The 100th Meridian 

Initiative:

A Strategic Approach to

Prevent the Westward

Spread of Zebra Mussels

and Other Aquatic

Nuisance Species

U.S. Fish & Wildlife Service 100th Meridian
The 100th Meridian 

Initiative:

A Strategic Approach to

Prevent the Westward Spread

of Zebra Mussels and Other

Aquatic Nuisance Species

Prepared by:

Susan Mangin

Division of Fish and Wildlife Management Assistance

U.S. Fish and Wildlife Service

Endorsed by:

The Western Regional Panel

cover Zebra mussel illustration: Rick Hill
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . 1

I. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

II. Preventing the Westward Spread . . . . . . . . . . . 7

III. The Initiative. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

IV. Operational Needs and Estimated Costs . . . . 14

Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table of

Contents

i
This Initiative is based on an action plan, developed by the Western

Regional Panel, to prevent the spread of aquatic nuisance species (ANS)

west of the 100th meridian (The 100th Meridian Initiative - Draft Action

Plan, January 1998). The basic tenets of the action plan have been

expanded and refined through the cooperative efforts of numerous

dedicated biologists and managers, many of whom are the front line

defense for combating ANS in the west. Their experience, knowledge,

and vision ensure that implementation of this Initiative will help prevent

the spread of zebra mussels and other ANS into the west. 

In particular, I would like to thank Gary Edwards and Robert Peoples

who were the driving forces behind this Initiative. Their concern about

the impact that zebra mussels and other ANS could have on native

ecosystems and manmade structures in the west motivated them to guide

this project to completion. Hannibal Bolton provided unwavering support

for this project and directed my work load so that the majority of my

time was dedicated to developing and completing this project. 

Finally, I would like to recognize Linda Drees, Bob Pitman, and Kim

Webb. Their professionalism and dedication to preventing, controlling,

and eradicating ANS has been an inspiration. Their willingness to share

insights and suggestions relative to this Initiative has been invaluable. 

It has been a tremendous pleasure working with all those who

contributed to this Initiative. 

Acknowledgments

ii
1

Zebra mussels are prolific alien invaders that have rapidly become

established in waters of the eastern United States and Canada. These

natives of the Black, Caspian, Azov and Aral Sea drainage basins were first

discovered in Lake St. Clair near Detroit, Michigan, in 1988. By 1991, they

had spread throughout the Great Lakes basin and are now established

throughout the Mississippi River basin and are spreading west into

Oklahoma. Except for Oklahoma, zebra mussels have not been detected in

open waters of the West. However, without effective prevention measures,

their invasion into the West is a real and imminent possibility. 

Zebra mussels are causing significant economic and ecological impacts

throughout their range. They have biofouled thousands of municipal and

industrial water delivery systems, resulting in annual expenditures of up to

several $100,000 for control and detection activities. They are significantly

impacting aquatic ecosystems, altering nutrient flow, decimating native

mussel populations, and providing a sink for environmental contaminants. 

The major pathway for zebra mussels to invade the West is not from the

ballast water of ships but from boats, personal watercraft, and related

equipment transported from infested to uninfested waters. Zebra mussels

attach to hulls, trailers, and other exposed locations on boats, boating

equipment, and personal watercraft. Their free-living larva can enter

motors, live wells, or other moist areas and may remain viable for more

than 10 days when attached to boat hulls (Tyus, Dwyer, and Whitmore

1993). Their adaptability, their lack of natural predators, and the propensity

of boaters to move their boats from one body of water to another have

facilitated the rapid spread of zebra mussels throughout their current

range. 

Additional pathways for the spread of zebra mussels and other ANS are

also a major concern for western States and Tribes and public and private

entities. These other pathways must be addressed, but formulating plans to

deal with them will take time and resources. Consequently, this Initiative’s

primary focus is on the transfer of zebra mussels and other ANS through

recreational activities and commercial boat hauling. Additional pathways

will be addressed as resources permit.

Amendments to Public Law 101-636 call for the development of a program

to prevent the spread of zebra mussels west of the 100th meridian. This

100th Meridian Initiative outlines management activities that will help

prevent, detect, and control zebra mussels and other ANS in 100th

meridian jurisdictions and west. The 100th meridian jurisdictions include

Texas, Oklahoma, Kansas, Nebraska, North and South Dakota, and

Manitoba. 

The goals of the 100th Meridian Initiative are to: 1) prevent the spread of

zebra mussels and other ANS in the 100th meridian jurisdictions and west

and 2) monitor and control zebra mussels and other ANS if detected in

these areas. These goals will be achieved by addressing seven components:

1) information and education, 2) voluntary boat inspections and boater

surveys, 3) commercially hauled boats, 4) monitoring, 5) rapid response, 6)

identification and risk assessment of additional pathways, and 7) evaluation. 

The 100th Meridian Initiative represents the first comprehensive and

strategically focused effort, involving Federal, State, Tribal and Provincial

entities, potentially affected industries, and other interested parties to

begin addressing pathways to prevent the westward spread of zebra

mussels and other ANS. Success will depend on the commitment and

support of these groups to aggressively combat the introduction and spread

of these destructive invaders. 

Executive

Summary
A. Dispersal

Zebra mussels (Dreissena polymorpha) are indigenous to the Aral,

Caspian, Azov, and Black Seas. In the 19th century, zebra mussels invaded

northern European rivers that empty into the Black Sea (Karnaukhov and

Karnaukhov 1993). They became dispersed throughout Europe by barges

once the canal system became connected over 200 years ago. By 1930, they

had spread into Great Britain. Since the early 1920’s, scientists postulated

that zebra mussels could be spread to the United States through shipping

(Nalepa and Schlosser 1993). 

Zebra mussels were first discovered in Lake St. Claire in the Great Lakes

region in 1988. They probably arrived in the ballast water of vessels

originating from Europe. They rapidly spread and by 1992 were found in

all five Great Lakes. They have now spread throughout the Mississippi

River drainage as far south as New Orleans and as far west as the

Arkansas River in Oklahoma. They have also spread eastward into the

Hudson River drainage and Lake Champlain. 

Attaching to ships and barges has been a major pathway by which zebra

mussels have become dispersed throughout the Great Lakes and the

Mississippi River basin. Other pathways such as waterways flowing

between infested and uninfested areas, trailered boats, personal

watercraft, aquaculture activities, the aquatic plant aquarium trade, and

fishing gear and bait have also contributed to their distribution.

Zebra mussels’ ability to spread by attaching themselves to boats, personal

watercraft, and related equipment is a major concern because they can

remain viable under adverse environmental conditions. Adults can live out

of water for up to 10 days if they are in shaded humid areas. Boats

spending as little as 1 or 2 days in infested water can carry zebra mussels

on their hulls, engine drive units, and anchor chains. Zebra mussel larvae

can be carried in boat bilge water, live wells, bait buckets, and engine

cooling water systems even if the boat has been in infested water for only a

short time (New York Sea Grant Extension Fact Sheet 1994). 

Conditions leading to the initial dispersion for zebra mussels in the East do

not exist for western waters. Specifically, transport on boats and barges in

western tributaries of the Mississippi River is constrained by relatively

short navigable reaches and limited riverine traffic. In addition, those

areas flow away from the area of concern. Also, environmental conditions

in the arid and semiarid West may aid in deterring the spread of zebra

mussels.

The primary pathways for the western spread of zebra mussels will be

through their transport on recreational boats, associated equipment, and

personal watercraft. A survey conducted at the U.S./Canada border of

boaters and boats in watersheds that contribute to surface water in

Manitoba produced alarming results. Ninety-three percent of the boats

originated from jurisdictions with waters containing zebra mussels, 5% had

been in waters with zebra mussels within the past 5 days, 60% had been

drained, and only 32% had been cleaned since boating in zebra mussel

infested waters (Fish Futures, Inc. 1994). A separate survey was conducted

for boats entering Glen Canyon National Recreation Area in Utah. Results

indicate that numerous boats entering Lake Powell were from areas

infested with zebra mussels (National Park Service information). 

Zebra mussel transfer via trailered boats is a real threat. Inspectors from

California’s Department of Food and Agriculture have found both live and

dead zebra mussels on 18 trailered boats transported into the State from

the fall of 1993 until the spring of 1999 (California Department of Food and

Agriculture). 

I. Background

2
B. Biology and Life History

Zebra mussels vary morphologically, hence the species name “polymorpha”

meaning many forms. Although most have jagged lateral black or brown

stripes, some have longitudinal bands while others are totally cream or

black (Marsden 1992). They can grow up to 2 inches in length but most are

under an inch (see Figure 1).

Figure 1. Zebra Mussels (Don Schloesser) 

Zebra mussels mature between 12 to 18 months under favorable conditions

and can spawn more than once annually. One female can produce over 1

million eggs per season (Miller et al. 1992). Fertilized eggs become free

swimming larvae (veligers) that eventually attach to hard surfaces and

develop into hard-shelled juvenile mussels (post veligers). Preferred

substrates include stone, wood, concrete, iron/steel, aluminum, plastics, and

fiberglass (O’Neill 1996). As many as 700,000 post veligers/m2 have settled in

raw water systems during one spawning season (Miller et al. 1992; McMahon

et al. 1993). They have formed mats up to 12-inches thick (Tyus, Dwyer, and

Whitmore 1993).

Zebra mussels spread rapidly to different areas and thus are also called the

“wandering mussel” (Nalepa and Schloesser 1993). They can drop their

attachments (byssal threads) and move to other locations and then

regenerate threads to reattach. They form buoyant strands that allow them

to drift with the currents. Zebra mussels can also use their muscular foot to

move (Tyus, Dwyer, and Whitmore, 1993). Zebra mussels have been found

in water as deep as 180 feet but most often occur at depths between 6 to 12

feet (Mackie, et al. 1989). 

3
C. Economic Impacts

Zebra mussels are having devastating economic effects on municipal and

residential drinking water delivery systems, power plant intakes, and

industrial facilities that use raw surface water. They biofoul water delivery

systems beginning at the site of water intake and then multiply throughout

the facility (O’Neill 1996) (see Figure 2).

Figure 2. Zebra Mussels Fouling Pipe (Don Schloesser)

Zebra mussel layers greater than 0.3 meters have been found in intake

mains of some Great Lakes facilities. A 1- to 2-mm layer of zebra mussels

throughout a pipeline can reduce water-carrying efficiency by 5% to 10%

due to increased friction. Unlike saltwater or estuarine raw water systems,

most inland raw water systems are generally not designed to deal with

macrofouling organisms. Screens used to prevent fish impingement or to

remove debris allow zebra mussel veligers to pass, resulting in the

colonization of the facility’s raw water piping system (O’Neill 1996). 

Biofouling of conduits results in head loss and increased pumping

resistance. Tubing may become clogged, ultimately leading to components

overheating. Zebra mussels can clog service and water lines and can

damage vital plant components or cause safety hazards if the flow for fire

control systems is impeded (ibid). 

Due to their filtration activities, they may not leave enough particulate

matter to provide effective coagulation at water treatment plants. This may

require the plant to change its treatment technology, increasing operating

costs. In addition, as zebra mussels selectively feed on green algae, an

increased portion of blue-green algae is present. This may cause water to

have a foul taste and odor, also increasing treatment costs (ibid).

Controlling zebra mussels is costly. Results of a 1995 study indicated that

between 1988 and 1995 facilities expended over $69 million in zebra musselrelated expenses such as monitoring and control (O’Neill 1995). A paper

company spent $1.4 million to remove 400 cubic yards of zebra mussels

from its intake in Lake Michigan (USGS 1997). In Ontario, Canada, the

costs of preventing zebra mussel infestations at 8 hydro power facilities, 86

municipal plants, and 67 industrial plants were over $172 million. To control

zebra mussels in the Great Lakes, small and large volume water users may

annually spend $20,000 and $460,000, respectively (Indiana DNR). 

4
D. Boating Impacts

Zebra mussels biofoul boat hulls causing surface damage and increasing

drag, which increases fuel costs. Boat motors are also affected and can

become overheated due to clogged water inlets. Although antifouling paints

may prevent zebra mussels from building up on hulls, their use is banned

or restricted in some States because of adverse effects on other aquatic

organisms. 

E. Ecological Impacts

Habitat loss is the primary cause for the decline in native mussels.

However, zebra mussels have added a new threat. Zebra mussels often

attach around the gape of native mussels, preventing them from opening

and closing their valves (see Figure 3). They may even cover the native

mussel’s entire surface and then begin settling on top of each other.

(Mackie, 1989).

Figure 3. Zebra Mussels Attached to Native Mussel (Don Schloesser)

Zebra mussels also compete with native mussels for food, which may be

responsible for the community-wide unionid decrease in some areas in the

East. In Lake Erie, mean densities of 6,777 zebra mussels per native

mussel were found (Schloesser and Kovalak 1991).

An adult zebra mussel can filter about one liter of water per day. These

filtering activities increase water clarity allowing deeper light penetration,

encouraging the growth of benthic organisms. Zebra mussels have

increased the water clarity of Lake Erie up to 600% and reduced some

types of phytoplankton by up to 80% (Sea Grant Great Lakes Network

1998). 

F. Potential Impacts

The establishment of zebra mussels west of the 100th meridian could

devastate water resource projects, raw water users, and aquatic

ecosystems. If zebra mussels become established in headwater reservoirs,

they would likely inhabit/colonize thousands of canals used to transport this

water. This infested water would also be pumped to agricultural and

municipal areas, thus spreading the mussels over large areas in a relatively

short time. In lower elevations and wetter climates, surface water could

become contaminated from waters originating at higher elevations. Once

this water is transported to downstream receiving areas, they too would

become infested (Tyus, Dwyer, and Whitmore 1993).

5
Although the western most point of the zebra mussel invasion is the

Arkansas River in Oklahoma, there is increasing concern that they could

severely impact western economies and ecology if they invade further west.

For example, if zebra mussels invaded California, they could negatively

impact hundreds of reservoirs, thousands of miles of steel and concrete

pipes and canals, water gates and intakes, fish screens, filter plants,

agricultural irrigation systems, and other water delivery system

components. A large portion of California’s population depends on the State

Water Project and the Central Valley Project to deliver their water from

upstream sources. These water management projects with their shallow,

warm canals could provide optimal chemical and physical conditions for

zebra mussels. If zebra mussels become established in areas such as the

Sacramento/San Joaquin delta, they could eliminate populations of rare

aquatic species, change biotic communities’ composition, and change the

physical and chemical conditions of aquatic habitats.

In a study of 160 potential sites for zebra mussel establishment in

California, 44% had a high potential, 2% had a moderate potential, and 54%

had low or no potential for colonization (Cohen and Weinstein 1998). Waters

conducive to zebra mussel establishment included facilities such as the

Delta-Mendota Canal, the California and South Bay Aqueducts, the Los

Angeles Aqueduct, the Colorado River Aqueduct, the All American Canal,

and associated reservoirs.

Zebra mussel infestations could increase the Central Arizona Project

operations and maintenance costs between $4 and $5 million annually. 

This does not include the costs to customers, farmers, and water treatment

plants (Dreissena! 1998). Water delivered in the west by the Bureau of

Reclamation is utilized by farmers to provide the annual food requirements

of 38 million people. These water deliveries can be adversely affected by

the presence of zebra mussels and other ANS, resulting in maintenance

costs in the 10’s of millions of dollars.

6
In an effort to prevent the western invasion of zebra mussels, the 1996

amendments to the Nonindigenous Aquatic Nuisance Prevention and

Control Act of 1990 (Act) require the Western Regional Panel (Panel)

(established by the Act) to make recommendations to the Aquatic Nuisance

Species Task Force (Task Force) “regarding an education, monitoring

(includes inspection), prevention, and control program to prevent the

spread of the zebra mussel west of the 100th meridian.” The 100th

Meridian Initiative is in response to that requirement (see Figure 4).

The Panel was established under Section 1203 of the Act and is comprised

of representatives from western Federal, State, Tribal, and local agencies,

and private and commercial interests. The basis for the 100th Meridian

Initiative was an action plan developed by the Panel that recognized the

significance of trailered boats as a pathway and the special circumstances

impeding the westward spread of zebra mussels. The Panel submitted the

100th Meridian Initiative to the Task Force for review and approval.

The Task Force, established under Section 1201 of the Act, is comprised of

Federal agencies and ex-officio members. The Task Force, chaired by the

U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric

Administration, is responsible for the development and implementation of a

program to prevent introduction and dispersal of ANS; to monitor, control,

and study such species; and to disseminate related information. Upon

approval of the 100th Meridian Initiative by the Task Force, Federal

funding may be available to cost share with other sources to support

implementation.

Figure 4. Zebra Mussel Sightings (1999 U.S. Geological Survey Map with

100th Meridian Added)

II. Preventing

the Westward

Spread

7

★ Zebra mussels on trailered boats

● Confirmed zebra mussel sightings

100th Meridian
The 100th Meridian Initiative is a unique program involving a wide range of

partners who are integral in preventing the westward spread of zebra

mussels and other ANS. The Initiative’s goals are attainable through the

combined effort of these partners and implementation of the following

components. 

Goals and Components

The goals of the 100th Meridian Initiative are to 1) prevent the spread of

zebra mussels and other ANS in the 100th meridian jurisdictions and

west and 2) monitor and control zebra mussels and other ANS if

detected in these areas. Seven components will be addressed to achieve

these goals.

1) Information and Education: Inform and educate the public about the

ecological and economic impacts of zebra mussels, the pathways by

which they spread, and what actions can be taken to prevent their

spread.

2) Voluntary Boat Inspections and Boater Surveys: Prevent the spread

of zebra mussels in the 100th meridian jurisdictions and west through

voluntary boat inspections and boater surveys (see Appendix).

3) Commercially Hauled Boats: Prevent the spread of zebra mussels in

the 100th meridian jurisdictions and west by boats being hauled

commercially and/or for professional fishing tournaments.

4) Monitoring: Establish monitoring sites on waters in the 100th

meridian jurisdictions and west to determine if zebra mussels and other

ANS are present.

5) Rapid Response: Eradicate or contain zebra mussels immediately

following detection.

6) Identification and Risk Assessment of Additional Pathways:

Establish a program to identify additional pathways by which zebra

mussels and other ANS could be introduced west of the 100th meridian.

Evaluate these pathways and develop an action plan for those having

potential risks.

7) Evaluation: Ensure the effectiveness of the 100th Meridian Initiative

in preventing the westward spread of zebra mussels and other ANS. 

III. The Initiative

8
This component builds on current efforts directed at preventing the spread

of zebra mussels by recreational water activities such as boating and using

personal watercraft. Component elements will focus on the detrimental

effects of zebra mussels; the impacts of transporting them in or on

recreational boats, related equipment, or personal watercraft; and the steps

necessary to avoid transport to uninfested waters. Recreationalists using

infested waters east of the 100th meridian and those trailering boats or

personal watercraft from the east to areas west of the 100th meridian 

will be targeted. Information will be disseminated through numerous

means including print and electronic news coverage, public service

announcements, billboards, articles in boating and fishing magazines, 

talks to sportsmen clubs, posters and brochures placed at marinas and 

boat landings, and brochures packaged with boating and fishing licenses.

As boaters using major highways approach the 100th meridian from the

east, the zebra mussel message will become more intense. Posters and

brochures identifying the problem and detailing the inspection and survey

process will be placed prominently in rest areas and at restaurants, motels,

and gas stations at interchanges. Key messages will be displayed on

billboards and highway signs along the 11 targeted interstate highway

corridors. Just prior to reaching the inspection sites, highway signs and

short-range radio announcements will inform travelers of the inspection

and survey sites and urge their participation.

Tasks required to implement this component include:

1) Complete development of a theme, brochure, poster, and sticker 

describing the Initiative. (This task has been completed.)

2) Print 500,000 brochures.

3) Produce 2,500 posters.

4) Produce 100,000 stickers.

5) Place and replenish brochures and posters at visitor centers, weigh 

stations, and rest areas west of the Mississippi River.

6) Produce and erect billboards to be used on 11 highway corridors.

7) Develop and print zebra mussel advisory signs.

8) Post zebra mussel advisory signs at public water access sites west of 

the Mississippi River.

9) Create TV and radio public information spots on preventative messages

including inspections.

10) Broadcast spots on radio and TV.

11) Attend boating and sportfishing shows to advertise the Initiative.

12) Place Initiative information in State boater registration packages and 

fishing regulations when feasible.

13) Develop articles for newspapers and magazines.

Component I

Information and Education

Objective: Inform and educate the

public about the ecological and

economic impacts of zebra mussels,

the pathways by which they spread,

and what actions can be taken to

prevent their spread.

9
Trained personnel will conduct voluntary boat inspections and boater

surveys at highway stops located on 11 major highway corridors entering

the 100th meridian jurisdictions and at marinas and launch ramps at

selected lakes in States west of the 100th meridian. These selected

highways are: US2, I-94, US12, I-90, I-80, I-70, US54, I-40, I-20, I-10, and

I-44 (see Figure 5). Locations for highway inspections will include weigh

stations, highway rest areas/welcome centers, restaurant/service/motel

complexes on interchanges, and retailers. Inspections will target boats,

trailers, and associated equipment such as anchors and anchor lines.

Boaters will be surveyed to learn where their boat has been, what is their

destination, etc. (see Appendix). Boaters will receive a brochure explaining

the Initiative and what actions they can take to prevent the spread of zebra

mussels. 

Component II

Voluntary Boat Inspections and

Boaters Surveys

Objective: Prevent the spread of

zebra mussels in the 100th meridian

jurisdictions and west through

voluntary boat inspections and

boater surveys. 

10

Data will be collected using the boat inspections and surveys and other

unobtrusive means such as counting the number of boats that passed by

inspection stations without stopping. Additional data including the number,

types, and timing of boats being trailered on each highway corridor and

why boaters declined to have their boats inspected will be collected. In

addition, State and provincial transportation departments will be asked to

develop data to expand the information collected at inspection sites by

identifying trailered boats in ongoing State vehicle surveys. Inspection and

survey results will be sent for processing to the USFWS, 500 Gold Avenue,

S.W., Albuquerque, NM 87102, Attn: Bob Pitman.

These data will be analyzed to include unit costs of various activities. The

cost effectiveness of alternative education and information approaches and

the adequacy of education efforts alone, in the absence of inspections, will

be assessed. These data will be used to evaluate the effectiveness of the

100th Meridian Initiative.

Tasks required to implement this component include:

1) Develop standard inspection procedures.

2) Hire and train boat inspectors.

3) Develop, reproduce, and disseminate inspection and survey forms.

4) Submit completed forms to the Service.

Figure 5. 

Major Highways
A. Commercial Boat Haulers

Between 1993 and l998, zebra mussels had been found on 18 vessels passing

through California Agricultural Inspection stations. Some of these vessels

were transported by commercial firms that either specialize in hauling

boats or manufacturers of new vessels who haul used boats on their return

trips. Although some firms require the hulls of boats they haul to be power

washed, this practice is not universal. Even when followed, it may not be

effective in removing all zebra mussels or other ANS present. Live

organisms may remain on the hull and in crevices, bilges, bait wells, and

cooling systems of motors. Component III will be supported through

information and education, certification, and inspection programs.

The information and education program will involve locating and contacting

commercial boat hauling firms. Through direct contact and follow up

correspondence, the firms will be informed of the zebra mussel problem,

alerted to the possibility that they may be transporting zebra mussels and

other ANS to uninfested waters, and advised of what actions they can take

to avoid this from occurring.

An ANS inspection training program will be established to teach employees

of boat hauling firms how to properly inspect and clean boats and related

equipment. Employees who successfully complete the training will receive a

certificate. Hauling firms will be encouraged to have their employees

complete the training program and to then begin implementing an

inspection and cleaning program of all boats before they are hauled.

Participating firms will be authorized to place a sticker on boats they haul,

certifying the boat has been inspected for zebra mussels and other ANS. 

B. Boats Hauled for Professional Fishing Tournaments

Numerous professional fishing tournaments are held around the country,

resulting in boats being transported from one body of water to another,

including those from zebra mussel infested to uninfested waters. Although

some tournaments require participants to sign a statement that they are

not carrying ANS, this requirement is spotty and often ineffective.

Information, certification, and inspection programs could be implemented

to help ensure that zebra mussels are not spread by those involved with

professional fishing tournaments. State and tribal agencies will be

encouraged to implement tournament regulations addressing the transport

of ANS.

As part of the information program, material about zebra mussels and

other ANS issues will be available at fishing tournaments. Tournament

organizers will be contacted and informed about the zebra mussel problem

and how they can help prevent their spread in 100th meridian jurisdictions

and west. Until an official inspection program is implemented, tournament

organizers will be encouraged to ask participants to inspect their boats

before the tournament begins. 

An ANS inspection training program could be established to teach

tournament representatives how to properly inspect and clean boats and

equipment that will be used during the tournament. Representatives who

successfully complete the training would receive a certificate. Tournament

organizers would be encouraged to have their representatives complete the

training program and to begin implementing an inspection and cleaning

program of all boats before they participated in a tournament. Tournament

participants who had their boats inspected would be authorized to place a

sticker on the windshield of their boat certifying the boat had been

inspected for zebra mussels and other ANS. Under this scenario, only boats

with these stickers would be allowed to participate in the tournaments.

Component III 

Commercially Hauled Boats

Objective: Prevent the spread of

zebra mussels in the 100th meridian

jurisdictions and west by boats

being hauled commercially and/or

for professional fishing

tournaments. 

11
Tasks required to implement this component include:

1) Locate firms that haul boats commercially.

2) Contact those firms explaining the Initiative and requesting their 

participation.

3) Meet with representatives of firms to discuss the Initiative.

4) Develop a training program and train boat inspectors.

5) Develop and produce certification for inspectors.

6) Develop, reproduce, and disseminate inspection forms.

7) Develop a list of contacts for professional fishing tournaments.

8) Contact tournament organizers and inform them about the Initiative 

and encourage their participation.

9) Attend professional fishing tournaments.

10) Train and certify tournament representatives to inspect boats.

11) Contact State and tribal agencies and encourage them to address the 

transportation of zebra mussels and other ANS in their regulations. 

A. Background

Although currently undetected, zebra mussels may have already spread

west of the 100th meridian. Effective monitoring is important to ensure

that if zebra mussels are present, they will be detected. Early identification

of zebra mussel infestation can decrease their potential impact on native

resources, manmade structures, and the economy. This component will

expand upon current management activities of Federal water management

agencies, the Service, States, electric utilities, and others. Monitoring

protocol will be developed through a workshop represented by Federal,

State, and private entities. The Service will coordinate efforts to monitor

for the presence or absence of zebra mussels. Findings will be reported to

the National Nonindigenous Aquatic Nuisance Species Information Center

in Gainesville, Florida. 

Water bodies in 100th meridian jurisdictions and west will be assessed by

Federal and State agencies to determine their potential for zebra mussel

infestation. Physical and chemical measurements will be evaluated using a

standardized risk assessment protocol along with recreational use patterns.

Maps of assessed sites will be provided to State resource agencies and

high-risk waters will be monitored periodically.

Tasks required to implement this component include:

1) Develop a list of zebra mussel monitoring activities west of the 100th

meridian.

2) Perform risk assessment of bodies of water west of the 100th meridian.

3) Develop maps indicating areas of high, medium, and low risk.

4) Monitor high-risk areas.

A cooperative rapid response effort among government agencies and the

private sector is required to contain zebra mussels once they are detected.

Zebra mussel sightings must be confirmed by qualified entities (Marsden,

1992). Jurisdictions along the 100th meridian and west will be asked to

identify points of contact for receiving and confirming reports and

coordinating response activities. Jurisdictions will also be asked to establish

rapid response teams. 

Once a new zebra mussel infestation has been identified, the next most

likely site of infestation will be determined. By reviewing watershed maps

and recreational use patterns, sites that are likely to be invaded next will

be identified. 

A national containment and control plan will be developed through a

workshop to identify techniques for controlling and eradicating zebra

mussels. This program will include outreach to educate the public about

where zebra mussels have been sighted and how their transfer from

infested sites can be prevented. Individuals making up a response team will

Component IV

Monitoring 

Objective: Establish monitoring

sites on waters in the 100th

meridian jurisdictions and west to

determine if zebra mussels and

other ANS are present. 

Component V

Rapid Response

Objective: Eradicate or contain

zebra mussels immediately

following detection.

12
be trained to implement certain aspects of the containment and control

plan if zebra mussel infestations are discovered in 100th meridian

jurisdictions and west. Decisions will be made as to how to handle zebra

mussel containment and control if they are found in large bodies of water

in the West.

Tasks required to implement this component include:

1) Develop a response/containment plan.

2) Train response team.

3) Equip response team.

4) Implement response/containment plan when necessary.

This component will involve the development and funding of a program for

identifying pathways, other than those that are boating and personal

watercraft related, by which zebra mussels and other ANS may become

introduced west of the 100th meridian. A risk assessment for each

pathway identified will be conducted and actions for risk reduction will be

developed. Once specific action plans have been developed, the focus and

funding will be directed toward implementation where feasible. Tasks

required to implement this component are the same as the objective. 

As the Initiative evolves, a timely and comprehensive evaluation of the

effectiveness of actions taken is required to respond to needed changes. An

evaluation protocol will be developed to assess whether Initiative

objectives have been and are being met. Deficiencies will be identified and,

if required, modifications will be made. 

Evaluations will be conducted by those who directly implement the

Initiative. An annual meeting will be held of key personnel, including

representatives from Federal, State, Provinces, Tribes, and private

agencies, who are implementing the Initiative to discuss the results of the

evaluation. An annual evaluation report will be prepared. Required

changes to the Initiative will be incorporated, and ineffective actions will be

eliminated.

Tasks required to implement this component include:

1) Develop assessment format and disseminate to key persons involved in

implementing the Initiative.

2) Set up an annual meeting to evaluate the Initiative.

3) Develop an annual assessment of the Initiative and make necessary 

modifications.

Component VI

Identification and Risk

Assessment of Additional

Pathways

Objective: Establish a program to

identify additional pathways by

which zebra mussels and other ANS

could become established west of

the 100th meridian. Evaluate these

pathways and develop an action

plan for those having potential

risks. 

Component VII

Evaluation

Objective: Ensure the effectiveness

of the 100th Meridian Initiative in

preventing the westward spread of

zebra mussels and other ANS.

13
The spread of zebra mussels and other ANS in the West will require a

concerted long-term campaign. Consequently, implementation of the 100th

Meridian Initiative will require a minimum of 5 years and approximately $5

million. First year’s start up costs will be higher than projected costs for

the following years. Cost breakdowns for each Initiative component for the

5-year program are identified in the “Operational Needs and Estimated

Costs” table. The projected costs for this Initiative are but a fraction of the

economic impact that zebra mussels will inflict if they invade and become

established in western waters. 

IV. Operational

Needs and

Estimated Costs

14

Operational Needs and Estimated Costs Table 

Tasks and associated costs required for implementing the 100th Meridian Initiative. 

Component I: Information and Education Participants Year 1 Year 2 Year 3 Year 4 Year 5 

Task 1: Complete development of a USFWS

theme, brochure, poster, and sticker Boat/U.S.

describing the Initiative (completed) BPA

Task 2: Print 500,000 brochures USFWS $50,000

Task 3: Produce 2,500 posters USFWS $1,875

Task 4: Produce 100,000 stickers USFWS $500

Task 5: Place and replenish brochures USFWS $5,000 $1,000 $1,000 $1,000 $1,000 

and posters at visitor centers, weigh 

stations, and rest areas west of the 

Mississippi River 

Task 6: Produce and erect billboards USFWS $25,000 $22,000 $22,000 $22,000 $22,000

to be used on 11 highway corridors Manitoba 

ND, SD, NE

KS, OK, TX 

Task 7: Develop and print a zebra USFWS $10,000

mussel advisory sign 

Task 8: Post zebra mussel advisory Jurisdictions $3,600

signs at public boat access sites west west of the 

of the Mississippi River MS River

Task 9: Create TV and radio public USFWS $10,000 $10,000 $2,000

information spots on preventative Sea Grant

messages including inspections 

Task 10: Broadcast spots on USFWS $10,000 $10,000 $10,000 $10,000 $10,000 

radio and TV 

Task 11: Attend boating and USFWS $15,000 $15,000 $15,000 $15,000 $15,000 

sportfishing shows to advertise Sea Grant

the Initiative States 

Task 12: Place Initiative information 100th meridian 

in State boater registration packages jurisdictions

and fishing regulations when feasible and those west 

Task 13: Develop articles for USFWS

newspapers and magazines Sea Grant

States

Provinces

Subtotals $130,975 $58,000 $50,000 $48,000 $48,000 
Component II: Voluntary Participants Year 1 Year 2 Year 3 Year 4 Year 5 

boat inspections and boater surveys 

Task 1: Develop standard inspection USFWS $10,000 $2,000 

procedures Manitoba

ND, SD, NB, 

KS, OK, TX 

Task 2: Hire and train boat inspectors USFWS $109,000 $252,000 $504,000 $504,000 $504,000 

States 

Task 3: Develop, reproduce, and USFWS $200 $100 $50 $50 $50 

disseminate inspection and survey forms 

Task 4: Submit completed forms USFWS $36 $36 $36 $36 $36 

to USFWS MB, ND, SD, 

NB, KS, OK, 

TX

Subtotals $119,236 $254,136 $504,086 $504,086 $504,086 

Component III: Commercially hauled boats 

Task 1: Locate firms that haul USFWS $20,000 $20,000 $20,000 $20,000 $20,000 

boats commercially

Task 2: Contact those firms 

explaining the Initiative and requesting 

their participation

Task 3: Meet with representatives of 

firms to discuss the Initiative 

Task 4: Develop training program for USFWS

boat inspectors 

Task 5: Develop and produce USFWS $1,500

certification for inspectors 

Task 6: Develop, reproduce and USFWS $150 $50 

disseminate inspection forms

Task 7: Develop a list of contacts for USFWS $4,000

professional fishing tournaments 

Task 8: Contact tournament organizers USFWS $5,000 $2,000

and inform them about the Initiative

and encourage their participation 

Task 9: Attend professional fishing USFWS $10,000 $10,000 $10,000 $10,000 $10,000 

tournaments States west

of the

MS River 

Task 10: Train and certify tournament USFWS

representatives to inspect boats

Task 11: Contact State and USFWS $10,000 $7,000 $5,000 $5,000 $5,000 

tribal agencies and encourage them 

to address the transportation of 

zebra mussels and other ANS in 

their regulations 

Subtotals $49,000 $39,000 $35,000 $36,650 $35,050 

15
Component IV: Monitoring Participants Year 1 Year 2 Year 3 Year 4 Year 5 

Task 1: Develop a list of zebra mussel USFWS $7,000

monitoring activities west of the 

100th meridian 

Task 2: Perform risk assessments USFWS $250,000 $175,000 $100,000 

of bodies of water west of the 100th BOR, Corps

meridian BLM, States,

Power Co.

Task 3: Develop maps indicating areas USFWS $30,000 $80,000 $50,000

of high, low, and medium risk

Task 4: Monitor high-risk areas USFWS $350,000 $350,000 $350,000 $350,000 $350,000

BOR, Corps

BLM, Tribes

States, Provinces,

Power Co. 

Subtotals $637,000 $605,000 $500,000 $350,000 $350,000

Component V: Rapid Response 

Task 1: Develop a response/containment plan USFWS $10,000

BOR, BLM

Tribes, States

Provinces 

Task 2: Train response team USFWS $50,000

Task 3: Equip response team USFWS $100,000

Task 4: Implement response/containment USFWS $30,000 $30,000 $30,000 $30,000 $30,000 

plan when necessary 

Subtotals $190,000 $30,000 $30,000 $30,000 $30,000 

Component VI: Identification and risk USFWS $10,000 $10,000 $10,000 $10,000 $10,000

assessment of additional pathways BOR $10,000 $10,000 $10,000 $10,000 $10,000

BLM $10,000 $10,000 $10,000 $10,000 $10,000

States 

Provinces 

Subtotals $30,000 $30,000 $30,000 $30,000 $30,000 

Component VII: Evaluation 

Task 1: Develop assessment format USFWS $1,000

and disseminate to key persons involved 

in implementing the Initiative

Task 2: Set up annual meeting to USFWS $3,000 $3,000 $3,000 $3,000 $3,000 

evaluate the Initiative 

Task 3: Develop an annual assessment USFWS $5,000 $5,000 $5,000 $5,000 $5,000 

of the Initiative and make necessary BOR, BLM

modifications States, Provinces 

Subtotals $9,000 $8,000 $8,000 $8,000 $8,000

Grand Totals $1,165,211 $1,024,136 $1,157,086 $1,006,736 $1,005,136 

16
TRAILERED BOAT SURVEY INTERVIEW FORM

Interviewer:_________________________Date:______Time:________am/pm

Location: _________________________________________________________ 

Type of Survey: Contact____ Observe____

Where From?

Purpose of Transport: Commercial ____ Personal ____ 

Other (explain) ____________________________________________________

Home State: ______ Zip Code: __________ Boat Number:______________ 

Trailer Tag: ______________________ 

How often has this boat been launched this year? __________

Do you remember where (you launched most recently)? 

Water body 1______________________________________________________

State: ________ County: ____________________________________________

Water body 2______________________________________________________

State: ________ County: ____________________________________________

Water body 3______________________________________________________

State: ________ County: ____________________________________________

Water body 4______________________________________________________

State: ________ County: ____________________________________________

Where are you going? Do you have a definite destination? 

Do you know where you are going to launch next?

Water body 1 _______________________________________ State: ______

Water body 2 _______________________________________ State: ______

Information Exchange: Viewed ____ Read _____Brochures Accepted _____

Results of boat inspection

Rejected: _________ Inspected: _______

Results Zebra Still Any Other Action

Mussels Alive? Vegetation? Exotics Taken 

Boat Deck ________ ________ ________ ________ ________

Boat Hull ________ ________ ________ ________ ________

Bilge, bait wells ________ ________ ________ ________ ________

Motor ________ ________ ________ ________ ________

Trailer ________ ________ ________ ________ ________

Fishing/other equip. ______ ________ ________ ________ ________

Other ________ ________ ________ ________ ________

Appendix

100th Meridian Initiative to

Prevent the Westward Spread of

Zebra Mussel

Comments

Comments

17
TRAILERED BOAT SURVEY INTERVIEW SHORT FORM

Lake ___________________________ Park ____________ Date __________

1. Home state __________ ZIP Code ___________

2. Where was the boat used last? 

Name of last water body ___________________________________________

State: _________

Number of days: ______

Name of second to last water body __________

State: _________

Number of days: ______

3. Boat was last used _________ (days) ago. 

4. Destination from this lake/park __________________ _________ (state)

5. Have you ever heard of zebra mussels? Yes No

6. Have zebra mussels ever been attached to your boat? Yes No

7. Do you remove vegetation from your boat & trailer

after loading the boat? Yes No

Have information describing zebra mussels and Eurasian watermilfoil

available for distribution. 

100th Meridian Initiative to

Prevent the Westward Spread of

Zebra Mussel

18
California Department of Food and Agriculture, personal communication. 

Cohen, A., A. Weinstein. 1998. The potential distribution and abundance of

zebra mussels in California Dreissena, Volume 9, #1, May 1998, pages 1,

2, and 3.

Dreissena, Volume 9, #1, May 1998, The 100th Meridian Initiative

introduction, page 4.

Fish Futures, Inc. 1994. Zebra mussel survey of boaters and inspection of

boats, summer 1994, border crossings and other key sites, Manitoba

watershed, Dwight Williamson, Manitoba Environment, Winnepeg,

Manitoba, Canada, page 10 (unpublished report).

Indiana Department of Natural Resources discussion with staff.

Karnaukhov, V. N., and A. V. Karnuakhov. 1993. Perspectives on the

ecological impacts of the zebra mussel (Dreissena polymorpha) in the

former USSR and in North America, pages 729-731 from Nalepa, T. F.

and D. W. Schloesser, Editors, Zebra mussels: biology, impacts and

controls, page 810 and from Tyus, H., P. Dwyer, and S. Whitmore, 1993.

Zebra mussels: Feasibility of preventing further invasion of the zebra

mussel into the western United States, page 9.

Machie, G. L. 1989. Biology of the zebra mussel (Dreissena polymorpha)

and observations of mussel colonization on unionid bivalves in Lake St.

Clair of the Great Lakes from Nalepa, T. F., D. W. Schloesser, Editors,

Zebra mussels: Biology, impacts, and control, pages 153 and 162.

Machie, G. L., W. N. Gibbons, B. W. Muncaster, and I. M. Gray. 1989. The

zebra mussel, Dreissena polymorpha: A synthesis of European

experiences and a preview of North America. Water Resources Branch,

Great Lakes Section, Ontario Ministry of the Environment, London,

Ontario, page 76 and appendices from Marsden, J. E., Standard

protocols for monitoring and sampling zebra mussels, page 4.

Marsden, J. E. 1992. Standard protocols for monitoring and sampling zebra

mussels, pages 2, 3, and 4.

McMahon, R. F., T. A. Ussery, and M.. Clarke. 1993. Use of immersion as a

zebra mussel control method, Department of Biology, University of

Texas at Arlington. Prepared for the U.S. Corps of Engineers, contract

EL-93-1, page 33 from Tyus, H., P. Dwyer, and S. Whitmore, Zebra

mussel feasibility of preventing further invasion of the zebra mussel into

the western United States, page 9.

Miller, A. C., B. S. Payne, and R. F. McMahon. 1992. The zebra mussel:

biology, ecology, and recommended control strategies, U.S. Army Corps

of Engineers, Waterways Experiment Station, Publications E-92-1,

Vicksburg, MS, page 5 from Tyus, H., P. Dwyer, and S. Whitmore, Zebra

mussel feasibility of preventing further invasion of the zebra mussel into

the western United States, page 9.

Nalepa, T. F., and D. W. Schloesser, editors. 1993. Zebra mussels: biology,

impacts, and control. Lewis publishers, Boca Raton, Florida, page 810

from Tyus, H., P. Dwyer, and S. Whitmore, Zebra mussels: Feasibility of

preventing further invasion of the zebra mussel into the western United

States, pages 8 and 9.

National Park Service information, Glen Canyon National Recreational

Area.

New York Sea Grant Extension Fact Sheet 1994. Don’t pick up hitchhikers!

Stop the zebra mussel!, 1994.

References

19
O’Neill, C. R. Jr. 1995. Economic impact of zebra mussels: The 1995

national zebra mussel information clearinghouse study, pages 1 and 2.

O’Neill, C. R. Jr. 1996. The zebra mussel: Impacts and control, pages 11, 12,

13, 14, and 17.

Schloesser, D. W., and W. P. Kovalak. 1991. Infestation of unionids by

Dreissena polymorpha in a power plant canal in Lake Erie. Journal of

Shellfish Research 10(2):355-359 from Tyus, H., P. Dwyer, and S.

Whitmore, Zebra Mussels: Feasibility of preventing further invasion of

the zebra mussel into the western United States, page 10.

Sea Grant Great Lakes Network April 7, 1998. Zebra mussels and other

nonindigenous species.

The 100th Meridian Initiative - Action Plan Draft, January 9, 1998. 

Tyus, H., Dwyer, W. P., and Whitmore S. 1993. Zebra mussels: Feasibility of

preventing further invasion of the zebra mussel into the western United

States. Pages 9, 19, and 20.

USGS news release September 18, 1997. Zebra mussels are spreading

rapidly, USGS reports.

20
U.S. FISH & WILDLIFE SERVICE

DEPARTMENT OF THE INTERIOR

U.S. Department of the Interior

U.S. Fish and Wildlife Service

1849 C Street, NW

Washington, DC 20240

1 800/344 WILD

http://www.fws.gov

February 2001