This document discusses invasive species and overexploitation as threats to biodiversity. It defines invasive species as exotic organisms introduced by humans that spread naturally and outcompete native species. Many examples are given of invasive species like eucalyptus in Pakistan, paper mulberry in Islamabad, and zebra mussels in the Great Lakes that have caused environmental and economic harm. Overexploitation is defined as the unsustainable use of natural resources and examples include the commercial whaling industry driving whale populations down and overfishing of bluefin tuna. Control methods proposed include regulating harvesting territories, seasons, and banning inefficient practices.

2. Invasive species and
Overexplotation
Exotic: Organisms that have been introduced
by human activity into an ecosystem where
they are not native.
Invasive
species:
Exotic that spreads
naturally into natural or semi-natural habitat,
they increase in abundance at the expense of
native species.
Introduction of Invasive species?
1.Accidental introduction.
2.Purposeful introduction
and
accidental 2

3. Harmful Impacts
1.
2.
3.
4.
Out-compete native species.
Cause disease in native species.
Prey on native species to point of extinction.
Degrade habitats so that native are no longer
to persist.
Invasive species of Pakistan
•
•
•
•
Eucalyptus plant was imported
Australia.
Consume more water (disturbed
water table).
It harm plants growth near by.
from
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4. Paper Mulberry in Islamabad
• Native to eastern Asia.
• Introduced for its scenic value, but is now
replacing the native flora at an alarming rate.
• High consumption of water, which leaves less
water to sustain the native flora.
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5. Purple loosestrife
• Introduced from Europe and dominated many
North America wet land.
• So aggressive that it chokes out native
plants, destroying wildlife habitat
1968
1978
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6. Zebra mussels
• First introduced in the Great Lakes by ballast
water.
• Multi-billion dollar threat.
• They out-compete native mussels.
• Within two year of introduction ,
they reached densities of 700,000.
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7. Comb jelly
• 1982
Black Sea introduction is
accidentally by ballast water.
• It caused a dramatic drop in fish
populations by competing for the same
food sources .
• Biological control was
tried with Beroe ovata,
another comb jelly,
with some degree of success
has been achieved.
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8. lamprey
• Primitive jawless fish—has a sucker mouth
• Parasite that attaches to large fish
• Came into the Great Lakes from the Atlantic
Ocean
• Only about 1 in 7 fish survive attack by
lamprey
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9. Fire Ants
• In southern United State, diversity of insect
species decline 40% after the invasion of
exotic fire ants
• abundance of northern bobwhite in Texas has
decline over a 20 year period(effect at nestling
stage)
• Nuisance to people.
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10. Brown Tree snake
• Introduced onto number of Pacific islands
• It devastate endemic bird population by
eating eggs, nestling and adult birds.
• Invasive species has driven 8 of 11 forest
species extinct.
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11. OVER EXPLOTATION
Def: Overexploitation is the use, by the
human, of a natural resources to an extant,
that is not sustainable.
• Also called as overharvesting.
Causes of Overexploitation
1.Possibly rich countries over consume.
2.Increase in human population number.
3.Lack of incentive to conserve biodiversity.
4.Results from large ,poor ,rural population
and
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12. extensive use of wildlife for both food and
traditional medicines
5. Improve methods of harvesting leading to the
empty habitat.
EXAMPLES:
Commercial exploitation of whale
• Whales are slaughtered for spermaceti oil (oil
form sperm whale) meat, baleen(whale bone)
leads to the decrease in the population of the
whale.
• International whaling
commission IWC regulates
whale hunting.
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13. International trade in fur
Mamo Bird
• A single ceremonial cloaks worn
by Hawaiian king were made
from feathers of Mamo birds.
• A single cloak use the feathers
of 70,000 birds of this now
extinct species.
Carolina parakeet
• The only parrot species native to
the eastern United States, was
hunted for crop protection and
its feathers.
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14. The Great Auk
• The bird had few natural predators, it has no fear
of human which made them easier to hunt.
• It was found in Canada, Greenland, Iceland,
Norway and great Britain.
• Being flightless it was a
hunters dream.
• The bird was used for
• food and feathers.
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15. Bluefin tuna
• The northern bluefin tuna is currently seriously
overexploited.
• Scientists say 7,500 tons annually is the
sustainable limit, yet the fishing industry
continues to harvest 60,000 tons.
• Commercial fishing demonstrates that industry
working one species after
another to the point of
diminishing returns a process
some time terms fishing down
the food chain.
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16. The Amphibian and Reptile Industry
,Food:
• Certain frog species are particularly
persecuted along with a few lizards, turtles,
crocodiles and alligators.
• The USA import 2.5 million kilogram frog legs
from Japan and India.
• Brightly colored frogs, such as the Poison or
dart frogs are also threatened by
overexploitation for sale in the pet trade.
• Because of bright colored they are highly
valued by hobbyists.
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17. • CORAL REEF
• The rich diversity of marine life inhabiting
coral reefs attracts bioprospectors. Many
coral reefs are overexploited.
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18. • Other species affected by overexploitation
include:
• The international trade in fur: chinchilla,
and numerous cat species.
• Insect collectors: butterflies
• Shell collectors: Marine molluscs
• Aquarium hobbyists: tropical fish
• Chinese medicine: bears, tigers
• Novelty pets: snakes, parrots and
primates
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19. • RHINOCEROS become rare due to
overexploitation the price of its horns rises
making its more value able on black
market .
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20. • CONTROL OF OVER EXPLOITATION:
• 1. RIGHTS TO SPECIFIC HARVESTING
TERRITORY were rigidly controlled.
• 2. Hunting and harvesting in certain areas
must be banned.
• 3. Prohibition against harvesting female
juvenile and undersized animals
• 4. Efficient methods of harvesting is not
allowed
• 5. Certain season of years and time of the
days were close for the harvesting.
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