Nonnative species in aquatic ecosystem (pretest)

Nonnative species are only introduced unintentionally.

False

Why are cane toads in Australia considered an invasive species rather than simply nonnative?
a.
They are destructive to native species and have no natural predators.
b.
They reproduce more quickly than native species.
c.
They have venom glands.
d.
Large adult specimens are able to hunt snakes.

a. They are destructive to native species and have no natural predators.

Invasive species often unbalance the ecosystems into which they are introduced because _______.
a.
they did not co-evolve with the natural species and lack natural controls, like predators
b.
they breed quickly and have the potential to overpopulate an area
c.
they consume local resources
d.
none of the above

a. they did not co-evolve with the natural species and lack natural controls, like predators

Which of the following is true concerning hull fouling from commercial shipping and recreational boating?
a.
It constitutes less than half of all nonnative species introductions.
b.
The revenue brought in from these industries is relatively small.
c.
It is difficult to prevent since ship hulls begin, conduct, and end voyages in water.
d.
It is best combated by chemical treatments.

c. It is difficult to prevent since ship hulls begin, conduct, and end voyages in water.

Hull fouling is a(n) _______ introduction of nonnative species.
a.
unintentional
b.
intentional
c.
unimportant
d.
land-based

a. unintentional

Which of the following is an example of mechanical control of nonnative species?
a.
pesticides
b.
herbicides
c.
net barriers
d.
inspections

c. net barriers

Why has the spread of the herbicide-resistant hydrilla through Florida’s waterways resulted in them no longer being navigable by most boats?
a.
Thy hydrilla has induced a drought that drained the waterways.
b.
The weed clogs propellers that boats use for propulsion.
c.
The sticky leaves of the weed hold boats in place.
d.
All of the above

b. The weed clogs propellers that boats use for propulsion.

Cane toads are highly successful as an invasive species in Australia because there is only one species that is believed to be able to prey on them.

true

All nonnative species in an ecosystem are considered invasive species.

False

All of the following are true of the Zebra mussels found in the Great Lakes EXCEPT:

a.
Zebra mussels are having are having a negative impact on the native population of mussels in the region.

b.
They were unintentionally introduced to the Great Lakes by humans.

c.
Zebra mussels have caused a great deal of environmental damage to the area.

d.
People of the Great Lake region are benefitting from the economic advantages of having zebra mussels in the region.

d. People of the Great Lake region are benefitting from the economic advantages of having zebra mussels in the region.