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Three-State Exotic Species Boater Survey:
What do boaters know and do they care?

by Jeff Gunderson

A survey of boaters in Minnesota, Wisconsin, and Ohio was conducted to:

  1. evaluate the effectiveness of aquatic nuisance exotic species boater education programs
  2. determine how best to reach boaters and change their behavior to reduce the risk of spreading exotics
  3. help define the risks boaters pose for spreading exotic species, and
  4. find out what boaters know about exotics.
The survey was conducted by the Minnesota Center for Survey Research in cooperation with the Minnesota Sea Grant College Program, the Great Lakes Sea Grant Network, and the Minnesota Department of Natural Resources. Mail surveys were sent to 2400 randomly selected boaters (800 in each state). Survey response rate averaged 56 percent and was highest in Minnesota (64%) and lowest in Ohio (44%). A telephone survey of 279 non respondents was conducted to determine if non-respondents differed from respondents. Because the mail survey response rate from Ohio was significantly lower than for the other states, more telephone surveys were conducted there (170) than in Wisconsin (53) or Minnesota (56).

The amount of effort put forth, and the educational methods or other incentives used to change boater behavior to reduce their risk of spreading exotic species, differed dramatically among the three states. More effort has been expended and a greater variety of techniques have been used in getting the exotic species message out in Minnesota than in the other two states surveyed. In Minnesota there are civil penalties for transporting exotic species, road checks to enforce the regulations, and inspection/education programs at accesses to infested waters. In addition, exotic species messages have been presented on billboards, the cover of the fishing regulations pamphlet, at boat accesses, via the media, at conferences/workshops and boat/sports shows, in fact sheets and brochures, and in educational packages distributed to lake and fishing associations. The efforts in Minnesota have been primarily directed at Eurasian watermilfoil and purple loosestrife but have included many other exotics including zebra mussels, Eurasian ruffe, Bythotrephes (the spiny water flea), and the rusty crayfish. Efforts to restrict the spread of exotics in Ohio and Wisconsin have been focused primarily on zebra mussels and have relied mainly on the media, information presented at conferences/workshops and boat/sport shows, and distribution of brochures and fact sheets. Throughout this paper, "exotic species" refers to nuisance aquatic exotic species and does not include intentionally introduced exotics like steelhead, chinook salmon, coho salmon, etc.

Survey results indicate Minnesota boaters are more knowledgeable about exotic species issues and have already changed their behavior to a greater extent (to prevent the spread of exotics) than boaters in the other two states (figure 1).

Figure 1

This suggests that educational programs are effective. Also, more Minnesota boaters (91%) felt that it was very important to take precautions to prevent the spread of Eurasian watermilfoil (figure 2) than boaters in Wisconsin (54%) and Ohio (29%). Generally, boaters in all three states felt that it was important to take precautions to prevent the spread of zebra mussels. However, a greater percentage of boaters in Minnesota and Wisconsin (80% for both states) felt it was very important to take steps to prevent spreading zebra mussels than boaters in Ohio (70%). Throughout the survey, Minnesota boaters were more concerned and aware of the threats posed by spreading exotic species than boaters in Wisconsin and Ohio. Ohio boaters were less concerned than Wisconsin boaters. For example, when asked to rank the importance of taking precautions to prevent the spread of Bythotrephes and Eurasian ruffe, 54 percent of Minnesota boaters felt it was very important compared to 42 percent of Wisconsin boaters and 31 percent of Ohio boaters (figure 2).

Figure 2

Boaters' responses to questions that asked where they obtained their information is subject to the availability of the source, as well as the effectiveness of the source of information. We, therefore, not only asked boaters to list the best sources of information on exotic species that they were exposed to, but we also asked them to rank the effectiveness of a variety of information sources, irrespective of whether they had been exposed to it.

The media, especially newspapers and television, were the two most important sources of information about exotic species for all three states. The third most important source of information for Minnesota boaters was signs at boat accesses, while for Wisconsin and Ohio boaters it was magazines. The high ranking of signs at boat access sites in Minnesota reflects their more extensive use than in Wisconsin and Ohio. However, when asked what they thought would be the most effective way to deliver the exotic species message (irregardless of what they had been exposed to), boaters in all three states highly ranked signs at boat accesses. Boat access signs were ranked first in Minnesota and Wisconsin, and third in Ohio. Boaters in all three states ranked the inclusion of exotic species information in boating and fishing regulations pamphlets second. Minnesota boaters ranked inspection/education programs at boat accesses third, while brochures were ranked third in Wisconsin and second in Ohio.

Boaters that reported boating in waters infested with exotic species in 1993, knew the waters were infested primarily because of signs at boat accesses in Minnesota (87%) and Wisconsin (56%), but in Ohio they found out primarily from newspapers (86%). The responses also reflected the importance of signs at boat accesses, and the news media.

Boaters were also asked what influenced them to take precautions against spreading exotic species. "A sense of personal responsibility and a desire to keep exotics out of my lake or stream" were the primary reasons reported in all three states. Signs at boat accesses, the media, and regulations (in Minnesota) were also influential. The fact that a high percentage of boaters are motivated to prevent the spread of exotic species through a sense of personal responsibility, is encouragement for continued educational efforts. It shows that boaters are receptive to exotic species messages and willing to change their behavior.

The survey found that boaters present a significant vector for the spread of exotic species. The shorter the time a boat is left out of water before it is moved to a different water body, and the more often it is used in two different water bodies, the greater the risk of spreading exotic species such as zebra mussels, Eurasian watermilfoil, and spiny water flea. In Minnesota and Wisconsin, 20 percent of respondents reported using their boat in different water bodies within the same day an average of 4 times during 1993 (figure 3).

Figure 3

Twenty three percent used their boat in different water bodies an average of six times within two days during 1993. Thirty percent used their boats in different water bodies an average of seven times within 3 to 5 days during 1993. Ohio respondents were less likely to boat in different water bodies within these time frames, which likely reflects the less abundant water resources compared with Minnesota and Wisconsin. Approximately 20 percent of Minnesota and Wisconsin boaters and 44 percent of Ohio boaters knew they boated in infested waters in 1993.

When asked why they didn't take precautions to prevent the spread of exotic species, boaters in all three states indicated that it was primarily because they didn't know what to do, or that they didn't boat in infested waters (figure 4). Very few boaters said taking precautions is useless, or that exotic species are not a problem (figure 4).

Figure 4

Again, this is encouragement for continued educational programs. Also, in Minnesota, where there has been a greater effort toward exotic species boater education than in the other two states, significantly fewer boaters reported that they didn't know what to do (28%) compared to boaters in Wisconsin (39%) and Ohio (45%).

Boaters were asked how often they took certain precautions to prevent the spread of exotic species. A high percentage of boaters in all three states indicated that they almost always made visual inspections of their boats and drained water from live wells and bilges. Since zebra mussels attach to aquatic vegetation and Eurasian watermilfoil can be spread by plant fragments, it is important to remove all vegetation from boats, trailers, equipment, etc. before going to another lake or river. Only in Minnesota did a high percentage of boaters (75%) report that they almost always remove vegetation and mussels from their boat and equipment. Fewer boaters removed vegetation and mussels in Wisconsin (49%) and Ohio (51%). This again seems to reflect positively on Minnesota's Eurasian watermilfoil educational campaign. In all three states, however, only about fifty percent of boaters reported almost always dumping out their bait on shore, and only about thirty percent said they almost always let their boat dry for ten days before going to another lake or river.

Boaters were asked what problems zebra mussels cause to try to find out what boaters knew about them. The top three responses in Minnesota were:

  1. disrupt the ecosystem,
  2. encrust boats, breakwalls and buoys and
  3. clog pipes.
In Wisconsin boaters listed the problems in a slightly different order:

  1. disrupt ecosystems,
  2. clog pipes and
  3. encrust boats breakwalls and buoys.
In Ohio, which has more experience with zebra mussels, a different problem made it into the top three responses:

  1. clog pipes,
  2. encrust boats, breakwaters, buoys, and
  3. damage boats.

In order to determine if boaters perceived exotic species as a threat to their lakes and streams, they were asked to rank a variety of possible threats. Only in Minnesota did exotic species rank among the top three concerns. Boaters in all three states felt that polluted runoff was more of a threat to lakes and streams than were exotic species. In Wisconsin and Ohio, Industrial pollution, fish contaminants, faulty septic systems, and habitat loss were also more of a concern than exotic species.

There was concern that non-respondents to the mail survey were significantly different in their behavior and knowledge of exotics than respondents. The telephone survey of non-respondents, however, found that the mail survey non-respondents did not differ significantly from respondents in their attitudes, behavior, or understanding of exotics. Non-respondents did, however, boat less often than mail survey respondents.

In conclusion, survey results suggest that:

  1. boater education programs and other incentives have been effective in changing boater behavior to reduce the risk of spreading exotic species,
  2. a majority of boaters believe it is important to prevent the spread of aquatic exotics,
  3. the best methods for reaching boaters include the media (especially newspapers), signs at boat accesses, and information included in fishing/boating regulation pamphlets, and
  4. boaters do present a significant risk for spreading aquatic exotic species.
There are still, however, many existing boaters who have not changed their behavior and many new boaters each year who must be reached. The threat posed by exotic species is a long term problem that will need continuing emphasis from management agencies and educational institutions.

Other exotic species pages:

AIS: An Educator's Information and Materials Guide (PDF download)
A Field Guide to Aquatic Exotic Plants and Animals
Eurasian Watermilfoil Factsheet
Eurasian Watermilfoil ID Card
Exotic Aquatics Traveling Trunk
Exotic Flowering Rush
Exotics To Go! CD
Fishhook Waterflea
Is it a White Bass or a White Perch
Purple Loosestrife ID Card
Purple Loosestrife: What You Should Know, What You Can Do
Round Goby ID Card
Round Gobies Invade North America
Ruffe: A New Threat to our Fisheries
Ruffe ID Card
Rusty Crayfish: A Nasty Invader
Sea Grant Nonindigenous Species Compact Disk Information
Sea Lamprey: The Battle Continues
Spiny Tailed Bythotrephes
Three-State Exotic Species Boater Survey
Threespine Stickleback
Zebra Mussel ID Card
Zebra Mussel Overview

Related Seiche articles:

One Million Exotics ID Cards Available!
Aquatic Exotics: Highlights of the Ninth International Zebra
    Mussel and Aquatic Nuisance Species Conference
Ballast Water Filtering Project Comes to Minnesota
"Bone-Cold Café" Suits Ruffe
Escaping Classroom Routines with Exotic Species
Exotics To Go! Presentations and Publications to Prevent the Spread of Aquatic Nuisance Species
Force of 3 to Cooperate on ANS, Food Web,
    and Fisheries Issues
Giving Exotic Species a Taste of Their Own Medicine
Goby Population Found in Duluth-Superior Harbor
Habitattitude™ Hopes to Stem Releases of Aquatic Plants and Fish
Highschoolers Write about Eurasian Species
Invasive Aquatic Plant Field Guide
Invasive Crayfish Discovered in St. Louis Bay
Lake Superior's Native Lampreys
Mail-Ordering Aquatic Plants Can Be Dangerous
Major Zebra Mussel Infestation in Harbor Impacts
    Native Mussels, Boaters
Marketing Lamprey in Europe: A Good News/
    Bad News Story
New Exotic Species Projects Funded
Our Lake Has Fleas
Preparing for Purple Eaters
Romancing the Sea Lamprey (Love Potion Number 3KPZS)
Ruffe Bibliography Available
The Smell of Fear: Ruffe "Alarm" Pheromones
Tubenose Goby "Leaps" to Duluth/Superior
Two Exotic Species Projects Funded
Water Gardeners and Businesses Concerned about Invaders
Where Have All the Purple Flowers Gone?
Workshops Benefit from New Training Video
Zebra Mussels "Pulse" in Duluth-Superior Harbor
return to the exotic species index
related exotic species links page





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