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. Please select the best answer from the choices provided
Nonnative species are only introduced unintentionally.
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.
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.
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.
Nonnative species disrupt the natural variability of an ecosystem.
Which of the following is not true concerning the zebra mussel in the United States?a.It was introduced accidentally.b.It was first introduced in the Great Lakes.c.It is still spreading throughout the United States.d.It can be eliminated from a river with minimal effort.
Why does the aquarium trade contribute to the introduction of nonnative species?a.Exotic species can escape or be released into local ecosystems.b.Aquarium owners do not always understand how ecosystems interact.c.Nonnative fish are shipped worldwide for aquariums.d.All of the above
Ships that use ballast water are not in danger of introducing invasive species into aquatic habitats.
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
Did you find these answers helpful?