April 30, 2015
Federal Efforts to Control Invasive Plant and Animal Species
An “invasive” species (also known as an alien, exotic,
carnivore, and killing large numbers of native species of
injurious, introduced or naturalized, non-native,
reptiles, birds, and mammals. Introductions also include
nonindigenous, nuisance, or noxious species) refers to an
various human parasites and diseases.
animal or plant that is introduced into an environment
where it is not native. Of particular concern are non-native
animal and plant species that have caused or seem likely to
Pathways for Invasive Species Introductions
cause substantial economic or ecological harm. However,
not all non-native species are invasive or harmful.
•
Transportation Corridors such as railroads, rivers, and
highways that may unintentionally spread invasive species
The introduction of invasive species to the United States
•
Intentional Introductions such as non-native landscaping
from around the globe—whether deliberate or
plants or fish species for use by aquaculture facilities, as wel
unintentional—can pose threats to native animal and plant
as other deliberate releases for propagation in the wild
communities and may result in extinctions of native
(such as tamarisk to control erosion along river banks)
species, ecosystems disruptions as native and non-native
•
Intentional Importation of Non-Native Pets that may
species compete for limited resources, reduced biodiversity,
escape or are released into local lakes, streams, or forests
and altered terrestrial or aquatic habitats. Invasive species
may also introduce new pests and diseases. An estimated
Basic Control Methods for Invasive Species
50,000 non-native invasive animal and plant species have
•
Preventing Dispersal After Entry by taking steps early to
been introduced to the United States, resulting in economic
limit the spread of an invasive species that has begun to
costs estimated at more than $100 billion annually.
escape confinement by removing the pests’ sources of food,
water, and shelter or blocking their access into buildings or
Various invasive species have had severe economic impacts
plants to prevent population growth
on U.S. industries and the natural environment. Damage
can span an enormous range of effects, such as power
•
Controls Designed for Confined Spaces such as using
outages; loss of farmland property value; contamination of
lethal substances to target pests in confined areas or to
grain; spread of human and other diseases; increased
prevent them from crossing a geographic bottleneck
operating costs; loss of irrigation water; collapse of
•
Cultural Controls such as agricultural production practices
buildings; competition with native plants; loss of sport,
that modify a pest’s environment or habitat to curtail its
game, or endangered species; and ecosystem disturbance.
spread by reducing its ability to survive, disperse, establish,
or reproduce (examples include crop rotation,
Some invasive plants have been notorious for years for
intercropping, managed application of water or fertilizer,
causing economic and ecological damage. For example,
improved sanitation and hygiene, timed plantings and
leafy spurge is lowering the forage value of western grazing
harvests, purchasing of certified plants, and other practices)
land and reducing overall land values. Others include
•
Mechanical and Physical Controls such as mowing and
kudzu, melaleuca, cordgrass, tamarisk, purple loosestrife,
use of heavy machinery (harvesters, shredders), traps, or
spotted knapweed, and Russian thistle. Their damage
mulches/barriers to manage weeds, and manual controls
includes lowering water tables, poisoning livestock,
(hand-pulling weeds, physical removal of a plant or animal)
decreasing crop yields, and increasing pest control costs.
•
Baits and Attractants to attract individuals of a target
species toward a potential source of food or mates, where
Invasive invertebrates are also well known and include
the target species can be trapped, kil ed, or studied
gypsy moths, Japanese beetles, Asian longhorn beetles,
zebra and quagga mussels, Asian tiger mosquitoes, fire
•
Biological Control Organism to compete with, prey on,
ants, and Africanized honey bees, among others. An
parasitize, or cause disease in a targeted pest species
example of a damaging non-native insect species is the light
•
Chemical Control Agents such as pesticides and other
brown apple moth, a native pest of Australia, which has
manufactured (conventional) controls as well as natural
been detected in California and is causing damage to a wide
(biological) sources and biopesticides derived from natural
range of plant species and commercial fruit and vegetable
materials, animals, plants, bacteria, and certain minerals
crops. Zebra and quagga mussels from Eastern Europe are
•
Site Removal of an area where the invasive species lives
clogging intakes for urban water supplies and nuclear
power plants in the Great Lakes and the Mississippi basin.
•
Bounties and Commercial Exploitation, where someone
is paid to catch and kill the target species
Introduced vertebrate pests, including walking catfish, lake
•
Use of Other Species for Detection such as training dogs
trout, cane toads, monk parakeets, starlings, bighorn sheep,
to detect a target species at high-risk entry points (airports,
nutria, and rats, can also have serious economic and
cargo terminals, dockyards)
ecological impacts. An example includes Burmese pythons,
which are multiplying in south Florida, becoming a top
www.crs.gov | 7-5700

---

Federal Efforts to Control Invasive Plant and Animal Species
Table 1. Estimated Funding for Invasive Species Activities, FY2014 ($1000)

DHS NOAA USACE DOI DOS DOT
USAID USDA
Total
(%)
Prevention
680,337
8 8,448
7,860
1,381
260
57,000 106,771
862,065 (37%)
Early Detect./Rapid Resp.
0
73 9,225 13,482 2,845
0 — 276,701
302,326 (13%)
Control/Management
0 315
109,705
46,930
9,710 0 —
547,104
713,764 (31%)
Research
0 1,348 4,648 6,321 2,076 250 — 239,095
253,738 (11%)
Restoration
0
1,315
12,244
18,301 0 0 0
34,297
66,157 (3%)
Educ./Public Awareness
0 13
2,796 720 19 0 —
92,162
95,710 (4%)
Leadership/International
0 0
1,505 689 16 80 0 3,133
5,423 (<1%)
Total
680,337
3,072
148,571
94,303
16,047
590
57,000
1,299,263
2,299,183
%Federal
Spending
30% <1% 6% 4% 1%
<1% 2% 57%
100%
Source: NISC, “Invasive Species Interagency Crosscut Budget,” December 2014, available at http://www.invasivespecies.gov/global/
org_collab_budget/org_collab_budget_documents/NISC_2012_Crosscut_Budget_Summary.pdf.
Notes: DHS (U.S. Department of Homeland Security); NOAA (National Oceanic and Atmospheric Administration); USACE (U.S. Army Corps
of Engineers); DOI (U.S. Department of the Interior); DOS (U.S. Department of State); DOT (U.S. Department of Transportation); USAID
(U.S. Agency for International Development); USDA (U.S. Department of Agriculture). These data are self-reported by the federal agencies
engaged in these activities and are not independently compiled; also the criteria used by agencies to compile these data are unclear and may be
inconsistent across different agencies.
Control of invasive species involves eradication where
In the United States, numerous federal and interagency
possible and reduction to manageable or tolerable levels
efforts share responsibilities regarding invasive species.
where eradication is not possible. Key to this effort is early
Among the federal agencies involved are the Departments
detection and rapid response in order to eradicate invasive
of Agriculture, Commerce, Defense, Homeland Security,
populations before they become established. Several
Interior, Transportation, as well as the Environmental
methods may be used to address an unwanted pest
Protection Agency and the Executive Office of the
population and cover a range of control methods (see text
President. Of these, three Departments—Agriculture,
box). To apply any of these strategies effectively, however,
Commerce, and Interior—play a major role by co-chairing
considerable knowledge of the target species’ behavior,
the National Invasive Species Council (NISC). Created by
biochemistry, dietary preferences, diseases, or other aspects
Executive Order 13112 in 1999, NISC provides high-level
of its biology is usually essential.
interdepartmental coordination of federal invasive species

actions and works with other federal and nonfederal groups
Comprehensive legislation on the treatment of invasive
to address invasive species issues at the national level.
species has never been enacted, and no single law directs
coordination among federal agencies. No laws focus on the
In FY2014, the Administration reports it allocated an
broad problems of invasive species—their interception,
estimated $2.3 billion across a range of federal agencies and
prevention, and control across a variety of industries and
activities in an effort to prevent, control, and eradicate
habitats. Instead, the current legal framework is largely
invasive species domestically (Table 1). Activities at
governed by a patchwork of laws, regulations, policies, and
USDA accounted for the bulk of available federal funding,
programs. Some laws are tailored to individual species or
nearly $1.3 billion (57% of total available funds). Activities
narrowly focused on what is affected by the species, such as
at the Department of Homeland Security, composed mostly
agricultural production or certain aquatic or terrestrial
of border protection and security activities, accounted for
ecosystems. Other laws have a broader intended purpose
$0.7 billion (30% of total funding). The U.S. Army Corps
and may only peripherally address invasive species, such as
of Engineers accounted for another 6%. The remainder of
certain environmental, resource management, and species
federal funding, about 6% of total funding, covers activities
or wildlife protection laws. Some laws, though they do not
across a range of agencies at the Departments of Interior
directly address invasive non-native species control or
and Commerce and other independent agencies.
prevention, have effects that may limit introductions.
For details, see CRS Report R44011, Invasive Species: Control
Control of invasive species is not often the major purpose
Options and Issues for Congress, and CRS Report R43258, Invasive
of the law, and agencies have little authority to eradicate
Species: Major Laws and the Role of Selected Federal Agencies.
invasives, except where they occur on federally managed
Renée Johnson, rjohnson@crs.loc.gov, 7-9588
lands, thus undermining the effectiveness of these
M. Lynne Corn, lcorn@crs.loc.gov, 7-7267
programs. In general, laws addressing threats to
agriculture—an industry for which the risks from invasive

species are well established—tend to be more developed
IF10217
than laws protecting other industries or ecosystems.
www.crs.gov | 7-5700

---