Exotic Species Boater Survey:
What do boaters know and do they care?
A survey of boaters in Minnesota, Wisconsin, and Ohio was conducted
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).
- evaluate the effectiveness of aquatic nuisance exotic species
boater education programs
- determine how best to reach boaters and change their
behavior to reduce the risk of spreading exotics
- help define the risks boaters
pose for spreading exotic species, and
- find out what boaters know about exotics.
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.
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).
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).
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.
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).
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
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).
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
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:
In Wisconsin boaters listed the problems in a slightly different order:
- disrupt the ecosystem,
- encrust boats, breakwalls and buoys and
In Ohio, which has more experience with zebra mussels, a different
problem made it into the top three responses:
- disrupt ecosystems,
- clog pipes and
- encrust boats breakwalls
- clog pipes,
boats, breakwaters, buoys, and
- 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:
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.
- boater education
programs and other incentives have been effective in changing boater behavior
to reduce the risk of spreading exotic species,
- a majority of boaters believe
it is important to prevent the spread of aquatic exotics,
- the best methods
for reaching boaters include the media (especially newspapers), signs at boat
accesses, and information included in fishing/boating regulation pamphlets, and
- boaters do present a significant risk for spreading aquatic exotic species.