Nonnative Species In Aquatic Ecosystems Answers

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

All nonnative species in an ecosystem are considered invasive species.

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.

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 predatorsb.they breed quickly and have the potential to overpopulate an areac.they consume local resourcesd.none of the above

Nonnative species are only introduced unintentionally.

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 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 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.

Why might it be beneficial to regulate what species of plants and animals people are allowed to own in particular environments?a.Some species might become invasive and destructive if they escaped.b.Some species may be dangerous to humans.c.Nonnative plants and animals should only be used for commercial purposes.d.There is no reason to restrict an individuals’ right to own plants or animals.