Overexploitation (class 12)

Question 1

What amount of endangered US vertebrates are threatened by overexploitation?

Answer 1

1/4

Question 2

In what way have traditional societies developed restrictions to prevent overexploitation?

Answer 2

They have created prohibitions against harvesting females, juveniles, and undersized adults

Question 3

What are the 2 reasons stated for the problem of overexploitation?

Answer 3

Human population growth & increasingly efficient technologies (ex. factory ships for bluefin tuna are extremely efficient in processing them for human consumption)

Question 4

Name 3 reasons regulations restricting exploitation might be weakened:

Answer 4

War, civil unrest, human migration

Question 5

Name 3 sites hunters are drawn to:

Answer 5

Areas near roads, national parks, recently logged sites

Question 6

Describe the bushmeat crisis

Answer 6

Decline in animal population caused by intensive hunting of animals, particularly in Africa

Question 7

What can eating primate bushmeat contribute to?

Answer 7

Transfer of zoonotic diseases

Question 8

Name the 6 solutions to curb the bushmeat crisis:

Answer 8

1) restricting sale and transport of bushmeat
2) restricting sale of firearms and ammunition
3) closing roads after logging
4) legally protecting endangered species
5) establishing protected reserves
6) providing alternate protein sources to humans to reduce demand for bushmeat

Question 9

What is overexploitation called in plants?

Answer 9

Overharvesting; involves intensive collection of fruits or seeds

Question 10

How can plant species recover from overharvesting?

Answer 10

They can recover if juveniles or root systems persist (only after harvesting stops)

Question 11

Who is usually a major exporter for the International wildlife trade?

Answer 11

Tropical countries

Question 12

Who are major importers for the International wildlife trade?

Answer 12

Canada, China, European Union, Japan, Singapore, Taiwan, USA

Question 13

What does IUCN stand for?

Answer 13

International Union for Conservation of Nature

Question 14

Name an animal listed “endangered” by the IUCN:

Answer 14

Long-tailed chinchilla. Numbers are low in the wild and continue to decline.

Question 15

What is the native habitat of the long-tailed chinchilla? How many colonies are remaining here?

Answer 15

Northern Chile. Only 2 known colonies.

Question 16

How many hairs in a single follicle for the long-haired chinchilla?

Answer 16

50 individual hairs per follicle. This makes them well suited for its cold habitat. (also makes its pelt highly prized :( )

Question 17

Name the main parrot type collected and how many have been in the last 25 years:

Answer 17

African grey parrot. 1.5 million collected in the last 25 years

Question 18

Name an endangered flower:

Answer 18

Orchids, small white ladies slipper. Endangered in Ontario. Illegal collecting a threat

Question 19

Name the major targeted groups of the worldwide trade in wildlife:
(slide 19 for more details)

Answer 19

1) primates
2) birds
3) reptiles
4) ornamental fish
5) reef corals
6) orchids
7) cacti

Question 20

Go through the pattern of exploitation: (9 steps)

Answer 20

1. wildlife source identified
2. local human populace mobilized to extract and sell resource
3. initial sales used to buy boats, guns, other tools
4. help extract resource more quickly
5. transportation network develops
6. supply diminishes
7. value increases, creating strong incentive for over-exploitation
8. resource becomes rare of extinct
9. market turns to another species or region to exploit

Question 21

“Pattern of exploitation condensed”

Answer 21

Resource identified, sell, money used to extract resources efficiently, transportation network develops, supply goes down, value increases, resource becomes rare, market turns to another species/region to exploit

Question 22

What does “fishing down the food chain mean”

Answer 22

Large individuals and top predators are removed rapidly. This affects the rest of the ecosystem greatly.

Question 23

When was whale harvesting banned?

Answer 23

1986

Question 24

What happened after the 1986 whale ban in Japan mainly?

Answer 24

Estimated value per whale went up exponentially

Question 25

What is the “maximum sustainable yield” or MSY?

Answer 25

the greatest amount of a resource that can be harvested each year and replaced through population growth without detriment to the population

Question 26

What is the equation for max yield?

Answer 26

=rK/4
r= population growth rate
K= carrying capacity

ex. if r=2, pop can double each year until it reaches K, so half the biomass can theoretically be harvested each year

Question 27

“If a population is at carrying capacity, what in theory happens to most juveniles in a pop. that experiences no harvesting?”

Answer 27

I would assume they die?

Question 28

Whats the best way to fish a population?

Answer 28

Fishing moderately- the pop. will first decline but then stabilize at an intermediate level

Question 29

What is TAC or “total allowable catch”?

Answer 29

It is a alternative to an unchanging MSY that is set annually by fisheries.

Question 30

When would max. sustainable yield work best?

Answer 30

Highly controlled situations like timber plantations

Question 31

What percentage of the world’s major fish stocks are classified as overfished?

Answer 31

80%

Question 32

What are 4 problems with yield management in the fishing industry?

Answer 32

1) MSY calculation say continued large catches are sustainable in the face of pop. decline
2) difficult to coordinate catches across international boundaries
3) illegal catch not accounted for
4) large proportion of juvenile pop can be damaged during harvesting operations

Question 33

What is the problem with optimistic harvest levels in the fishing industry?

Answer 33

The resource base fluctuates, so a normal harvest in a bad year (when fish stocks are low) can severely reduce/destroy the species

Question 34

Why are governments more frequently closing fishing grounds?

Answer 34

They are hoping the species will recover

Question 35

Explain the events of the 1980s Newfoundland cod problem

Answer 35

• continued large harvests of cod
• cod stocks dropped to 1% of original numbers
• government closed fishery in 1992, eliminating 35,000 jobs

Question 36

True or false:

For many species, direct exploitation is less important than the INDIRECT effects of commercial fishing

Answer 36

TRUE

Question 37

What is bycatch?

Answer 37

Bycatch: many marine invertebrates and vertebrates are caught accidentally during fishing operations, and are killed or injured in the process

Question 38

What percentage of harvest in fishing operations is dumped back into the sea to die?

Answer 38

25-75%

Question 39

Name 3 groups affected by bycatch:

Answer 39

Skates, rays, seabirds (148 species)- usually death

Question 40

How many species of albatross are threatened with extinction b/c of results of bycatch?

Answer 40

22- all of them around the world

Question 41

What can be done to stop overexploitation?

Answer 41

• conservation projects (linking conservation of biodiversity and local economic development)
• sustainable harvesting of natural resource with certification
• parks, reserves, sanctuaries
• enforcement of international regulations