State governments,
scientific and technical experts and societies, and other stakeholders
-- including affected industries and environmental groups. The
system will include recommendations regarding implementation
issues, including: the scope of taxonomic coverage, the degree
of initial screening coverage, and the role of appropriate regulatory
and non-regulatory risk-reducing tools.
- By 2006, the same
Federal agencies (as designated under a-e
below) will develop modifications to the screening system or
other comparable management measures (i.e., codes of conduct,
pre-clearance or compliance agreements) to formulate a realistic
and fair phase-in evaluation of those intentional introductions
currently moving into the U.S., in consultation with ISAC, State
governments, scientific and technical experts and societies,
and other stakeholders, including affected industries and environmental
Recommendations will be provided
to the Council for the following screening processes:
Introduction of non-native biological control organisms for animal
pest control within the continental U.S. to complement measures
already in place for screening of plant biological control organisms.
Lead Departments: USDA, Interior, and Environmental Protection
b. Introduction of all non-native
freshwater or terrestrial organisms for any purpose into Hawaii,
Puerto Rico, the U.S. Virgin Islands, or U.S. territories or
possessions in the Pacific and the Caribbean (because of the
vulnerability of insular areas, a separate screening process
for those areas is needed). Lead Departments: USDA, Interior
and EPA, the State of Hawaii, and the Governments of Puerto Rico
and the Virgin Islands.
c. Introduction of non-native
propagative plants or seeds for any purpose (e.g., horticulture
or botanical gardens) within the continental United States. Lead
Departments: USDA and Interior.
d. Introduction of non-native
land animals for any purpose (e.g., insects, zoo animals, terrestrial
pets, or food animals) within the continental United States.
Lead Departments: USDA and Interior.
e. Introduction of non-native
aquatic organisms for any purpose (e.g., fish or shellfish stocking,
aquarium organisms, aquaculture stock, aquatic plants and biological
control agents) within the continental United States. Lead Departments:
USDA, Interior, and Commerce, EPA, and the Army Corps of Engineers.
The most effective method of
preventing the unintentional introduction of non-native species
is to identify the pathways by which they are introduced and
to develop environmentally sound methods to interdict introductions.
Some pathways are already known to be significant sources of
invasive species. For example, ballast water is probably the
largest single source of non-native species introductions into
coastal and estuarine waters. Solid wood packing materials are
a source of serious forest pests. As a first step in dealing
with unintentional introductions, Federal agencies should take
steps to address pathways already known to be significant. In
addition, it is important that other pathways be analyzed to
determine their significance as a source of invasive species.
The term "pathways" is also used in another context
to describe the means by which an already established species
may be spread to other areas. For example, the movement of aquatic
species among watersheds is through interconnecting waterways
and the weed seeds move in forage. Such pathways and action items
to address them are covered under Section D, Control and Management.
- Federal agencies
will take the following steps to interdict pathways that are
recognized as significant sources for the unintentional introduction
of invasive species:
a. By July 2001, NOAA, the Coast
Guard, Interior, and EPA will sponsor research to develop new
technologies for ballast water management, because the current
method of ballast water management--ballast water exchange--is
recognized as only an interim measure to address non-native species
b. By January 2002, the U.S.
Coast Guard will issue standards for approval of ballast water
management technologies, because actual deployment of new ballast
water technologies on ships is contingent on a standard by which
to judge their efficacy.
c. By January 2002, USDA will
issue additional regulations to further reduce the risk of species
introductions via solid wood packing materials.
Species Pathways Team Final Report(October 29, 2003)
- By January 2002,
the Council will implement a process for identifying high priority
invasive species that are likely to be introduced unintentionally,
e.g., Mediterranean fruit fly and brown tree snake, and for which
effective mitigation tools are needed.
See Invasive Species Pathways Team Final
- By June 2001, the
Council will outline a plan for a campaign that will encourage
U.S. travelers to voluntarily reduce the risk of spreading invasive
species overseas. This project will seek to engage a diverse
array of organizations related to aviation, travel and tourism.
- By December 2002,
the Council, led by USDA, Defense, and Interior and in cooperation
with the U.S. Agency for International Development (USAID), will
develop a risk assessment program for the intentional and accidental
introduction of non-native species through U.S. international
assistance programs and encourage other countries and international
organizations to do the same.
- By January 2003,
the Council will implement a system for evaluating invasive species
pathways and will issue a report identifying, describing in reasonable
detail, and ranking those pathways that it believes are the most
significant. The report will discuss the most useful tools, methods,
and monitoring systems for identifying pathways, including emerging
or changing pathways, and for intervening and stopping introductions
See Invasive Species Pathways Team Final
Water Introductions of Nonindigenous Species
Ballast water is the water used
by ships to provide stability and adjust a vessel's trim for
optimal steering and propulsion. It is carried in ballast tanks
that are distributed along the bottoms, tops, and sides of vessels.
Ballast water often originates from ports and other coastal regions
that are rich in planktonic organisms. Ballast water may be discharged
as cargo is loaded or unloaded or when sea conditions change.
The discharged water may contain myriad aquatic organisms from
a wide range of taxonomic groups.
Currently, ballast water is probably
the most significant pathway for the introduction of non-native
species into coastal ecosystems. An estimated 50,000 commercial
vessels enter the United States each year from overseas. A single
vessel may carry more than 21 million gallons of ballast water.
In 1991, the total volume of ballast water discharged into U.S.
waters was estimated to be less than 79 million metric tons,
most of which originated from foreign ports. With a typical transoceanic
voyage duration of about 10-14 days, many of the organisms contained
in ballast water survive the journey and are capable of invasion.
For example, a large commercial vessel (such as a bulk carrier)
arriving in the Chesapeake Bay from Europe will often carry millions
of large planktonic organisms in their ballast water, and microorganisms
occur in even greater abundance.
Historically, the transfer of
organisms by ships has resulted in the unintentional introduction
and establishment of hundreds of freshwater and marine non-native
species into the United States. Ballast water was the likely
pathway for the introduction of species such as the clam Potamocorbula
amurensis into San Francisco Bay and zebra mussels and the fishhook
water flea into the Great Lakes. Introduced dinoflagellates have
contributed to harmful algal blooms in Australia, and recent
studies have shown that ballast water may contain microbes that
can cause human disease, including cholera. In recent years,
the rate of new invasions in coastal ecosystems is apparently
increasing, and most of this increase is attributed to shipping
through a combination of ballast water discharge and hull fouling.
At present, ballast water exchange
is the only management tool used routinely to reduce the risk
of ballast-mediated invasion. Ballast water exchange involves
replacing coastal water with open-ocean water during a voyage.
This process reduces the density of coastal organisms in ballast
tanks that may be able to invade a recipient port, replacing
them with oceanic organisms with a lower probability of survival
in near shore waters. There are two shortcomings with this procedure.
First, the ability to safely conduct ballast water exchange depends
upon weather and sea surface conditions; thus, it is not always
possible to perform an exchange. Second, there is still some
residual density of coastal organisms in ballast tanks following
exchange, so this process is only partly effective. To address
these shortcomings, additional ballast management practices (e.g.,
design and testing of shipboard technologies) are also being
advanced as long-term strategies.
Ballast water management has
been encouraged through a variety of national and international
- Ballast water exchange is recommended
as a voluntary measure by the International Maritime Organization
- The Nonindigenous Aquatic Nuisance
Prevention and Control Act of 1990 (P.L. 101-646) required that
all vessels entering Great Lakes ports or the upper Hudson River
from overseas undergo ballast exchange or some comparably effective
- The National Invasive Species
Act (NISA) of 1996 (P.L. 104-332) reauthorized and amended the
Nonindigenous Aquatic Nuisance Prevention and Control Act of
1990. NISA requires mandatory ballast management reporting and
voluntary ballast exchange guidelines for most vessels that enter
U.S. waters. Recognizing that ballast water exchange is likely
to be only an interim measure, the law also sets up a research
program for the development of new technologies for ballast water
management. Among technologies being evaluated are filtration,
ozone injection, ultraviolet radiation, and chemical treatment.
Gregory Ruiz-Smithsonian Environmental