Invasive species ecology

Question 1

How many introduced species will become pests?

Answer 1

10% of importations will APPEAR in the WILD;
10% of those will become ESTABLISHED;
10% of those will become PESTS.

Question 2

What seven reasons explain species introductions?

CHETDLH

Answer 2

1. Commerce / globalisation
2. Horticulture
3. Exotic pets
4. Tourism
5. Deliberate release (malicious, ignorant)
6. Lack of biosecurity
7. Historic lack of policy / strategy

Question 3

What 3 areas do invasive’s IMPACT?

Answer 3

1. Environment
2. Ecology
3. Economy

Question 4

What 6 attributes make a good INVADER?

Answer 4

1. Fast growth
2. Generalist (diet & habitat)
3. High dispersal ability
4. Rapid reproduction
5. Phenotypic plasticity
6. Environmental tolerance

Question 5

What makes a good area to invade? Give an example.

Answer 5

Recently disturbed / early succession
Unexploited resources
Little or no competition
E.g. Islands with simple food webs.

Question 6

Example of Invasive: Ruddy Duck.

How did the Ruddy Duck become a good invader & why was it managed?

Answer 6

Ruddy Duck spread through Europe and started mating with the White headed duck. It was exterminated from 2005 to conserve the genetics of the white headed duck.

Question 7

The effect of invasive non-indigenous species on native species & ecosystems have become?

Answer 7

One of the world’s most serious conservation issues.

Question 8

Example of Invasive: Chinese Mitten Crab

Where did it originate & how has it spread?

Answer 8

The FAR EAST (HONG KONG to N.KOREA)

SHIPPING: Ballast water

Question 9

Example of Invasive: Chinese Mitten Crab

What are the impacts?

Answer 9

1. FISHING (commercial & recreation) BAIT removal & NET damage
2. BANK EROSION by bank digging
3. DIRECT COMPETITION with current species

Question 10

Example of Invasive: Chinese Mitten Crab

Life Cycle:
Eggs, Juveniles, Sexual maturity age, Reproduce & after.

Answer 10

Eggs - ESTUARIES
Juveniles - MIGRATE UPSTREAM (grow & mature)
Sexual maturity age - 3-5 yrs (Europe)
Reproduce  - a few times in ESTUARIES.
after - MARINE

Question 11

What is the definition of invasive species?

Answer 11

ALIEN species whose
introduction does or is likely to cause
economic or environmental HARM to
HUMAN HEALTH
(Executive Order 13112, Federal Register 1999).