Question 1

Based on California's experience with Caulerpa, the killer algae, explain why it is important to regulate the pet and aquarium trade.

Accepted Answer

Even species that are kept as pets and in aquariums should be regulated and tracked because their accidental release can have serious negative environmental impacts. Some owners and aquarium keepers intentionally release these species into the wild rather than destroy them, and accidental release is always a risk. Therefore, if a potentially destructive species is going to be kept as a pet or in an aquarium they should be regulated so proper safety precautions can be taken.

Question 2

What factor determines when a species is considered invasive?

Accepted Answer

b.It is environmentally damaging.

Question 3

Why might it be beneficial for governments to restrict the types of plants and animals that individuals can keep as pets in a particular environment?

Accepted Answer

For many exotic pet species, if they escape or are released into the environment they have the potential to become invasive and do extensive damage to the local environment. In order to preserve the local environment for everyone, it may therefore be beneficial to restrict individuals' rights to own exotic species.

Question 4

Since invasive species did not co-evolve with the other species in the ecosystem where they were introduced _______.

Accepted Answer

d.all of the above

Question 5

As a vector for the introduction of nonnative species, why is hull fouling particularly difficult to combat?

Accepted Answer

Recreational boating and commercial shipping are an immense source of revenue and commerce around the world. Therefore, the need to protect the environment must be balanced against the needs of individuals and communities to earn a living. People who financially benefit from these industries do not want too many obstacles erected in the way of such businesses.

Question 6

Nonnative species disrupt ecosystems by _______.

Accepted Answer

c.disrupting food chains

Question 7

Which of the following is not a reason that nonnative species are reared outside their native ecosystems?

Accepted Answer

d.None of the above

Question 8

Explain why the fact that invasive species did not co-evolve with the native species unbalances an ecosystem.

Accepted Answer

Because invasive species did not co-evolve with the other species of an ecosystem, they lack controls on their population, such as predators, that native species possess. As a result the population of an invasive species can grow uncontrolled and will eventually unbalance an ecosystem.

Question 9

Which of the following is an example of chemical control of nonnative species?

Accepted Answer

b.herbicides

Question 10

Explain why the cane toad was a failure as a biological control method in Australia.

Accepted Answer

The cane toad was introduced into Australia to control the population of sugarcane beetles. However, upon introduction, the toads did not eat the beetle, but instead began damaging local ecosystems by preying upon other organisms and poisoning most animals that tried to prey on them.

Question 11

Why are cane toads in Australia considered an invasive species rather than simply nonnative?

Accepted Answer

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

Question 12

Why has the spread of the herbicide-resistant hydrilla through Florida's waterways resulted in them no longer being navigable by most boats?

Accepted Answer

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

Question 13

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.

Accepted Answer

true

Question 14

Why might it be beneficial to regulate what species of plants and animals people are allowed to own in particular environments?

Accepted Answer

a.Some species might become invasive and destructive if they escaped.

Question 15

Invasive species often unbalance the ecosystems into which they are introduced because _______.

Accepted Answer

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

Question 16

The rusty crayfish is harmful to native species of crayfish because it clear cuts the bottom of waterways leaving native species without a food supply.

Accepted Answer

true

Question 17

Which of the following is an example of mechanical control of nonnative species?

Accepted Answer

c.They can be introduced within their natural range.

Question 18

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

Accepted Answer

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

Question 19

Which of the following is not true concerning the zebra mussel in the United States?

Accepted Answer

d.It can be eliminated from a river with minimal effort.

Nonnative Species In Aquatic Ecosystems

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