Nonnative Species In Aquatic Ecosystems Answers

Which of the following is not true about nonnative species?a.They can have positive impacts on an ecosystem.b.They can have negative impacts on an ecosystem.c.They can be introduced within their natural range.d.A nonnative species can be an invasive species.

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

Hull fouling is a(n) _______ introduction of nonnative species.a.unintentionalb.intentionalc.unimportantd.land-based

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.

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

Which of the following is an example of mechanical control of nonnative species?a.pesticidesb.herbicidesc.net barriersd.inspections

Introducing invasive species to an ecosystem results in an increase in biodiversity.

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.

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.