STOPPING THE SPREADRECOMMENDATIONS FOR

COMBATING FLORIDA’S COSTLY

INVASIVE SPECIES EPIDEMIC

Predatory catfish, weeds thatfuel wildfires, disease-carryinginsects — Florida is faced withan onslaught of harmful invasive, non-native species.These pests threaten wildlife,economies and human health.New species arrive daily, andmost spread across the state and beyond.

While federal and state agen-cies already recognize and arewrestling with the problem ofinvasive species, the scale of thisissue requires immediate imple-mentation of a new comprehen-sive approach. If decisive actionis not taken soon, the spread of invasive, non-native speciesand the cost to control them willincrease exponentially.

The problem is severe, but it isnot too late to act. This bookletprovides an overview of the cur-rent problem in Florida and offersrecommendations to stem the tide of non-native invaders andreduce their present impacts.

THE PROBLEM IS SEVERE1

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WHY INVASIVE SPECIES

ARE A PROBLEM

On their home turf, plant and animalpopulations are kept in check by natu-ral controls. However, when a speciesis introduced into a new landscape,the consequences can be devastating.Invasive plants and animals can spreadunchecked, disrupting natural cycles,crowding out native species and cost-ing billions in property damage andlost economic productivity.

Not all non-native species are a prob-lem. Most are benign, and several, suchas citrus and cattle, have been benefi-cial for generations of Floridians. Anon-native plant or animal is onlyharmful if it is invasive and displacesnative species or threatens health and property.

Invasive species can become estab-lished in natural, urban and agricul-tural areas with or without humanassistance. Non-native invaders havecaused major economic setbacks forforestry, farming, fishing, boating,ranching and other endeavors criticalto the well-being of Florida’s peopleand can harm human health.Additionally, invasive species threatento permanently alter Florida’s irreplace-able conservation areas, native speciesand ecosystems.

Approximately 1.5 million acres ofFlorida’s remaining natural areas areinfested with invasive, non-nativeplants; an estimated 1,000 non-nativeinsects have invaded the state; andFlorida has the highest number of non-native fishes in the continentalUnited States.

BUT IT IS NOT TOO LATE TO ACT

Even though cattle are non-native, they are not invasive and are an important part of our economy. Invasive species threaten both Florida’s agriculture and natural areas. For example,heartwater disease is carried by non-native ticks imported on non-native reptile species in the pet trade. If it arrives in Florida it could devastate cattle and native deer. This disease isalready as close as the Caribbean islands and could arrive here soon if preventive action is not taken. Tropical soda apple invades rangeland and natural areas alike.

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FLORIDA’S UNIQUE VULNERABILITY

Nowhere in the continental UnitedStates is the threat of invasive, non-native species more severe than inFlorida. Our climate, industries andlandscape make the state a suitablenew home for these pests. SouthFlorida, for example, has more non-native animals than any other region inthe United States. A lack of under-standing among Floridians and visitorsabout the damage invasive non-nativescause further exacerbates the problem.

Florida also serves as a major hub forinternational travel and trade, whichbring a host of potential invaders toFlorida’s ports every day. The U.S.Department of Commerce reports thatFlorida currently trades directly withmore than 200 different countries.International trade and travel toFlorida continues to grow, increasingthe probability that more and newinvasive species will arrive in the state.

Economic ImpactsInvasive non-natives cost taxpayers a tremendous amount of money, both in terms of damage to crops,forests, fisheries and navigation, and in costs to eradicate and control them.Crop damage losses caused by invasive, non-native plants, animal pests anddiseases are estimated to cost Florida$179 million in sales every year. In one year alone (1999-2000), agricultural pests forced the FloridaDepartment of Agriculture andConsumer Services to spend $45.9 million for prevention, monitoring,eradication, control and restoration.

These costs keep escalating: Just to keep up with invasive plants in public natural areas, the FloridaLegislature allocated $25 million peryear to the Department of Environ-mental Protection starting in 2002.

INVASIVE SPECIES COST TAXPAYERSA TREMENDOUS AMOUNT OF MONEY

Over

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)WHY FLORIDIANS SHOULD

CARE ABOUT INVASIVES

Invasive species pose a direct and

urgent threat to Floridians. The

problem affects our state’s econo-

my, health and precious wildlife.

Invasive species are second only to habitat destruction in harming native wildlife.

Invasive species like water hyacinth can cover lakes, smothering fish spawninggrounds, causing fish kills and blocking boat traffic. Removing invasive aquaticplants is a difficult, expensive process.

3

Source: The Nature Conservancy and NatureServe

Recreational ImpactsFlorida’s lakes and rivers bring in mil-lions of recreation dollars each year.Species like hydrilla and waterhyacinth can cover lakes, smotheringfish spawning grounds, causing fishkills and blocking boat traffic. In doingso they cause severe economic losses toboat operators and property owners.For instance, a study of Orange Lakerevealed that economic activity was allbut lost in years when hydrilla coveredthe lake — representing an estimatedloss of almost $11 million per yearin revenues.

Health ImpactsInvasive, non-native species alsodirectly threaten the health of manyFloridians. Recent arrivals includeWest Nile virus, which causes criti-cal disease in horses, deer and birds,as well as people. Floridians also suf-fer from allergies caused by fire ant andAfricanized bee stings and non-nativeplants, such as melaleuca and Brazilianpepper trees. Climbing ferns carry fire into tree canopies, exacerbatingwildfire threats, smoke impacts, anddamage to people and property.

Wildlife ImpactsScientists have determined that inva-sive, non-native species are secondonly to habitat destruction in harmingnative wildlife. Almost half of thespecies covered under the EndangeredSpecies Act are endangered because ofinvasive species.

The South Florida EcosystemRestoration Task Force has identi-fied invasive species as one of themost serious threats to the restora-tion of the south Florida ecosystem.Non-native invasive species impactnative species and communities bychanging habitat, preying on or infect-ing native species, and out-competingnatives for food and space. For exam-ple, introduced fish are responsible formore than 95 percent of new infectiousfish diseases in Florida.

Fire ants sting humans aggressively andcan cause serious health effects to thosewho are allergic to them.

Invasive vines allow wildfiresto climb into tree canopies,

making the fire more danger-ous and difficult to control.

Invasive, non-native species directly threaten

the health of many Floridians4

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250

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Num

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(in m

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1994 1995 1996 1997 1998

Number of Plants Imported Through Miami International Airport CURRENT STATE ACTION

Recognizing the economic, health andenvironmental impacts of invasive,non-native species, the State of Floridahas increased funding to a variety ofactivities related to control. More than50 percent of expenditures in thelast several years have been to con-trol citrus canker, fruit flies, hydrillaand melaleuca alone.

This approach has seen some success.For example, the distribution of waterhyacinth was reduced statewide from120,000 acres in the late 1950s andearly 1960s to fewer than 1,000 acresin 2000, following implementation of acentralized approach for control.

However, the threats continue to growexponentially. As both the numbers ofspecies and acres invaded increased,our current individual species-based,variably funded approach falters. Wecontinue to find new species, like flat-head catfish and the pink hibiscusmealybug that appear likely to holdmore negative impacts — both eco-nomically (on fisheries, horticultureand agriculture) and environmentally(on aquatic communities and manyplant species) — than any other speciesseen before.

Several recent developments indicatethat both federal and state governmenthave acknowledged the problem. Theneed for a coherent strategy on invasivespecies was identified in the 1999Executive Order signed by PresidentClinton. The executive order createdthe National Invasive Species Council

MORE SEVERE THAN IN FLORIDANOWHERE IN THE CONTINENTAL UNITED STATES IS THE THREAT

New species, like the cactus moth (larva shown here inside a semaphore cactus pad), continueto arrive in Florida. Since landing on Big Pine Key in 1989, the cactus moth has rapidly movednorthward, destroying Florida’s native prickly pear cactuses along the way. If its spread is notstopped, the moth will likely invade the Southwest and affect horticulture and agriculture in the United States and Mexico. For Mexico, the effects will be economically and culturally devastating. Scientists have developed control methods, including the release of sterilized moths. However, inadequate funding has prevented full-scale field testing and implementation.

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(NISC), which developed a nationalmanagement plan (approved in 2001)to do the following:

• control and manage existing prob-lem species;

• restore invaded lands, includingproviding incentives for privatelandowners;

• coordinate leadership across agen-cies and budgets;

• prevent the import of potentialinvasives;

• implement an early detection andrapid response plan for invasivesthat enter the country; and

• improve public education andawareness of the problem.

Subsequently, Governor Bush askedFlorida state agencies to develop acoordinated invasive species manage-ment plan. The agencies completed the Statewide Invasive SpeciesManagement Plan in 2002. However,while the plan is a call to action, no immediate changes have been recommended. To date, funding hasnot followed the planning.

In a complementary process, the South Florida Ecosystem RestorationWorking Group, a cooperative stateand federal agency effort, developedWeeds Won’t Wait in 2002. The reportpresents a comprehensive look at theproblem and presents a strategic planfor addressing invasive, non-nativeplant issues in Florida. A similar planfor non-native animals is under way.

Threats continue to grow

EXPONENTIALLY 6

Invasive species spread unchecked. For example, Old World climbing fern cover in southFlorida increased by 328% between 1993 and 1999. If not controlled, models predict that thespecies will invade across almost all south Florida counties.

25,000 acres

Spread of Old World Climbing Fern in South Florida

107,000 acres

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1993 1997

1999 2009

39,000 acres

Projected acreage

Take Aggressive Action on Prevention

The import and distribution of new invaders, like the brown tree snake, must be prevented.Experts predict that the snake could thrive in Florida with damaging effects. In Guam, thisinvader has eliminated several native bird species, caused power outages, and has hospital-ized many of the island’s residents. Florida must ensure that inspection services at ports of

entry are sufficient to prevent the accidental arrival of this species.

The keys to a successful invasive

species strategy are prevention,

early detection and rapid response.

While we will continue to need to

control, manage and restore areas

with existing infestations, the most

cost-effective strategy is ensuring

populations do not get established.

Success also depends on a well-

coordinated, carefully designed,

and sufficiently funded approach.

For example, an invasion of

African giant snails was prevented

in 1969 when, within 10 days

of learning of an invasion in

Miami, the Florida Division of

Plant Industry launched a targeted

emergency campaign that invol-

ved quarantine and eradication.

Although more than 25,000 snails

and eggs had been documented, no

snails have been found since 1974.

Action on the strategies proposed

in Weeds Won’t Wait and by

the Statewide Invasive Species

Management Plan must be initiat-

ed. These strategies are outlined

in the pages that follow.

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STRATEGIES TO STOP

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Initial infestation (ha)0.1 1.0 100 1000

As illustrated using data from eradication projects on 18 invasive plant species in 53independent infestations in California, it is both more cost effective and more successfulto remove invaders when the area invaded is small. As the area invaded increases, theeffort and cost involved in control increases with diminishing likelihood of successfuleradication (Rejmánek and Pitcairn 2002).

Take Aggressive Action on PreventionThe import and distribution of newinvaders must be prevented. Floridashould adopt a science-based protocolfor screening new plant and animalspecies before they are released into thestate, and its ports need to be staffedsufficiently to intercept invaders.Further, trade in known invasive, non-native species should cease.

Establish an Effective Early Warning System for Detecting New PestsFlorida needs a system for systematical-ly and comprehensively detecting newinvasive species. Clear pathways forthe exchange of information amongagencies and organizations need tobe established. The system must con-sider all taxa (plants, vertebrate andinvertebrate animals, fungi and otherpathogens of plants and wildlife), andintegrate a network of trained volun-teers with a professional cadre at thelocal, state and federal level.

Enhance Rapid Response CapabilitiesRapid response, by definition, meansthe rapid deployment of people andresources to eradicate a plant or animalpopulation prior to its establishment orspread. Even the most effective inter-diction programs will not prevent every

invader from entering the state.Therefore, the detection programshould link directly to a rapid-responsesystem designated for each type oforganism. Rapid response includesassessment and action before an inva-sive, non-native species can becomeestablished.

Eradication is both possible andcost-effective if control needs arerecognized, coordinated and ade-quately funded.

Resolve Conflicting Agency MandatesOverlapping authority among state,federal and local agencies involved inthis issue has resulted in inefficient andconflicting policies on invasive species.To resolve this problem, Florida shouldestablish a formal multi-agency (state,federal and local) organization, with adesignated lead agency, to implementthe state’s invasive species managementstrategy and coordinate agency actionswithin the state and with national andinternational programs. The multi-agency organization should developprograms to share resources, such asstaff, equipment, chemicals, data andtechnology, and develop interagencysupported research, education andtraining.

Sharing resources and developing clearcommunication pathways will signifi-cantly enhance statewide efficiency.

Improve Public Awareness PROVIDE RESOURCES TO AREAS OF GREATEST NEED

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THE SPREADA comprehensive program to address the threat of invasive,non-native species must:

Take Aggressive Action on Prevention

Establish an Effective Early Warning System for Detecting New Pests

Enhance Rapid Response Capabilities

Resolve Conflicting Agency Mandates

Provide Adequate Funding

Provide Resources to Areas of Greatest Need

Improve Public AwarenessAbout the Problem

Provide Adequate FundingFlorida needs to establish a perma-nent fund for control of invasivespecies. Funding for control shouldnot be reduced prematurely, since inva-sive species can rebound, resulting inthe need for increased spending toachieve the same level of control.

Provide Resources to Areas of Greatest Need Florida must establish procedures,mechanisms and an information network that identifies, assesses andranks invasive species problems on an integrated statewide or regionalbasis. Designated conservation areasshould have priority for protection.Integrated species-based managementplans that define coordinated actionsagainst priority invaders must be devel-oped and implemented.

Because the prevention, eradicationand control of invasive species areoften a matter of local management, we

The threat of invasive species to our ecological

must stimulate local stakeholders totake action and provide them with theresources to do so. For instance, thestate should provide private landown-ers and corporations with support andother incentives for controlling invasivespecies on their properties, particularlythose in proximity to designated conser-vation areas. Florida should establish“invasive-free zones” buffering conserva-tion areas, starting with species most likely to colonize and threatenthose areas.

Improve Public AwarenessAbout the ProblemAll of these recommendations requirepublic support for funding and publicunderstanding of the threats invasivespecies pose. Public outreach andeducation efforts should aim to dis-suade people from importing or pur-chasing known invaders. The publicmust be encouraged to support fund-ing and implementation of programsthat remove and prevent importation ofinvasive species.

Hydrilla Acres vs. Funding in Florida Public Waters 1982-99

Year

Acr

es (t

hous

ands

)

Dol

lars

(mill

ions

)

Florida needs a permanent fund to provide consistent control of invasive species. As this graph shows,the acres of hydrilla consistently decreased when funding to control the species was increased. All gainswere lost, however, when funding was cut.

Sour

ce: W

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Won

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A volunteer pulling an Australian pineseedling from a conservation area. Public

understanding of the threats posed byinvasive species is critical to support forfunding and implementing strategies to

stop the spread.

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Hydrilla AcresFunds Expended

As indicated by the National

Invasive Species Management

Plan, Weeds Won’t Wait and the

Statewide Invasive Species

Management Plan, Florida

needs to dramatically increase

its commitment to address the

problem of invasive, non-native

species. Florida must be poised

to seize the opportunity for fed-

eral funding when it is available.

The threat of invasive species to

our ecological and economic

stability has real and practical

solutions. As we devise new

strategies to mitigate this threat,

we must treat invasion as a con-

dition to be managed, not as a

one-time problem to be solved

and forgotten. Emphasis must be

on preventing new introductions

of the most harmful invasive

species, while increasing our

ability to rapidly respond and to

mitigate the impacts of estab-

lished invaders.

and economic stability HAS REAL AND PRACTICAL SOLUTIONS

We must treat invasion as a condition to be managed, not as a one-time problem to be solvedand forgotten. This photo shows how many seedlings can sprout from one melaleuca tree thatreleased its seeds after being treated with herbicide.

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Eradication is possible and cost-effective if control needs are recognized, coordinated andadequately funded, as was the case with the pink hibiscus mealybug. An invasive pest withthe potential to devastate Florida’s $8 billion nursery industry, the pink hibiscus mealybugwas first detected in Broward and Miami-Dade counties on June 14, 2002. A parasitic waspto control the pest was released by June 21, with larger releases July 8 and in subsequentweeks. The USDA’s Offshore Biological Control Initiative predicts a 60 percent to 80 percentreduction of mealybugs within six months of the wasps’ release. This experience shows howrapid response and a well-coordinated research program can prevent serious economic lossesand environmental damage from new invasive species.

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BIBLIOGRAPHY

Many of the findings and recommendations inthis report come from the Noxious Exotic WeedTask Team’s extensive study, Weeds Won’t Wait —A Report to the South Florida Ecosystem RestorationTask Force and Working Group (2002). For moreinformation and a copy of the report on CD or asa PDF document, please see: www.sfrestore.org.

Other resources for information on invasivespecies include:

Simberloff, D., D.C. Schmitz, and T.C. Brown,Strangers in Paradise: Impact and Management ofNonindigenous Species in Florida, Island Press,Washington, DC: 1997.

Langeland, K.A., and K. Craddock Burks (eds.),Identification and Biology of Non-Native Plants inFlorida’s Natural Areas, University of Florida,Gainesville, FL: 1998.

Pimentel, David, Lori Lach, Rodolfo Zuniga, andDoug Morrison, Environmental and Economic CostsAssociated with Non-Indigenous Species in the UnitedStates, Cornell University, Ithaca, NY: 1999.Available online at http://www.news.cornell.edu/releases/Jan99/species_costs.html.

U.S. Congress, Office of Technology Assessment,Harmful Non-Indigenous Species in the UnitedStates, OTA-F-565, U.S. Government PrintingOffice, Washington, DC: September 1993.Available online at: http://www.wws. princeton.edu/~ota/disk1/1993/9325_n.html.

Hosansky, David, “Invasive Species,” CQ Researcher,October 5, 2001.

Barnett, Cynthia, and Marilyn Adams, “What’sEating Florida,” Florida Trend, October 1999.

Rejmánek, M. and M.J. Pitcairn. “When isEradication of Exotic Pest Plants a RealisticGoal?” Pp. 94-98 in: C.R. Veitch and M.N. Clout(eds.) Turning the Tide: The Eradication of InvasiveSpecies. In press: 2002.

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Cover photos: Africanized bees, © Texas Cooperative Extension Air potato, © D. Gordon