Chapter 5 (Exotic/Invasive Species) Flashcards
Why did Europeans introduce exotic species to the areas they colonized?
-Food sources
-Recreational
-Familiar
Why are exotic species deliberately introduced to areas?
-Ornamentals: visually appealing
-Economic: Species brought in to develop fisheries industry, recreational game hunting/fishing
-Biological Control: Introductions of exotics, need control
What are the most common ways in which Exotics are introduced accidentally?
-Agriculture: weed seeds often hitch a ride with agriculture seeds
-Transport: Ships, planes, crates, ballast water (in boat water)
-Scientific research: African bees
-Hobbyists/pet owners releasing exotics
Why is using the green alga Caulerpa taxifolia in your aquarium a potential problem if you live near the ocean? How did California officials react to its introduction?
-Could get into the water (killer algae)
-California acted quickly and eradicated it
What do some people do with their pets they can no longer care for… Can you provide examples?
They release them into the wild, can compete with native species. i.e, lionfish
Species that live in isolation (like plants on Hawaii) may not develop the defenses found in species that are wide ranging (not isolated). Why is this the case?
-They do not have a need to develop the defenses until the exotics arrive, migration in or out is prevented
What types of defensive mechanisms may plants have to protect themselves from herbivores? How do plants that lack these defenses fair when exotic herbivores are introduced? How can this help exotic plants in these communities gain a competitive edge?
-Structural (spines, bristles, hairs) Toxins, 3 trophic level (can call for help)
-They are not able to defend themselves
-The exotic plants can remove native species and take over
Why might it be important to try to eradicate an exotic species quickly after its introduction?
To reduce the harmful effect, stop it before it becomes unstoppable.
How have several exotic species gotten to the great lakes? How did the zebra /quagga mussels get to the Great lakes?
-Ballast water, stick to boats, etc
-Ballast Water
What problems has the zebra mussel caused in the Great Lakes? (Recreational, economic, health concerns?)
-Choke native mussels and crustaceans
-Clog intake valves
Are most exotic species that reach a new habitat successful there? Why are some successful? What does it mean to become invasive?
-Sometimes
-Lack of natural parasites or predators
-When there is enough of the exotic species to become harmful or expand
How can the additive effects of several exotic species work to eliminate a native species? (especially in relation to native plant species…)
There is increased competition with different methods of attack.
