Lecture 6 Flashcards
Invasive species: zebra mussel
Native to Black, Aral and Azov seas
Introduced to Europe, Russia and North America
Brought in ballast water (water carried by ships to help them stay balanced at sea)
Also attach to outside of boats
They are one of the most aggressive freshwater invaders because their population numbers can grow so quickly
Severely impact native plankton, leaving less food for fish or other mussels
No North America predator has been shown to significantly reduce their numbers
Grow so densely they block pipelines
Latin name for zebra mussel
Dreissena polymorpha
How to prevent zebra mussels living on surfaces
Cannot grow on cupronickel alloys so these have been used to coat buoys, boats, grates and motors
Potential positive effects of zebra mussels
Resulted in increased population and size of smallmouth bass in Lake Erie and yellow perch in Lake St. Clair
They also cleanse the waters of inland lakes, resulting in increase sunlight penetration and the growth of native algae at greater depths - this also filters out pollutants
Brown Tree Snake Latin name
Boiga irregularis
Where is brown tree snake native to?
Arboreal colubrid snake, mildly venomous
Native to eastern and northern coastal Australia, eastern Indonesia, Papua New Guinea and northwestern Melanesia islands
How did the brown tree snake become an invasive species?
Shortly after WWII, the brown tree snake was accidentally transported from Papua New Guinea to Guam, probably as a stowaway in ship cargo or in a Guam-bound aircraft
What have brown tree snakes caused in Guam?
Extirpation of most of the native forest vertebrate species
10/12 native bird species now only live in captivity - forests eerily quiet
Thousands of power outages (by crawling in power lines)
Widespread loss of domestic birds and pets
Potential to bite small children causing residents great stress
Guam is major transportation hub so risk of further spread of this species
What is done to combat brown tree snake invasion?
Trained dogs used to search for, locate and remove brown tree snakes from cargo that is leaving the island
Poisonous mice containing acetaminophen (paracetamol) dropped into forest as prey, which will kill snakes
Kudzu latin name
Pueraria spp.
What is kudzu?
Aggressive vine, can grow up to 26cm per day
Smothers other plants, even mature trees
Prevents native plants from growing
Where did kudzu originate from?
Eastern Asia and some Pacific islands
Where was kudzu introduced to?
North America and Europe
What percentage of invasive species are under threat in their native area?
10-15%
