Transcript Invasive Species – Fact or Fiction?

Invasive Species – Fact or
Fiction?
Name
Date
Fact or Fiction…All non-native
species are invasive.
Brown trout
Rainbow trout
Fact or Fiction…If it is pretty or
beneficial it can’t be a problem.
Dave Brenner, MI Sea Grant
Fact or Fiction…Biological controls
should be avoided at all cost
because the solution may be worse
than the initial problems.
Kurt Stepnitz, Michigan State University
Fact or Fiction…By the time you
notice the spread of an exotic
species, it is too late to control it.
GLSGN Exotic Species Library
Fact or Fiction…All aquatic plants
are weeds.
WI Lakes Partnership
Fact or Fiction - It is natural for
plants and animals to move
around. And since it is nature, it’ll
all even out in the end.
WI Lakes Partnership
Fact or Fiction…All exotic species
are spread by “natural mechanisms
such as birds and the wind”.
Fact or Fiction…Some non-native
species are beneficial/desirable.
Chinook and Coho
Salmon
Fact of Fiction…Using only
herbicides is preferred to hand
pulling specimens as a control
method or vice-versa.
Fact or Fiction…Herbicide use is
always bad and inappropriate.
WI DNR
Fact or Fiction…Wetland invasive
plants such as reed canary grass
and purple loosestrife are only a
problem in wetlands, and not
upland habitats.
Fact or Fiction…Native species do
not become nuisance or problem
species.
Fact or Fiction…If a plant is
available for purchase at a garden
center, it must not be invasive.
Water hyacinth
Fact or Fiction…Some invasive
plants also have beneficial uses.
John Lyons, WI DNR
Fact or Fiction…A cattail marsh is a
good example of a wetland
community.
Fact or Fiction…It is okay to release
unused live bait into a water body.
MN Sea Grant
Fact or Fiction…Commercial fishing
for carp or white perch is a
common sense approach to
removing PCBs from Green Bay.
White Perch, John Lyons, WI DNR
Fact or Fiction…The decline in
yellow perch populations in Green
Bay can be attributed to exotic
species like carp, white perch and
zebra mussels.
Illustration by Virgil Beck
Fact or Fiction…The introduction of
invasive plant species can add to
the number of species in an area,
which will be good for biodiversity.
WI Lakes Partnership
Fact or Fiction…Zebra mussels can
increase water clarity.
Fact or Fiction…The increased
water clarity as a result of zebra
mussel’s filtering activities will
benefit people who live on, or
recreate on lakes.
Fact or Fiction…Zebra mussels will
not do well in northern Wisconsin
lakes because the water
temperatures are too cold.
David Brenner, MI Sea Grant
Fact or Fiction…Zebra mussels
densities will be higher in
euthrophic or nutrient rich waters
where there is more food compared
to oligotrophic or nutrient poor
waters.
Fact or Fiction…It is inevitable that
zebra mussels will eventually infest
all Wisconsin water bodies;
therefore we should not waste our
time in trying to control their
spread.
Fact or Fiction…Diving ducks, an
important predator of zebra
mussels, are capable of effectively
controlling their populations.
Fact or Fiction…When striped snails
show up in a lake, it must be zebra
mussels.
Fact or Fiction…Rusty crayfish are
no longer spreading to new waters
in Wisconsin.
Jeff Gunderson, MN Sea Grant
Fact or Fiction…Rusty Crayfish can
only move through water.
WI DNR
Fact or Fiction…Rusty crayfish are
only carnivorous feeders (animal
matter feeders), and therefore only
affect the fish population by eating
eggs and fry, small adult or juvenile
fish, and dead fish on the bottom.
MN Sea Grant
Fact or Fiction…Because rusty
crayfish can destroy large amounts
of aquatic vegetation, they can and
should be used to control nuisance
aquatic plants, native or nonnative.
Richerson, Myriah and Amy Benson - USGS
Fact or Fiction…Once introduced
into new waters the negative
impact of rusty crayfish is on going,
and the damage done is
permanent.
Roger Thoma
Fact or Fiction…Rusty crayfish
cannot take over a lake if a native
crayfish species already inhabits
that lake.
Fact or Fiction…Increased numbers
of crayfish either native or nonnative will improve the overall
fishery in a lake.
Richerson, Myriah and Amy Benson - USGS
Fact or Fiction…It is legal to
possess live crayfish and angling
equipment simultaneously on any
Wisconsin inland waters.
Fact or Fiction…Commercial or
private harvest of any crayfish
including rusty crayfish requires a
permit.
Fact or Fiction…Commercial or
private harvest of rusty crayfish can
help control the problem.
Fact or Fiction…The purple
loosestrife problem in Wisconsin
has already been brought under
control by past efforts of the
Wisconsin DNR.
Fact or Fiction…Once a biological
control agent has been released
into a purple loosestrife infested
area, nothing more needs to be
done to control the problem.
Fact or Fiction…Purple loosestrife
can be eradicated by physically
removing the plant or by chemical
treatment.
Dave Brenner, MI Sea Grant
Fact or Fiction…The insects
released to control purple
loosestrife have no predators of
their own.
Kurt Stepnitz, Michigan State University
Fact or Fiction…Once these insects
run out of purple loosestrife, they
will likely eat something else.
Dave Brenner, MI Sea Grant
Fact or Fiction…Purple loosestrife
(Galerucella) beetles are stationary.
Fact or Fiction…Enough of these
insects have already been raised
and released in all the important
locations across the state to
eventually control purple loosestrife
in Wisconsin.
Doug Landis, MI Sea Grant
Fact or Fiction…Purple loosestrife
doesn’t spread in my garden, so it
will not spread to a wetland.
Dave Brenner, MI Sea Grant
Fact or Fiction…Purple loosestrife is
legal to sell or distribute in
Wisconsin.
Dave Brenner, MI Sea Grant
Fact or Fiction…Once introduced
into a new location, purple
loosestrife quickly becomes the
dominant plant.
Dave Brenner, MI Sea Grant
Fact or Fiction…Plants with purple
flowers growing along the shoreline
means purple loosestrife is present.
Fact or Fiction…The beetles that
have been used to control purple
loosestrife are the same as the
nuisance Asian lady beetles.
Kurt Stepnitz, Michigan State University
Fact or Fiction…In a lake with just
a few aquatic plants or structure
for fish habitat, it would be a good
idea to introduce Eurasian watermilfoil.
Dave Brenner, MI Sea Grant
Fact or Fiction…Drawing down an
impoundment will kill Eurasian
water-milfoil.
Fact or Fiction…The native milfoil
weevil is effective at eradicating
Eurasian water-milfoil so we don’t
need to worry about controlling the
spread.
Wendy Crowell, MN DNR
Fact or Fiction…There is nothing we
can do to control the spread of
Eurasian water-milfoil.
Ted Ritter
Fact or Fiction…If Eurasian watermilfoil enters a lake via the boat
landing, the launch site should be
closed.
Dave Brenner, MI Sea Grant
Fact or Fiction…If Eurasian watermilfoil has been found in a lake, in
no time it will be so choked with
plants that the lake will be
unusable.
Fact or Fiction…The weevil that
feeds on Eurasian water-milfoil
must be an invasive species.
Fact or Fiction…Eurasian watermilfoil has absolutely no value.
Fact or Fiction…All species of milfoil
are bad.
Northern water-milfoil, UW Herbarium
Both native species!
Whorled water-milfoil, UW Herbarium
Fact or Fiction…Rainbow smelt are
a native Wisconsin fish species.
John Lyons, WI DNR
Fact or Fiction…Smelt have no
impact on native fish communities.
John Lyons, WI DNR
Fact or Fiction…Smelt are only
found in big lakes like Lakes
Michigan and Superior.
John Lyons, WI DNR
Fact or Fiction…Opening up
fisheries to smelt harvest will
control smelt numbers.
John Lyons, WI DNR
Fact or Fiction…Smelt are spread to
inland lakes on the feet of ducks
and other birds.
Fact or Fiction…Reed canary grass
is a beneficial forage grass and
should be planted in wetlands.
Fact or Fiction…Reed canary grass
was widely planted as “marsh hay”
during the last century.
Fact or Fiction…Forested areas do
not have a reed canary grass
problem.