Concept of Invasive Species

1. •An invasive species can be any kind of living plant, insect, fish, fungus,
bacteria, or even an organism’s seeds or eggs—that is not native to an
ecosystem and causes harm.
•They can harm the environment, the economy, or even human health.
Species that grow and reproduce quickly, and spread aggressively, with
potential to cause harm, are given the label “invasive.”
•Invasive species are among the leading threats to native wildlife.
•Approximately 42 percent of threatened or endangered species are at risk
due to invasive species
Invasive species

3. Identification of invasive species
• When invasive species take over an area, they
kill off all the other species that live there.
They might get too big to handle.
• Their goal is to get rid of our natural species.
• This leads to a single culture.
• They don't have a natural predator.

4. Entry of
invasive
species?
• Through roots
• By accidental
transportation (ships
vessels)
• By seeds
• Transported by wind
or water
• Hitch on to our shoes,
or an animal’s body

5. negative effects of
invasive species?
• Invasive species don't give us
food.
• They beat out our local species for
scarce resources like food and
shelter.
• Because they don't have a natural
predator, their numbers grow very
quickly.
• They pose a danger to our
ecosystems, business, and people.

6. Examples

7.  It is possible for one invasive species to devastate an entire ecosystem, as
happened in Africa’s Lake Victoria.
 In the 1950s, British colonists introduced Nile perch to the lake’s waters to
make for better fishing.
 Within a few decades, the perch had eaten most of the lake’s native fish.
 Because those small fish were no longer eating the algae off the lake’s
aquatic plants, oxygen levels in the water plummeted, which meant that
the rich marine life far below the surface could no longer be maintained.
 That, in turn, has left the perch with less to eat.

9.  The environment around Lake Victoria is almost destroyed, which
is dangerous for the people who live there.
 People who lived along the shores of Lake Victoria used to dry the
small fish they caught before eating them before the perch came
along.
 But the bigger perch had to be cooked, so huge sections of the
forest around them were cut down to make fires.
 Now that the fish are going out, the people who live around the
lake have lost not only their main source of food, but also the
beauty of their surroundings.

10. Parthenium hysterophorus (Congress Grass)
•In 1950s, india was going through a famine/deficiency of wheat.
•Indian National Congress decided to import wheats from USA.
•The wheat was of inferior quality and was a controversial one.
•With that wheat, the seeds of this deadly weed were mixed.
•Some says it was a deliberate mistake, other says it was an innocent mistake.

12. • The brown tree snake is an alien
species that first showed up on the
island of Guam in the early 1950s.
• People are usually 3 to 4 feet long,
but "honkers" up to 10 feet long
have been seen.
• The snakes likely got to the island
from the Admiralty Islands in
northern New Guinea, where they
were hidden in ship goods.
• Which person is happy when they
have a 7-foot snake in their hand?

15. • In Guam, the brown tree
snake has flourished
exceptionally well.
• Up to 3 million brown tree
snakes are thought to live
on the island, with up to
3,000 snakes per square
mile in their preferred
habitat.
• These numbers are among
the highest ever reported
for a snake population!

16. • The brown tree snake
has almost wiped out all
of Guam's native forest
birds.
• Twelve kinds of birds
have died off, including
some that were found
nowhere else in the
world.

17. How can we help?
• Do not release your aquatic pets or plants into the
natural environment
• Learn how to spot alien species.
• You can call a number to report any sightings of
invasive species.
• Clean your boats and motors by draining the water.
• Clean off your boots of any dirt or other things that
came with you from nature.
• Don't move fish from one place to another.

20. Thank You