IMPACTS ON BIODIVERSITYMichaelis
Overfishing and Overhunting One threat to biodiversity occurs
when humans cause ecosystems to ____________ by using too many natural resources or taking away a ______________________.
collapse
keystone species
Overfishing and Overhunting
____________________: An organism that is necessary for keeping an ecosystem in _____________.
Example: Sea Otter
Keystone speciesbalance
Overfishing and Overhunting Facts: Only marine mammal without
___________...blubber
Overfishing and Overhunting
How do they stay warm in the cold ocean? Otters have the
____________________ fur of any mammal.
Fur is so thick that their skin never gets wet when they swim: ___________ hairs per square centimeter.
densest fur
400,000
Overfishing and Overhunting During the fur trade
humans hunted otters almost to _____________ for their ____________________.
By 1911 the sea otter population had dropped to roughly 1,000 individuals.
extinctionthick warm pelts
Overfishing and Overhunting Sea Otter’s Niche: Eats _______________. Uses ___________________ to break
open sea urchins.
sea urchinsrocks and shells
Overfishing and Overhunting Sea Otter’s Niche: Predators:
_____________________________ Uses ________________________
themselves while they eat and sleep.
sharks and humansseaweed to
anchor
How Sea Otters Keep Their Ecosystem in Balance Otters keep the
___________________________. Sea urchins eat away at the _______ of
sea weed. Fish and other sea life rely on the sea
weed forests for _____________________________.
sea urchin population down base
food and shelter
Overhunting Keystone Species:How do you think the decreasing otter population affects the ocean ecosystem? Otter population is DOWN Sea Urchin Population =
______________ Sea Weed Population =
_______________ Fish Population =
____________________ Seal Population =
____________________ Orca Population =
____________________
increasesdecrea
sesdecreasesdecreasesdecreases
Overhunting Keystone Species:What are the long term implications on the food web in this situation?Urchin Barrens
Biological Magnification
When carnivores eat herbivores that have been _________________________________.
Causes concentrations of harmful substances to ___________________________________.
contaminated with pollution
accumulate in higher trophic levels
Biological Magnification
Class Demonstration In this demo assume that __________
of pollutant will cause this animal to: ___________ Make them ___________ Make them very ______________
100 ppm
diesterile
unhealthy
Biological Magnification
Class Demonstration How many parts per million does the
guppy have? How many parts per million does the
salmon have? How many parts per million does the
eagle have?
Biological Magnification
Class Demonstration1. What type of organisms are affected
the most by biological magnification?
2. How do you think biodiversity will be affected?
Invasive SpeciesSpecies that are brought to an ecosystem by humans and _________________________ because they ______________________________.
harm the ecosystemdo not have any natural
predators
Invasive Species
_______________ exotic species live in the U.S.
_____________________ spent to help undo the damage they cause
Invasive species also threaten _____________
of the species currently protected under the ________________________
50,000
$130 billion per year
nearly half
Endangered Species Act
Kudzu in Alabama
Zebra Mussels
Invasive Species – Burmese Python, Florida
Introduced Beavers - Tierra Del Fuego, South America
Cane Toad Video
Invasive Species
Example: ___________________________I’iwi Birds are ________________. They are an ________________________. I’iwi are one of many Hawaiian Birds that _______________________________________
Rats in Hawaiinative to Hawaii
endangered speciesface
extinction due to invasive species.
Hawaii Invasive Species
Hawaii Invasive Species Video
Invasive Species
Questions:How do you think rats harm the I’iwi bird population?
Why do you think the rat population does so well in Hawaii?
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